Обучение по природни науки и върхови технологии

2017/5, стр. 737 - 753

SYNTHESIS OF TiO 2-M (Cd, Co, Mn) AS A PHOTOCATALYST DEGRADATION OF METHYLENE BLUE DYE

Candra Purnawan
E-mail: candra_pr@staff.uns.ac.id
Analytical and Environmental Chemistry Research Group
Chemistry Department
Sebelas Maret University
Surakarta Central Java
57126 Indonesia
Sayekti Wahyuningsih
Sebelas Maret University
Surakarta Central Java
57126 Indonesia
Dwita Nur Aisyah
Sebelas Maret University
Surakarta Central Java
57126 Indonesia

Резюме: TiO\(_{2}\)-M (M = Cd, Co, Mn) were synthesized by sol-gel method using titanium(IV) isopropoxide (TTIP) and cadmium sulfate octahydrate (CdSO\(_{4}\).8H\(_{2}\)O), manganese(II) sulfate monohydrate (MnSO\(_{4}\).H\(_{2}\)O), cobalt(II) sulfate heptahydrate (CoSO\(_{4}\).7H\(_{2}\)O) as precursors. M-doped TiO\(_{2}\) was performed with molar ratio 1:3; 1:2; 1:1; 2:1; 3:1 (mol Ti / mol M) and photocatalytic processes using visible light with irradiation time for 5, 10, 15, 20, 25 and 30 minutes. This study was carried out to determine the effect of different metal ions, the composition of Ti:M and the exposure time on the photocatalytic degradation of methylene blue dye. The results showed that different metal ions influenced crystal size and affected electronic properties (band gap). Crystal size of TiO\(_{2}\) > TiO\(_{2}\)-Mn > TiO\(_{2}\)-Co > TiO\(_{2}\)-Cd and band gap of TiO\(_{2}\) > TiO\(_{2}\)-Cd > TiO\(_{2}\)-Co > TiO\(_{2}\)-Mn. In addition, differences of Ti:M composition also influenced the photocatalytic activity. The longer of applied time exposure, the higher photocatalytic degradation of methylene blue was achieved. The optimum composition of Ti:M was obtained at Ti:M ratio by 3:1 with degradation values by 92.56% (TiO\(_{2}\)-Cd), 90.44% (TiO\(_{2}\)-Co), and 89.42% (TiO\(_{2}\) -Mn).

Ключови думи: methylene blue; metal doping; photocatalytic degradation; TiO\(_{2}\)-M; visible light

Introduction

Indonesia is one of textile industrial based country producing wastewater. Most of wastewater generated from textile industry contain dyes which difficult to eliminate and to degrade. One of dyes often used in textile industry is methylene blue. Methylene blue, one of cationic dyes with chemical formula \(\mathrm{C}_{16} \mathrm{H}_{18} \mathrm{ClN}_{3} \mathrm{~S}\), is frequently employed in cotton, paper and hair dying process (Alzaydien, 2009). This aromatic hydrocarbon compound has strong adsorption and it was categorized as thiazine dyes. It also has toxic properties causing some effects in health, including skin irritation, cyanosis, and gastrointestinal track irritation (Hamdaoui & Chiha, 2007).

Nowadays, the researchers utilized \(\mathrm{TiO}_{2}\) semiconductor to degrade the dyes through photocatalytic, electrocatalyst, and photoelectrocatalyst degradation methods (Hamadanian et al., 2010; Purnawan et al., 2016; Wahyuningsih et al., 2013). The use of photocatalyst material, however, is limited since it only absorbs \(5 \%\) ultraviolet light from sun with broad band gap: \(3.0-3.2 \mathrm{eV}\) (Ni et al., 2007). Thus, modification is required to improve optical property in visible light range.

Figure 1. Photocatalytic mechanism of \(\mathrm{TiO}_{2}\left(\mathrm{hv}_{1}=\right.\) origin \(\mathrm{TiO}_{2}, \mathrm{hv}_{2}=\) metals ion doped \(\mathrm{TiO}_{2}, \mathrm{hv}_{3}=\) non-metal doped \(\mathrm{TiO}_{2}\) ) (Zaleska, 2008)

Modification of \(\mathrm{TiO}_{2}\) can be performed by adding metals or doping metals like transition metals (Binas et al., 2012; Chen et al., 2005; Deng et al., 2011; Purnawan et al., 2016). The addition of metals into \(\mathrm{TiO}_{2}\) semiconductor with increasing concentration caused lowering band gap energy up to visible light absorption area (Ganesh et al., 2012; Tian et al., 2012).

Dopant ion formed electron trapping which it minimizes recombination process between electron and hole. Not only it resulted new band gap, metal doping also accelerated photocatalytic activities (El-Bahy et al., 2009; Zaleska, 2008). Fig. 1 illustrated the effect of metals doping on electron excitation of \(\mathrm{TiO}_{2}\) photocatalyst.

The addition of metals into \(\mathrm{TiO}_{2}\) semiconductor will decrease the particle size of doped semiconductor compared to the origin one. Introducing Cd metal into \(\mathrm{TiO}_{2}\) affected in lowering band gap of \(\mathrm{TiO}_{2} / \mathrm{CdS}\) (Li et al., 2014) and enhanced its photocatalytic activities in visible light (Shi et al., 2012). The decreasing of TiO2012). The decreasing of \(\mathrm{TiO}_{2}\) band gab and enhancing of its photocatalytic activities in visible light was also reported by adding Co (Miao et al., 2014; Yang et al., 2007) and Mn metals (Binas et al., 2012; Deng et al., 2011; Papadimitriou et al., 2011; Wang et al., 2015). The dopant Mn decreased the band gap thus it can be adsorbed the visible light. However, it could defect the \(\mathrm{TiO}_{2}\) crystal and reduce the photocatalytic activities when Mn metal was added in high concentration (Deng et al., 2011).

The \(\mathrm{TiO}_{2}\) doped with \(\mathrm{Mn}(0.1 \%, 1 \%\) and \(5 \%)\) degraded the methylene blue up to \(70 \%\) by irradiating in visible light for 30 minutes (Binas et al., 2012; Papadimitriou et al., 2011). Another researcher, Wang et al. (2015), obtained optimum result by doping \(6 \% \mathrm{Mn}\) to \(\mathrm{TiO}_{2}\). T They also found that by increasing Mn concentration increased the rutile phase which reduce the \(\mathrm{TiO}_{2}\) photocatalytic sensitivity. However, the comparative study of three kind of metals, \(\mathrm{Co}, \mathrm{Cd}\) and Mn, doping \(\mathrm{TiO}_{2}\) is not yet studied. Thus, in this research successfully prepared the \(\mathrm{TiO}_{2}\) doped metals (\(\mathrm{Co}, \mathrm{Cd}\) and Mn) and evaluated their photocatalytic performance on methylene blue degradation.

Experimental

Materials and instrument

All reagents employed in this research were commercially available from E-Merck except mentioned. They were titanium(IV) isopropoxide (TTIP), \(\mathrm{CdSO}_{4} \cdot 8 \mathrm{H}_{2} \mathrm{O}, \mathrm{Mn}\)\(\mathrm{SO}_{4} \cdot 1 \mathrm{H}_{2} \mathrm{O}, \mathrm{CoSO}_{4} \cdot 7 \mathrm{H}_{2} \mathrm{O}\), acetic acid glacial, and ethanol. The methylene blue dye was commercially available from Surakarta, Indonesia. Aquades was purchased from Chemistry Laboratory of Universitas Sebelas Maret. The Instruments used in this study were XRD (X-Ray Diffraction, Bruker), SEM-EDX (Scanning Electron Microscopy – Energy Dispersive X-ray), FTIR (Spektrofotometer Fourier Transform Infrared, Shimadzu 6000) and visible lamp osram ultra vitalux (300W 230V AC).

Synthesis of \(\mathrm{TiO}_{2}\)-M (Cd, Mn, Co)

Titanium (IV) isopropoxide solution was hydrolyzed in acetic acid glacial solution at \(14{ }^{\circ} \mathrm{C}\) with solution ration \(1: 10 \mathrm{v} / \mathrm{v}\). The mixture was stirred continuously until the white and viscous solution achieved. Then, it was heated at \(90^{\circ} \mathrm{C}\) to obtain white gel form. Afterward, each \(\mathrm{CdSO}_{4}, \mathrm{MnSO}_{4}\) or \(\mathrm{CoSO}_{4}\) solutions was added drop wise into \(\mathrm{TiO}_{2}\) gel. The ratio of each metal sulfate toward \(\mathrm{TiO}_{2}\) gel was 1:3, \(1: 2,1: 1,2: 1\) and \(3: 1 \mathrm{~mol} / \mathrm{mol}\). After it was cooled at room temperature, the gel was dried at \(150^{\circ} \mathrm{C}\) for 24 h, then calcined at \(400^{\circ} \mathrm{C}\) at 2 h.

Photocatalytic degradation of methylene blue

Photodegradation of methylene blue was conducted by adding \(0.3 \mathrm{~g} \mathrm{TiO}_{2}-\mathrm{M}\) powder into 30 mL of \(5 \mathrm{mg} . \mathrm{L}^{-1}\) methylene blue solution. Under stirring condition, the mixture was irradiated with visible light in Black Box reactor. The visible light irradiation was carried out at \(5,10,15,20,25\) and 30 minutes. Afterward, the solution was separated using centrifugation at 6000 rpm for around 3 minutes. The solution absorbance was then analyzed using UV-Vis spectrophotometer.

Results and discussion

Characterization of crystal structure and size by XRD

The XRD characterization of \(\mathrm{TiO}_{2}-\mathrm{M}\) was conducted to evaluate crystallinity of \(\mathrm{TiO}_{2}-\mathrm{M}\) powder by comparing the samples diffractogram with JCPDS standard. It was carried out on the \(3: 1\left(\mathrm{TiO}_{2}: \mathrm{M}\right)\) ratio of synthesized \(\mathrm{TiO}_{2}-\mathrm{M}\) at 2 2thetha 15–85 \({ }^{\circ}\). Based on the XRD spectra of \(\mathrm{TiO}_{2}-\mathrm{M}(3: 1)\) showed in Fig. 2 can be seen the primary characteristic peak of \(\mathrm{TiO}_{2}\) at \(2 \theta 25.490^{\circ}, 37.792^{\circ}\) and \(48.043^{\circ}\). T This peak was confirmed as anatase phase corresponding to JCPDS number 78-2486. This anatase peak was also observed in \(\mathrm{TiO}_{2}-\mathrm{Cd}, \mathrm{TiO}_{2}-\mathrm{Co}\) and \(\mathrm{TiO}_{2}-\mathrm{Mn}\) diffractograms.

Table 1. The crystal size of TiO2and TiO2-M

MaterialCrystal size (nm) TiO2-Cd6,907TiO2-Co7,223TiO2-Mn7,404TiO215,622
20304050607080AAAA(a) AAA(b) AAIntensity(c) A=AnataseAA2theta(deg) (e) (d) A

Figure 2. Difraktogram X-Ray (a) \(\mathrm{TiO}_{2}-\mathrm{Co}(3: 1)\) (b) \(\mathrm{TiO}_{2}-\mathrm{Mn}(3: 1)\) (c) \(\mathrm{TiO}_{2}-\mathrm{Cd}\) (3:1) (d) \(\mathrm{TiO}_{2}\) (e) \(\mathrm{JCPDS} \mathrm{TiO}_{2}\) No 78-2486

The addition of metals into \(\mathrm{TiO}_{2}\) influenced the product crystal size. All of the \(\mathrm{TiO}_{2}-\mathrm{M}\) crystal size was lower than \(\mathrm{TiO}_{2}\). Comparing to another \(\mathrm{TiO}_{2}-\mathrm{M}\), the \(\mathrm{TiO}_{2}-\) Cd was the synthesized product having lowest crystal size, as shown in Table 1. This phenomena was also discovered by Deng et al. (2011), where after Mn metals was doped into \(\mathrm{TiO}_{2}\), it resulted 7 nm of \(\mathrm{TiO}_{2}-\mathrm{Mn}\) crystal size.

Morphological study of \(\mathrm{TiO}_{2}\)-M

Morphological study of \(\mathrm{TiO}_{2}-\mathrm{Cd}, \mathrm{TiO}_{2}-\mathrm{Mn}\) and \(\mathrm{TiO}_{2}-\mathrm{Co}\) was conducted at each \(\mathrm{TiO}_{2}: \mathrm{M}\) ratio by \(3: 1\). All of the \(\mathrm{TiO}_{2}-\mathrm{M}\) surface morphology was offered in Fig. 3.

All of the measurement were captured at magnificent 5000x. The morphology of \(\mathrm{TiO}_{2}-\mathrm{M}\) was not significantly different observed in this research. This indicated that the addition of metals was not change the morphology of \(\mathrm{TiO}_{2}-\mathrm{M}\). From the SEM image was calculated the particle size distribution using JImage application. The calculation result gave same values, where the particle size of \(\mathrm{TiO}_{2}-\mathrm{M}\) was distributed in range of \(100-200 \mathrm{~nm}\). Fig. 4 revealed the particle size distribution of each \(\mathrm{TiO}_{2}-\mathrm{M}\).

The SEM-EDAX result showed that the doped metal concentration contained in \(\mathrm{TiO}_{2}-\mathrm{M}\) as presented in Table 2 were 8.62, 3.26 and \(7.21 \%\) for \(\mathrm{Cd}, \mathrm{Co}\) and Mn, respectively. It was mean that the Cd was easily doped into \(\mathrm{TiO}_{2}\) than Co or even Mn.

This was caused by the ionic radius of Cd was higher than Co and Mn, however its covalent radius of ionic hydrant was smaller than others, i.e. \(\mathrm{Cd}(144 \pm 9 \mathrm{pm}) \lt \mathrm{Co}\)

\((150 \pm 7 \mathrm{pm}) \lt \mathrm{Mn}(161 \pm 8 \mathrm{pm})\). Due to it has small covalent radius of ionic hydrant, the Cd ion was readily to bind and to attach into \(\mathrm{TiO}_{2}\) semiconductor.

Table 2. Elemental analysis of TiO -M generated from SEM-EDAX

2ElementsComposition (%) TiO2-CdTiO2-MnTiO2-CoC5,764,596,13O29,5038,1433,53M (Cd, Mn or Co) 8,623,267,21Ti53,5451,8551,83
(a) (b)
(c)

Figure 3. Morphology of (a) TiO2-Cd, (b) TiO2-Mn and (c) TiO2-Co

0-100100-200200-300300-400400-500500-600600-700700-800051015202530FrequencyParticlesize(nm) (a)
0-100100-200200-300300-400400-500500-600600-700700-800800-900900-10001000-11001100-1200051015202530FrequencyParticlesize(nm)
0-100100-200200-300300-400400-500500-600600-700700-800800-900900-10001000-11001100-120005101520FrequencyParticlesize(nm) (c)

Figure 4. Particle size distribution of (a) \(\mathrm{TiO}_{2}-\mathrm{Cd}\), (b) \(\mathrm{TiO}_{2}-\mathrm{Mn}\) and (c) \(\mathrm{TiO}_{2}-\mathrm{Co}\)

Band gap energy

The band gap energy was conducted via thin layer method. The \(\mathrm{TiO}_{2}\) and \(\mathrm{TiO}_{2}-\mathrm{M}\) samples was transformed to the transparency film at glass substrate then their absorbance were recorded using UV-Vis spectrophotometer. The band gap was calculated using Touc Plot method, a method to determine band gap using extrapolate from E (eV) versus (Ahv) \({ }^{2}\) as shown in Fig. 5. Based on the Touch Plot graph can be evaluated band gap energy of each samples presented in Table 3.

1, 52, 02, 53, 03, 54, 00, 00E+0005, 00E-0231, 00E-0221, 50E-0222, 00E-0222, 50E-0223, 00E-022E(eV) TiO2(Ahv) 2TiO2-CdTiO2-MnTiO2-Co

Figure 5. Touc plot graph of TiO2 and TiO2-M (3:1)

Table 3. The band gap and wave length values of TiO2-M (3:1)

SampelBand gap (eV) λ (nm) TiO23,35370,15TiO2-Cd3,15393,65TiO2-Co3,00413,33TiO2-Mn2,5496,00

The addition of metals into \(\mathrm{TiO}_{2}\) triggered the lowering band gap energy as presented in Table 3, the Eg of \(\mathrm{TiO}_{2} \gt \mathrm{TiO}_{2}-\mathrm{Cd} \gt \mathrm{TiO}_{2}-\mathrm{Co} \gt \mathrm{TiO}_{2}-\mathrm{Mn}\). T The band gap energy of \(\mathrm{TiO}_{2}-\mathrm{Mn}\) was lowest to others \(\mathrm{TiO}_{2}-\mathrm{M}\). T This initiated a fast recombination of electron-hole which will inhibit oxidation reaction of methylene blue dye.

FTIR analysis of \(\mathrm{TiO}_{2} \mathrm{M}\)

Analysis of \(\mathrm{TiO}_{2}\)-Cd using FTIR was performed to identify a bonding between \(\mathrm{Ti}-\mathrm{O}\) and Cd as result of Cd addition to \(\mathrm{TiO}_{2}\). In Fig. 6, the synthesized \(\mathrm{TiO}_{2}\) spectra has absorbance bands around \(3405.47 \mathrm{~cm}^{-1}, 1627.99 \mathrm{~cm}^{-1}\) as well as strong and broad band at \(576.74-421.46 \mathrm{~cm}^{-1}\) which they are characteristic band of \(\mathrm{TiO}_{2}\). The wave number at \(3405.47 \mathrm{~cm}^{-1}\) indicated the \(\mathrm{O}-\mathrm{H}\) stretching vibration of water entrapping in \(\mathrm{TiO}_{2}\) structure (Kuvarega et al., 2011). Another characteristic peak of water was also observed around \(1625-1650 \mathrm{~cm}^{-1}\) corresponding to the \(\mathrm{O}-\mathrm{H}\) bending vibration. The vibration of O-Ti-O was also discovered in the IR spectra at around \(609.5-420.5 \mathrm{~cm}^{-1}\) (Wahyuningsih et al., 2013).

45004000350030002500200015001000500(a) %T (a.u) (b) (c) (d) Ti-O-OHbendCd-O-OHstr(f) Wavenumber(cm-1) (e)

Figure 6. IR spectra of \(\mathrm{TiO}_{2}-\mathrm{Cd}\), with ratio (a) \(1: 3\) (b) \(1: 2\) (c) \(1: 1\) (d) \(2: 1\) (e) \(3: 1\), dan (f) \(\mathrm{TiO}_{2}\)

The IR spectrum of \(\mathrm{TiO}_{2}-\mathrm{Cd}\) showed the broad absorbance band at around 3400 \(\mathrm{cm}^{-1}\) indicating the O-H stretching vibration (Kuvarega et al., 2011). The water characteristic band was also observed in \(\mathrm{TiO}_{2}\)-Cd IR spectra appearing at \(1600 \mathrm{~cm}^{-1}\) (Li et al., 2011; Wu & Chen, 2004). A new absorbance band also appeared around \(1115-1057 \mathrm{~cm}^{-1}\) indicated the Ti-O-Cd stretching vibration. In addition, the absorbance band around \(540-425 \mathrm{~cm}^{-1}\) corresponding to Ti-O-Cd bending vibration. Both of this peaks were sharpen by decreasing of \(\mathrm{TiO}_{2}: \mathrm{Cd}\) ratio. T This peaks related to the Ti-O-Cd bonding formation as result of Cd insertion in \(\mathrm{TiO}_{2}\).

The two peaks around \(1100 \mathrm{~cm}^{-1}\) and \(980 \mathrm{~cm}^{-1}\) were characteristic peak of TiO-Cd stretching vibration in accordance with what has been done by Ge (2012). Both of that peaks showed different intensity on each \(\mathrm{TiO}_{2}: \mathrm{Cd}\) composition ratio, the more concentration of Cd was added then the peak became sharpen. This also occurred at peak around \(619.18-618.21 \mathrm{~cm}^{-1}\) which corresponding to Cd stretching vibration.

45004000350030002500200015001000500(a) (b) (c) %T(a.u) (d) (e) Co-OWavenumber(cm-1) (f) Ti-O-OHstr-OHbend

Figure 7. The \(\mathrm{TiO}_{2}\)-Co IR spectrum at \(\mathrm{TiO}_{2}\) : Co ratio (a) \(1: 3\) (b) \(1: 2\) (c) \(1: 1\) (d) 2:1 (e) 3:1, and (f) \(\mathrm{TiO}_{2}\)

In \(\mathrm{TiO}_{2}-\mathrm{Co}\) IR spectra offered in Fig. 7 revealed a peak at \(1627 \mathrm{~cm}^{-1}\) corresponding to a bending vibration of H-O-H bonding. Peaks around \(600-400 \mathrm{~cm}^{-1}\) was an absorbance band of Ti-O-Ti. It was also exposed a weak and broad band around \(2840 \mathrm{~cm}^{-1}\) becoming strong peak by adding more Co, indicate the OH absorbance band of \(\mathrm{H}_{2} \mathrm{O}\) bonded to \(\mathrm{Co}-\mathrm{O}\). Absorbance band around \(1000-1250 \mathrm{~cm}^{-1}\) was a

characteristic peak of Co evidenced by increasing of its intensity with addition more concentration of Co while weaken by decreasing of Co composition (Ganesh et al., 2012).

A new absorbance band at \(660 \mathrm{~cm}^{-1}\) was found in \(\mathrm{TiO}_{2}-\mathrm{Mn}\) spectra presented in Fig. 8 indicating the \(\beta-\mathrm{MnO}_{2}\) vibration. Moreover, peaks at \(620 \mathrm{~cm}^{-1}\) and \(530 \mathrm{~cm}^{-1}\) was a characteristic vibration of \(\mathrm{O}-\mathrm{Ti}-\mathrm{O}\) and \(\mathrm{Mn}-\mathrm{O}-\mathrm{Ti}\), respectively. Identification of \(\mathrm{MnO}_{\mathrm{x}}\) was difficult to evaluate due to this peak over lapped with other peaks. This was also observed by other researchers (Kernazhitsky et al., 2010; Othman et al., 2007; Šurca et al, 2006). However, a peak around 1140-997 \(\mathrm{cm}^{-1}\) was predicted as \(\mathrm{Mn}-\mathrm{O}\) characteristic absorbance band since its intensity became sharpen at high ratio of Cd.

45004000350030002500200015001000500(a) (b) (c) (d) Mn-OTi-O-OHbend%T(a.u) (e) -OHstrWavenumber(cm-1) (f)

Figure 8. \(\mathrm{TiO}_{2}-\mathrm{Mn}\) IR spectrum with \(\mathrm{TiO}_{2}\) : Mn ratio (a) \(1: 3\) (b) \(1: 2\) (c) \(1: 1\) (d) \(2: 1\) (e) \(3: 1\), and (f) \(\mathrm{TiO}_{2}\)

Photocatalytic degradation of methylene blue

Qualitative analysis of methylene blue using UV-Vis spectrophotometer was conducted to determine its maximum wavelength (\(\lambda_{\text {maks }}\) ). It was scanned in range of \(800 \mathrm{~nm}-350 \mathrm{~nm}\) with methylene blue concentration by \(5 \mathrm{mg} . \mathrm{L}^{-1}\). It was resulted that the maximum wavelength was obtained at 664 nm. This maximum wavelength was then used to identify the decreasing of methylene blue concentration in aqueous solution after photocatalytic degradation carried out.

This research focused to compare the photocatalytic activity of each \(\mathrm{TiO}_{2}-\mathrm{M}\) using visible light at same time and amount. After photocatalytic degradation, it was observed that the absorbance of methylene blue decreased. Photocatalytic degradation is a reaction process involved catalyst assisted with a photon. Fig. 9 showed the degradation result of each \(\mathrm{TiO}_{2}-\mathrm{Cd}\) composition. All of composition revealed that the longer of contact time, the degradation percentages enhanced. They resulted a degradation closing to \(90 \%\) at 30 minutes. The role on photocatalytic degradation was obtained as follow \(\mathrm{TiO}_{2}-\mathrm{Cd}(3: 1) \gt (2: 1) \gt (1: 3) \gt (1: 2) \gt (1: 1)\). T The same pattern was also discovered for \(\mathrm{TiO}_{2}-\mathrm{Co}\) and \(\mathrm{TiO}_{2}-\mathrm{Mn}\) where the highest degradation percentages was achieved at \(\mathrm{TiO}_{2}: \mathrm{M}\) ratio \(3: 1\) while the lowest was at \(1: 1\). The percentage degradation data of \(\mathrm{TiO}_{2}-\mathrm{Co}\) and \(\mathrm{TiO}_{2}-\mathrm{Mn}\) were presented in Fig. 10 and Fig. 11, respectively.

Figure 9. Methylene blue degradation percentages using \(\mathrm{TiO}_{2}-\mathrm{Co}\) at ratio \(\mathrm{TiO}_{2}\) : Co = 1:3 (blue); 1:2 (red); 1:1 (green); 2:1 (violet) and 3:1 (orange)

Figure 10. Methylene blue degradation percentages using \(\mathrm{TiO}_{2}-\mathrm{Mn}\) at ratio \(\mathrm{TiO}_{2}: \mathrm{Mn}=1: 3\) (blue); 1:2:Mn = 1:3 (blue); 1:2 (red); 1:1 (green); 2:1 (violet) and 3:1 (orange)

Figure 11. Methylene blue degradation percentages using \(\mathrm{TiO}_{2}-\mathrm{Cd}\) at ratio \(\mathrm{TiO}_{2}: \mathrm{Cd}=1: 3\) (blue); \(1: 2\) (red); \(1: 1\) (green); 2:1 (violet) and \(3: 1\) (orange)

The addition of high concentration of metals caused on decreasing of photocatalytic activity. High metal concentration has high number of defect structure and created more trapper. It triggered a charge carrier generated from energy induction result on \(\mathrm{TiO}_{2}\) photocatalyst can stuck more than one time thus it slow down the mobility and it could undergo a recombination before reaching photocatalyst surfaces. This phenomena initiating at high composition of dopant resulted low degradation percentage compared to a sample added by low composition of dopant.

Based on the experiment result can be revealed that the optimum composition of all \(\mathrm{TiO}_{2}-\mathrm{M}\) was obtained at ratio 3:1. In addition, \(\mathrm{TiO}_{2}-\mathrm{Cd}\) was the best formulation compared to others \(\mathrm{TiO}_{2}-\mathrm{M}\) with degradation percentages of \(92.83 \%\) followed by \(\mathrm{TiO}_{2}-\mathrm{Co}\) and \(\mathrm{TiO}_{2}-\mathrm{Mn}\) which they had degradation percentages of \(91.64 \%\) and \(89.79 \%\), respectively as seen in Fig. 12.

The \(\mathrm{Cd}, \mathrm{Co}\) and Mn have different ionic radius inducing the resulted \(\mathrm{TiO}_{2}-\mathrm{M}\). The ionic radiation of \(\mathrm{Cd}^{2+}\) is larger than \(\mathrm{Co}^{2+}\) and \(\mathrm{Mn}^{2+}\). The metals, which have large ionic radius, were doped into \(\mathrm{TiO}_{2}\) reducing the steric hydrant and make them easily to interact with oxygen thus a bonding with \(\mathrm{TiO}_{2}\) semiconductor was effortlessly achieved. The Mn, however, has small ionic radius causing the entrance to \(\mathrm{TiO}_{2}\) difficult to accomplish due to it has high steric hydrant.

Figure 12. Methylene blue photocatalytic degradation percentages by \(\mathrm{TiO}_{2}-\mathrm{Cd}\) (\(3: 1\), blue), \(\mathrm{TiO}_{2}-\mathrm{Co}\) (\(3: 1\), red), \(\mathrm{TiO}_{2}-\mathrm{Mn}(3: 1\), green \()\)

The photocatalytic activity was also influenced by oxidation number where the oxidation number of \(\mathrm{Cd} \lt \mathrm{Co} \lt \mathrm{Mn}\). The more of oxidation number of metals affected the number of species also more diverse thus the formed catalyst became irregular. This generated that \(\mathrm{TiO}_{2}-\mathrm{Mn}\) has low degradation percentages than others. Moreover, the band gap energy of \(\mathrm{TiO}_{2}-\mathrm{Cd} \gt \mathrm{TiO}_{2}-\mathrm{Co} \gt \mathrm{TiO}_{2}-\mathrm{Mn}\) also influenced in the photocatalytic activity because of the broad band gab will slow down electron-hole recombination process. All of that metals have reduction potential, where \(\mathrm{Cd} \lt \mathrm{Co} \lt \mathrm{Mn}\). The lower of their reduction potential, the more easily they oxidized and more stable in excitation state thus the number of empty orbital as an electron trap increased and recombination process became longer.

Photocatalyst degradation process was determined by reaction rate constant values (k) to identify the reaction kinetic on methylene blue degradation following first, second and third order reaction using Eqs. (1-3), respectively. From the first, second and third order reaction graphs was pointed the linearity value \(\left(\mathrm{R}^{2}\right)\). The \(\mathrm{R}^{2}\) value closing to 1 showed the occurring order reaction and degradation of methylene blue. The k and R value of TiO\(_{2}\)-M was presented in Table 4.

(1) \[\ln C=-k \cdot t+\ln C o \]

(2) \[ \tfrac{1}{C}=k \cdot t+\tfrac{1}{C o} \]

(3) \[\tfrac{1}{c^{2}}-\tfrac{1}{C o^{2}}=2 k \cdot t \]

Table 4. The reaction rate constant (\(k\) ) and R values of methylene blue photocatalyst degradation by \(\mathrm{TiO}_{2}-\mathrm{M} 3: 1\)

Kinetic modelk (ppm.menit-1) R2TiO2-Cd (3:1) First order0,01620,734Second order0,03540,771Third order0,07860,805TiO2-Mn (3:1) First order0,04690,963Second order0,05420,967Third order0,06820,930TiO2-Co (3:1) First order0,00890,972Second order0,01520,975Third order0,02610,975

Conclusion

Synthesis of \(\mathrm{TiO}_{2}\) and \(\mathrm{TiO}_{2}-\mathrm{M}(\mathrm{M}=\mathrm{Cd}, \mathrm{Co}\) and Mn\()\) have been successfully conducted through sol-gel method. The addition of metals influenced on not only the \(\mathrm{TiO}_{2}\) crystal growth but also the material electronic properties (\(\mathrm{Eg} \mathrm{TiO}_{2}=3,35\) \(\mathrm{eV} ; \mathrm{TiO}_{2}-\mathrm{Cd}=3,15 \mathrm{eV} ; \mathrm{TiO}_{2}-\mathrm{Co}=3 \mathrm{eV}\) dan \(\mathrm{TiO}_{2}-\mathrm{Mn}=2,5 \mathrm{eV}\) ). The more metals ion doped into \(\mathrm{TiO}_{2}\) semiconductor affected on decreasing of photocatalytic activity. It was revealed that the optimum composition of \(\mathrm{TiO}_{2}-\mathrm{M}\) was obtained at \(\mathrm{TiO}_{2}: \mathrm{M}\) ratio by \(3: 1\). The \(\mathrm{TiO}_{2}-\mathrm{Cd}\) optimum photocatalytic degradation value was \(92.56 \%\) followed by \(\mathrm{TiO}_{2}-\mathrm{Co}(90.44 \%)\) and \(\mathrm{TiO}_{2}-\mathrm{Mn}(89.42 \%)\) making it to be the best \(\mathrm{TiO}_{2}-\mathrm{M}\) composition compared to others.

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И. Милкова-Томова, Д. Бухалова, К. Николова, И. Алексиева, И. Минчев, Г. Рунтолев

THE EFFECT OF EXTRA VIRGIN OLIVE OIL ON THE HUMAN BODY AND QUALITY CONTROL BY USING OPTICAL METHODS

Carsten Tottmann, Valentin Hedderich, Poli Radusheva, Krastena Nikolova

ИНФРАЧЕРВЕНА ТЕРМОГРАФИЯ ЗА ДИАГНОСТИКА НА ФОКАЛНА ИНФЕКЦИЯ

Рая Грозданова-Узунова, Тодор Узунов, Пепа Узунова

ЕКСПЕРИМЕНТЪТ ПО ПРИЛОЖНА ФИЗИКА И НЕГОВАТА РОЛЯ ПРИ УСВОЯВАНЕТО НА ПРАКТИКО-ПРИЛОЖНИТЕ ЗНАНИЯ ОТ КУРСАНТИТЕ И СТУДЕНТИТЕ

Николай Тодоров Долчинков, Бонка Енчева Караиванова-Долчинкова, Nikolay Dolchinkov, Bonka Karaivanova-Dolchinkova

ЕЛЕКТРИЧНИ СВОЙСТВА НА КОМПОЗИТНИ ФИЛМИ ОТ ПОЛИМЛЕЧНА КИСЕЛИНА

Ася Виранева, Иван Бодуров, Теменужка Йовчева

Книжка 3
PHYSICS IS AN EVER YOUNG SCIENCE

Temenuzhka Yovcheva

ТРИ ИДЕИ ЗА ЕФЕКТИВНО ОБУЧЕНИЕ

Гергана Карафезиева

МАГИЯТА НА ТВОРЧЕСТВОТО КАТО ПЪТ НА ЕСТЕСТВЕНО УЧЕНЕ В УЧЕБНИЯ ПРОЦЕС

Гергана Добрева, Жаклин Жекова, Михаела Чонос

ОБУЧЕНИЕ ПО ПРИРОДНИ НАУКИ ЧРЕЗ МИСЛОВНИ КАРТИ

Виолета Стоянова, Павлина Георгиева

ИГРА НА ДОМИНО В ЧАС ПО ФИЗИКА

Росица Кичукова, Ценка Маринова

ТЪМНАТА МАТЕРИЯ В КЛАСНАТА СТАЯ

Симона Стоянова, Анета Маринова

ПРОБЛЕМИ ПРИ ОБУЧЕНИЕТО ПО ФИЗИКА ВЪВ ВВМУ „Н. Й. ВАПЦАРОВ“

А. Христова, Г. Вангелов, И. Ташев, М. Димидов

ИЗГРАЖДАНЕ НА СИСТЕМА ОТ УЧЕБНИ ИНТЕРНЕТ РЕСУРСИ ПО ФИЗИКА И ОЦЕНКА НА ДИДАКТИЧЕСКАТА ИМ СТОЙНОСТ

Желязка Райкова, Георги Вулджев, Наталия Монева, Нели Комсалова, Айше Наби

ИНОВАЦИИ В БОРБАТА С ТУМОРНИ ОБРАЗУВАНИЯ – ЛЕЧЕНИЕ ЧРЕЗ БРАХИТЕРАПИЯ

Георги Върбанов, Радостин Михайлов, Деница Симеонова, Йорданка Енева

NATURAL RADIONUCLIDES IN DRINKING WATER

Natasha Ivanova, Bistra Manusheva

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АДАПТИРАНЕ НА ОБРАЗОВАНИЕТО ДНЕС ЗА УТРЕШНИЯ ДЕН

И. Панчева, М. Недялкова, П. Петков, Х. Александров, В. Симеонов

INTEGRATED ENGINEERING EDUCATION: THE ROLE OF ANALYSIS OF STUDENTS’ NEEDS

Veselina Kolarski, Dancho Danalev, Senia Terzieva

Книжка 1
ZAGREB CONNECTION INDICES OF \(\mathrm{TiO}_{2}\) NANOTUBES

Sohaib Khalid, Johan Kok, Akbar Ali, Mohsin Bashir

SYNTHESIS OF NEW 3-[(CHROMEN-3-YL) ETHYLIDENEAMINO] -PHENYL] -THIAZOLIDIN-4ONES AND THEIR ANTIBACTERIAL ACTIVITY

Ramiz Hoti, Naser Troni, Hamit Ismaili, Malesore Pllana, Musaj Pacarizi, Veprim Thaçi, Gjyle Mulliqi-Osmani

2017 година
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GEOECOLOGICAL ANALYSIS OF INDUSTRIAL CITIES: ON THE EXAMPLE OF AKTOBE AGGLOMERATION

Zharas Berdenov, Erbolat Mendibaev, Talgat Salihov, Kazhmurat Akhmedenov, Gulshat Ataeva

TECHNOGENESIS OF GEOECOLOGICAL SYSTEMS OF NORTHEN KAZAKHSTAN: PROGRESS, DEVELOPMENT AND EVOLUTION

Kulchichan Dzhanaleyeva, Gulnur Mazhitova, Altyn Zhanguzhina, Zharas Berdenov, Tursynkul Bazarbayeva, Emin Atasoy

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47-А НАЦИОНАЛНА КОНФЕРЕНЦИЯ НА УЧИТЕЛИТЕ ПО ХИМИЯ

В последните години тези традиционни за българското учителство конфе- ренции се организират от Българското дружество по химическо образование и история и философия на химията. То е асоцииран член на Съюза на химици- те в България, който пък е член на Европейската асоциация на химическите и

SYNTHESIS OF TiO 2-M (Cd, Co, Mn) AS A PHOTOCATALYST DEGRADATION OF METHYLENE BLUE DYE

Candra Purnawan, Sayekti Wahyuningsih, Dwita Nur Aisyah

EFFECT OF DIFFERENT CADMIUM CONCENTRATION ON SOME BIOCHEMICAL PARAMETERS IN ‘ISA BROWN’ HYBRID CHICKEN

Imer Haziri, Adem Rama, Fatgzim Latifi, Dorjana Beqiraj-Kalamishi, Ibrahim Mehmeti, Arben Haziri

PHYTOCHEMICAL AND <i>IN VITRO</i> ANTIOXIDANT STUDIES OF <i>PRIMULA VERIS</i> (L.) GROWING WILD IN KOSOVO

Ibrahim Rudhani, Florentina Raci, Hamide Ibrahimi, Arben Mehmeti, Ariana Kameri, Fatmir Faiku, Majlinda Daci, Sevdije Govori, Arben Haziri

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„СИМВОЛНИЯТ КАПИТАЛ“ НА БЪЛГАРСКОТО УЧИЛИЩЕ

Николай Цанков, Веска Гювийска

KINETICS OF PHOTO-ELECTRO-ASSISTED DEGRADATION OF REMAZOL RED 5B

Fitria Rahmawati, Tri Martini, Nina Iswati

ALLELOPATHIC AND IN VITRO ANTICANCER ACTIVITY OF STEVIA AND CHIA

Asya Dragoeva, Vanya Koleva, Zheni Stoyanova, Eli Zayova, Selime Ali

NOVEL HETEROARYLAMINO-CHROMEN-2-ONES AND THEIR ANTIBACTERIAL ACTIVITY

Ramiz Hoti, Naser Troni, Hamit Ismaili, Gjyle Mulliqi-Osmani, Veprim Thaçi

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OPTIMIZATION OF ENGINE OIL FORMULATION USING RESPONSE SURFACE METHODOLOGY AND GENETIC ALGORITHM: A COMPARATIVE STUDY

Behnaz Azmoon, Abolfazl Semnani, Ramin Jaberzadeh Ansari, Hamid Shakoori Langeroodi, Mahboube Shirani, Shima Ghanavati Nasab

CHEMOMETRICASSISTEDSPECTROPHOTOMETRIC ESTIMATION OF LANSOPRAZOLE AND DOMEPERIDONE IN BULK AND COMMERCIAL DOSAGE FORM

Farheen Sami, Shahnaz Majeed, Tengku Azlan Shah Tengku Mohammed, Noor Fatin Amalina Kamaruddin, Mohammad Zulhimi Atan, Syed Amir Javid Bukhari, Namra, Bushra Hasan, Mohammed Tahir Ansari

EVALUATION OF ANTIBACTERIAL ACTIVITY OF DIFFERENT SOLVENT EXTRACTS OF <i>TEUCRIUM CHAMAEDRYS</i> (L. ) GROWING WILD IN KOSOVO

Arben Haziri, Fatmir Faiku, Roze Berisha, Ibrahim Mehmeti, Sevdije Govori, Imer Haziri

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ПРИРОДОНАУЧНАТА ГРАМОТНОСТ НА УЧЕНИЦИТЕ В НАЧАЛОТО НА XXI ВЕК – В ТЪРСЕНЕ НА КОНЦЕПТУАЛНО ЕДИНСТВО

Теодора Коларова, Иса Хаджиали, Мимия Докова, Веселин Александров

COMPUTER SIMULATORS: APPLICATION FOR GRADUATES’ADAPTATION AT OIL AND GAS REFINERIES

Irena O. Dolganova, Igor M. Dolganov, Kseniya A. Vasyuchka

SYNTHESIS OF NEW [(3-NITRO-2-OXO-2H-CHROMEN4-YLAMINO) -PHENYL] -PHENYL-TRIAZOLIDIN-4-ONES AND THEIR ANTIBACTERIAL ACTIVITY

Ramiz Hoti, Hamit Ismaili, Idriz Vehapi, Naser Troni, Gjyle Mulliqi-Osmani, Veprim Thaçi

STABILITY OF RJ-5 FUEL

Lemi Türker, Serhat Variş

A STUDY OF BEGLIKTASH MEGALITHIC COMPLEX

Diana Kjurkchieva, Evgeni Stoykov, Sabin Ivanov, Borislav Borisov, Hristo Hristov, Pencho Kyurkchiev, Dimitar Vladev, Irina Ivanova

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2016 година
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THE EFFECT OF KOH AND KCL ADDITION TO THE DESTILATION OF ETHANOL-WATER MIXTURE

Khoirina Dwi Nugrahaningtyas, Fitria Rahmawati, Avrina Kumalasari

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VOLTAMMERIC SENSOR FOR NITROPHENOLS BASED ON SCREEN-PRINTED ELECTRODE MODIFIED WITH REDUCED GRAPHENE OXIDE

Arsim Maloku, Liridon S. Berisha, Granit Jashari, Eduard Andoni, Tahir Arbneshi

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ИЗСЛЕДВАНЕ НА ПРОФЕСИОНАЛНО-ПЕДАГОГИЧЕСКАТА РЕФЛЕКСИЯ НА УЧИТЕЛЯ ПО БИОЛОГИЯ (ЧАСТ ВТОРА)

Надежда Райчева, Иса Хаджиали, Наташа Цанова, Виктория Нечева

EXISTING NATURE OF SCIENCE TEACHING OF A THAI IN-SERVICE BIOLOGY TEACHER

Wimol Sumranwanich, Sitthipon Art-in, Panee Maneechom, Chokchai Yuenyong

NUTRIENT COMPOSITION OF CUCURBITA MELO GROWING IN KOSOVO

Fatmir Faiku, Arben Haziri, Fatbardh Gashi, Naser Troni

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CONTEXT-BASED CHEMISTRY LAB WORK WITH THE USE OF COMPUTER-ASSISTED LEARNING SYSTEM

N. Y. Stozhko, A. V. Tchernysheva, E.M. Podshivalova, B.I. Bortnik

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ПО ПЪТЯ ON THE ROAD

Б. В. Тошев

INTERDISCIPLINARY PROJECT FOR ENHANCING STUDENTS’ INTEREST IN CHEMISTRY

Stela Georgieva, Petar Todorov, Zlatina Genova, Petia Peneva

2015 година
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COMPLEX SYSTEMS FOR DRUG TRANSPORT ACROSS CELL MEMBRANES

Nikoleta Ivanova, Yana Tsoneva, Nina Ilkova, Anela Ivanova

SURFACE FUNCTIONALIZATION OF SILICA SOL-GEL MICROPARTICLES WITH EUROPIUM COMPLEXES

Nina Danchova, Gulay Ahmed, Michael Bredol, Stoyan Gutzov

INTERFACIAL REORGANIZATION OF MOLECULAR ASSEMBLIES USED AS DRUG DELIVERY SYSTEMS

I. Panaiotov, Tz. Ivanova, K. Balashev, N. Grozev, I. Minkov, K. Mircheva

KINETICS OF THE OSMOTIC PROCESS AND THE POLARIZATION EFFECT

Boryan P. Radoev, Ivan L. Minkov, Emil D. Manev

WETTING BEHAVIOR OF A NATURAL AND A SYNTHETIC THERAPEUTIC PULMONARY SURFACTANTS

Lidia Alexandrova, Michail Nedyalkov, Dimo Platikanov

Книжка 5
TEACHER’S ACCEPTANCE OF STUDENTS WITH DISABILITY

Daniela Dimitrova-Radojchikj, Natasha Chichevska-Jovanova

APPLICATION OF LASER INDUCED BREAKDOWN SPECTROSCOPY AS NONDESDUCTRIVE AND SAFE ANALYSIS METHOD FOR COMPOSITE SOLID PROPELLANTS

Amir Hossein Farhadian, Masoud Kavosh Tehrani, Mohammad Hossein Keshavarz, Seyyed Mohamad Reza Darbany, Mehran Karimi, Amir Hossein Rezayi

THE EFFECT OF DIOCTYLPHTHALATE ON INITIAL PROPERTIES AND FIELD PERFORMANCE OF SOME SEMISYNTHETIC ENGINE OILS

Azadeh Ghasemizadeh, Abolfazl Semnani, Hamid Shakoori Langeroodi, Alireza Nezamzade Ejhieh

QUALITY ASSESSMENT OF RIVER’S WATER OF LUMBARDHI PEJA (KOSOVO)

Fatmir Faiku, Arben Haziri, Fatbardh Gashi, Naser Troni

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БЛАГОДАРЯ ВИ!

Александър Панайотов

ТЕМАТА ВЪГЛЕХИДРАТИ В ПРОГРАМИТЕ ПО ХИМИЯ И БИОЛОГИЯ

Радка Томова, Елена Бояджиева, Миглена Славова, Мариан Николов

BILINGUAL COURSE IN BIOTECHNOLOGY: INTERDISCIPLINARY MODEL1)

V. Kolarski, D. Marinkova, R. Raykova, D. Danalev, S. Terzieva

ХИМИЧНИЯТ ОПИТ – НАУКА И ЗАБАВА

Елица Чорбаджийска, Величка Димитрова, Магдалена Шекерлийска, Галина Бальова, Методийка Ангелова

ЕКОЛОГИЯТА В БЪЛГАРИЯ

Здравка Костова

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SYNTHESIS OF FLUORINATED HYDROXYCINNAMOYL DERIVATIVES OF ANTI-INFLUENZA DRUGS AND THEIR BIOLOGICAL ACTIVITY

Boyka Stoykova, Maya Chochkova, Galya Ivanova, Luchia Mukova, Nadya Nikolova, Lubomira Nikolaeva-Glomb, Pavel Vojtíšek, Tsenka Milkova, Martin Štícha, David Havlíček

SYNTHESIS AND ANTIVIRAL ACTIVITY OF SOME AMINO ACIDS DERIVATIVES OF INFLUENZA VIRUS DRUGS

Radoslav Chayrov, Vesela Veselinova, Vasilka Markova, Luchia Mukova, Angel Galabov, Ivanka Stankova

NEW DERIVATIVES OF OSELTAMIVIR WITH BILE ACIDS

Kiril Chuchkov, Silvia Nakova, Lucia Mukova, Angel Galabov, Ivanka Stankova

MONOHYDROXY FLAVONES. PART III: THE MULLIKEN ANALYSIS

Maria Vakarelska-Popovska, Zhivko Velkov

LEU-ARG ANALOGUES: SYNTHESIS, IR CHARACTERIZATION AND DOCKING STUDIES

Tatyana Dzimbova, Atanas Chapkanov, Tamara Pajpanova

LACTOBACILLUS PLANTARUM AC 11S AS A BIOCATALYST IN MICROBIAL ELECYTOLYSIS CELL

Elitsa Chorbadzhiyska, Yolina Hubenova, Sophia Yankova, Dragomir Yankov, Mario Mitov

STUDYING THE PROCESS OF DEPOSITION OF ANTIMONY WITH CALCIUM CARBONATE

K. B. Omarov, Z. B. Absat, S. K. Aldabergenova, A. B. Siyazova, N. J. Rakhimzhanova, Z. B. Sagindykova

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TEACHING CHEMISTRY AT TECHNICAL UNIVERSITY

Lilyana Nacheva-Skopalik, Milena Koleva

ФОРМИРАЩО ОЦЕНЯВАНЕ PEER INSTRUCTION С ПОМОЩТА НА PLICКERS ТЕХНОЛОГИЯТА

Ивелина Коцева, Мая Гайдарова, Галина Ненчева

VAPOR PRESSURES OF 1-BUTANOL OVER WIDE RANGE OF THEMPERATURES

Javid Safarov, Bahruz Ahmadov, Saleh Mirzayev, Astan Shahverdiyev, Egon Hassel

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РУМЕН ЛЮБОМИРОВ ДОЙЧЕВ (1938 – 1999)

Огнян Димитров, Здравка Костова

NAMING OF CHEMICAL ELEMENTS

Maria Atanassova

2014 година
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LUBRICATION PROPERTIES OF DIFFERENT PENTAERYTHRITOL-OLEIC ACID REACTION PRODUCTS

Abolfazl Semnani, Hamid Shakoori Langeroodi, Mahboube Shirani

ALLELOPATHIC AND CYTOTOXIC ACTIVITY OF ORIGANUM VULGARE SSP. VULGARE GROWING WILD IN BULGARIA

Asya Pencheva Dragoeva, Vanya Petrova Koleva, Zheni Dimitrova Nanova, Mariya Zhivkova Kaschieva, Irina Rumenova Yotova

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GENDER ISSUES OF UKRAINIAN HIGHER EDUCATION

Н.H.Petruchenia, M.I.Vorovka

МНОГОВАРИАЦИОННА СТАТИСТИЧЕСКА ОЦЕНКА НА DREEM – БЪЛГАРИЯ: ВЪЗПРИЕМАНЕ НА ОБРАЗОВАТЕЛНАТА СРЕДА ОТ СТУДЕНТИТЕ В МЕДИЦИНСКИЯ УНИВЕРСИТЕТ – СОФИЯ

Радка Томова, Павлина Гатева, Радка Хаджиолова, Зафер Сабит, Миглена Славова, Гергана Чергарова, Васил Симеонов

MUSSEL BIOADHESIVES: A TOP LESSON FROM NATURE

Saâd Moulay Université Saâd Dahlab de Blida, Algeria

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ЕЛЕКТРОННО ПОМАГАЛO „ОТ АТОМА ДО КОСМОСА“ ЗА УЧЕНИЦИ ОТ Х КЛАС

Силвия Боянова Професионална гимназия „Акад. Сергей П. Корольов“ – Дупница

ЕСЕТО КАТО ИНТЕГРАТИВЕН КОНСТРУКТ – НОРМАТИВЕН, ПРОЦЕСУАЛЕН И ОЦЕНЪЧНО-РЕЗУЛТАТИВЕН АСПЕКТ

Надежда Райчева, Иван Капурдов, Наташа Цанова, Иса Хаджиали, Снежана Томова

44<sup>-ТA</sup> МЕЖДУНАРОДНА ОЛИМПИАДА ПО ХИМИЯ

Донка Ташева, Пенка Василева

ДОЦ. Д.П.Н. АЛЕКСАНДЪР АТАНАСОВ ПАНАЙОТОВ

Наташа Цанова, Иса Хаджиали, Надежда Райчева

COMPUTER ASSISTED LEARNING SYSTEM FOR STUDYING ANALYTICAL CHEMISTRY

N. Y. Stozhko, A. V. Tchernysheva, L.I. Mironova

С РАКЕТНА ГРАНАТА КЪМ МЕСЕЦА: БОРБА С ЕДНА ЛЕДЕНА ЕПОХА В ГОДИНАТА 3000 СЛЕД ХРИСТА. 3.

С РАКЕТНА ГРАНАТА КЪМ МЕСЕЦА:, БОРБА С ЕДНА ЛЕДЕНА ЕПОХА, В ГОДИНАТА 000 СЛЕД ХРИСТА. .

Книжка 3
ВИСША МАТЕМАТИКА ЗА УЧИТЕЛИ, УЧЕНИЦИ И СТУДЕНТИ: ДИФЕРЕНЦИАЛНО СМЯТАНЕ

Б. В. Тошев Българско дружество за химическо образование и история и философия на химията

ВАСИЛ ХРИСТОВ БОЗАРОВ

Пенка Бозарова, Здравка Костова

ЖИВАТА ПРИРОДА

Б. В. Тошев

БИБЛИОГРАФИЯ НА СТАТИИ ЗА МИСКОНЦЕПЦИИТЕ В ОБУЧЕНИЕТО ПО ПРИРОДНИ НАУКИ ВЪВ ВСИЧКИ ОБРАЗОВАТЕЛНИ НИВА

Б. В. Тошев Българско дружество за химическо образование и история и философия на химията

Книжка 2
BOTYU ATANASSOV BOTEV

Zdravka Kostova, Margarita Topashka-Ancheva

CHRONOLOGY OF CHEMICAL ELEMENTS DISCOVERIES

Maria Atanassova, Radoslav Angelov

Книжка 1
КАК ДА МОТИВИРАМЕ УЧЕНИЦИТЕ OT VII КЛАС ДА УЧАТ

Маргарита Бозова, Петко Бозов

ОБРАЗОВАНИЕ ЗА ПРИРОДОНАУЧНА ГРАМОТНОСТ

Адриана Тафрова-Григорова

2013 година
Книжка 6
DIFFERENTIAL TEACHING IN SCHOOL SCIENCE EDUCATION: CONCEPTUAL PRINCIPLES

G. Yuzbasheva Kherson Academy of Continuing Education, Ukraine

АНАЛИЗ НА ПОСТИЖЕНИЯТА НА УЧЕНИЦИТЕ ОТ ШЕСТИ КЛАС ВЪРХУ РАЗДЕЛ „ВЕЩЕСТВА И ТЕХНИТЕ СВОЙСТВА“ ПО „ЧОВЕКЪТ И ПРИРОДАТА“

Иваничка Буровска, Стефан Цаковски Регионален инспекторат по образованието – Ловеч

HISTORY AND PHILOSOPHY OF SCIENCE: SOME RECENT PERIODICALS (2013)

Chemistry: Bulgarian Journal of Science Education

45. НАЦИОНАЛНА КОНФЕРЕНЦИЯ НА УЧИТЕЛИТЕ ПО ХИМИЯ

„Образователни стандарти и природонаучна грамотност“ – това е темата на състоялата се от 25 до 27 октомври 2013 г. в Габрово 45. Национална конфе- ренция на учителите по химия с международно участие, която по традиция се проведе комбинирано с Годишната конференция на Българското дружество за химическо образование и история и философия на химията. Изборът на темата е предизвикан от факта, че развиването на природонаучна грамотност е обща тенденция на реформите на учебните програми и главна

Книжка 5

ЗА ХИМИЯТА НА БИРАТА

Ивелин Кулев

МЕТЕОРИТЪТ ОТ БЕЛОГРАДЧИК

Б. В. Тошев Българско дружество за химическо образование и история и философия на химията

Книжка 4
RECASTING THE DERIVATION OF THE CLAPEYRON EQUATION INTO A CONCEPTUALLY SIMPLER FORM

Srihari Murthy Meenakshi Sundararajan Engineering College, India

CHEMICAL REACTIONS DO NOT ALWAYS MODERATE CHANGES IN CONCENTRATION OF AN ACTIVE COMPONENT

Joan J. Solaz-Portolés, Vicent Sanjosé Universitat de Valènciа, Spain

POLYMETALLIC COMPEXES: CV. SYNTHESIS, SPECTRAL, THERMOGRAVIMETRIC, XRD, MOLECULAR MODELLING AND POTENTIAL ANTIBACTERIAL PROPERTIES OF TETRAMERIC COMPLEXES OF Co(II), Ni(II), Cu(II), Zn(II), Cd(II) AND Hg(II) WITH OCTADENTATE AZODYE LIGANDS

Bipin B. Mahapatra, S. N. Dehury, A. K. Sarangi, S. N. Chaulia G. M. Autonomous College, India Covt. College of Engineering Kalahandi, India DAV Junior College, India

ПРОФЕСОР ЕЛЕНА КИРКОВА НАВЪРШИ 90 ГОДИНИ

CELEBRATING 90TH ANNIVERSARY OF PROFESSOR ELENA KIRKOVA

Книжка 3
SIMULATION OF THE FATTY ACID SYNTHASE COMPLEX MECHANISM OF ACTION

M.E.A. Mohammed, Ali Abeer, Fatima Elsamani, O.M. Elsheikh, Abdulrizak Hodow, O. Khamis Haji

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G. Yuzbasheva Kherson Academy of Continuing Education, Ukraine

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КОНЦЕПТУАЛНА СХЕМА НА УЧИЛИЩНИЯ КУРС П О ХИМИЯ – МАКР О СКОПСКИ ПОДХОД

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TEACHING THE CONSTITUTION OF MATTER

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