Ti O2 films and N- doped Ti O2 films were prepared by magnetron sputtering methodology.The films were illuminated at365 nm for5— 2 0 min followed by the measurementof contactangles and surface photovoltage spectrosco...Ti O2 films and N- doped Ti O2 films were prepared by magnetron sputtering methodology.The films were illuminated at365 nm for5— 2 0 min followed by the measurementof contactangles and surface photovoltage spectroscopy.The results show thatfor n- type Ti O2 film,UV illumination treatment can in- crease the photovoltage,while for p- type Ti O2 film,such treatment can decreases the photovoltage.The photovoltaic changing was explained by Ti— OH group increasing due to photo- induced hydrophility.For n- type Ti O2 film,Ti— OH groups can increase the photo- induced charge separation and thus iucrease the photovoltage;for p- type Ti O2 film,Ti—OH groups decrease the photo- induced charge separation and thus decrease the photovoltage.展开更多
Redox behavior and electrocatalytic activities of the Ti/nano\|TiO\-2 electrode were investigated by cyclic voltammetry(CV) and bulk electrolysis. The results indicate that there are two pairs of well\|defined redox p...Redox behavior and electrocatalytic activities of the Ti/nano\|TiO\-2 electrode were investigated by cyclic voltammetry(CV) and bulk electrolysis. The results indicate that there are two pairs of well\|defined redox peaks for Ti/nano\|TiO\-2 film electrode in the 1 mol/L H\-2SO\-4 and 1 mol/L NaOH at 0.1 V/s corresponding to TiO\-2/ Ti\-2O\-3 and TiO\-2/Ti(OH)\-3 reversible electrode process. In 1 mol/L NaOH medium the peak potential evidently shift to the negative value with \%E\%\+r\-\{1/2\} being -1.38 and -1.72 V(\%vs\%.SCE), and the heterogeneous electrocatalytic reduction activities of TiO\-2/Ti\-2O\-3 redox for \%p\%\|nitrobenzoic acid (PNA) is very high. The indirect electroreduction of PNA to \%p\%\|aminobenzoic acid (PAA) by Ti\+Ⅳ/Ti\+Ⅲ redox system on nanocrystalline TiO\-2 film surface was found, and the electrode reaction mechanism is called electro\|catalytic(EC) mechanism. In the preparative electrolysis, the current efficiency was over 90%.展开更多
TiO 2/glass film photocatalysts have been prepared by a sol gel method with titanium tetrabutoxide as precursor, and used in photocatalytic degradation of 2,4 dichlorophenol(DCP) in aqueous solution. The experiments i...TiO 2/glass film photocatalysts have been prepared by a sol gel method with titanium tetrabutoxide as precursor, and used in photocatalytic degradation of 2,4 dichlorophenol(DCP) in aqueous solution. The experiments indicated that the TiO 2/glass film coated with five layers of TiO 2 sol in the case of higher pH value(≥10) or lower pH value(≤2) showed a higher catalytic activity, and the relationship between initial DCP concentration( c 0) and reaction rate( r 0) follows Langmuir Hinshelwood equation. The photocatalytic degradation kinetics of DCP( c 0≤0 5 mmol/L) is of first order kinetics.展开更多
本试验利用阳极氧化的方法在纯钛基体上直接获得锐钛相T iO2多孔膜,解决T iO2光催化剂的涂敷固定问题。用场发射扫描电镜(F ie ld em iss ion scann ing e lectron m icroscope,FESEM)和X射线衍射仪(X-ray d iffractionm eter,XRD)对纯...本试验利用阳极氧化的方法在纯钛基体上直接获得锐钛相T iO2多孔膜,解决T iO2光催化剂的涂敷固定问题。用场发射扫描电镜(F ie ld em iss ion scann ing e lectron m icroscope,FESEM)和X射线衍射仪(X-ray d iffractionm eter,XRD)对纯钛表面生成的T iO2多孔膜的形貌和晶体结构进行分析。以10m g/L甲基橙溶液为降解物进行光催化试验,分别研究了阳极氧化电压、溶液的初始pH值、T iO2膜的面积、T iO2膜的使用次数对降解率的影响。试验结果表明,当溶液初始pH值为1时,140V阳极氧化所得T iO2膜的光催化性能最好,同时随着T iO2膜使用次数的增加,但其光催化效果有所下降。展开更多
TiO2 membranes were prepared on aluminum-alloy thin plates by electrophoretic deposition and dip coating in a colloid solution of TiO2, respectively. The photocatalytic activity of TiO2 membrane was compared using eth...TiO2 membranes were prepared on aluminum-alloy thin plates by electrophoretic deposition and dip coating in a colloid solution of TiO2, respectively. The photocatalytic activity of TiO2 membrane was compared using ethylene as reactant, and the crystal and morphological structure of the membrane were characterized by XRD and SEM. The results showed that a more compact membrane with high loading of TiO2 but lower photocatalytic activity of unit TiO2 mass was obtained by electrophoresis compared with dip coating method. The addition of polyethylene glycol (PEG) to the sol of TiO2 could improve the specific photocatalytic activity (ethylene conversion per unit mass TiO2 and unit area of membrane piece) of the electrophoresis-membrane prepared from the sol, but could not change the specific photocatalytic activity of the dip-coating membrane from the sol. The ethylene conversion on the electrophoresis membrane prepared from the sol containing PEG (50 g·L-1) was 9 times of that on the dip coating membrane. The effect of PEG on the properties of electrophoresis-membrane of TiO2 was attributed to the change of electrokinetic properties of sol. Addition of PEG decreased of colloid particles and the electroosmosis velocity of diffuse layer of colloid particles. These favored the formation of a low compact and porous membrane on the electrode in electric field, and thus increasing the availability of TiO2 in photocatalytic process.展开更多
文摘Ti O2 films and N- doped Ti O2 films were prepared by magnetron sputtering methodology.The films were illuminated at365 nm for5— 2 0 min followed by the measurementof contactangles and surface photovoltage spectroscopy.The results show thatfor n- type Ti O2 film,UV illumination treatment can in- crease the photovoltage,while for p- type Ti O2 film,such treatment can decreases the photovoltage.The photovoltaic changing was explained by Ti— OH group increasing due to photo- induced hydrophility.For n- type Ti O2 film,Ti— OH groups can increase the photo- induced charge separation and thus iucrease the photovoltage;for p- type Ti O2 film,Ti—OH groups decrease the photo- induced charge separation and thus decrease the photovoltage.
文摘Redox behavior and electrocatalytic activities of the Ti/nano\|TiO\-2 electrode were investigated by cyclic voltammetry(CV) and bulk electrolysis. The results indicate that there are two pairs of well\|defined redox peaks for Ti/nano\|TiO\-2 film electrode in the 1 mol/L H\-2SO\-4 and 1 mol/L NaOH at 0.1 V/s corresponding to TiO\-2/ Ti\-2O\-3 and TiO\-2/Ti(OH)\-3 reversible electrode process. In 1 mol/L NaOH medium the peak potential evidently shift to the negative value with \%E\%\+r\-\{1/2\} being -1.38 and -1.72 V(\%vs\%.SCE), and the heterogeneous electrocatalytic reduction activities of TiO\-2/Ti\-2O\-3 redox for \%p\%\|nitrobenzoic acid (PNA) is very high. The indirect electroreduction of PNA to \%p\%\|aminobenzoic acid (PAA) by Ti\+Ⅳ/Ti\+Ⅲ redox system on nanocrystalline TiO\-2 film surface was found, and the electrode reaction mechanism is called electro\|catalytic(EC) mechanism. In the preparative electrolysis, the current efficiency was over 90%.
文摘TiO 2/glass film photocatalysts have been prepared by a sol gel method with titanium tetrabutoxide as precursor, and used in photocatalytic degradation of 2,4 dichlorophenol(DCP) in aqueous solution. The experiments indicated that the TiO 2/glass film coated with five layers of TiO 2 sol in the case of higher pH value(≥10) or lower pH value(≤2) showed a higher catalytic activity, and the relationship between initial DCP concentration( c 0) and reaction rate( r 0) follows Langmuir Hinshelwood equation. The photocatalytic degradation kinetics of DCP( c 0≤0 5 mmol/L) is of first order kinetics.
文摘本试验利用阳极氧化的方法在纯钛基体上直接获得锐钛相T iO2多孔膜,解决T iO2光催化剂的涂敷固定问题。用场发射扫描电镜(F ie ld em iss ion scann ing e lectron m icroscope,FESEM)和X射线衍射仪(X-ray d iffractionm eter,XRD)对纯钛表面生成的T iO2多孔膜的形貌和晶体结构进行分析。以10m g/L甲基橙溶液为降解物进行光催化试验,分别研究了阳极氧化电压、溶液的初始pH值、T iO2膜的面积、T iO2膜的使用次数对降解率的影响。试验结果表明,当溶液初始pH值为1时,140V阳极氧化所得T iO2膜的光催化性能最好,同时随着T iO2膜使用次数的增加,但其光催化效果有所下降。
文摘TiO2 membranes were prepared on aluminum-alloy thin plates by electrophoretic deposition and dip coating in a colloid solution of TiO2, respectively. The photocatalytic activity of TiO2 membrane was compared using ethylene as reactant, and the crystal and morphological structure of the membrane were characterized by XRD and SEM. The results showed that a more compact membrane with high loading of TiO2 but lower photocatalytic activity of unit TiO2 mass was obtained by electrophoresis compared with dip coating method. The addition of polyethylene glycol (PEG) to the sol of TiO2 could improve the specific photocatalytic activity (ethylene conversion per unit mass TiO2 and unit area of membrane piece) of the electrophoresis-membrane prepared from the sol, but could not change the specific photocatalytic activity of the dip-coating membrane from the sol. The ethylene conversion on the electrophoresis membrane prepared from the sol containing PEG (50 g·L-1) was 9 times of that on the dip coating membrane. The effect of PEG on the properties of electrophoresis-membrane of TiO2 was attributed to the change of electrokinetic properties of sol. Addition of PEG decreased of colloid particles and the electroosmosis velocity of diffuse layer of colloid particles. These favored the formation of a low compact and porous membrane on the electrode in electric field, and thus increasing the availability of TiO2 in photocatalytic process.
