Particles of TiO2 modified with poly 3-(2-thienyl) aniline (PThA) and occluded in poly 2,2 bithiophene (PBTh), were subjected to optical, electrochemical impedance spectroscopic (EIS) and photoelectrochemical (PEC) in...Particles of TiO2 modified with poly 3-(2-thienyl) aniline (PThA) and occluded in poly 2,2 bithiophene (PBTh), were subjected to optical, electrochemical impedance spectroscopic (EIS) and photoelectrochemical (PEC) investigation in aqueous, acetate, citrate, and phosphate electrolytes. EIS studies revealed that the assembly film of TiO2/PThA/PBTh possess porous-type structure. They also confirmed the approximate value of Ef obtained from electrochemical studies. Both EIS and optical studies indicated that ac conductivity is much greater than dc conductivity. Guided by the properties of PBTh, no large changes in the energy band structure occurred due to occlusion of TiO2 in PBTh films. Occlusion of TiO2/PThA into the network structure of PBTh inhibits the energy dissipation process and impeded charge polarization process of the material. Photoelectrochemical outcome suggested possible band alignments between the organic film and TiO2 and formation of hybrid sub-bands. Inclusion of TiO2 in the thiophene-based polymers enhanced the charge separation and consequently charge transfer processes and widen the absorption in visible light range.展开更多
Homogenous and heterogeneous production of hydrogen via photo-dissociation of water has been achieved with visible range solar radiation without any external potential at room temperature. Potassium ferrocyanide as a ...Homogenous and heterogeneous production of hydrogen via photo-dissociation of water has been achieved with visible range solar radiation without any external potential at room temperature. Potassium ferrocyanide as a solvated-electron supplier and electron exchanger in basic buffers was used as a homogenous media for hydrogen production. Aqueous colloidal solutions of p-type Fe2O3 doped with MgO （Fe1.8Mg0.2O3） or with ZnO （Fe1.9Zn0.1O3） suspensions in ferrocyanide solutions were used as heterogeneous media for hydrogen generation by reduction of ferricyanide. The effects of the hole-scavengers such as oxo-anions and solvated-electron- suppliers were investigated. Results showed that Fe2O3 doped with ZnO was more efficient than that doped with MgO. The studies also showed that the aqueous nano-systems we used retained their stability as indicated by the reproducibility of their photocatalytic activities. Solar radiated assemblies of doped Fe2O3/[Fe（CN）6]4^- sustained cyclic systems for continuous hydrogen production.展开更多
文摘Particles of TiO2 modified with poly 3-(2-thienyl) aniline (PThA) and occluded in poly 2,2 bithiophene (PBTh), were subjected to optical, electrochemical impedance spectroscopic (EIS) and photoelectrochemical (PEC) investigation in aqueous, acetate, citrate, and phosphate electrolytes. EIS studies revealed that the assembly film of TiO2/PThA/PBTh possess porous-type structure. They also confirmed the approximate value of Ef obtained from electrochemical studies. Both EIS and optical studies indicated that ac conductivity is much greater than dc conductivity. Guided by the properties of PBTh, no large changes in the energy band structure occurred due to occlusion of TiO2 in PBTh films. Occlusion of TiO2/PThA into the network structure of PBTh inhibits the energy dissipation process and impeded charge polarization process of the material. Photoelectrochemical outcome suggested possible band alignments between the organic film and TiO2 and formation of hybrid sub-bands. Inclusion of TiO2 in the thiophene-based polymers enhanced the charge separation and consequently charge transfer processes and widen the absorption in visible light range.
基金supported by Indiana University Sum-mer Faculty Fellowship Program
文摘Homogenous and heterogeneous production of hydrogen via photo-dissociation of water has been achieved with visible range solar radiation without any external potential at room temperature. Potassium ferrocyanide as a solvated-electron supplier and electron exchanger in basic buffers was used as a homogenous media for hydrogen production. Aqueous colloidal solutions of p-type Fe2O3 doped with MgO （Fe1.8Mg0.2O3） or with ZnO （Fe1.9Zn0.1O3） suspensions in ferrocyanide solutions were used as heterogeneous media for hydrogen generation by reduction of ferricyanide. The effects of the hole-scavengers such as oxo-anions and solvated-electron- suppliers were investigated. Results showed that Fe2O3 doped with ZnO was more efficient than that doped with MgO. The studies also showed that the aqueous nano-systems we used retained their stability as indicated by the reproducibility of their photocatalytic activities. Solar radiated assemblies of doped Fe2O3/[Fe（CN）6]4^- sustained cyclic systems for continuous hydrogen production.
