Qian Zhang,Ying Zhou,Fang Wang,Fan Dong,Wei Li,Haimin Li,Greta R. Patzke
Elemental photocatalysts have recently been proposed as interesting materials to be used as alternatives to conventional semiconductor compounds. In this study, we demonstrate that not only elements with semiconducting properties are photocatalytically active by introducing semimetallic bismuth for the photooxidation of NO. Black Bi films were prepared via an electrochemical deposition approach. Both density functional theory (DFT) calculations and temperature dependence electrical resistivity measurements pointed out that the obtained films exhibited semimetallic behavior. The Bi films were easily oxidized upon exposure to air. However, electrochemical reduction of the surface amorphous oxide layer led to a more than 4-fold enhancement of the photocurrent density of the Bi films. The detection of hydroxyl radicals with electron spin resonance (ESR) investigations further confirmed the photogeneration of electrons and holes. A 37.7% removal ratio of NO over Bi films was observed under UV light irradiation with no significant reduction of photocatalytic activity after five cycles. Given that the conduction and valence bands of semimetallic Bi overlap, the associated excitation processes are more complex in comparison with semiconductor photocatalysts, thereby indicating a different photocatalytic mechanism. The present study points out new directions for developing semimetallic photocatalysts.
Mai Manfang,Liao Bin,Liao Yijun,Lin Donghai,Ma Xinzhou
GaTe thin films are electrochemically deposited on indium tin oxide for photoelectrochemical applications. The electrochemical deposition behavior of GaTe thin films in acidic solution of HTeO 2 + with Ga 3+ is studied with cyclic voltammetry combining with operando transmittance spectroscopy. Underpotential deposition of Ga on Te starts at potential of − 0.35 V. The presence of Ga 3+ in the solution can strongly suppressed the formation of H 2 Te. XPS analysis reveals that Ga-rich GaTe is deposited over a wide potential range. The photoelectrochemical performance of the thin films as photocathodes is strongly dependent on the deposition potential. The GaTe films deposited at − 1.0 V produced the highest photocurrent of about − 0.03 mA cm −2 . Meanwhile the film deposited at − 0.35 V shows improved performance during photoelectrochemical measurement, which can be ascribed to the increased GaTe content during photoelectrochemical measurements, as confirmed by XPS analysis. Graphical
Hang Bai,Yufang Li,Honglie Shen,Long Wang,Hechao Li,Zhihong Xie,Andi Chen,Zheng Shi,Wei Wang
Antimony selenide (Sb 2 Se 3 ) has become a potential semiconductor material for a wide range of optoelectronic applications because of its unique one-dimensional crystal structure and corresponding excellent anisotropic optical and electronic properties. Herein, uniform and flat Sb 2 Se 3 thin films with [hk1]-optimized growth orientation are prepared by adjusting the deposition potentials and selenization temperatures using a facile electrochemical deposition method. Then these films are applied in heterojunction-type photodetectors with the structure of Mo/Sb 2 Se 3 /CdS/ZnO/ITO/Ag. The best performances are obtained for devices with a deposition potential of −0.55 V and a selenization temperature of 300 °C. At 0 bias, the detector yielded a responsivity of 25.4 mA/W and a detectivity of 1.06 × 10 11 Jones at 635 nm visible light with a light intensity of 5 mW. The results show that high-quality Sb 2 Se 3 thin films can be prepared by electrochemical deposition under proper preparation conditions, which lays the foundation for the application of the electrochemical deposition method in the field of optoelectronic devices .
危险品化学品经营许可证（带存储）