Visible-light-driven photocatalytic H sub(2) evolution from water splitting with band structure tunable solid solution (AgNbO sub(3)) sub(1-x)(SrTiO sub(3)) sub(x</ sub>)

• Published in: International journal of hydrogen energy Vol. 39; no. 15; pp. 7705 - 7712
• Main Authors: Zhao, Weirong, Ai, Zhuyu, Zhu, Xi, Zhang, Meng, Shi, Qiaomeng, Dai, Jiusong
• Format: Journal Article
• Language: English
• Published: 01.05.2014
• Subjects: Band structure of solids; Band theory; Energy gaps (solid state); Evolution; Hydrogen evolution; Methyl alcohol; Photocatalysis; Solid solutions
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2014.03.102

(AgNbO sub(3)) sub(1-x)(SrTiO sub(3)) sub(x) samples were successfully employed as photocatalysts for photocatalytic hydrogen evolution under visible light. The samples were characterized by a series of techniques, including X-ray diffractometry, scanning electron microscopy, UV-Vis spectrophotometry, and electrochemistry technology. The band gaps of (AgNbO sub(3)) sub(1-x)(SrTiO sub(3)) sub(x</ sub> solid solutions can be tuned continuously from 3.21 to 2.65 eV and the flat-band potentials (V) sub(f)b can be shifted positively from -0.79 to -0.31 V vs. SHE when x decreased from 1 to 0. Band positions of (AgNbO sub(3)) sub(1-x)(SrTiO sub(3)) sub(x</ sub> samples were further testified by density functional theory, suggesting that the band gap narrowing of the solid solutions derived from the hybridization of (Ti 3d and Nb 4d) and (O 2p and Ag 4d) orbital. The photocatalytic activities of samples for H) sub(2)evolution with Pt cocatalyst were evaluated in aqueous methanol solution under visible light irradiation. The highest photocatalytic activity was obtained at (AgNbO sub(3)) sub(0.25)(SrTiO sub(3)) sub(0.75). Photocatalytic activity in hydrogen evolution of these solid solutions proved to be closely dependent on band structures.