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Efficient Photocatalytic Oxygen Production over Nitrogen‐Doped Sr 4 Nb 2 O 9 under Visible‐Light Irradiation
Author(s) -
Wu Fangfang,
Lv Meilin,
Sun Xiaoqin,
Xie Yinghao,
Chen Hongmei,
Ni Shuang,
Liu Gang,
Xu Xiaoxiang
Publication year - 2016
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201501035
Subject(s) - photocatalysis , visible spectrum , photocurrent , water splitting , photochemistry , oxygen , doping , oxygen evolution , irradiation , materials science , valence (chemistry) , quantum efficiency , nitrogen , analytical chemistry (journal) , inorganic chemistry , chemistry , optoelectronics , catalysis , electrochemistry , electrode , physics , biochemistry , organic chemistry , chromatography , nuclear physics
Photocatalytic water splitting is an appealing process for solar energy conversions yet it is often limited by the slow oxidation of water to oxygen half‐reaction. Here we performed an investigation on N‐doped Sr 4 Nb 2 O 9 as a water oxidation photocatalyst. Our results show that N doping is an effective approach to improve the visible‐light response of Sr 4 Nb 2 O 9 . Efficient photocatalytic oxygen production was observed after N doping, and the highest production rate of ∼27 μmol h −1 under visible‐light irradiation corresponds to an apparent quantum efficiency of ∼0.31 %. Clear anodic photocurrent can be generated under visible‐light illumination, and the flat‐band potential was determined to be ∼−1.25 V vs. Ag/AgCl at pH 7. Theoretical calculations reveal that N doping introduces additional valence bands and is responsible for the visible‐light response. Variations in light absorption and photo‐oxidation performance can be controlled by modifying these valence band positions using different nitridation temperatures.