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Operando Oxygen Vacancies for Enhanced Activity and Stability toward Nitrogen Photofixation
Author(s) -
Hou Tingting,
Xiao Yu,
Cui Peixin,
Huang Yining,
Tan Xiaoping,
Zheng Xusheng,
Zou Ying,
Liu Changxi,
Zhu Wenkun,
Liang Shuquan,
Wang Liangbing
Publication year - 2019
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201902319
Subject(s) - nanoporous , catalysis , materials science , oxygen , adsorption , ammonia , nanocrystal , nanoparticle , chemical engineering , nitrogen , nanotechnology , ammonia production , irradiation , photochemistry , chemistry , organic chemistry , physics , nuclear physics , engineering
Photocatalysts with oxygen vacancies (OVs) have exhibited exciting activity in N 2 photofixation due to their superiority in capture and activation of N 2 . However, the surface OVs are easily oxidized by seizing the oxygen atoms from water or oxygen during the catalytic reaction. Here, it is reported that the grain boundaries (GBs) in nanoporous WO 3 induce plenty of operando OVs under light irradiation to significantly boost catalytic activity toward N 2 photofixation. Impressively, nanoporous WO 3 with abundant GBs (WO 3 ‐600) exhibit an ammonia production rate of 230 µmol g cat. −1 h −1 without any sacrificial agents at room temperature, 17 times higher than that for WO 3 nanoparticles without GBs. Moreover, WO 3 ‐600 also manifests remarkable stability by maintaining nearly ≈100% catalytic activity after ten successive reaction rounds. Further mechanistic studies reveal that both OVs and GBs regulate the band structures of WO 3 nanocrystals, as well as favor the delivery of photogenerated electrons to adsorbed N 2 by enhancing W–O covalency. More importantly, plenty of operando OVs induced by GBs generate during catalytic reaction, directly contributing to the excellent catalytic performance for WO 3 ‐600. This work opens a novel avenue to developing efficient photocatalysts by construction of operando OVs.