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g‐C 3 N 4 /BiYO 3 Composite for Photocatalytic Hydrogen Evolution
Author(s) -
Ma Rujun,
Dong Lihui,
Li Bin,
Su Tongming,
Luo Xuan,
Qin Zuzeng,
Ji Hongbing
Publication year - 2018
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201800556
Subject(s) - photocatalysis , materials science , dielectric spectroscopy , photocurrent , band gap , composite number , hydrogen , acceptor , electrochemistry , visible spectrum , spectroscopy , analytical chemistry (journal) , photochemistry , catalysis , chemistry , composite material , electrode , optoelectronics , physics , organic chemistry , condensed matter physics , quantum mechanics
g‐C 3 N 4 /BiYO 3 composites were prepared by an electrostatic self‐assembly of g‐C 3 N 4 and BiYO 3 and were used as photocatalysts for photocatalytic hydrogen evolution. The UV‐vis DRS revealed that the band gaps of BiYO 3 and g‐C 3 N 4 were 2.58 eV and 2.96 eV, respectively, and the g‐C 3 N 4 /BiYO 3 composites showed stronger visible light absorption than that of g‐C 3 N 4 because the composite with BiYO 3 served as a narrow bandgap catalyst. Electrochemical impedance spectroscopy (EIS) proved that the g‐C 3 N 4 /BiYO 3 composites exhibited a better electronic transmission capacity and a larger photocurrent than that of g‐C 3 N 4 or BiYO 3 because the BiYO 3 acted as an electron acceptor in the composites. The PL spectra showed that g‐C 3 N 4 combined with BiYO 3 inhibited the recombination of photo‐generated electron holes in g‐C 3 N 4 and enhanced the photocatalytic activity for hydrogen evolution. Furthermore, the photocatalytic activities for hydrogen evolution with the g‐C 3 N 4 /BiYO 3 composites were higher than those of the individual g‐C 3 N 4 or BiYO 3 alone due to the transfer of photogenerated electrons from the conduction band of g‐C 3 N 4 to the conduction band of BiYO 3 and the transfer of photogenerated holes from the valence band of BiYO 3 to the valence band of g‐C 3 N 4 . The composite with a g‐C 3 N 4 /BiYO 3 mass ratio of 2 showed an optimal hydrogen evolution rate of 37.6 μmol⋅h –1 ⋅g cat –1 , which was 8.4‐ and 6.4‐fold higher than that of g‐C 3 N 4 and BiYO 3 , respectively.