posted on 2022-06-30, 17:03authored byLu Shen, Zhengzheng Xie, Lili Hou, Jianjun Yang, Qiuye Li
Defective TiO2–x and WO3–y were
successfully synthesized by
a chemical reduction method, and then they were subsequently combined
to construct a heterojunction. The results of the photoelectrochemical
test and spectral characterization indicated that the synergistic
effect of defects and the heterojunction promotes the separation and
transmission of photogenerated charge carriers. In addition, the selectivity
of photocatalytic carbon dioxide reduction products of semiconductors
has been improved remarkably by loading a co-catalyst. When 0.8% Pd
was loaded on WO3–y/TiO2–x as the co-catalyst, the photocatalytic CH4 yield reached 3.34 μmol g–1 h–1 and the product selectivity increased up to 100%. Meanwhile, the
internal mechanism of photogenerated charge transfer in semiconductors
and the conversion path of photocatalytic carbon dioxide reduction
have been revealed by in situ Fourier transform infrared
spectroscopy. This work provides a novel and effective multifactor
collaborative strategy to fabricate a photocatalytic carbon dioxide
reduction composite catalyst with high CH4 selectivity.