Fabrication of an Efficient N, S Co-Doped WO3 Operated in Wide-Range of Visible-Light for Photoelectrochemical Water Oxidation

Nanomaterials

Caiyun Gao¹  Fachao Wu¹  Dong Li²  Fei Han²  Zhanlin Chen²  Hongfang Shen²  Fenglan Han² 

[1] Chemical Science and Engineering College, North Minzu University, Yinchuan 750021, China;School of Material Science and Engineering, North Minzu University, Yinchuan 750021, China;

关键词: N, S co-doped;    water oxidation;    tungsten trioxide;    photoanode;    photoelectrochemical;    water splitting;   

DOI  :  10.3390/nano12122079

来源: DOAJ

【 摘 要 】

In this work, a highly efficient wide-visible-light-driven photoanode, namely, nitrogen and sulfur co-doped tungsten trioxide (S-N-WO₃), was synthesized using tungstic acid (H₂WO₄) as W source and ammonium sulfide ((NH₄)₂S), which functioned simultaneously as a sulfur source and as a nitrogen source for the co-doping of nitrogen and sulfur. The EDS and XPS results indicated that the controllable formation of either N-doped WO₃ (N-WO₃) or S-N-WO₃ by changing the n_W:n_(NH4)2S ratio below or above 1:5. Both N and S contents increased when increasing the n_W:n_(NH4)2S ratio from 1:0 to 1:15 and thereafter decreased up to 1:25. The UV-visible diffuse reflectance spectra (DRS) of S-N-WO₃ exhibited a significant redshift of the absorption edge with new shoulders appearing at 470–650 nm, which became more intense as the n_W:n_(NH4)2S ratio increased from 1:5 and then decreased up to 1:25, with the maximum at 1:15. The values of n_W:n_(NH4)2S ratio dependence is consistent with the cases of the S and N contents. This suggests that S and N co-doped into the WO₃ lattice are responsible for the considerable redshift in the absorption edge, with a new shoulder appearing at 470–650 nm owing to the intrabandgap formation above the valence band (VB) edge and a dopant energy level below the conduction band (CB) of WO₃. Therefore, benefiting from the S and N co-doping, the S-N-WO₃ photoanode generated a photoanodic current under visible light irradiation below 580 nm due to the photoelectrochemical (PEC) water oxidation, compared with pure WO₃ doing so below 470 nm.

【 授权许可】

Unknown