TY  - JOUR
AU  - Zhu, Bicheng
AU  - Tan, Haiyan
AU  - Fan, Jiajie
AU  - Cheng, Bei
AU  - Yu, Jiaguo
AU  - Ho, Wingkei
PY  - 2021
TI  - Tuning the strength of built-in electric field in 2D/2D g-C3N4/SnS2 and g-C3N4/ZrS2 S-scheme heterojunctions by nonmetal doping
JO  - Journal of Materiomics
SN  - 2352-8478
SP  - 988
EP  - 997
VL  - 7
IS  - 5
AB  - Single photocatalysts usually exhibit unsatisfactory performance due to the serious recombination of photogenerated electron‒hole pairs. Combining two photocatalysts to construct S-scheme heterojunction could solve this problem. In S-scheme mechanism, the interfacial built-in electric field (IEF) provides a vital driving force for efficient charge separation. Modifying the IEF is a feasible strategy to further improve the photocatalytic activity. Herein, a novel idea of tuning the strength of IEF in 2D/2D graphitic carbon nitride (g-C3N4)/MS2 (M = Sn, Zr) S-scheme heterojunctions by nonmetal doping was developed by employing density functional theory calculation. Three nonmetal elements (O, P, and S) were severally introduced into g-C3N4/MS2 composites. Charge density difference suggested that O and S doping led to increased interfacial electron transfer, while P doping had minimal influence. As expected, the calculated field strength of O- and S-doped g-C3N4/MS2 composites was significantly larger than that of pristine and P-doped g-C3N4/MS2 composites. Therefore, O and S doping endowed g-C3N4/MS2 S-scheme heterojunctions with enhanced IEF and more thorough charge transfer. Correspondingly, the experimentally synthesized O-C3N4/SnS2 composite exhibited better photocatalytic H2-production activity than g-C3N4/SnS2 composite. This work proposed an original idea of employing proper nonmetal doping to magnify the advantage of S-scheme heterojunction in accelerating charge separation.
UR  - https://doi.org/10.1016/j.jmat.2021.02.015
DO  - 10.1016/j.jmat.2021.02.015