Nanoarchitectonics on Z-scheme and Mott-Schottky heterostructure for photocatalytic water oxidation via dual-cascade charge-transfer pathways

Yao Li; Siyuan Liu; Runlu Liu; Jian Pan; Xin Li; Jianyu Zhang; Xiaoxiao Zhang; Yixin Zhao; Dawei Wang; Hengdao Quan; Shenmin Zhu

doi:10.1039/d3na00182b

Nanoarchitectonics on Z-scheme and Mott-Schottky heterostructure for photocatalytic water oxidation via dual-cascade charge-transfer pathways

Nanoscale Adv. 2023 May 10;5(12):3386-3395. doi: 10.1039/d3na00182b. eCollection 2023 Jun 13.

Authors

Yao Li¹, Siyuan Liu¹, Runlu Liu¹, Jian Pan², Xin Li³, Jianyu Zhang¹, Xiaoxiao Zhang¹, Yixin Zhao³, Dawei Wang², Hengdao Quan⁴, Shenmin Zhu¹

Affiliations

¹ State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University Shanghai 200240 P. R. China smzhu@sjtu.edu.cn.
² Particles and Catalysis Research Group, School of Chemical Engineering, University of New South Wales Sydney 2052 Australia.
³ School of Environmental Science and Engineering, Shanghai Jiao Tong University Shanghai 200240 China.
⁴ School of Chemical Engineering and Environment, Beijing Institute of Technology Beijing 100081 China.

Abstract

The bottleneck for water splitting to generate hydrogen fuel is the sluggish oxidation of water. Even though the monoclinic-BiVO₄ (m-BiVO₄)-based heterostructure has been widely applied for water oxidation, carrier recombination on dual surfaces of the m-BiVO₄ component have not been fully resolved by a single heterojunction. Inspired by natural photosynthesis, we established an m-BiVO₄/carbon nitride (C₃N₄) Z-scheme heterostructure based on the m-BiVO₄/reduced graphene oxide (rGO) Mott-Schottky heterostructure, constructing the face-contact C₃N₄/m-BiVO₄/rGO (CNBG) ternary composite to remove excessive surface recombination during water oxidation. The rGO can accumulate photogenerated electrons from m-BiVO₄ through a high conductivity region over the heterointerface, with the electrons then prone to diffuse along a highly conductive carbon network. In an internal electric field at the heterointerface of m-BiVO₄/C₃N₄, the low-energy electrons and holes are rapidly consumed under irradiation. Therefore, spatial separation of electron-hole pairs occurs, and strong redox potentials are maintained by the Z-scheme electron transfer. These advantages endow the CNBG ternary composite with over 193% growth in O₂ yield, and a remarkable rise in ·OH and ·O₂^- radicals, compared to the m-BiVO₄/rGO binary composite. This work shows a novel perspective for rationally integrating Z-scheme and Mott-Schottky heterostructures in the water oxidation reaction.