Role of transition metal oxides in g-C3N4-based heterojunctions for photocatalysis and supercapacitors

g-C(3)N(4 )emerges as a star 2D photocatalyst due to its unique layered structure, suitable band structure and low cost. However, its photocatalytic application is limited by the fast charge recombination and low photoabsorption. Rationally designing g-C3N4-based heterojunction is promising for improving photocatalytic activity. Besides, g-C3N4 exhibits great potentials in electrochemical energy storage. In view of the excellent performance of typical transition metal oxides (TMOs) in photocatalysis and energy storage, this review summarized the advances of TMOs/g-C3N4 heterojunctions in the above two areas. Firstly, we introduce several typical TMOs based on their crystal structures and band structures. Then, we summarize different kinds of TMOs/g-C3N4 heterojunctions, including type I/II heterojunction, Z-scheme, p-n junction and Schottky junction, with diverse photocatalytic applications (pollutant degradation, water splitting, CO2 reduction and N-2 fixation) and supercapacitive energy storage. Finally, some promising strategies for improving the performance of TMOs/g-C3N4 were proposed. Particularly, the exploration of photocatalysis-assisted supercapacitors was discussed. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

g-C3N4 has emerged as a promising 2D photocatalyst due to its unique structure and low cost, but faces limitations. Designing heterojunctions based on g-C3N4 is a promising approach to improving photocatalytic activity and showing potential in electrochemical energy storage.