2D/2D Z-scheme photocatalyst of g-C3N4 and plasmonic Bi metal deposited Bi2WO6: Enhanced separation and migration of photoinduced charges

An ideal photocatalyst should have high redox capacity, efficient charge separation, and large reaction surface area. However, it is an extreme challenge to construct a photocatalytic system with above three merits. Herein, the g-C3N4/Bi@Bi2WO6 composite photocatalyst was prepared by simple wet chemical method. Then the separation pathway of photoinduced charges through the interface was explored by XPS, EPR and active species capture experiments, confirming that the Z-scheme charge transfer route was followed. The optimized composite photocatalyst exhibited the photocatalytic hydrogen production rate of 1219.3 mu mol h-1g-1, which is 2.29 times that of pure g-C3N4 (533.4 mu mol h-1g-1). Moreover, the photocatalytic degradation rates of RhB and TC were 82.43% and 66.7%, respectively, which were 7.55 times and 1.92 times that of pure Bi2WO6. Ultimately, the enhanced photocatalytic performances were attributed to the synergistic effect of 2D/2D coupling interface and the deposited metal Bi, which not only benefited the efficient charge separation and fast charge migration but also provided the large reaction surface area. In addition, surface plasmon resonance effect of metal Bi can boost the visible light absorption and broaden the light absorption range to the full spectrum. Our study provides a new idea to design high-performance Z-scheme photocatalyst for highly efficient utilization of solar energy. (c) 2023 Elsevier B.V. All rights reserved.

Automated summary

In this study, a novel photocatalyst g-C3N4/Bi@Bi2WO6 composite was prepared by a simple wet chemical method, showing excellent photocatalytic performance. The separation pathway of photoinduced charges through the interface was investigated, and it was confirmed that a Z-scheme charge transfer route was followed. The optimized composite photocatalyst exhibited a photocatalytic hydrogen production rate 2.29 times higher than that of pure g-C3N4, and the photocatalytic degradation rates of RhB and TC were 7.55 times and 1.92 times that of pure Bi2WO6, respectively. The enhanced photocatalytic performances were attributed to the synergistic effect of the 2D/2D coupling interface and the deposited metal Bi, which facilitated efficient charge separation, fast charge migration, and provided a large reaction surface area. Additionally, the surface plasmon resonance effect of metal Bi enhanced visible light absorption and broadened the light absorption range to the full spectrum. This study provides a new idea for the design of high-performance Z-scheme photocatalysts for highly efficient utilization of solar energy.