Dual Z-scheme 2D/3D carbon-bridging modified g-C3N4/BiOI-Bi2O3 composite photocatalysts for effective boosting visible-light-driven photocatalytic performance

A dual Z-scheme carbon-bridged g-C3N4/BiOI-Bi2O3 photocatalyst were synthesized by simple solvothermal and calcination methods. The physical and chemical properties of prepared samples were explored via a series of characterization and Density Functional Theory (DFT) calculations. The formation mechanism of the composite photocatalyst was systematically studied and the formation process was simulated. Under the irradiation of visible light, 10% carbon-bridged g-C3N4/BiOI-Bi2O3 exhibited the best photocatalytic performance. And the kinetics reaction model was followed pseudo-first-order kinetics. Moreover, the possible TC degradation pathways were established based on LC-MS. The enhanced photocatalytic activity was mainly attributed to the dual Z-scheme heterojunction formed by carbon-bridged g-C3N4 deposition on the surface of Bi2O3 and BiOI and a higher charge transfer rate of carbon-bridged g-C3N4, which effectively promoted the separation and transfer of electron-hole pairs. The trapping experiments were carried out to further explore its photocatalytic mechanism. This work provided an in-depth understanding of g-C3N4 and bismuth-based catalysts.