One-photo excitation pathway in 2D in-plane heterostructures for effective visible-light-driven photocatalytic degradation

Broad-spectrum absorption and highly effective charge-carrier separation are two essential requirements to improve the photocatalytic performance of semiconductor-based photocatalysts. In this work, a fascinating one-photon system is reported by rationally fabricating 2D in-plane Bi2O3/BiOCl (i-Cl) heterostructures for efficient photocatalytic degradation of RhB and TC. Systematic investigations revealed that the matched band structure generated an internal electric field and a chemical bond connection between the Bi2O3 and BiOCl in the Bi2O3/BiOCl composite that could effectively improve the utilization ratio of visible light and the separation effectivity of photo-generated carriers in space. The formed interactions at the 2D in-plane heterojunction interface induced the one-photon excitation pathway which has been confirmed by the experiment and DFT calculations. As a result, the i-Cl samples showed significantly enhanced photocatalytic efficiency towards the degradation of RhB and TC (RhB: 0.106 min(-1); TC: 0.048 min(-1)) under visible light. The degradation activities of RhB and TC for i-Cl were 265.08 and 4.08 times that of pure BiOCl, as well as 9.27 and 2.14 times that of mechanistically mixed Bi2O3/BiOCl samples, respectively. This work provides a logical strategy to construct other 2D in-plane heterojunctions with a one-photon excitation pathway with enhanced performance.