Visible-light responsive Z-scheme Bi@β-Bi2O3/g-C3N4 heterojunction for efficient photocatalytic degradation of 2,3-dihydroxynaphthalene

Abstract In this study, all-solid-state Z-scheme Bi@β-Bi2O3/g-C3N4 heterojunction was successfully constructed by in situ deposition and oxidation, where the mediator bismuth acted as a bridge to shuttle electrons between β-Bi2O3 and g-C3N4. The micromorphology, crystal structure, electronic environment and optical property of Z-scheme catalysts were systematically studied by XRD, XPS, SEM, TEM, UV-vis DRS, etc. techniques. The characterizations confirmed Bi@β-Bi2O3/g-C3N4 with the core-shell structure was successfully fabricated at 230°C. The Z-scheme heterojunction exhibited the superior visible-light degradation capacity for 2,3-dihydroxynaphthalene (2,3-DHN) with a removal ratio of 87.0% after 100 min irradiation. The significantly enhanced photoactivity was attributed to Z-scheme heterojunction facilitating the spatial and temporal separation of photoinduced carriers and maintaining the original strong oxidation and reduction reaction center of correlative component. The possible photodegradation pathway of 2,3-DHN was proposed by the determined degradation byproducts. This study could inspire new ideas for building efficient metal-bridge Z-scheme heterojunctions, and also provided novel insights into the elimination mechanism of polycyclic aromatic hydrocarbons and their derivatives in photocatalysis.