Tailored Polymeric Carbon Nitride Coupled with Bi2O3 for Constructing Z‐Scheme Heterojunction with Enhanced Photocatalytic Activity

The great demand for visible-light-induced catalysts with high photocatalytic performance has stimulated extensive interest in constructing g-C3N4-based Z-Scheme heterojunctions. In this research work, the g-C3N4/Bi2O3 Z-Scheme heterojunction by precipitation-hydrothermal method was constructed, and characterized by various techniques. The g-C3N4/Bi2O3-1 composite exhibited a transient photocurrent response approximately 7 and 5 times higher than that of bare g-C3N4 and Bi2O3, respectively, and showed higher visible photocatalytic activity with 99.8 % degradation of methylene blue (MB) within 75 min. Meanwhile, the pH effect on the photocatalytic degradation of MB was investigated. Radicals trapping experiments showed that center dot OH free radical played a predominant role for the degradation of MB, EPR analysis confirmed the presence of superoxide radicals, which combined with the band structure of the composites, confirmed the Z-Scheme of the heterojunction. A possible mechanism for photocatalytic degradation of MB dyes in g-C3N4/Bi2O3-1 composites was also proposed. This study provided a new avenue for the development of novel g-C3N4-based Z-Scheme heterojunction materials with prospective applications in the fields of energy and environment.