Synthesis of novel p‐n heterojunction g‐C3N4/Bi4Ti3O12 photocatalyst with improved solar‐light‐driven photocatalytic degradation of organic dyes

Abstract

AbstractWater contamination is now a big issue all around the world. So the discovery and progress of efficient and long‐lasting visible‐light‐active photocatalysts are the most difficult current research fields. Using a simple sonication process followed by thermal polymerization, a p‐n heterojunction structure of g‐C3N4/Bi4Ti3O12 (g‐C3N4/BTO) photocatalyst was prepared. The photocatalyst's morphologies, structures, and optical characteristics were meticulously investigated using XRD, FT‐IR, SEM, TEM, EDAX, and UV–DRS. The increased photodegradation efficiency might be attributed to the p‐n heterojunction of g‐C3N4/BTO, which has a high oxidative capacity, a smaller bandgap, greater visible‐light absorption capacity, and a decreased recombination rate of photo‐excited electron‐hole pairs. At pH 3, maximal photodegradation of 98% for RhB and 93% for MG dye was reported in 20 and 30 min, respectively. Furthermore, rhodamine B (RhB) and malachite green (MG) photocatalytic degradation proceeded at pseudo‐first‐order rates, with K values of 0.193 min–1 and 0.089 min–1, approximately. Based on the experimental results, a plausible mechanism for the improved photocatalytic activity was proposed. Meanwhile, the recycling experiment validated the g‐C3N4/BTO's high stability and endurance. The matching band locations and successful charge separation might be the mechanism underlying the improvements of photodegradation. Apart from that, based on the scavenger test, photogenerated superoxide radical ( and holes (h+) might be the major radicals in the degradation process. This research is likely to pave the way for the development of innovative visible‐light‐driven materials via nanostructure design.