Multifunctional Roles of g-C₃N₄ in Synthesizing N-TiO₂/g-C₃N₄ Heterojunction Photocatalyst for Photodegradation of Bisphenol A

BPA (Bisphenol A), an endocrine disrupting compound commonly detected in various water bodies, has been found to be hazardous because it can mimic and disrupt the hormone functions in the body. Photocatalysis is among the most efficient methods for eliminating BPA from water sources. Creating efficient heterojunctions has been shown as a successful approach to tackle the main obstacles encountered by a single photocatalyst and, thereby, improving photocatalytic performance. Thus, choosing the right dopant and/or semiconductor for the formation of an effective heterojunction is crucial to ensure the cost and production feasibility for upscaling is viable. A simple two-step calcination method was employed in this work to synthesize N-TiO₂/g-C₃N₄, where g-C₃N₄ served not only as a precursor for the preparation of the heterojunction but also as a source for nitrogen doping of TiO₂ to promote the photocatalytic degradation of BPA. The optimized N-TiO₂/g-C₃N₄ with a mass ratio of 1:2 (TGN-2) resulted in the optimal photocatalytic degradation of BPA, which was 7.23 times better than pure TiO₂. The enhanced photocatalytic performance of the composite may be attributed to the establishment of the Ti–N bond, higher crystallinity of TiO₂ anatase, and better separation of photoinduced charge carriers compared to other synthesized composites.