Enhancing photocatalytic water treatment efficiency via nitrogen Self-Doping and Hive-Like Structuring in isotype homojunctions of g-C3N4 generated from Thiourea-Melamine copolymerization

Abstract

The combination of overpopulation and rapid industrial progress has led to a pronounced increase in water contamination. Photocatalysis emerges as a viable solution for mitigating water pollution, and graphitic carbon nitride (g-C₃N₄) is considered as a particularly promising photocatalyst due to its advantageous properties, such as low cost, and high chemical stability. Nonetheless, the effectiveness of g-C₃N₄ is often compromised by its limited surface area and substantial recombination of photogenerated charge carriers. To address these challenges, in this work, we propose a systematic approach to develop photocatalytically efficient surface structures and intimate isotype homojunctions through the copolymerization of various g-C₃N₄ precursors. A range of photocatalysts, each with distinctly tailored morphologies and homojunctions, was produced and their photocatalytic performance was assessed through the removal efficiencies of model pollutants, bisphenol A (BPA), and methylene blue (MB), with each at a concentration of 10 mg L^-1. The enhanced photocatalytic activity observed in the optimized sample is primarily attributed to its significantly increased surface area, which is ten times greater than that of standard g-C₃N₄, and a marked reduction in charge recombination, which is four times lower, facilitated by the intimate homojunction. Thus, this work will open the door to the synthesis of various highly efficient photocatalysts for application in the photodegradation of diverse pollutants, consequently mitigating adverse environmental effects.