Current progress in polymeric graphitic carbon nitride-based photocatalysts for dye degradation

Amongst several water pollutants, dye effluent contamination from various dyeing industries is a major contributor to water pollution. Considering the toxicity and carcinogenicity of dyes, a plenty of methods for remediation and inactivation of dyes have been suggested over time. Out of all the available methods, graphitic carbon nitride (g-C₃N₄) based photocatalyst has proved their worth in dye degradation. The use of pure g-C₃N₄ as a photocatalyst in dye degradation has displayed many shortcomings, such as poor charge separation, restricted surface area and low charge mobility. To overcome these bottlenecks, in the use of g-C₃N₄ as a photocatalyst, various modifications have been suggested. These include coupling with other semiconductors to form heterostructures, exfoliation of bulk to produce nanosheets, morphological modifications and doping with metals and non-metals. This review aims to present and explore the recent modifications of g-C₃N₄ as a photocatalyst in dye degradation, with respect to trending ways such as doping with foreign elements and composite formation. This review also delves on some of the major works, note their motivations, the theories behind them, and their future impact. The functioning of as-presented strategies and Z-scheme heterojunctions are also discussed. The process is a sustainable and efficient treatment of wastewater with controllable and active photocatalyst and can be considered as an environment friendly technique for dye degradation.