Carbon nitride- and graphene-based materials for the photocatalytic degradation of emerging water pollutants

Photocatalytic degradation is a promising way to treat emerging pollutants in wastewater. Recently, metal-free photocatalysts such as carbon nitride- and graphene-based materials have attracted much interest in the photocatalytic degradation of emerging water pollutants owing to their visible light activity and unique electrical properties, respectively. Graphitic carbon nitride (GCN) is considered a superior visible light-active photocatalyst because of its suitable bandgap (2.7 eV). Moreover, the facile synthesis process and the high chemical and thermal stability of GCN make it one of the research hotspots in photocatalytic wastewater treatment. Besides GCN, graphene and its derivatives are utilized to support main photocatalysts by enhancing their light absorption, pollutant adsorption, and photogenerated charge separation. Furthermore, the vast modification of these materials has promoted various outstanding performances in carbon nitride- and graphene-based photocatalysts in the application of pollutant degradation. In this review, we highlight recent developments in carbon nitride- and graphene-based photocatalysts (2018-2023), focusing on the strategies to improve the activity of GCN as a visible light-active photocatalyst and the role of graphene and its derivatives as supporting materials in wastewater pollutant remediation applications. This review highlights several advantages and improvement strategies for carbon nitride as a visible light-active photocatalyst and graphene derivatives as a supporting material for the photocatalytic degradation of emerging water pollutants.