Graphitic Carbon Nitride as a Sustainable Photocatalyst Material for Pollutants Removal. State-of-the Art, Preliminary Tests and Application Perspectives

Materials (Basel). 2021 Dec 1;14(23):7368. doi: 10.3390/ma14237368.

Abstract

Photocatalysis is an attractive strategy for emerging pollutants remediation. Research towards the development of new, efficient and effective catalytic materials with high activity under wide irradiation spectra is a highly active sector in material science. Various semiconductor materials have been employed as photocatalysts, including TiO2, SrTiO3, CdS, BiVO4, Ta3N5, TaON, Ag3PO4, and g-C3N4. The latter is a metal-free, low cost polymer, providing high adsorption and catalytic properties, shown to be promising for photocatalysis applications under visible light. Furthermore, g-C3N4 composites are among the most promising advanced photocatalytical materials that can be produced by green synthesis processes. In this paper, the state-of-the-art of g-C3N4 applications is reviewed, and application perspectives are discussed. Photocatalysis tests with g-C3N4 under Xenon irradiation were performed to gather first-hand information to improve photoreactor design. Xenon light spectrum appears to be a suitable radiation source to replace direct sunlight in engineered pollutants removal processes catalyzed by g-C3N4, in lieu of other currently used heterogeneous photocatalysis processes (e.g., TiO2-UV). LED sources are also very promising due to higher energy efficiency and customizable, catalyzer-specific irradiation spectra.

Keywords: AOPs; Xenon lamp; adsorption; graphitic carbon nitride; organic pollutants; photocathalysis; titanium dioxide.