Study of Graphitic Carbon Nitride and Bismutite Photocatalysts for Efficient Sunlight Driven Removal of Carbamazepine

Organic pollutants such as pharmaceutical waste are widely detected in water sources. The pharmaceutical waste is resistant to the natural degradation, and the recent wastewater treatment plant is not able to degrade it due to its recalcitrant properties. Photocatalysis under sunlight irradiation is one of the most promising technologies to degrade pharmaceutical waste, as the degradation only requires the addition of an oxidative photocatalyst to the pollutant. Compared to synthetic light such as UV light, ultilization of natural sunlight is more sustainable and economic as it is free, unlimited and consists of a wide light spectrum. In this study, g-C3N4 and Bi2O2CO3 are proposed photocatalysts that are used to degrade the targeted pollutant, carbamazepine. Both photocatalysts are prepared through a simple synthesis route, and a series of characterization were conducted to study the physical–chemical properties of the photocatalysts. FESEM, XRD, and UV–vis DRS were used to determine the surface morphology, crystallinity, and optical properties of the photocatalysts respectively. Meanwhile, the experimental result showed good photocatalytic performance for both photocatalysts, but g-C3N4 had stronger photocatalytic strength compared to Bi2O2CO3. After 4 h of irradiation, g-C3N4 reported 96% removal efficiency while Bi2O2CO3 had 89% removal efficiency. Superoxide anion radicals and holes were responsible for the photocatalytic reaction in both photocatalysts while hydroxyl radicals and electrons were involved only in Bi2O2CO3.