Visible light degradation of organic pollutants using Cu modified TiO2 supported on g-C3N4

Photocatalytic technology, powered by clean solar energy, has been extensively applied in clean energy generation, biotechnology, and medicine. In organic wastewater treatment, photocatalysis has garnered significant attention due to its rapid reaction kinetics, minimal waste emissions, and high selectivity. Although TiO₂ and g-C₃N₄ have been extensively studied as traditional photocatalysts, their inherent limitations hinder practical applications. In this study, a novel photocatalyst, Cu-TiO₂/C₃N₄, was synthesized via a combination of photodeposition and chemical vapor deposition (CVD). Experimental results revealed that metallic Cu atoms are uniformly dispersed as single atoms within the Z-scheme heterojunction of TiO₂/C₃N₄. Under 460 nm LED and 300 W xenon lamp (λ > 400 nm) irradiation, the catalyst demonstrated outstanding photocatalytic performance, achieving degradation rates of 93.58 % and 98.66 % within 180 and 105 min, respectively. These rates were 2.9 and 3.7 times higher than those of TiO₂, and 5.4 and 3.2 times greater than those of g-C₃N₄. Additionally, Cu-TiO₂/C₃N₄ exhibited superior adsorption capacity and stability compared to TiO₂/C₃N₄, enabling more effective visible light absorption and utilization. After seven testing cycles, its performance remained stable and even improved, ultimately achieving a degradation rate of 99.76 %. Overall, the Z-scheme heterojunction structure of Cu-TiO₂/C₃N₄ effectively enhanced photogenerated charge carrier separation, resulting in exceptional visible light photocatalytic activity and stability, making it highly suitable for degrading organic pollutants in aqueous environments.