Efficient degradation of methylene blue by g-C3N4@CaCO3 photocatalyst via synergistic adsorption and catalysis under visible light irradiation

A novel nonmetal-based nanocomposite, protonated g-C 3 N 4 @CaCO 3 (CN-BPCC), was synthesized using a simple calcination method. The construction of this binary composite photocatalyst enhanced the adsorption and photocatalytic degradation performances of pure g-C 3 N 4 . The adsorption and photocatalytic degradation efficiencies under visible-light irradiation were analyzed using methylene blue (MB) as the target organic pollutant. The binary nanocomposite with 1.5 g of CaCO 3 (BPCC) exhibited high adsorption and photocatalytic performance, achieving approximately 100 % degradation of MB under 90 min of xenon lamp irradiation. Furthermore, the nanocomposite displayed enhanced visible-light utilization efficiency and improved separation efficiency of photogenerated carriers. The adsorption and photocatalytic degradation mechanisms were investigated through radical trapping experiments and electron spin resonance (ESR) spectroscopy. Furthermore, the binary CN-BPCC nanocomposite exhibited exceptional reusability after regeneration, indicating its potential as a promising photocatalyst for the treatment of wastewater containing organic pollutants.