Nanostructured MnOx/g-C3N4 for photodegradation of sulfamethoxazole under visible light irradiation

The effectiveness of g-C3N4 as photocatalyst is hindered by the rapid recombination of photo-generated electron/hole pairs. To improve its photocatalytic performance, the incorporation of g-C3N4 with co-catalysts can promote charge separation efficiency and enhance redox capabilities. In our study, a two-step approach involving calcination and solvothermal method was utilized to fabricate a proficient MnOx/g-C3N4 heterojunction photocatalyst with high photocatalytic activity. MnOx is effective at capturing holes to impede the recombination of electron/hole pairs. The MnOx/g-C3N4 composite shows a notable improvement in photocatalytic degradation of SMX, obtaining an 85% degradation rate, surpassing that of pure g-C3N4. Furthermore, the MnOx/g-C3N4 composite exhibits remarkable and enduring catalytic degradation capabilities for sulfamethoxazole (SMX), even after four consecutive reuse cycles. The intermediates produced in the MnOx/g-C3N4 system are found to be less hazardous to common aquatic creatures such as fish, daphnids, and green algae when compared to SMX. With its high tolerance, exceptional degradation ability, and minimal ecological risk, the MnOx/g-C3N4 composite emerges as a promising candidate for eliminating antibiotics from wastewater resources.