Nitrogen-doped carbon skeleton loaded with PDI/MZO S-scheme photocatalyst with enhanced adsorption and photocatalysis activity

This report describes an organic-inorganic hybrid heterostructure comprising a nitrogen-doped carbon skeleton modified with perylene diimide and manganese-doped ZnO (NC@PDI/MZO). The high surface area of NC@PDI (596.11 m2g−1) significantly facilitated the tetracycline adsorption. Theoretical calculations reveal that NC@PDI/MZO has a maximum adsorption capacity of 224.72 mg/g of tetracycline under hydrogen bonding and π-π interaction. The suitable band structures of PDI and MZO promoted efficient separation of photogenerated charge carriers and the formation of •O2- and 1O2. The degradation rate of 50 mg/L tetracycline reached 99.9% after 40 min, and the degradation rate of 20 mg/L tetracycline reached 95.0% after only 10 min. In addition, due to the good match of adsorption rate and photocatalytic rate, NC@PDI/MZO has an unprecedented kinetic constant of 0.11 min−1. This study provides insights that can guide the development of catalysts with well-matched adsorption and photocatalytic activity to remove contaminants from wastewater.