Optimizing the Band Structure of Crystalline Potassium Poly(heptazine imide) for Enhanced Photocatalytic H<sub>2</sub>O<sub>2</sub>Production and Pollutant Degradation
Zhenchun Yang, Lina Li, Jingyu Gao, Shiqi Zeng, Jiahao Cui, Siting Shao, Kun Wang, Dongge Ma, Chun Hu, Yubao Zhao
Abstract
The photocatalytic selective oxygen reduction reaction on a polymeric carbon nitride framework is one of the most promising approaches toward sustainable H2O2 production. Potassium poly(heptazine imide) (K-PHI) was highly active for photocatalytic H2O2 production. Most importantly, by introducing 1-methyl-1H-tetrazole-5-thiol (MTT) into the precursor for the K-PHI synthesis, the size of the layer stacking structure was reduced, the polymerization in the heptazine plane was improved, and the conduction band position was negatively shifted. The MTT-regulated K-PHI (K-PHI-2) showed remarkable H2O2 photoproduction performance, for example, a record high H2O2 photoproduction rate of 41.7 μmol h–1 mg–1 in an acidic environment. Meanwhile, K-PHI-2 showed a significantly enhanced performance in the photocatalytic degradation of the carbamazepine. Additionally, by introducing 5 ppm O3 in the reaction system, ciprofloxacin at a concentration of 100 ppm was eliminated rapidly on K-PHI-2 via a peroxone reaction.