Enhanced hydrogen peroxide production under visible light via pyrimidine and glucose polymer modified graphitic carbon nitride in pure water

Abstract

Photocatalytic H2O2 production by g-C3N4 (CN) has drawn intense research attention in the past decade. However, it suffers from drawbacks of weak light absorption capacity and rapid recombination of photogenerated electron-hole pairs. Here, we report a 4, 6-diamino-2-mercaptomidine (DAMP) and glucose (GLU) polymer modified CN (CN-DAMP-GLU) to enhance the photocatalytic performance of CN. The reported modified CN shows a high H2O2 production rate of 284.0 μmol g−1h−1 in pure water, surpassing most of the reported modified g-C3N4 catalysts. The mechanistic study confirms that the rapid conversion of •O2− is the key step in the visible-light-driven 2e− oxygen reduction reaction. This step favors efficient H2O2 generation and ensures the stable photocatalytic performance of the system. Experimental and DFT results further reveal that the donor-mediator-acceptor structure (polyfuran-DAMP-CN) with DAMP as the electron transfer mediator can inhibit the electron-hole recombination. We also demonstrate that this photocatalytic H2O2 production system can effectively degrade ciprofloxacin (CIP) through Fenton reaction. This work will promote the development of g-C3N4 for efficient photocatalytic production of H2O2 and possible applications in organic pollutant removal.