Promoting Piezocatalytic H2O2 Production in Pure Water by Loading Metal-Organic Cage-Modified Gold Nanoparticles on Graphitic Carbon Nitride

Piezocatalytic hydrogen peroxide (H2O2) production is a green synthesis method, but the rapid complexation of charge carriers in piezocatalysts and the difficulty of adsorbing substrates limit its performance. Here, metal-organic cage-coated gold nanoparticles are anchored on graphitic carbon nitride (MOC-AuNP/g-C3N4) via hydrogen bond to serve as the multifunctional sites for efficient H2O2 production. Experiments and theoretical calculations prove that MOC-AuNP/g-C3N4 simultaneously optimize three key parts of piezocatalytic H2O2 production: i) the MOC component enhances substrate (O-2) and product (H2O2) adsorption via host-guest interaction and hinders the rapid decomposition of H2O2 on MOC-AuNP/g-C3N4, ii) the AuNP component affords a strong interfacial electric field that significantly promotes the migration of electrons from g-C3N4 for O-2 reduction reaction (ORR), iii) holes are used for H2O oxidation reaction (WOR) to produce O-2 and H+ to further promote ORR. Thus, MOC-AuNP/g-C3N4 can be used as an efficient piezocatalyst to generate H2O2 at rates up to 120.21 mu mol g(-1) h(-1) in air and pure water without using sacrificial agents. This work proposes a new strategy for efficient piezocatalytic H2O2 synthesis by constructing multiple active sites in semiconductor catalysts via hydrogen bonding, by enhancing substrate adsorption, rapid separation of electron-hole pairs and preventing rapid decomposition of H2O2.