Polyoxometalates covalently combined with graphitic carbon nitride for photocatalytic hydrogen peroxide production

The polyoxometalate (POM) cluster [SiW11O39](8-) (SiW11) with photoreductive ability has been successfully covalently combined with graphitic carbon nitride (g-C3N4) through an organic linker strategy. The hybrid catalyst g-C3N4-SiW11 exhibits efficient catalytic performance (15.2 mol h(-1)) for photocatalytic H2O2 production in the presence of methanol and can stabilize the formed H2O2 under sunlight irradiation (AM 1.5 filter). The Koutecky-Levich plot obtained from electrochemical rotating disk electrode (RDE) analysis of the oxygen reduction reaction (ORR) for g-C3N4-SiW11 reveals that the value of electron transfer during the ORR process is 2.76. Combining the electron spin resonance (ESR), Koutecky-Levich plots, O-2 temperature programmed desorption (O-2-TPD) and density functional theory (DFT) calculation results, the enhanced O-2 adsorption of g-C3N4-SiW11 can promote the two-electron reduction of O-2 to H2O2.