Unraveling structural properties of Cu2O loaded on gC3N4 for enhanced photocatalytic hydrogen generation
Unraveling structural properties of Cu2O loaded on gC3N4 for enhanced photocatalytic hydrogen generation
In this study, we load Cu2O into gC3N4 via an ultrasonic reduction method. By doing so, the steady-state electron population is increased by 3 times. Due to the revealed critical role of Cu2O in enhancing the electron population in gC3N4, the structural features of the loaded Cu2O are studied with synchrotron x-ray absorption spectroscopy (XAS), including x-ray absorption near edge spectroscopy (XANES) and extended x-ray absorption fine structure (EXAFS). Results show that the Cu species are present in +1 oxidation state in the form of nano-sized Cu2O. Each Cu cation is approximately coordinated to 2 O anions with an average length of 1.85 Å. Loading 1 wt% of Cu2O into gC3N4 generates H2 with a rate of 7.53 μmol/g centerdot h, which is more than 5-fold of bare gC3N4 (1.44 μmol/g centerdot h), under visible light irradiation in the presence of methanol as holes scavenger. The examined Cu2O/gC3N4 shows appreciable stability within 5 cycles of H2 generation.