Fabrication of ultra-thin g-C3N4 nanoplates for efficient visible-light photocatalytic H2O2 production via two-electron oxygen reduction

Photocatalytic generation of hydrogen peroxide (H2O2) is a sustainable technique to realize the solar-energy conversion. Here, ultrathin graphitic carbon nitride (g-C3N4) nanoplates with thickness of 1–3 nm was introduced for the efficient H2O2 production. The as-obtained nanoplates demonstrated the H2O2 production rate of 43.07 μmol g−1 h−1 and about 4 times as high as the pristine g-C3N4. Experimental results reflected that the ultrathin morphology offered an increased surface area, more active sites, smaller charge transfer length and stronger redox ability than that of the bulk counterparts. Moreover, the introduction of ultrathin structure switched the H2O2 production pathway from a two-step single-electron reduction to a one-step two-electron reduction route. This study offered the deep elucidation of the influence of ultrathin structure on the photoactivity of semiconductor photocatalysts.