Efficient production of H2O2 via two-channel pathway over ZIF-8/C3N4 composite photocatalyst without any sacrificial agent

Abstract

Hydrogen peroxide (H2O2) is a valuable chemical for various industries, while the current H2O2 production still suffers from multistep reaction processes, large consumption of organic solvents and waste-intensive. The photo-oxidation of water coupled with photo-reduction of oxygen is the cheapest and cleanest pathway to produce H2O2. Herein, we demonstrated that ZIF-8/C3N4 composite, as an efficient dual-channel photocatalyst, can produce H2O2 under visible light (λ ≥ 420 nm) with high efficiency (2641 μmol h−1 g−1) at normal pressure and without any sacrificial agent. The apparent quantum efficiency (AQE) can be calculated to be 19.57 % at the wavelength of 420 nm. Notably, the concentration of H2O2 generated is up to 0.71 wt.% at 420 nm (10 mg catalyst with 15 mL O2 saturated H2O), which is very close to the concentration of industrial production (1 wt.%) by anthraquinone method. Our work may provide a ultra-green pathway for the photo-production of H2O2 to meet industrial requirement.