Enhanced Visible-Light HO Production over Pt/g-CN Schottky Junction Photocatalyst.

Photocatalytic for hydrogen peroxide (HO) production is thought as a promising technology owing to its clean and green properties with the cheap and easily available raw materials of HO and O. Herein, Pt/g-CN Schottky junction photocatalysts with ultralow Pt contents (0.025-0.1 wt %) were successfully fabricated by an impregnation-reduction method. It can efficiently reduce O to generate HO without a sacrificial agent under visible-light irradiation. The yield of HO produced over Pt0.05/g-CN with the optimal 0.05 wt % Pt reached 31.82 μM, which was 2.46 times that of g-CN and higher than most of those in the literature. It also showed good stability in three repeated tests. The deposition of highly dispersed metal Pt nanoparticles with low and limited content can expose enough active Pt atoms, significantly enhance the separation efficiency of photogenerated carriers, and reduce its negative effect on HO decomposition, resulting in improved and outstanding efficiency of HO production. The ·O radicals were found to be the main active species. The mechanism of photocatalytic HO production was confirmed to be a two-step single electron route (O + e→ ·O → HO).