Enhanced Photocatalytic H₂-Production Activity of Graphitic Carbon Nitride Modified Using a MnO_x Cocatalyst

Herein, we have designed and synthesized a series of MnOx/g-C3N4 composite photocatalysts via a one-step heat treatment method using a mixture of melamine and manganese acetate precursors. The as-prepared MnOx/g-C3N4 composite photocatalysts show high photocatalytic H2 production activity, and an optimal loading of 1.8[Formula: see text]wt.% MnOx can enhance the H2 production by approximately 2.7 times than that with pure g-C3N4. The high photocatalytic H2-production activity can be attributed to the hole trapping and absorbing ability of the MnOx cocatalyst, which can significantly inhibit the recombination rate of the photogenerated electrons and holes. This work not only shows a simple way to enhance the photocatalytic H2-production activity of g-C3N4 but also demonstrates that MnOx can be used as an efficient and low-cost cocatalyst for the photocatalytic production of H2.