Modification of Layered Graphitic Carbon Nitride by Nitrogen Plasma for Improved Electrocatalytic Hydrogen Evolution.

As a layered nano-sheet material, layered graphitic carbon nitride (g-C₃N₄) has attracted attention in multifunctional photocatalytic applications. However, g-C₃N₄ is electrochemically inert consequently hampering electrochemical applications. In this work, low-temperature nitrogen plasma processing was conducted to modify g-C₃N₄ to enhance the electrocatalytic performance in the hydrogen evolution reaction (HER). The plasma produced significant morphological and chemical changes on the surface of g-C₃N₄ via active species, and nitrogen atoms were incorporated into the surface while the bulk properties did not change. The modification improved the surface hydrophilicity and electrocatalytic HER activity, as well as excellent stability in HER after 2000 cycles. Our results revealed that plasma treatment was a promising technique to improve the HER of carbon-based layered nano-sheet materials.