Building oxime-Ni2+ complex on polymeric carbon nitride : molecular-level design of highly efficient hydrogen generation photocatalysts

Abstract

We report an effective strategy to in situ construct the oxime-Ni2+ complex unit on polymeric carbon nitride (PCN) as a molecular catalyst for the highly efficient hydrogen evolution reaction (HER). The PCN was functionalized with oxime groups that allowed for immobilizing Ni2+ to form oxime-Ni2+ complex units on the PCN surface with uniform distribution. The electrochemical characterizations reveal that these oxime-Ni2+ units can effectively capture photogenerated electrons from PCN and serve as active catalytic sites for proton reduction. Notably, the oxime-Ni2+ enriched PCN showed even higher activities for photocatalytic hydrogen evolution than the Pt-loaded PCN. This work provides a new way to synthesize low-cost photocatalysts with surface grafting of noble-metal-free molecular HER catalysts for efficient light-driven hydrogen generation.