Marrying luminescent metal nanoclusters to C3N4 for efficient photocatalytic hydrogen peroxide production

Photocatalytic oxygen (O₂) reduction has been considered a promising method for hydrogen peroxide (H₂O₂) production. However, the poor visible light harvesting and low-efficient separation and generation of charge carriers of conventional photocatalysts strongly limited their photocatalytic H₂O₂ generation performance. Herein, we design a highly efficient photocatalyst in this work by marrying luminescent gold-silver nanoclusters (AuAg NCs) to polyethyleneimine (PEI) modified C₃N₄ (C₃N₄-PEI). The key design in this work is the utilization of highly luminescent AuAg NCs as photosensitizers to promote the generation and separation of charge carriers of C₃N₄-PEI, thereby ultimately producing abundant e⁻ for O₂ reduction under visible light illumination (λ ≥ 400 nm). As a result, the as-designed photocatalyst (C₃N₄-PEI-AuAg NCs) exhibits excellent photocatalytic activity with an H₂O₂ production capability of 82 μM in pure water, which is 3.5 times higher than pristine C₃N₄ (23 μM). This interesting design provides a paradigm in developing other high-efficient photocatalysts for visible-light-driven H₂O₂ production.