Carbon‐Rich Carbon Nitride with Synergistic Gd‐N ₄ Sites and Z‐Scheme Heterojunction for Non‐sacrificial Hydrogen Peroxide Photosynthesis

Abstract Carbon nitride (CN), a highly promising photocatalyst for hydrogen peroxide (H ₂ O ₂ ) production, still suffers from rapid electron‐hole recombination and sluggish kinetics in both the O ₂ reduction reaction (ORR) and water oxidation reaction (WOR). Here, a molecular engineering strategy enables the controlled synthesis of carbon and Gd‐N ₄ single‐atoms co‐incorporated CN nanotubes. Subsequently, a Z‐scheme heterojunction is constructed via electrostatic self‐assembly with Bi ₂ WO ₆ nanosheets (BWO). The optimized composite exhibits exceptional performance in visible‐light‐driven H ₂ O ₂ synthesis (749.5 µmol g ⁻¹ h ⁻¹ ) in pure water, achieving a 37‐fold enhancement compared to pristine CN. Moreover, the apparent quantum yield (AQY) reaches an impressive 11.13% at 420 nm. The enhanced activity is primarily attributed to the synergistic effects of C/Gd co‐incorporation and the Z‐scheme heterojunction, which collectively promote the separation of photogenerated charges in CN. Particularly, the unsaturated coordination Gd‐N ₄ sites effectively facilitate O ₂ adsorption and the 2e ⁻ ORR pathway, enabling efficient H ₂ O ₂ production. Meanwhile, BWO enhances the WOR, thus improving the matching efficiency of redox reactions in the system. This study establishes a facile molecular engineering strategy for single‐atoms anchoring with tailored coordination environments, while highlighting the critical role of redox dual‐regulation in achieving efficient H ₂ O ₂ photosynthesis.