Synergistic NaCl-template and precursor engineering of carbon nitride enables highly selective and stable photocatalytic H2O2 production

Na + intercalation and cyano-group modified carbon nitride (Na-MDCN) was synthesized. • Na-MDCN exhibits superior photocatalytic H 2 O 2 yield rate of 8.8 mmol g −1 h −1 . • In-situ DRIFTS shows a stepwise ·O 2 - pathway kinetically blocking H 2 O 2 decomposition. • The in-situ generated H 2 O 2 shows practical potential in rapid dye degradation. A key challenge in solar-driven hydrogen peroxide (H 2 O 2 ) production lies in the precise modulation of photocatalysts that enable efficient charge separation, selective two-electron oxygen reduction, and stable catalytic performance. To address this, we developed a novel carbon nitride photocatalyst through a synergistic strategy combining NaCl salt-template-assisted synthesis with precursor structure construction. Through the precursor engineering of melamine and dicyandiamide, sodium chloride serves a dual function as a pore-forming agent and a high-temperature template, promoting the formation of a highly crystalline, porous architecture with well-structured tri-s-triazine units with incorporated Na⁺ species. This approach enables the incorporation of Na⁺ ions and the integration of terminal cyano groups, which are likely to collectively promote charge transport and light absorption. As a result, the optimized catalyst displays a prominent H 2 O 2 production rate of 8.8 mmol g −1 h −1 , substantially outperforming single-precursor counterparts, alongside excellent long-term stability and good selectivity for two-electron oxygen reduction pathway. The synergy between salt-template-mediated structural evolution and precursor structure design represents a distinctive strategy that not only yields an efficient photocatalyst for H 2 O 2 production but also offers a broadly applicable pattern for the rational construction of advanced catalytic systems. Download: Download high-res image (356KB) Download: Download full-size image The introduction of NaCl salt-template and precursor engineering construction into C 3 N 4 (functionalized with cyano groups and Na + ) creates a synergistic effect that enhanced light harvesting ability, effective oxygen adsorption actives and boosted two electron selectivity, leading to superior photocatalytic H 2 O 2 evolution performance.