Synergistic Defect and Hole Engineering in K-Doped Cyano-Rich Porous Graphitic Carbon Nitride to Boost Photocatalytic...

Photocatalytic conversion of H₂O and O₂ into H₂O₂ provides a promising sustainable ambient-condition route alternative to energy-intensive anthraquinone processes for on-site H₂O₂ production. Herein a series of K-doped cyano-rich g-C₃N₄ with porous structure (g-PC₃N₄K) have been successful synthesized by a molten salt assisted pyrolysis with subsequent secondary pyrolysis under the assistance of sublimated sulfur. Experimental and theoretical results demonstrate that the synergistic effects of K─N electron channels and the introduction of ─C≡N as well as porous structure is beneficial to the exposure of catalytically activity sites and the rapid separation and transfer of photogenerated electron-hole pairs, which contributes to the improved photocatalytic performance for H₂O₂ production. As expected, the optimal g-PC₃N₄K exhibits a 14.05-fold higher H₂O₂ yield than pristine g-C₃N₄ and high H₂O₂ yield of 1625 µM and high solar-to-chemical conversion (SCC) efficiency of 5.93% can be also achieved within one hour under sunlight illumination, indicating its excellent performance and potentially practical application for photocatalytic H₂O₂ synthesis.