Mild‐Condition Photocatalytic Reforming of Methanol‐Water by a Hierarchical, Asymmetry Carbon Nitride

As a reproducible intermediate for hydrogen (H₂) and carbon cycling, methanol mixed with water (H₂O) in a ratio of 1 : 1 can multiply the outcome of green H₂ generation via Photocatalytic reforming of methanol-H₂O (PRMW). Hitherto, low-energy and mild-condition PRMW remains a serious challenge. Here, the amino acid-derived carbon nitrides (ACN) were synthesized supramolecular precursor strategy for PRMW and achieved excellent performance (H₂, 35.6 mmol h^-1 g^-1; CO₂, 11.5 mmol h^-1 g^-1) under sunlight at 35 °C. It was revealed that the surface-terminating carboxyl groups (-COOH) promote the dark dehydrogenation of methanol on MetCNx to form methoxy (*OCH₃) and methylol (*CH₂OH) simultaneously, with the hydroxyl (*OH) generated by photostimulated H₂O oxidation promotes the C-H activation of formaldehyde, then leads the whole reaction into the formation of CO₂ and three H₂. The extended light absorption, enhanced charge separation and transport, and efficient surface reaction improve photocatalytic efficiency.