| Abstract: | Carbonyl‐grafted g‐C3N4 porous nanosheets (COCNPNS) were fabricated by means of a two‐step thermal process using melamine and oxalic acid as starting reagents. The combination of melamine with oxalic acid to form a melamine–oxalic acid supramolecule as a precursor is key to synthesizing carbonyl‐grafted g‐C3N4. The bulk carbonyl‐grafted g‐C3N4 (COCN) was further thermally etched onto porous nanosheets by O2 under air. In such a process, the carbonyl groups were partly removed and the obtained sample showed remarkably enhanced visible‐light harvesting and promoted the separation and transfer of photogenerated electrons and holes. With its unique porous structure and enhanced light‐harvesting capability, under visible‐light illumination (λ >420 nm) the prepared COCNPNS exhibited a superior photocatalytic hydrogen evolution rate of 83.6 μmol h−1, which is 26 times that of the p‐CN obtained directly from thermal polycondensation of melamine. |
