Ultrathin Porous Carbon Nitride Bundles with an Adjustable Energy Band Structure toward Simultaneous Solar Photocatalytic Water Splitting and Selective Phenylcarbinol Oxidation.

Rational design of photocatalysts with multiple functions, including organic synthesis and water-splitting, is promising and challenging. Herein, we synthesized actiniae-like carbon nitride (ACN) bundles based on the pyrolysis of an asymmetric supramolecular precursor prepared from L-arginine (L-Arg) and melamine. ACN has adjustable band gaps (2.25 eV ~ 2.75 eV) and hollow microtubes with ultrathin pore walls, which enrich reaction sites, improve visible-light absorption and enhance charge separation. In the presence of phenylcarbinol, ACN exhibited excellent pure water-splitting ability (95.3 μmol/h) and in the meanwhile phenylcarbinol was selectively oxidized to benzaldehyde (conversion of 90.9%, selectivity of 99.7%) under solar irradiation. For the concurrent reactions, 2 D isotope labeling, separation and detection were conducted to confirm that the proton source of released hydrogen is water. Further, we theorized the mechanism of water splitting and phenylcarbinol oxidation and hope that it provides inspiration for simultaneous utilization of photogenerated electrons and holes in one system.