Metal-free porous phosphorus-doped g-C3N4 photocatalyst achieving efficient synthesis of benzoin

Abstract

Photocatalytic organic synthesis is mostly limited by the shortcomings of insufficient light absorption, high photogenerated electron–hole recombination rate and inadequate reactive sites of photocatalysts. To solve these problems, phosphorus-doped g-C₃N₄ with a porous structure was constructed. Benefiting from enhanced light absorption and electron–hole separation efficiency, PCNT has intensive oxygen activation ability to generate superoxide radicals, and is highly active in organic synthesis. In addition, PCNT has enhanced surface nucleophilicity, which is conducive to the carbon–carbon coupling process of the intermediate product benzaldehyde molecules and benzyl alcohol molecules in the benzoin condensation reaction. Metal-free PCNT is expected to replace the previously used highly toxic cyanide catalysts and provide a new way for the low-cost and efficient photocatalytic synthesis of benzoin.