Controllably solar-driven C‒C coupling organic synthesis integrated with H2 production over P-doped g-C3N4 with NiS nanoparticles modification

The development of mild and environmental method for direct transformation of aromatic alcohol into hydrobenzoin via controlled C‒C coupling is a highly attractive but challenging goal. In this paper, a P-doped g-C 3 N 4 photocatalyst with NiS nanoparticles modification is first reported to apply the visible-light-driven C‒C coupling of aromatic alcohol into hydrobenzoin, as well as integrating with the production of clean H 2 fuel. The synergistic effect of doped P atoms and formed type-II heterojunction between PCN and NiS improves the light absorption ability of g-C 3 N 4 and greatly suppresses the charge recombination. Optimized 2.0% NiS/PCN composite achieves the complete conversion of aromatic alcohol within 6 h reaction time, as far as we known, which is the highest efficiency so far for aromatic alcohol conversion via photocatalytic strategy. Hydrobenzoin is controllably formed with 68% selectivity, together with a highly-efficient H 2 production rate of 994.8 μmol·g −1 ·h −1 . In-situ EPR studies reveal a preferential activation of C‒H bond than O‒H bond in aromatic alcohol by photoexcited holes, forming C 6 H 5 ĊH 2 OH radicals for subsequent coupling. The residual protons interact with photoexcited electrons to generate H 2 . Our study not only offers an efficient g-C 3 N 4 -based photocatalyst for the synthesis of hydrobenzoin under mild conditions, but also opens up a new avenue for manipulating the activation of C‒H or O‒H bonds for high selectivity of hydrobenzoin product.