Edge-functionalized boron carbonitride nanosheets enable enhanced photooxidation of aromatic alcohols

Engineering the edge structure in two-dimensional metal-free boron carbonitride (BCN) photocatalysts hold particular significance in heterogeneous catalysis, but it remains challenge in tailoring the catalytic behavior for specific reactions. Herein, this work imparts versatile edge sites comprising –COOH and –OH groups onto two-dimensional inert BCN nanosheets using an improved Hummer's method. Experimental observations reveal that the edge-functionalized BCN are terminated by certain atom arrangements and under-coordination, leading to an upward shift in the energy band position of BCN, accompanied by alterations in charge state. This exploration identifies a novel BCN structure (BCN-COOH/OH) with high efficiency in the selective conversion of aromatic alcohols to aldehydes (conversion > 83%, selectivity > 96%) driven by oxygen and solar energy. These advancements elucidate the mechanisms underlying the optimized electronic structure, ultimately proposing an enhanced oxygen activation and charge transfer mechanism involved in alcohol oxidation. This study lays a solid foundation for the edge-functionalized strategy in the realm of two-dimensional inert nanosheets for heterogeneous catalysis.