Vacancy engineered polymeric carbon nitride nanosheets for enhanced photoredox catalytic efficiency

Abstract

Polymeric carbon nitrides (PCNs) have emerged as promising heterogeneous photocatalysts for organic transformations as they are metal-free, inexpensive, and possess tunable bandgaps, with excellent chemical stability and photo-stability. However, current application of PCNs in organic synthesis is rather limited to several well-established materials, which limits the scope of reaction patterns and efficiency. We herein report the synthesis and fabrication of two PCN nanosheets by incorporating nanostructure construction, element doping, and vacancy engineering into one hybrid platform. The heteroatom doped PCN nanosheets with vacancies feature highly porous structures with extremely large substrate-catalyst interface areas and enhanced charge separation. The generated heterogeneous catalysts demonstrate impressive photoredox catalytic performances in a variety of organic transformations (e.g., defluoroborylation; [2+2] cycloaddition; C–N, C–S, C–O cross-couplings; and an unprecedented regioselective hydrosilylation), providing efficiencies comparable to reported optimized homogeneous catalysts and exceeding those with commonly utilized PCNs. Heteroatom doped polymeric carbon nitrides (PCNs) nanosheets with vacancies Notable performance for various photoredox transformations Improved photocatalytic efficiency compared to commonly utilized PCNs Avenue for rational design and development of heterogeneous PCN photocatalysts Polymeric carbon nitrides (PCNs) are promising heterogeneous photocatalysts. Liu et al. synthesize heteroatom doped PCN nanosheets with vacancies that demonstrate competitive photoredox catalytic performances. The efficiencies are comparable to optimized homogeneous photocatalysts and exceed commonly utilized PCNs. This finding may provide new insights for the design of effective heterogeneous PCN photocatalysts.