Effect of gamma-ray radiation on defect engineering and photocatalytic properties of boron nitride nanosheets

The development of low-cost, abundant, and efficient non-metal catalysts has always been a research focus on photocatalytic hydrogen evolution reactions. Boron nitride nanosheet (BNNS), which is a promising non-metallic two-dimensional material, possesses remarkable properties. However, its inherently wide bandgap significantly limits their potential for visible-light-responsive catalysis, and conventional chemical methods struggle to overcome this limitation. In this study, we employed high-energy ionizing radiation to precisely regulate defect formation in BNNS at ambient temperature and pressure. The results showed that gamma-ray radiation markedly enhanced the efficiency of photocatalytic hydrogen production of the irradiated BNNS with increasing absorbed dose. The maximum hydrogen production rate of the samples reached 1 033.7 μmol/(g·h), which represents an increase of almost two orders of magnitude compared to commercial BNNS. The structural characterization also confirmed that the introduction of three-boron-center defects results in forming intermediate energy levels and improving the charge carrier separation efficiency of BNNS. This transformation converts BNNS from a wide bandgap semiconductor to a visible-light-responsive catalyst. This work not only provides a novel approach for the application of BNNS in visible-light photocatalysis, but also demonstrates the unique role of radiation technology in quantitatively regulating defects and improving catalytic activity.