One‐Step Exfoliation and Hydroxylation of Boron Nitride Nanosheets with Enhanced Optical Limiting Performance

Hexagonal boron nitride (h‐BN) nanosheets are attracting increased attention because of their excellent optical properties. Inspired by the natural exfoliation of seaside rocks, we propose a “chemical weathering” concept for fabricating h‐BN nanosheets from their bulk counterparts. We experimentally demonstrate that chemical weathering‐assisted exfoliation is a simple and efficient method for preparing h‐BN nanosheets. These nanolayers have a high solubility in water because of the hydroxylation of h‐BN (OH‐BNNS). Interestingly, the as‐prepared OH‐BNNSs exhibit excellent optical limiting properties with fascinating two‐photon absorption. It is a new and advanced optical material in the application of sensitive optical components, and shield human eyes from laser‐induced damage.