Low-temperature synthesis of oxygen-rich fish-scale-like porous boron nitride for effective water cleaning

Effective removal of the organic pollutants from aqueous solution is significative and challenging for environmental sustainability. The high-performance adsorbent materials need to be developed. In this study, oxygen-rich fish-scale-like porous boron nitride (O-PBN) was facilely synthesized only at 900[Formula: see text]C (about 400[Formula: see text]C lower than that of the conventional process) through the molten salt method. The adsorption capacity of the as-prepared O-PBN for Methylene Blue (MB) from water was 422.6 mg/g, resulting from oxidizing groups and B–O bonds induced by oxygen doping as well as fish-scale-like structure composed of the BN nanoflakes. Moreover, the initial removal capacity of O-PBN only lost 7.6% even after 10 adsorption–regeneration cycles due to their strong resistance to oxidation. The unique B–O polar covalent bond, fish-scale-like two-dimensional nanostructure exposing the active adsorption sites to the surface ((002) crystal plane) and high specific surface area of O-PBN are confirmed to be the key factors in significantly enhancing water purification and regeneration performance. Overall, the synthetic method should help to a low-temperature and facile fabrication of O-PBN for effective water cleaning.