Although carbon-doped BN nanosheet (BCN) has been successfully synthesized and used, it has not been reported as a photocatalyst for the degradation of organic pollutants. In this study, 4-chloroguaiacol (4-CG) was selected as a representative substance to investigate the potential of utilizing BCN as photocatalyst for organic removal by use of computational simulation. The adsorption mechanisms, degradation mechanisms, and kinetics of 4-CG with the presence of different catalysts were determined. The adsorption energy of 4-CG on BCN was 10.71 kcal mol(-1), and the Delta G(not equal)s of initial reactions of 4-CG with center dot OH were also reduced onto the BCN substrate. The band gap of BCN was 1.54 eV. Our computations depicted that the doping of aromatic carbon into BN narrows bandgap, and retains well catalytic performance and adsorption properties. Therefore, BCN nanosheet is a promising photocatalyst for organic pollutants removal. Possible degradation pathways of 4-CG and aquatic toxicity assessment during degradation were also carried out. More toxic products would be formed and the transformation products were still harmful to three trophic levels of aquatic organisms (fish, green algae, and daphnia). (C) 2019 Elsevier Inc. All rights reserved.