Carbon doped boron nitride nanosheet as efficient metal-free catalyst for peroxymonosulfate activation: Important role of B-N-C moieties

Carbon doped boron nitride was synthesized via a simple one-step pyrolysis method. The generated B-N-C moieties could induce the electron transfer from catalyst to PMS to promote the generation of superoxide radicals for fast BPA removal. The particularly low activation energy made it stand out for water purification at 0 ℃. • Carbon doped boron nitride nanosheet was fabricated by simple one-step pyrolysis method. • The carbon doped boron nitride nanosheets achieved simultaneously low activation energy and high reaction rate. • The catalytic system could even be competent for water purification at 0 ℃. • The specific mechanism of B-N-C moieties for PMS activation was disclosed for the first time. • The possible pathway of superoxide radicals (O 2 •− ) formation was proposed. Developing metal-free catalysts for persulfate-mediated oxidation process has been extensively pursued in environmental remediation, yet the activity of these catalysts is typically low and the mechanism is ambiguous. Herein, a facile one-step pyrolysis method was employed to synthesize the carbon doped boron nitride (C-BN) derived from polydopamine coated BN nanosheets. The C-BN could readily activate peroxymonosulfate (PMS) with the activation energy as low as 14.95 kJ/mol, giving rise to admirable performance for bisphenol A removal even at 0 ℃, which was superior to most reported metal-free catalysts. The combined experimental and density functional theory (DFT) analyses pointed out that the remarkable performance of C-BN originated from the B-N-C moieties, which could induce the electron transfer from catalyst to PMS to promote the fast generation of superoxide radicals (O 2 •− ) as the dominant reactive species. These findings take a step toward exploring the highly efficient metal-free catalysts for realistic applications.