Synthesis oxygen vacancies enriched CuO hierarchical nanosheets for peroxymonosulfate activation toward P-nitrophenol degradation and mechanism

[Display omitted] •CuO nanosheets were prepared with biotemplates derivatization method.•CuO-II exhibited an excellent catalytic efficiency and recycle ability.•100 % of PNP can be removed in 10 min by the CuO-II/PMS system.•Cu(III) species and SO4•– were dominantly responsible for PNP degradation. In this work, hierarchical copper oxide (CuO) nanosheet with rich oxygen vacancies was prepared with a facile biotemplates derivatization method. Results show that the as-prepared optimum CuO-II exhibited excellent catalytic performance for peroxymonosulfate (PMS) activation mainly benefiting from large specific surface area and electron transfer efficiency, abundant Cu+ and oxygen vacancies in catalyst. Almost 100 % of P-nitrophenol (PNP) can be degrade within 10 min by CuO-II activating PMS process. The electron paramagnetic resonance (EPR) spectroscopy, reactive species quenching tests and density functional theory (DFT) calculation results revealed that Cu(III)-mediated electron transfer and sulfate radicals were identified as the dominantly responsible for PNP degradation. Meanwhile, CuO-II/PMS system can degrade PNP in a wide range of pH (pH 3 ∼ 10) and with inorganic anions and natural organic matter presence. In addition, CuO-II catalyst has good stability and reusability and performed well toward PNP degradation in the continuous operation. This work not only obtained a facile preparation strategy for obtaining CuO catalyst with excellent catalytic performance, but also gave a new idea for studying the mechanism of CuO activating PMS.