Experiment and theoretical insights into CuNi/CoMoO4 multi-functional catalyst with laccase-like: Catalysis mechanism, smartphone biosensing and organic pollutant efficient degradation

In this work, CuNi/CoMoO4 nanozyme was synthesized the hydrothermal method, followed by calcination and impregnation techniques, which had laccase-like activity and could be used as peroxymonosulfate (PMS) activator. Thus, the total antioxidant capacity (TAC) of commercial beverage measurement and phenolic pollutants degradation were studied systematically. Besides, the portable smartphone platform integrated with an intelligence analysis APP and colorimetric signals was further established for on-site determination of epinephrine (a typical phenol). Simultaneously, as PMS activator, CuNi/CoMoO4 could activate PMS to yield ·OH and SO4·−, which was applied for organic pollutants (acid fuchsin, AF) degradation, and the degradation efficiency could reach up to 99.45% within 40 min. The results displayed that CuNi/CoMoO4 had practical value in anti-oxidant food quality evaluation and pollution degradation. Furthermore, the theoretical calculation revealed that the activation energy of the rate-determining step over Cu/CoMoO4 was decreased from 0.819 eV to 0.524 eV due to the enhanced interaction between Cu(I) of CuNi/CoMoO4 and 2,4-dichlorophenol (2,4-DCP). It not only provided a multifunctional catalyst for evaluating oxidative capacity in food quality and pollutant degradation, but also provided some new evidences for further study of laccase-like mechanism.