Ultrasound-assisted synthesis of CuMnO2/CN with cation–π interactions for enhanced ozone decomposition

Abstract

A novel delafossite-type CuMnO₂/CN catalyst, engineered with cation–π interactions, was successfully synthesized via an ultrasound-assisted co-precipitation method for efficient ozone decomposition. The physicochemical properties of the catalyst were systematically characterized using XRD, SEM, BET, TEM, EIS, Raman, EPR, and XPS. Ultrasonic treatment enabled nanoscale dispersion, yielding well-crystallized CuMnO₂ nanowires with a crednerite structure and hexagonal g-C₃N₄ nanosheets. The cation–π interaction, mediated by Cu–NC linkages, facilitates dynamic electron transfer from the conjugated π-system of g-C₃N₄ to the metal centers. This electron redistribution results in increased ratios of Cu⁺ and Mn³⁺, reduced charge transfer resistance, and enhanced oxygen mobility. The resulting electron-rich metal active sites promote ozone adsorption and its subsequent decomposition into *O₂ and *O species, which further generates ˙O₂⁻ radicals. With an exceptionally low activation energy of 19.84 kJ mol⁻¹, this catalyst significantly improves ozone utilization efficiency and exhibits excellent catalytic activity in water treatment, holding broader significance for sustainable chemistry applications.