Abstract
This work effectively synthesized the novel heterojunction (BiO)(2)CO(3)@ZnCo(2)O(4) using precipitation and co-precipitation methods facilitated by microwave and ultrasonic techniques. The crystal structure and morphology of the synthesized samples were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), X-ray Photoelectron Spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and energy-dispersive spectroscopy (EDS) mapping, respectively. The photodegradation effectiveness of the heterojunction was evaluated by degrading the indigo carmine dye under visible light. The research findings demonstrated that the combination of (BiO)(2)CO(3) and ZnCo(2)O(4) at a mass ratio of 12% exhibited the most significant IC decomposition capability, attaining a photocatalytic efficiency of 98.6% after 60 minutes in darkness and 100 minutes of light exposure. The most appropriate approach was to establish a first-order kinetic model for the indigo carmine degrading process of (BiO)(2)CO(3)@ZnCo(2)O(4). The Z-scheme mechanism was more relevant than the conventional type-II heterojunction, whereby O(2)˙(-) and ˙OH were the primary contributors to the photocatalytic process. The stable heterostructure (BiO)(2)CO(3)@ZnCo(2)O(4) has advanced the method for effective heterojunction photocatalysis. DFT-Fukui analysis shows that the indigo carmine molecule donates electrons, acting as a nucleophile, and TD-DFT calculations using B3LYP/6-311G(d,p) in aqueous solution produce a HOMO-LUMO gap for IC that aligns more closely with experimental data than previous results.