Find in Library

A nano-HTiO₂@activated carbon-amorphous silica nanocomposite catalyst (HTiO₂@AC/SiO₂) is utilized to photo breakdown catalytically and adsorb chlorpyrifos insecticide. SEM, TEM, and X-ray diffraction were used to examine HTiO₂@AC/SiO₂, synthesized through sol–gel synthesis. With an average size of 7–9 nm, the crystallized form of HTiO₂ is the most common form found. At varied pH, catalyst doses, agitation speed, initial pesticide concentrations, contact periods, and temperatures, HTiO₂@AC/SiO₂ was examined for efficiency under visible light and in darkness. Because of the pseudo-second-order kinetics observed for chlorpyrifos, chemisorption is believed to dominate the adsorption process, as indicated by an estimated activation energy of 182.769 kJ/mol, which indicates that chemisorption dominates the adsorption process in this study. The maximal adsorption capacity of chlorpyrifos is 462.6 mg g⁻¹, according to the Langmuir isotherms, which infer this value. When exposed to visible light, the adsorption capacity of HTiO₂@AC/SiO₂ increased somewhat as the temperature rose (283 k 323 k 373 k), indicating an exothermic change in Gibbs free energy during the process (−1.8 kJ/mol), enthalpy change (−6.02 kJ/mol), and entropy change (0.014 J/mol K), respectively, at 298.15 K. Negative (ΔS) describes a process with decreased unpredictability and suggests spontaneous adsorption. HTiO₂@AC/SiO₂ may be a promising material.