Characterization and photocatalytic activity of Al₂O₃ nanopores/InSnO₂ electrode for methyl orange degradation

In this research work, the photocatalytic degradation methyl orange (MO) was carried out using Al₂O₃-NP/InSnO₂ nanocomposite under UV illumination. The Al₂O₃-NP electrode was successfully formed by a two-step anodization method and Al₂O₃-NP/InSnO₂ electrode was obtained via the sol–gel spin coating method. The structural properties of the samples have been characterized by a series of techniques, including field-emission scanning electron microscope, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and the contact angle and surface energy measurements. The influence of variables such as initial MO concentration, initial pH value, temperature, and reusability was researched. The kinetics of the photocatalytic degradation of MO can be best described by the pseudo-first-order model. Moreover, the activation energy (E_a), change of enthalpy (ΔH), free energy (ΔG), and entropy (ΔS) are evaluated. The activation energy has been found at 20.89 kJ/mol. The results indicated that the Al₂O₃-NP/InSnO₂ photocatalyst has an excellent activity for photocatalytic degradation in the treatment of wastewater.