Thermal activation and loading of Clay/TiO₂/CTAB composite: physicochemical characterization and adsorption-photodegradation of methyl orange

The discharge of textile effluents induces organic pollutants that necessitate attention to ensure environmental sustainability. This study presents eco-synthesis and an enhanced adsorption-photocatalyst over a Clay/TiO2/CTAB composite for photodegradation of an organic dye pollutant (Methyl Orange; MO). Natural clay used in this work was purified via hydrothermal treatment to produce activated clay. Subsequently, TiO2 was intercalated with CTAB surfactant and combined with clay to obtain the Clay/TiO2/CTAB composite. The material was synthesized via a dispersion and centrifugation process. The presence of TiO2 pillared Clay/CTAB showed important photocatalytic properties and high-adsorption performance for the degradation of the MO compound. The Clay/TiO2/CTAB was found to be the most effective adsorption-photocatalyst when compared using homogeneous material. The natural clay was characterized by X-ray fluorescence (XRF), while Clay/TiO2/CTAB was identified using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM). The successful formation of the Clay/TiO2/CTAB was indicated by FTIR analysis under the wavenumber shown in the fingerprint region predicting the presence of Al-OH and O-Ti-O elements (450-1000 cm-1), while CTAB was generalized to form amide bonds (1360 cm-1). Confirmation of the XRF data shows Clay contains high SiO2 and Al2O3 with good crystallinity, as well as Clay/TiO2 and Clay/TiO2/CTAB, showing crystallinity patterns of quartz, kaolinite, anatase, rutile, and montmorillonite. The micrographs of the synthesized materials show rough surfaces and non-uniform surfaces with different TiO2 grains widely dispersed on the surface. The adsorption-photocatalyst performance of the Clay/TiO2/CTAB composite was evaluated in three parameters, namely pH optimization, contact time, and degradation ability, showing excellent degradation performance at a pH 5 with 60 minutes contact time with a degradation efficiency of 89.90%. Clay/TiO2/CTAB material influenced the adsorption ability and changed the acidity of the waste to make the treated wastewater environmentally safe.