Enhanced photocatalytic potential of TiO₂ nanoparticles in coupled CdTiO₂ and ZnCdTiO₂ nanocomposites

Photodegradation of organic pollutants is the most suitable and cheaper technique to counter decontamination issues. Among the metal-based nanoparticles, TiO₂ is considered to be the most effective heterogeneous photocatalyst for the photodegradation of organic pollutants. However, the large band gap and the high electron-hole pair recombination rate limit its practical applications. Herein, an approach was introduced to minimize the mentioned limitations by preparing CdTiO₂ and ZnCdTiO₂ nanocomposites by co-precipitation method. The as-synthesized TiO₂, CdTiO₂, and ZnCdTiO₂ were characterized by scanning electron microscopy, transmission electron microscopy (TEM), energy dispersive X-ray, X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and UV-visible spectrophotometry. Morphological analysis revealed that TiO₂ are mostly agglomerated with different shapes and sizes and the nanocomposites are mostly in dispersed form. The components of the nanocomposites are strongly intercalated in the ternary nanocomposite as confirmed from TEM analysis. XRD analysis confirmed the anatase TiO₂ while the UV-visible analysis showed the shifting toward higher wavelength. The band gap energy of TiO₂ (2.65) decreased to 2.6 and 2.56 eV for CdTiO₂ and ZnCdTiO₂, respectively. BET analysis has shown a 47.2 m²/g surface area for the ternary ZnCdTiO₂ nanocomposite. The photodegradation results revealed that TiO₂, CdTiO₂, and ZnCdTiO₂ degraded about 74%, 86%, and 97.61% methylene blue dye, respectively, within 2 h. Maximum photodegradation is achieved in the basic medium and the ternary ZnCdTiO₂ nanocomposite degraded 98% dye at pH 10.