Abstract
•Mesoporous γ-Al2O3 coupled 2D hexagonal CdO nanoplates as photocatalyst•Prepared using ultrasonic assisted method with good crystallinity•Tailored bandgap energy of CdO/Al2O3 was 2.95 eV with visible light sensitization•Photodegradation of synthetic cationic dye followed first order kinetics•The particles exhibited excellent antibacterial activity
The mesoporous network of γ-Al2O3 ceramic support was coupled with the two dimensional (2D) hexagonal CdO nanoplates by ultrasonic assisted method. The fabricated photocatalyst was analyzed for its structural, morphological and optoelectrical properties by employing X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), photoluminescence, electron spin resonance (ESR) analysis and electrochemical impedance spectroscopy (EIS). The X-ray powder diffraction (XRD) result supports the good crystallinity of the fabricated nanohybrid with co-existence of pure phases of γ-Al2O3 and CdO nanoparticles (NPs). The nanohybrid was tailored to narrow down the bandgap to visible-light region. The bandgap energy obtained by UV–visible diffuse reflectance spectroscopy (DRS) for CdO/Al2O3 nanocomposite (NCs) was 2.95 eV. The Brunauer-Emmett-Teller (BET) surface area analysis shows porosity of material with high surface area. During photocatalysis, e- from CdO migrates to defect levels of Al2O3 that facilitated charge separation. The kinetic rate of degradation of methylene blue (MB) by NCs was 3.5 and 14 times higher than CdO and Al2O3 respectively. The performance was optimized and it showed good reusability. In addition, the multiple applications of the CdO/Al2O3 were evaluated by testing the bactericidal activity. The nanohybrid posed high growth inhibition activity towards both gram positive and negative bacterial strains. The maximum colour removal (97.3%) and high mineralization (87%) was verified by UV–visible and total organic carbon (TOC) measurements. This promotes the nanohybrid to act as a better candidate for environmental remediation and disinfectant applications.