CaO/CeO2 nanocomposite dispersed macro-/meso-porous polymer monoliths as new generation visible light heterogeneous photocatalysts

Abstract

This work highlights the synthesis of CaO doped CeO2 nanocomposites (NCs) prepared by a sonochemical-assisted temperature-controlled hydrothermal method. Considering the toxicology and recovery issues with nano-particles/composites, we have attempted a novel approach by homogeneously dispersing CaO/CeO2 NCs onto a 3D network of macro-/meso-porous monolithic polymer templates. The structural and morphological properties of the synthesized photocatalyst materials have been characterized by p-XRD, FE-SEM-EDAX, HR-TEM-SAED, XPS, FT-IR, UV–Vis-DRS, PLS, and BET analysis. The visible-light photocatalytic performance has been observed using varying stoichiometric ratios of CaO/CeO2 NCs. The CaO/CeO2 NCs dispersed porous polymer monolith reveals superior photocatalytic activity than bare CaO/CeO2 NCs that tend to agglomerate in aqueous solutions, reducing their efficiency. The CaO/CeO2 NCs dispersed polymer monolith exhibits excellent porosity and surface area for the ultra-fast dissipation of organic pollutants. A fluoroquinolone-based antimicrobial drug, namely moxifloxacin, has been chosen as the target pollutant, considering the growing bacterial resistance due to the uncontrolled discharge/discarding of pharmaceutical medications. The best results were achieved using the monolithic photocatalyst dispersed with 20:80 CaO/CeO2 NC, for the complete dissipation of moxifloxacin drug molecules (≥99% degradation), at a pH of 6.0, using 100 mg of photocatalyst to dissipate 15 ppm of moxifloxacin drug, within 2 h of visible-light irradiation. The proposed photocatalyst is cost-effective, durable, reusable, and efficient for the real-time dissipation of environmental pollutants.