Porous Polymer Monoliths as Adsorptive Host Template for CeO2-CaO Nanocomposite Dispersion for Visible Light Heterogeneous Photocatalysis

Abstract

In this work, we report on the synthesis of CaO doped CeO₂ nanocomposites (NCs) prepared by a sonochemical-assisted temperature-controlled hydrothermal method. Considering the toxicity and recovery issues associated with nano-particles/composites, a novel approach has been attempted through the uniform dispersion of the CeO₂-CaO NCs across a macro-/meso-porous polymer monolith template [1]. The structural and morphological properties of the synthesized photocatalyst materials have been monitored by p-XRD, FE-SEM-EDAX, HR-TEM-SAED, XPS, FT-IR, UV-Vis-DRS, PLS, and BET analysis. The visible-light photocatalytic performance is monitored using varying stoichiometric ratios of CeO₂-CaO NCs with best results achieved using, 20 wt.% CaO doped CeO₂ NCs that are homogeneously dispersed on a 3D network of the porous polymer monolithic network. The CeO₂-CaO NCs dispersed polymer monolith reveals superior photocatalytic activity in comparison to CaO doped CeO₂ NCs that are likely to agglomerate in aqueous solutions that eventually reduce their process efficiency. The CeO₂/CaO NCs dispersed polymer monolith exhibit excellent porosity and surface area, for the ultra-fast dissipation of organic molecules, apart from being durable and reusable. For photocatalysis studies, we have chosen an antimicrobial drug namely moxifloxacin, for the visible-light-induced dissipation, to counter the problems associated with the emergence of resistant bacteria. We hereby state that the prepared monolithic NCs are easy to synthesize, cost-effective, and reusable, thus making them an ideal heterogeneous photocatalyst for pollutant dissipation.

Scheme 1. Graphical representation of the proposed photocatalytic work.