Enhanced photocatalytic activity and effect of titanium doping in CeO2 nanoparticles

Abstract

Photocatalytic degradation studies of methyl orange (MO) are investigated using Ce1−xTixO2−δ nanoparticles (NPs), synthesized by egg-white assisted co-precipitation method with microwave irradiation. The sample is characterized using XRD, TEM, XPS, FTIR, UV–visible, Raman, and PL techniques to investigate morphology and oxygen vacancy concentration. Ce1−xTixO2−δ NPs with crystallite size 7.4 nm-9.8 nm are calculated from XRD for various concentrations of Ti. The existence and role of the functional groups in the as-prepared NPs are examined with the FTIR technique. The nanoparticle’s surface area (25–42 m2/g) and pore sizes (30–60 Å) are determined by analyzing the adsorption isotherm with BET analysis. The bandgap energies of the as-synthesized doped samples are found to decrease (3.1 eV-2.88 eV) with doping concentrations. The degradation efficiency of MO is investigated under UV light at a pH level of 4, 50 mg catalyst dosage, and 16 min of exposure. 95.68 % decolorization efficiency and 94 % total organic carbon (TOC) removal efficiency are exhibited by the as-synthesized 9 % Ti-doped CeO2. All the models are evaluated for their applicability to photocatalytic degradation through regression studies. The statistical parameters showed the appropriateness of these models for photocatalytic activities. Recycling experiments using 9 % Ti-doped CeO2 proved the model’s suitability for MO activation after the fourth regeneration cycle.