Enhanced Photocatalytic Degradation of <i>p</i>-Nitrophenol and Phenol Red Through Synergistic Effects of a CeO<sub>2</sub>-TiO<sub>2</sub> Nanocomposite

Abstract

Organic compounds are one of the most severe pollutants occurring in the environment. Hence, it is important to remove these compounds from the environment through remediation processes such as photocatalysis. The present study investigated the photocatalytic degradation of <em>p</em>-nitrophenol (NP) and phenol red (PR) using a cerium oxide-titanium oxide nanocomposite (CeO<sub>2</sub>-TiO<sub>2</sub>nc) under UV light. CeO<sub>2</sub>-TiO<sub>2</sub>nc was synthesized using the co-precipitation method. An X-ray diffraction (XRD) analysis confirmed the phase purity of the material. A UV-Vis absorption study revealed a broad peak in the 250–310 nm region. The photocatalytic study was performed under three irradiation conditions: no light, visible light (λ > 400 nm), and UV light (λ < 400 nm). The maximum degradation percentage for NP and PR was 97.3% and 99.8%, respectively, with the reaction rate constant (k) of 0.42 and 0.54, respectively. This is the first study to utilize the synergistic effects of TiO<sub>2</sub> and CeO<sub>2</sub> for degrading NP and PR. Over 97% degradation was achieved for both the compounds in 80 min; this result shows the high photocatalytic activity of CeO<sub>2</sub>-TiO<sub>2</sub>nc<sub>.</sub> Thus, CeO<sub>2</sub>-TiO<sub>2</sub>nc<sub> </sub>can be used as a cost-effective adsorbent with a high capacity to degrade harmful organic compounds.