CeNiO₃/rGO composite as an efficient photocatalyst for the removal of environmental pollutants

Abstract

The main objective of this study was the synthesis and utilization of a novel CeNiO3/rGO composite for the photocatalytic degradation of rhodamine B (RhB) and oxytetracycline (OTC) pollutants. A hydrothermal technique was employed to synthesize pure CeNiO3 and CeNiO3/rGO composites with different rGO proportions (5, 10, and 15%). PXRD, SEM, EDX, Raman, UV-vis, and PL techniques were used to examine the physical properties of the synthesized materials. The synergistic interaction between CeNiO3 and rGO greatly enhanced the stability of the photocatalysts. The band gap energies of CeNiO3, rGO, and CeNiO3/rGO are determined as 2.3, 1.9, and 1.97 eV, respectively. Photoluminescence spectra of CeNiO3 and CeNiO3/rGO show a lower peak intensity of composite than pure CeNiO3 which indicates the enhanced charge separation in charge carriers. The influence of various factors, including initial RhB/OTC concentration, pH, catalyst quantity, and duration of the reaction, on the photocatalytic degradation process was examined. The 15% CeNiO3/rGO composite showed efficient photocatalytic degradation of a 20 ppm RhB aqueous solution within 25 min and a 20 ppm OTC aqueous solution within 30 min. With rate constants of 0.124 min−1 for OTC photocatalytic degradation and 0.2148 min−1 for RhB photocatalytic degradation, respectively, both processes followed a pseudo-first-order kinetic model. CeNiO3/rGO composite exhibited remarkable photocatalytic efficiency in degrading RhB and OTC, achieving removal rates of up to 99%. Additionally, the CeNiO3/rGO photocatalysts showed high stability for up to three cycles.