Synergistic design and fabrication of g-C3N4 decorated Ni-doped CeO2 nanocomposite: A highly efficient photo and electrocatalyst for enhanced energy storage and environmental remediation

Abstract

Environmental pollution and energy storage are two of the most important problems in the modern world. There is an urgent need for the development of materials with multifunctional properties to successfully address these issues. In this study, we investigate the potential applications of the g-C3N4/Ni-doped CeO2 binary composite, specifically focusing on supercapacitor and photocatalytic performance. To synthesize the pristine CeO2, Ni-doped CeO2 and g-C3N4/CeO2 hybrid samples, we employed an ultrasonic-assisted hydrothermal method and employed various characterization techniques to gain insights into their morphological, structural, optical and compositional characteristics. The synthesized materials are studied for their electrochemical behavior as supercapacitor electrodes using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). Additionally, their photocatalytic performance is evaluated under sunlight with Methylene Blue (MB) dye. The hybrid composite electrode demonstrated a peak specific capacitance (Cs) of 269 F/g at a current density of 1 A/g. Moreover, the device maintained an 85.22 % retention rate even after undergoing 5000 consecutive charge/discharge cycles. Moreover, following 60 min of exposure to natural light irradiation, the photocatalytic degradation rates for MB were observed to be 52.5 %, 69.3 %, and 82.3 % for pristine CeO2, Ni-CeO2, and g-C3N4/Ni-CeO2, respectively. The hybrid composite material, g-C3N4/Ni-CeO2, outperforms both CeO2 and Ni-doped CeO2 nanoparticles in terms of enhanced photocatalytic efficiency and improved electrochemical performance, making it highly promising for applications in wastewater treatment and supercapacitors.