PHOTOCATALYTIC CO2 REDUCTION USING g-C3N4/CeO2 COMPOSITE WITH PLATINUM COCATALYST: SYNTHESIS, CHARACTERIZATION, AND PERFORMANCE EVALUATION

Abstract

Global climate change and rising atmospheric carbon dioxide (CO2) levels present critical environmental and energy challenges. Photocatalytic CO2 reduction offers a promising solution by converting CO2 into valuable chemicals and fuels using renewable solar energy. This research presents a comprehensive investigation of a novel ternary photocatalytic system comprising graphitic carbon nitride (g-C3N4), cerium oxide (CeO2), and platinum (Pt) cocatalyst. The composite material was synthesized through controlled thermal decomposition and photodeposition methods. Extensive characterization using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), and UV-Visible spectroscopy revealed a well-defined heterostructure with efficient charge separation capabilities. The photocatalytic CO2 reduction experiments demonstrated promising results, with the optimized CeO2-g-C3N4(3) composite achieving steady methane production at approximately 30 μmol/g/h and hydrogen production at 35 μmol/g/h under visible light conditions. The addition of g-C3N4 to CeO2 resulted in decreased crystallite size and increased BET surface area, enhancing surface reactivity and photocatalytic performance. The Pt cocatalyst effectively promoted electron transfer and product desorption, significantly improving CO2 conversion efficiency. These findings demonstrate the potential of this ternary system for sustainable energy production and environmental remediation.