Evaluation of the Impact of Reduced Graphene Oxide (rGO) Additions on the Structural and Optical Properties of ZnO Nanocomposite for Optoelectronic Applications

This study investigates the thermal, structural, and optical properties of reduced graphene oxide (rGO)-doped ZnO nanocomposites. Thermogravimetric analysis (TGA) reveals distinct weight loss stages in rGO, attributed to moisture removal, oxygen release, and carbon chain degradation, while ZnO shows minimal weight loss, indicating the stability of its structure. X-ray diffraction (XRD) analysis shows that the hydrothermal reduction of graphene oxide (GO) to rGO significantly alters the interlayer spacing, confirming the reduction process. The addition of rGO to ZnO results in a decrease in XRD peak intensity, suggesting that rGO acts as a nucleating agent for ZnO growth. The crystallite size and lattice strain increase with rGO content, indicating enhanced crystallization and structural distortion. Energy Dispersive X-ray Spectroscopy (EDX) confirms the elemental composition of the composites, with varying rGO content influencing the intensity of key peaks. Optical properties, including transmittance, absorption coefficients, and band gaps, demonstrate that rGO influences the electronic structure and optical absorption of the ZnO matrix, making the nanocomposites suitable for UV-blocking applications. Additionally, photoluminescence (PL) spectra show reduced recombination rates and enhanced charge separation in ZnO/rGO composites, highlighting their potential in photocatalysis and optoelectronic devices. These findings underscore the potential of rGO-doped ZnO composites for advanced material applications, including solar cells, sensors, and smart coatings.