Polymeric Synthesis of Metallic Oxide Nanocomposite in the Presence of Rare Earth for their Water-Splitting Applications

https://doi.org/10.5281/zenodo.17562263

Abstract

The production of hydrogen and oxygen from water, driven by solar energy through photoelectrochemical and electrocatalysis processes, represents a promising avenue toward clean fuel generation. This study focuses on the synthesis and comprehensive characterization of Bismuth oxide-based nanocomposites, specifically Bi2O3/NiO, Bi2O3/NiO/CeO2, and Bi2O3/NiO/CeO2/PVP, using the Sol-gel method. To evaluate the synthesized nanocomposites, a diverse array of characterization techniques were employed, including X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), cyclic voltammetry (CV), and Scanning Electron Microscopy (SEM). The XRD patterns confirmed the formation of Bi2O3/NiO, Bi2O3/NiO/CeO2, and Bi2O3/NiO/CeO2/PVP nanocomposites, exhibiting a cubic crystalline structure. Crystallite size and lattice strain were meticulously determined using the Scherrer formula, Williamson-Hall, and Scherrer plot methods, revealing average crystallite sizes of 15.41 nm, 13.64 nm, and 15.01 nm, respectively. SEM was used to determine the surface morphology and particle distribution. Furthermore, cyclic voltammetry was employed to ascertain the electrochemical performance of the Bi2O3/NiO/CeO2/PVP nanocomposites. Our findings indicate that Sol-gel synthesized Bi2O3/NiO, Bi2O3/NiO/CeO2 and Bi2O3/NiO/CeO2/PVP composites exhibit promising characteristics for water splitting applications. Through extensive electrochemical testing, including CV, LSV, and EIS, we observed that these prepared nanocomposites exhibit higher current densities of 10 mAcm-2 at significantly lower over potential (190 mV and 25.7 mV vs RHE) and smaller Tafel slopes (88.3 mVdec-1 and 261 mVdec-1 ) in the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) compared to other composite materials. Additionally, electrochemical impedance measurements indicated that the resistance of the modified electrode and the bare electrode ranged from 0 to 160 Ω. These results collectively demonstrate the promising potential of Bi2O3/NiO-based nanocomposites as efficient catalysts for sustainable water-splitting processes.