Facile synthesis of neodymium-doped biomass-derived graphene nanosheets and electrochemical properties

This research aims to develop a sustainable and high-performance electrode materials by synthesizing neodymium-doped graphene nanosheets (Nd/GNS) from renewable candlenut shell biomass using a facile impregnation method. The study investigates the structural, electronic, and electrochemical properties of Nd/GNS with varying Nd concentrations (10–30 % ( w / v )). Advanced characterization techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman Spectroscopy and X-ray photoelectron spectroscopy (XPS), confirmed the successful incorporation of Nd, the formation of Nd- O -C bonds, and enhanced oxygen functionalities without disrupting the original graphene lattice. XPS analysis revealed stable Nd 3+ oxidation states and strong coordination interactions, enhancing chemical stability. Electrochemical performance, evaluated through cyclic voltammetry (CV) and linear sweep voltammetry (LSV), demonstrated that 20 % Nd-doped GNS achieved optimal results, with a maximum current density of 2.011 A cm −2 and a charge storage capacity of 0.1634 A V, surpassing commercial graphene by 38 %. This enhancement is attributed to Nd-induced lattice defects, expanded interlayer spacing, and increased pseudo capacitance, offering more active sites for electrochemical reactions. By integrating biomass utilization with rare-earth doping, this study provides a cost-effective and scalable pathway for producing high-performance materials for energy storage and catalytic applications, particularly in supercapacitors and water splitting. • Novel Approach: We employed a two-stage pyrolysis method to synthesize Nd/GNS, achieving enhanced structural integrity and electronic properties through rare-earth metal doping. • Superior Performance: The 20 % Nd/GNS composite exhibited outstanding electrochemical performance with a specific capacitance of 312 F g −1 and an HER overpotential of 210 mV at 10 mA cm −2 . • Sustainability: This study aligns with global efforts toward sustainable materials science, reducing dependency on non-renewable resources. • Comprehensive Analysis: The successful incorporation of Nd and elucidate the underlying mechanisms contributing to the enhanced functionality of the doped graphene.