Enhanced energy storage and solar hydrogen generation via Mg-VO2@ZnO-MWCNT composites

Abstract

Pursuing high-performance energy storage systems and sustainable hydrogen production technologies is critical for addressing global energy challenges. This study reports the synthesis, characterization, and application of a novel Mg-VO2@ZnO-MWCNT (MVZM) composite designed for enhanced energy storage and solar hydrogen generation. The composite material consists of magnesium-doped vanadium dioxide (MV), zinc oxide (ZnO) and multi-walled carbon nanotubes (MWCNTs), creating a synergistic structure with superior electronic properties, enhanced surface area, and improved charge transfer efficiency. Comprehensive characterization techniques, including Raman, Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical analysis, were employed to investigate the structural, morphological, and electrochemical properties of the composite. The MVZM exhibited excellent energy storage capabilities, demonstrating high specific capacitance in three-electrode systems. Furthermore, the MVZM composite demonstrated remarkable photocatalytic activity under visible light irradiation, facilitating efficient hydrogen evolution at the rate of 3150 mu molh-1g- 1 from a partial water splitting experiment. This multifunctional composite offers a promising platform for integrating energy storage and solar-driven hydrogen generation, presenting a sustainable approach to address future energy demands.