A simplified low-temperature green synthesis approach for solution-processed vanadium oxide

Vanadium oxide (V2O5) has been widely studied for various applications, including energy storage or catalysis, with conventional synthesis methods commonly employed such as chemical or thermal precipitation, ion exchange, or solvent extraction. However, these methods often involve high-temperature processing, the use of environmentally harmful precipitating agents, and the generation of liquid waste, leading to significant environmental and economic challenges. This study presents a simplified, environmentally friendly method for synthesizing V2O5 powders by dissolving metallic vanadium in a hydrogen peroxide/ethanol solution, followed by dehydration at temperatures ranging from 60 to 150 °C. This novel approach eliminates the need for precipitating agents and complex solvents, reducing the environmental impact and the residual treatment costs. The synthesized V2O5 powders were characterized using thermogravimetric analysis, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), UV–Vis spectroscopy, and Scanning Electron Microscopy (SEM). The results revealed significant material losses during thermal processing in thermogravimetric analysis such as H2O and OH, characteristic vibrational modes of V2O5 of the O–V–O and V = O groups were determined and optical parameters such as the optical band gap in a range of 3.24–2.21 eV and Urbach energy. SEM analysis confirmed a consistent spherical morphology with an average diameter of 200 nm. The proposed synthesis method offers a more sustainable and efficient solution processing alternative than conventional approaches, with the potential for the development of semiconductor materials as protective layers in flexible V2O5-based technologies.