The Li:V molar ratio of 10:1 was used to ensure an excess of Li + . The solution was stirred for 1 h at room temperature and subsequently heated to 60 °C with constant stirring for 3 h to form a dark red gel. The material was aged for four days at room temperature where the product precipitated in the form of a green powder. The product was dissolved in 3 M LiCl solution and hydrothermally treated at 220 °C for 24 h in the autoclave. Lastly, the sample was filtered through a PTFE filter paper, washed with deionized water, and dried at 80 °C for 24 h.