Fig. 3

Fabrication procedure and chemical characterization. a Synthesis process of VSM. Ti₃C₂ nanosheets were obtained by etching Ti₃AlC₂ through LiF and hydrochloric acid. Na₃VO₄ and CH₃CSNH₂ were mixed into Teflon-lined stainless autoclaves and then heated to 160 °C for 24 h to form VS₄ nanorods. The mixture of VS₄ and Ti₃C₂ were successfully performed to obtain VSM heterostructure. TEM images and lattice spacing of b VS₄, c Ti₃C₂. d 3VSM, e Schottky junction; f high-Angle Annular Dark Field (HAADF) scanning TEM images and corresponding area-element mapping of V, S, C, Ti in 3VSM using high resolution transmission electron microscopy. g XRD patterns of VS₄, MXene and 3VSM. Energy-dispersive X-ray spectroscopy elemental mapping of V and S in VS₄ and 3VSM. h V 2p spectra of VS₄ and 3VSM. i S 2p spectra of VS₄ and 3VSM. j valence band of VS₄ and 3VSM. k UV–vis adsorption spectrum of VS₄ and 3VSM. l band gap energy of VS₄ and 3VSM