Two-Dimensional Porous Structure of V-Doped NiO with Enhanced Electrochromic Properties

In this work, a two-dimensional porous structure of a V-doped NiO film with excellent electrochromic properties on an ITO substrate was synthesized by a hydrothermal method. The influence of V⁵⁺ ions on the NiO film was explored by adjusting the amount of V doping, including refining the crystal grains, increasing the specific surface area of the film, and accelerating the diffusion rate of OH^- in the film. Compared with the undoped NiO film, a 3 atom % V-doped NiO film comes out with superior electrochromic properties with large optical transmittance modulation (81.9% at 600 nm), fast response times (1.2 and 0.9 s), and excellent cycle stability (90.6%). This work creates innovation direction in the field of intelligent energy-saving window materials with high electrochromic properties.