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

Abstract

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.

Investigation on the Properties and Mechanism of W-Doped TiO2 Electrochromic Films Deposited by Cosputtering

“…The SEM and AFM (Figure S2) images reveal that all of the film surfaces are mainly composed of nanocrystals and the morphology is generally smooth, with film Figure a exhibiting higher density and less pores. As the doping amount of W increases, more pores start to appear on the film surface, especially there are a large number of pores on the surface of the W2 film (Figure c) which is beneficial to the injection and extraction of Li + to improve the electrochromic properties of the film. , Of course, excessive pores will form cracks, resulting in a decrease in performance shown in the W3 film.…”

“…As the doping amount of W increases, more pores start to appear on the film surface, especially there are a large number of pores on the surface of the W2 film (Figure 1c) which is beneficial to the injection and extraction of Li + to improve the electrochromic properties of the film. 33,34 Of course, excessive pores will form cracks, resulting in a decrease in performance shown in the W3 film.…”

Electrochromic materials: Scope for the cyclic decay mechanisms and performance stability optimisation strategies

“…Similarly, Zhan et al 56 synthesised vanadium-doped NiO films on ITO substrates with a stability of more than 990 cycles by hydrothermal method. Wen et al 57 attempted to add an appropriate amount of iridium [Ir/(Ir + Ni) = 7.6 atomic %] to NiO films, which not only improved the stability of NiO films to more than 10,000 cycles in lithium-conducting electrolytes but also significantly improves its optical modulation (Figure 9).…”

“…Because terbium ions introduce amorphous and porous mesh structure in WO 3 films and their occupation in the WO 3 lattice leads to the inhibition of directional growth, this allows the material not to degrade after long cycles and has a stability of more than 600 cycles. Similarly, Zhan et al 56 synthesised vanadium‐doped NiO films on ITO substrates with a stability of more than 990 cycles by hydrothermal method. Wen et al 57 attempted to add an appropriate amount of iridium [Ir/(Ir + Ni) = 7.6 atomic %] to NiO films, which not only improved the stability of NiO films to more than 10,000 cycles in lithium‐conducting electrolytes but also significantly improves its optical modulation (Figure 9).…”

Porous NiMoO4 Nanosheet Films and a Device with Ultralarge Optical Modulation for Electrochromic Energy-Storage Applications

“…Since the discovery of the EC phenomenon by Platt, EC materials as an important part of EC smart windows have attracted worldwide attention . Due to their good electrochemical properties, excellent EC activity, and ease of preparation, , inorganic materials have been widely investigated for EC applications, especially transition metal oxides (TMOs), such as WO 3 , − TiO 2 , MoO 3 , Nb 2 O 5 , Co 3 O 4 , V 2 O 5 , MnO 2 , and NiO. , Among them, MnO 2 , NiO, Co 3 O 4 , and V 2 O 5 exhibit neutral coloration. In particular, NiO not only shows good EC performance but also meets the standard of human visual comfort …”