Electrochemical behavior of spray deposited nickel oxide (NiO) thin film in Alkaline electrolyte

Abstract

Nickel oxide (NiO) Thin film was successfully deposited on the glass substrate using an inexpensive spray pyrolysis (SP) technique. The structural, morphological, and optical properties have been studied, thus the electrochemical behavior of NiO film in Alkaline electrolytes has been investigated. The X-ray diffraction (XRD) analysis showed that NiO thin film exhibit a polycrystalline cubic rock-salt structure with a preferential orientation on the plane (111). This result was confirmed using Raman spectroscopy. The Scanning Electron Microscopy (SEM) images exhibit a smooth and dense surface without major cracks. Optical analysis shows an average transmission of about 55% in the visible light range, and the optical band gap energy was estimated by Tauc’s method and showed a value of 3,71 eV. Electrochemical properties as specific capacitance (Csp), optical density variation (ΔOD), and Coloration efficiency (CE) were studied using cyclic voltammetry in 1M KOH and 1M NaOH electrolytes. The results indicated that the behavior of the NiO layer in KOH is more effective than in NaOH electrolytes.

Ultrathin sputtered NiO films for enhanced electrochromic performance in smart windows

“…The improved CE in 0.4 lm is attributed to the porous and crystalline structure of NiO, providing an effective interface with the electrolyte. 31 In general, EC materials with an amorphous nature are expected to provide high CE. 73 However, the NiO lms with a good polycrystalline nature in the present work showed superior CE.…”

“…30 Doping of certain elements can also bring enhancement in EC properties. For example, Brioual et al 31 have reported that an increment in the optical modulation, from 27 to 38%, of a 120 nm lm was possible by doping with 2 at% In. There are also other examples of anodic NiO in the literature (see Table 1).…”