Electrochromic properties of electrochemically fabricated nanostructure nickel oxide and manganese oxide films

Thin films of mesoporous lamellar nickel oxides and nanotube manganese oxides were electrochemically fabricated on indium tin oxide (ITO) glass using sodium n-dodecyl sulfate (SDS) as a template agent under different controlled potentials in 10 mM Ni(NO3)2 and 100 mM MnSO4 solutions. Electrochromic characterization together with the morphological observation by transmission electron microscopy (TEM), structure analysis by X-ray diffraction (XRD) and electron diffraction (ED) was made. Nickel and manganese oxide films of nanostructures, compared with conventional structure ones, showed marked changes in optical transmittance and electric charge with regard to the electrochromic reactions in aqueous solution of 100 mM LiOH. However, in a non-aqueous γ-butyrolactone (GBL) solution of 100 mM Bis(trifluoromethane)sulfonimide lithium, the nickel oxide films did not show any notable electrochromic reactions, while the manganese oxide films of both nanostructure and conventional structure are electrochromically active and the effect of nanostructure on the electrochromic properties was remarkable.