Electrochromic and electrochemical capacitive properties of tungsten oxide and its polyaniline nanocomposite films obtained by chemical bath deposition method

Polyanine and its nanocomposite WO3/PANI films were deposited on fluorine doped tin oxide (FTO) glassslides by simple chemical bath deposition method. The morphology structure of the composite film wasstudied using atomic force microscopy (AFM) and scanning electron microscopy (SEM), while the elec-trochemical capacitive properties were determined using cyclic voltammetry (CV), chronopotentiometry(CP) and electrochemical impedance spectroscopy (EIS). The WO3/PANI nano-composite exhibited mul-tiple colors (electrochromism) during the CV scans, from brownish green to transparent to light greenthen back to brownish green. Surprisingly, the integration of the PANI with the WO3led to synergisticperformance of nanohybrid wherein a true electrochemical double layer capacitor was obtained. Also,interestingly and unlike literature reports, the CBD method led to excellent capacitance retention (>98%)of the PANI even at 1000 continuous cycles. This work demonstrates that simple CBD can be used toget WO3/PANI films that give good electrochromism and pseudo-capacitance comparable to the onesobtained by other methods. Hence the obtained nanocomposite film of WO3/PANI can be a promisingmaterial for electrochromic and energy storage applications.US Army Research Laboratory–Broad Agency Announcement (BAA) (under Contract number W911NF-12-1-0588).http://www.elsevier.com/locate/electactahb201