Electrodeposited Polyaniline in a Nanoporous WO3 Matrix: An Organic/Inorganic Hybrid Exhibiting Both p- and n-Type Photoelectrochemical Activity

Abstract

This study focuses on the electrodeposition of a conducting polymer such as polyaniline (PANI) into a tungsten trioxide nanoporous host framework. Nanoporous WO3 films were initially electrosynthesized on tungsten foil by anodization at different voltages in a fluoride-containing medium. The PANI layer was electrografted onto the entire surface of the WO3 using potentiodynamic electrodeposition in sulfuric acid electrolyte. The morphological features of oligomer/polymer formed in the nanoporous oxide template were monitored by field-emission scanning electron microscopy. Systematic changes in the morphology afforded insights into the evolution of the WO3/PANI hybrid assembly. This assembly was subsequently characterized by Raman spectroscopy, X-ray photoelectron spectroscopy, cyclic voltammetry, and photoelectrochemical measurements. Photovoltammetric data indicated the complex behavior of the hybrid, featuring the properties of both of its components: namely, p-type behavior in the cathodic polarization ...