Synthesis, characterization and ab initio study of WO3 nanocubes with peculiar electrochemical properties

A non-energy intense route was used for the synthesis of highly crystalline WO 3 nanocubes. The morphological studies confirmed the cuboidal shape of the nanocrystals. Raman spectrum result for the synthesized sample revealed that the vibrational modes correspond to those ones assigned to single phase stoichiometric WO 3 . The band gap Eg was derived based on UV-Vis diffuse reflectance result and found to be 2.58 eV, whereas the photoluminescence (PL) result confirmed the blue emission for the synthesized sample. The structural and electronic properties of the orthorhombic WO 3 were studied within the spin-polarized density functional theory (SDFT) using various functionals. Results indicated that the orthorhombic WO 3 is non-magnetic and has a direct band gap in the range of 2.15–3.75 eV which depends on the exchange-correlation functional used in the theory. The electrochemical studies showed that the nanocubes exhibited a peculiar electrochemical behaviour. In fact, the charge transfer resistances relatively enhanced which may results in decreasing the capacitance of the highly crystalline WO 3 nanocubes.