MWCNT/WO3 nanocomposite photoanode for visible light induced water splitting

The Multi-walled carbon nanotube (MWCNT)/WO3 nanocomposite thin films with different MWCNT's weight percentages were prepared by sol–gel method as visible light induced photoanode in water splitting reaction. Weight percentage of MWCNT in the all nanocomposite thin films was confirmed by TGA/DSC analysis. According to XPS analysis, oxygenated groups at the surface of the MWCNT and stoichiometric formation of WO3 thin films were determined, while the crystalline structure of the nanocomposite samples was studied by XRD indicating (0 0 2) peak of MWCNT in the monoclinic phase of WO3. The influence of different weight percentage (wt%) of MWCNT on WO3 photoactivity showed that the electron conductivity, charge transfer and electron life time had improved as compared with the pure WO3. Based on linear sweep voltammetry and chronoamperometry measurements, the (1 wt%) MWCNT/WO3 nanocomposite thin films photoanode has a maximum photocurrent density of ∼4.5 A/m2 and electron life time of about 57 s. - Graphical abstract: Photocurrent density versus time at constant potential (0.7 V) for the WO3 films containing different MWCNT weight percentages annealed at 400 °C under 1000 Wm−2 visible photo-illumination. Display Omitted - Highlights: • MWCNT/ WO3 nanocomposite thin films were synthesized using sol–gel derived method. • TGA/DSC confirmed the weight percentage of MWCNT in the all nanocomposite thin films. • XPS analysis revealed that WO3 was attached on the oxygenated group of MWCNT surface. • The Highest Photoelectrochemical activity is achieved for (1 wt%)MWCNT/WO3 thin film