Fabrication of Ceramic Oxide thin Films for Photo- Electrochemical Applications

Abstract

Some unique monometallic and homo-heterobimetallic complexes [Cu (dmae)2(H2O)]1,[Cu(dmae)(OAc)(H2O)]22,[Sn(dmae)(OAc)]23,[Cu4Y2(dmae)6(OAc )6(H2O)2] 4 and [Cu6Y2Cl0.7(dmae)6(OAc)7.3(OH)4(H2O)2].3H2O.0.3CH3C6H5 5 were successfully synthesized and analyzed for their stoichiometry and structure by physiochemical methods such as melting point, microanalysis, fourier transform infra red (FT-IR), proton nuclear magnetic resonance (1HNMR), thermogravimetric analysis (TGA/DTA) and X-ray single crystal diffraction analysis. The thermo gravimetric analysis ascertains that all the precursors undergo facile thermal decomposition at relatively low temperatures ranging from 400 to 600 oC to yield metal oxide residues. All the designed precursors except 2 were applied for the deposition of ceramic oxide composite thin films on plane and fluorine doped tinoxide (FTO) coated glass substrates by aerosol assisted chemical vapor deposition (AACVD). The precursor 1, 4 and 5 were found suitable for deposition of Cu2O and nanocomposites oxide Cu- YO2-0.5Cu2O and Y2CuO4–5CuO thin films respectively under inert ambient of argon gas. All the deposited thin films were characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and powder X-ray diffraction (PXRD) for their surface morphology, elemental composition and phase crystallinity. XXIII The precursor 3 was applied for deposition of fullerene-like structured mesoporous SnO2 nanoball thin films on FTO and plane glass substrates by using an in-house built electro-spun aerosol spray pyrolysis (ESASP) technique. The field emission scanning electron microscopic (FESEM) and focused ion beam (FIB) images of the exterior and interior surfaces of the SnO2 nanoball thin films disclose the presence of fullerene-like structures having mesopores of the sizes ranging from 33.5 to 35.0 nm in exterior and 8.0 to 160 nm in interior surfaces respectively. All the fabricated films were found to be impurity and crack free, have good adhesion to the substrate and nanocrystalline in nature ensuring clear grain boundaries with average particle size ranges from 28 nm to 40 nm thus making them suitable for photo electrochemical (PEC) applications. The PEC measurements carried out by three-electrode electrochemical set-up with Ag/AgCl as a reference electrode and a platinum mesh as a counter electrode show an increase of photocurrent observed under illumination of 150W halogen lamp as compared to dark at potentials of 0.6 V and 0.8 V respectively. The performance of the fabricated SnO2 nanoball thin films for application in super capacitors was evaluated by capacitance measurements and all the results provide exciting new opportunities towards mesoporous ceramic nanomaterials for application in energy sector