Undoped ZnO and Mg-doped ZnO (MZO) thin films were synthesized by sol–gel dip-coating technique. The effect of Mg dopant on the structural, surface-morphological, and optical properties together wi...

Enhanced photocatalytic activity of Mg-doped ZnO thin films prepared by sol–gel method

For the first time, we report on successful fabrication of 1-dimensional (1D) nanoprism and 2-dimensional (2D) nanocone shaped surface patterned amorphous indium titanium oxide (INTO) sol-gel based mesoporous thin films on glass by soft lithography. Structural evaluation of the surface patterns over amorphous thin film surfaces was performed by atomic force and transmission electron microscopes as well as X-ray diffraction study. Chemical bonding/oxidation state of constituent elements in INTO film matrix was analyzed by FTIR and X-ray photoelectron spectroscopies. Maximum optical absorption and minimum specular surface reflection in visible region were noticed in 2D patterned film. The thin film with physical thickness over 100 nm was mesoporous in nature (~ 14% porosity) as measured by spectroscopic ellipsometer. A significant improvement in photoelectrochemical (PEC) activity was found in 2D patterned film under visible light that could be associated with the enhancement in light absorption/trapping by the periodic nanocones. Moreover, the existence of mesopores could provide excess active sites for electrolyte diffusion and mass transportation. Thus, the mesoporous 2D patterned thin film could have substantial opportunity in solar energy conversion. The facile technique could create an avenue for fabrication of complexed surface patterned thin films with improved PEC property.

Fabrication, structural evaluation, optical and photoelectrochemical properties of soft lithography based 1D/2D surface patterned indium titanium oxide sol-gel thin film

A dense and amorphous AlPO4/CePO4 film was prepared on the surface of rutile TiO2 particles by chemical deposition method. Compared with plain rutile TiO2 particles, the water dispersibility, whiteness and brightness were obviously improved. The fabricated CePO4/AlPO4 hybrid layer effectively suppressed the photo-catalytic activity of rutile TiO2 particles. Optimum cerium phosphate content (counted by CeO2) of hybrid coating should not exceed 0.5 wt-% when AlPO4 (counted by Al2O3) was 2 wt-% to effectively balance the whiteness, brightness and photo-stability.

Properties of AlPO4/CePO4 hybrid coating on rutile TiO2

Influence of Aloe vera and PEG on the evaluation of photocatalytic degradation of MG dye under UV light and visible light irradiation of ZnO nanomaterials

Transparent conducting oxide films of boron and gallium co-doped ZnO (BGZO) were prepared on glass substrates by radio frequency magnetron sputtering at room temperature and 200°C, respectively. The dependence of structural, electrical and optical properties on the thickness and substrate temperature were investigated. All films demonstrated c-axis preferred orientation and showed highly transparent in the visible wavelength region. With the increase thickness and substrate temperature, the grain size of BGZO films increased and the full width at half maximum decreased, the carrier mobility increased and resistivity decreased, which indicated that the crystallinity and conductivity of films were improved. The research also found that the optical band gap (Eg) of BGZO thin films decreased with increased substrate temperature and thickness.

Substrate temperature and thickness dependence of properties of boron and gallium co-doped ZnO films

We report the fabrication of surface patterned zinc indium oxide thin films by pressure assisted capillary force lithography from the precursor solutions of varying indium content 55 maximum. The presence of various morphologies spherical, hexagonal plate, cotton ball, flower and islandlike of hexagonal ZnO together with the formation of light surface patterns was observed from electron microscopes field emission scanning electron microscope, TEM for the films deposited from the precursors of 45 indium. However, at 55 indium ZI55, the development of high fidelity surface patterns average periodicity 15m peak height 15nm was observed from atomic force microscopy (AFM) study. A gradual increase in photocatalytic activity PA of the films towards decomposition of rhodamine 6G dye under UV 254nm was found on increasing indium content. Moreover, an improvement of the PA over 13 times was noticed by nanoAu coating on ZI55. This fabrication strategy could be used for PA improvement of metal oxide semicond...

A. Haldar

Papers

Zinc-indium-oxide sol-gel thin film: surface patterning, morphology and photocatalytic activity