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In the present work, Nickel doped Molybdenum trioxide (NixMoO3) where Ni = X (X = 5, 10, and 15%) nanoparticles (NPs) were synthesized by a wet chemical method. These nano crystals are structurely analysized by X-ray diffraction and confirm the formation of orthorhombic structure in both MoO3 and Ni-doped MoO3 samples. The impact of Ni doping on crystallite size, micro strain, and texture co efficient are obtained from XRD pattern. The morphology studies of FE-SEM and HR-TEM show that the presence of one dimensional (1D) nanorods with an average diameter of particle size around 28–32 nm and the compositional stoichiometry is confirmed by EDAX technique. The functional group and the vibrational mode of metal oxide (Mo = O) are confirmed by FT-IR spectra. The photocatalytic activities of pure and Ni-doped MoO3 are attributed to the degradation efficiency under UV–Visible light irradiation. The result shows that these structure exhibits promising degradation of Methylene blue (MB) is calculated along with the kinetic study, cyclic efficiency, and growth mechanism. The ability of the catalysts generates electron-hole pairs which create free radicals and also help to undergo the secondary reactions. The MoO3 and Ni-doped MoO3 samples normally reveal better results against in antibacterial activity such as Escherichia Coli (E. Coli) and Staphylococcus aureus (S. aureus) bacteria. Overall, the results demonstrate that the doping of Ni2+ ions inside the MoO3 matrix enhances the performance in antibacterial activity.

ZnO nanorods (NRs) have been grown by sol–gel dip-coating method on FTO glass plates. The CdS quantum dots (QDs) were deposited on the as-prepared ZnO NRs by successive ionic layer adsorption and reaction method. The structural characteristics of the ZnO NRs, CdS QD and CdS QD-sensitized ZnO NRs films have been studied using X-ray diffraction method. ZnO NRs exhibit hexagonal structure. CdS QD had a size of 2 nm. The FESEM image showed the presence of CdS quantum dots on the ZnO NRs. From the optical studies, the optical band gap energy of ZnO thin film was found to be 3.26 eV and the band gap energy of CdS quantum dot was observed to be 2.1 eV. The optical absorption edge was found at 370 nm for ZnO NRs and at 460 nm for the CdS QD. The PL spectra of the prepared ZnO NRs and CdS QDs sample exhibit a strong emission peak at 395 and 688 nm. Solar cells have been fabricated using the CdS quantum dot sensitized ZnO nanorods, and the efficiency of the cell was 1.3 %.

Zeolite NaA and zeolite NaY coating on mild steel has been assessed in the current study. The synthesized zeolite NaA and NaY samples have also been studied using X-ray powder diffraction (XRD) method and scanning electron microscopy (SEM), and the samples with different concentrations of zeolite have been tested for its corrosion resistance property for against H2SO4 acid at temperatures up to 60 °C under stagnant as well as stirred conditions by polarization/impedance method. Zeolite NaA and NaY were dispersed in cyanoacrylate-based adhesive in the ratio 1:20 and coated on mild steel for the formation of membrane. XRD analysis revealed the formation of zeolite coating on mild steel substrate. Microstructure analysis using SEM images of the coated samples showed the formation of cubic structure. The coated zeolite layer consisted of top layer with thickness of 2.4–3.6 µm. Results from polarization/impedance revealed that zeolite NaA is more corrosion resistant than zeolite NaY having inhibition efficiency of 89.2 %.

Linde Type A (LTA) zeolites have been synthesized in the current study by simple sol–gel technique. The crystal growth has been controlled by varying the hydrogel synthesis time and annealing temperature. The resulting products obtained at various crystallization times and temperatures have been studied using X-ray powder diffraction (XRD) method, High resolution transmission electron microscopy images, scanning electron microscopy (SEM) micrographs, energy dispersive study and Brunauer–Emmett–Teller (BET) analysis. The TEM images of the final LTA zeolite annealed at 500 °C revealed the formation of cubic structure. XRD analysis revealed that the crystallinity improved with annealing. BET analysis revealed that the synthesized LTA is a well crystallized 4A zeolite. LTA zeolites were dispersed in poly ethylene glycol in the ratio 3:100 and 5:100 and coated on porous alumina beads for the formation of membrane. The SEM images revealed excellent formation of fine structure LTA zeolite membrane with uniform coating. The membrane consisted of a top layer with thickness of 1.14–2.0 µm. Crystals in the top layer showed cubic morphology and amorphous phase was observed at the grain boundaries present between LTA zeolite and alumina substrate.

Quaternary Cu2ZnSnS4 (CZTS) thin films, a promising absorber material for solar cells has been successfully deposited on glass substrates by cost effective simple dip-coating method without using either polluting chemicals or expensive vacuum facilities. X-ray diffraction pattern reveals the formation of CZTS films with tetragonal type kesterite structure. The Raman spectra of the prepared films exhibited resonance peaks corresponding to the CZTS phase. The scanning electron microscopic image shows the formation of films with smooth surface. The surface topography studied using atomic force microscope gives an rms roughness of 1.6 nm. The Hall effect studies indicate that the prepared films are p-type with a carrier concentration of 4.77 × 1020 cm−3. The energy dispersive X-ray analysis result indicate the presence of Cu, Zn, Sn and S in the film. The absorption coefficient was found to be the order of 104 cm−1 and the band gap has been found to be 1.5 eV.

Flower like structure TiO2 thin films have been grown onto ITO coated glass substrates by sol–gel method. TiO2 nano flowers have been sensitized using CdS quantum dots prepared using simple precursors by chemical method. The assembly of CdS quantum dots with TiO2 nano flower has been used as photo-electrode in quantum dot sensitized solar cells. The surface morphology has been studied using scanning electron microscope; it shows that the film exhibits flower like structure. The absorption spectra reveals that the absorption edge of CdS quantum dot sensitized TiO2 nano flower shifts towards longer wavelength side when compared to the absorption edge of TiO2 nano flower. The efficiency of the fabricated CdS quantum dot sensitized TiO2 nano flower based solar cell is 0.66%.