The selectively new type of heterogeneous consisting of vanadium substituted polyphosphomolybdate with keggin structure H₄[PMo₁₁VO₄₀] · 32H₂O (11-molybdo-1-vanadophosphoric acid) supported on montmorillonite K10 clay (PVMo-K10). The keggin type heteropoly acid is known to possess Bronsted acidity, which is stronger than many mineral acids and then strong oxidative power. HPAK10 used as a catalyst for various syntheses of organic reactions. A green synthesis of quinoxaline derivatives from a two-component one-pot condensation reaction of substituted 1,2-dicarbonyl compounds or diacetyl and 1,2-diamines in the presence of catalyst under the solvent conditions has been described. This type of catalyst offers advantages such as shorter reaction time, excellent yield, recovery, the reaction work up is very simple and reused several times there is no change in loss of surface in catalytic activity.

In present study, petite rod like nanostructure of Nb₂O₅ is synthesized via hydrothermal route and employed as the photo-anode material for dye sensitized solar cells (DSSCs). The Nb₂O₅ nanopowder was characterized by using scanning and transmission electron microscopies, X-ray diffraction pattern (XRD), optical absorption spectroscopy (UV-vis), current-potential curve and incident-photon-to-current efficiency (IPCE) experiments. In XRD and FESEM study the powder mainly displayed orthorhombic crystalline nature and petite rod like morphology with the rod length in the range of about 50–100 nm and a diameter of about 30–40 nm. For Nb₂O₅ as photoanode in DSSC, the IPCE values up to 40% was obtained with the N719 dye and iodine/iodide couple in acetonitrile with open circuit voltage of 0.528 V and 1.29% power conversion efficiency.

The sources of the petroleum crude oils are decreasing day by day and there is the great risk of exhaustion of the current available reserves. The price of oil is increasing rapidly in market and crude oil is available at higher cost, especially in India. The mineral oils are the great threat to the environment and health due to their high eco-toxicity and low biodegradability features. The diesel oil contaminates the soil, air and drinking water and affects the plant and human life upto a great extent. Vegetable oils are the best alternative options for the lubricating oils used in auto vehicle and industrial applications. The high oleic contents make the vegetable oils environment friendly and cheaper. The non-edible vegetable plants contain larger amount of oils in their seeds that can be converted into biolubricants and further use engines and industrial applications. Biolubricants are renewable lubricants and having zero greenhouse effect, nontoxic and biodegradable. The research article presents the review of the different vegetable oils and their fatty acid contents. The tribological or friction behavior of the oils is also studied. The reviewed oils are Mahua, Coconut, Palm, Sal, Neem, Olive, Castor, Canola, Cashew nut and Jatropha.

In this study, the cuprite which is considered an important kind of gemstones could be prepared in well morphology nanoparticles using novel treatment for the poly(vinyl alcohol)/copper acetate electrospun nanofiber mats. Initially, smooth, beads-free and good morphology electrospun nanofibers could be obtained from an aqueous sol–gel composed of poly(vinyl alcohol) and copper acetate. The prepared nanofiber mats have been treated by water gas which was synthesized in an autoclave by passing hot water vapor through graphite particles bed. The utilized physicochemical characterizations indicated that the treatment temperature strongly affects the chemical composition and morphology of the final product. Typically, at a treatment temperature of 300 °C, three dimension trapezoid nanoparticles from cuprite (Cu₂O) were obtained. However, increasing the temperature to 350 °C led to form highly crystalline copper sheet decorated by small spherical nanoparticles which is considered a novel low temperature synthesis of pristine copper nanostructures. Overall, the study opens new avenues for different utilization of the electrospun nanofibers as well as introducing new technology for preparation of an expensive gemstone for industrial applications.

Highly porous flakes-like ZnO nanostructures are successfully synthesized by hydrothermal route using zinc acetate as precursor and DI water as a solvent. HMT and ammonia were used as additive and surfactant, respectively. The two different sets of ZnO nanostructures are synthesized by varying ammonia solution amount (Z1-H and Z2-H). The structural, morphological and optical properties of as-prepared powder were studied by different characterization techniques. The structural analysis of synthesized powder shows the formation of hexagonal wurtzite ZnO. The optical absorption peak of synthesized ZnO exhibited blue shift as compared to the bulk ZnO. Morphological study showed formation of highly perforated flakes like morphology with different thickness revealing their high surface area. The efficiency characteristics for DSSCs were measured under simulated sunlight illumination of 100 mW/cm² intensity. It was found that the best results of DSSCs were observed with power conversion efficiency of 2.08% and 2.81% for Z1-H and Z2-H as photoanodes, respectively, which was significantly 3 to 4 times higher than the commercial ZnO. The efficiency enhancement can be explained by increasing of dye adsorption on perforated ZnO flakes due to enhancement of the active surface area of photoanode. The charge recombination behavior of cells was inspected by electrochemical impedance spectra (EIS), and the results showed that Z2-H based cell with lower thickness of nanoflakes have the lowest transfer resistance and the longest electron lifetime, which could facilitate the reduction in recombination processes and thus would promote the solar-cell performance.

Mg–Al layered double oxide/graphene oxide/sodium carboxymethyl cellulose (Mg–Al LDH/GO/CMC) composite was prepared via a straightforward solution mixing process for efficient methylene blue (MB) removal. The structure, morphology of the ternary composite and adsorption property towards MB were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM). The results indicated that the LDH and GO were dispersed in the CMC matrix, forming a stable LDH/GO/CMC ternary composite. In addition, the composite film exhibited an improved adsorption capacity to MB in comparison to the neat CMC film. The maximum MB removal efficiency was found to be 95.3%. Therefore, the as-obtained ternary composite film can be employed as materials for the efficient removal of MB in water purification applications.

Nowadays, some problems such as environmental pollutions caused by consumption of fossil fuels have led to distortion of ecologic conditions and emergence of environmental hazards. Similarly, restrictions of fossil fuel deposits have led different countries to pay due attention to other types of energy. As such, physical and chemical properties of biodiesel produced from animal waste oil were examined in the present research. For this purpose, ethyl ester was prepared for single-phase transesterification of sheep waste oil and ethylic alcohol and calcined eggshell were used as catalysts at 72 °C. The application of the calcined eggshell (ES) at 1200 °C was enumerated as one of the distinguished characteristics of this study that this substance might be easily isolated from the produced fuels due to its heterogeneity and it would reduce the number of washings. Besides, biodiesel extraction phase was executed in a single stage and, thus, the time duration of production was reduced. A total of 17 laboratory samples was extracted exerting changes in the solvent-oil ratio and respecting the quantity of catalysts and reaction period under various conditions (including 5 hr period, 4.5 g of catalyst amount and an ethanol-to-oil ratio equal to 3). The best quantities came from the given product samples, including the cetane index, dynamic viscosity, kinematic viscosity, flash point, and specific weight of pure ethyl ester of animal waste showed 52, 0.018 (Pa · s), 1.68 (mm² · s^–1), 92.3 °C and 1.14 (N · m^–3) respectively. The values of the given parameters such as heat value, cloud point, pour point, and freezing point of ethyl ester are 37.2 (MJ · kg^–1), 37.1, 26.7, and 21.9 °C, respectively.

The present work reports the synthesis of Schiff base Cu(II) complexes 1–3 condensed with significant dicarboxylic acids as co-ligands. They have been synthesized and characterized by various spectral and analytical methods like microanalytical data, magnetic susceptibility values, molar conductivity measurements, UV-vis, IR, ¹H NMR, ¹³C NMR and EPR techniques. In addition to that XRD, morphological studies were also carried out. The complexes were found to reveal excellent catalytic activity. In this work, p-nitrophenol (p-NP) was reduced to p-aminophenol (p-AP) where novel dicarboxylic acid conjugated Cu(II) complexes were acting as catalysts. The demand to reduce the toxic p-NP, found in water bodies in a soluble and stable form has prompted us to undertake the work and carry it out effectively. These classified environmental hazards and their solubility posed a major problem in employing traditional water purification methods for the removal of p-NP from contaminated waste waters. The limited reports available on the metal complex catalytic reduction of p-NP encouraged us to carry out the same using the complexes synthesized by us. The efficiency of the catalytic reduction carried out in water medium has been evaluated towards the reduction of p-NP and the complete reduction was achieved within 70 min. The outcome of various physicochemical parameters and stability of the catalyst was also investigated. Fascinatingly, the catalyst was stable up to its 5th cycle and its efficiency was about 70%. Interestingly, the process is environmentally benign, universal, efficient, safe and operationally simple.

Zinc selenide films of variable composition have been synthesized electrochemically under different conditions of deposition potential, time interval, pH and concentration of electroplating solution to identify the optimal condition under which films of higher photoactivity and substantial stability may be produced. The deposited films have been characterized on the basis their photoresponse, corrosion and capacitance behavior. The band gap values determined by photoaction spectral studies show that these values are almost independent to the concentration of electroplating solution and deposition potential applied. The capacitance studies, photoactivity data in combination to current voltage behaviour in the dark and under illumination show that the deposited zinc selenide films exhibit p-type semiconductivity.