The study was aimed at evaluating the effect of nanosilica and different sources of silicon on soil properties, total bacterial population and maize seed germination. Nanosilica was synthesised using rice husk and characterised. Silica powder was amorphous (50 nm) with >99.9% purity. Sodium silicate treated soil inhibited plant growth promoting rhizobacteria in contrast to nanosilica and other bulk sources. Surface property and effect of soil nutrient content of nanosilica treatment were improved. Colony forming unit (CFU) was doubled in the presence of nanosilica from 4 × 105 CFU (control) to 8 × 105 CFU per gram of soil. The silica and protein content of bacterial biomass clearly showed an increase in uptake of silica with an increase in nanosilica concentration. Nanosilica promoted seed germination percentage (100%) in maize than conventional Si sources. These studies show that nanosilica has favourable effect on beneficial bacterial population and nutrient value of soil.

This review focuses on the various synthetic approaches to upconversion nanocrystals and recent developments in the photovoltaic applications of upconversion nanomaterials.

The electronic and optoelectronic properties of tin selenide nanostructures are of great interest for application in energy conversion and storage devices. Despite the great progress achieved in nanoparticle synthesis, controlling the crystal phase in tin selenide nanostructures remains a challenge. In this article, we present a simple solvothermal approach for the phase controlled synthesis of SnSe and SnSe 2 hierarchical nanostructures (HNs) for the first time. SnSe HNs have been prepared by reacting SnCl 4 and SeO 2 under solvothermal conditions using oleylamine as solvent. By adding a calculated amount of 1-dodecanethiol (1-DDT) to the reaction mixture the crystal phase can be tuned from SnSe to SnSe 2 . The obtained HNs were composed of single crystalline thin nanosheets with thickness in the range of 7-12 nm. A possible mechanism has been proposed for the phase controlled synthesis of tin selenides. The obtained SnSe and SnSe 2 HNs showed good electrocatalytic activity in the redox reaction of the I − /I 3 − shuttle. Dye sensitized solar cells (DSSC) employing SnSe and SnSe 2 HNs as counter electrodes showed photovoltaic performances similar to the device made with a conventional platinum (Pt) counter electrode.

Magnesia (MgO) nanoparticles were produced from magnesite ore (MgCO3) using ball mill. The crystalline size, morphology and specific SSA were characterized by X-ray diffraction analysis, transmission electron microscopy and Brunauer-Emmett-Teller method, respectively. MgO nanoparticle-incorporated nylon 6 solutions were electrospun to produce nanofiber mats. Surface morphology and internal structure of the prepared hybrid nanofiber mats were examined by scanning electron microscopy and high-resolution transmission electron microscopy, respectively. The fire retardancy and antibacterial activity (Staphylococcus aureus and Escherichia coli) of coated fabrics made from MgO/nylon 6 hybrid nanofiber are better than those from nylon 6 nanofiber.

Bifunctional electrocatalysts based on non-precious metals were developed for the dioxygen reduction and methanol oxidation reactions. These electrocatalysts can be considered as candidate cathode and anode materials for anion-exchange membrane (AEM) alkaline alcohol fuel cells. A series of Ni-doped cobalt oxide (NixCo3-xO4) hierarchical nanostructures composed of one-dimensional nanorods was prepared by an inexpensive hydrothermal method. X-ray diffraction patterns showed that the NixCo3-xO4 crystallized in a cubic spinel phase. The electrochemical performance of the catalysts was investigated using a conventional cyclic voltammetry technique. The electrocatalytic behaviour of the NixCo3-xO4 hierarchical nanostructures was compared with the behaviour of Co3O4 and Co0.33Ni0.67O. The synergistic behaviour of the Ni in the NixCo3-xO4 nanostructures was established with respect to the Ni content. NixCo3-xO4 hierarchical nanostructures show a better catalytic behaviour than Co3O4 and Co0.33Ni0.67O. Although the NixCo3-xO4 compositions all showed good catalytic behaviour, Ni1Co2O4 was identified as a superior bifunctional electrocatalyst for the oxygen reduction and methanol oxidation reactions in alkaline media. The effect of the Ni content on the electrocatalytic properties of the NixCo3-xO4 hierarchical nanostructures was clearly shown. The use of these electrocatalysts based on non-precious metals could have a commercial impact on the development of non-platinum electrocatalysts for application in AEM alkaline alcohol fuel cells.