Metal sulfides are of great interest for future electrode materials in supercapacitor and solar cell applications owing to their superior electrochemical activity and excellent electrical conductivity. With this scope, a binary transition metal sulfide (CoS) is prepared via one-step hydrothermal synthesis. Hexagonal phase of CoS with space group of P6₃/mmc(194) is confirmed by XRD analysis. Additional cubic Co₃S₄ phase in the prepared sample originates the mixed valence state of Co (Co²⁺ and Co³⁺) is affirmed from XPS analysis. Morphological features are visualized using HRSEM images that shows nanoflower shaped star-anise structure. Employing the prepared CoS as active electrode material, interfacial charge transport kinetics is examined by EIS-Nyquist plot. The supercapacitive performances are tested in two and three-electrode system which exhibited respective specific capacitances of 57 F/g and 348 F/g for 1 A/g. Further, the fabricated asymmetric CoS//AC supercapacitor device delivers an appreciable energy density of 15.58 Wh/kg and power density of 700.12 W/kg with excellent cyclic stability of 97.9% and Coulombic efficiency of 95% over 2000 charge-discharge cycles. In addition, dye-sensitized solar cells are fabricated with CoS counter electrode and the obtained power conversion efficiency of 5.7% is comparable with standard platinum based counter electrode (6.45%). Curie-Weiss plot confirms the transition of paramagnetic nature into ferrimagnetic behavior at 85 K and Pauli-paramagnetic nature at 20 K respectively. Temperature dependent resistivity plot affirms the metallic nature of CoS sample till 20 K and transition to semiconducting nature occurs at <20 K owing to Peierl’s transition effect.

Mesoporous aluminosilicate (Al-SBA-15) support synthesised via a direct hydrothermal method was post loaded with monometals such as 1.0 wt% RuO₂ and 7.0 wt% NiO separately. Different weight percentages of bimetallic catalysts such as RuO₂ (0.2–1.0 wt%) with 7.0 wt% NiO were loaded jointly on mesoporous Al-SBA-15 support by a wet impregnation method for hydrodeoxygenation of anisole. The XRD and BET results revealed that the materials were hexagonally ordered, indicating the presence of mesoporosity. NH₃-TPD results confirmed the presence of acidic sites on materials, which enhanced the HDO activity of anisole. The oxidation state of Ni²⁺ and Ru⁴⁺ was confirmed by XPS analysis. H₂-TPR revealed the strong metal-support interaction in monometal catalysts of 7.0 wt% NiO, whereas in the case of bimetallic catalysts the reduction temperature of Ni was lowered below 440 °C by addition of Ru, which is lower than the that of 7.0 wt% NiO (524 °C). HR-TEM images further confirmed the presence of the mesoporous nature along with RuO₂ and NiO crystallites largely located over the surface of Al-SBA-15. The activity of all the synthesised catalysts was tested over vapour phase hydrodeoxygenation of anisole (biomass compound). Variation in temperature and time-on-stream with atmospheric pressure was optimised to obtain high conversion and selectivity. A reaction temperature of 400 °C was found to be optimum. The 1.0 wt% RuO₂/7.0 wt% NiO catalyst gave the highest conversion of about 46% of anisole and selectivity towards benzene of 45%. Bimetallic catalysts (1.0 wt% RuO₂/7.0 wt% NiO) showed high activity compared with monometallic catalysts (1.0 wt% RuO₂ and 7.0 wt% NiO) because of the synergism of Ni and Ru. Also the bimetallic catalysts showed good activity compared with other reported catalysts under variable experimental conditions.

The present study focuses on the aqueous dispersion of BNNTs via noncovalent functionalization with four surfactants including pluronic (P123), polyethyleneimine (PEI), pluronic (F127) and ammonium oleate (A.O). The morphology of the modified BNNTs was characterized by transmission electron microscopy (TEM). Pristine BNNTs and surfactant coated BNNTs were examined to elucidate their antibacterial activity and cytotoxicity levels in different cells (Vero, Chang liver, MCF7 and A549) by an in vitro method. The quantitative antibacterial efficacy was evaluated by measuring the optical density growth of a bacterial culture. The optical density growth curves and TEM results indicate that PEI coated BNNTs exhibit strong bacterial activity against Escherichia coli and Staphylococcus aureus. The cytotoxicity levels were intensively studied by the MTT method and the results reveal the biocompatible nature of F127 coated BNNTs (F-BNNTs) in different cells. The chemotherapeutic drugs, tamoxifen and paclitaxel blended F-BNNTs were tested in MCF7 and A549 cells. DNA fragmentation and fluorescence images indicate the apoptotic pathway of cell death in cancer cells. The results of this investigation explore the cytocompatability of F-BNNTs and it can be designed as a nanovector for targeted drug delivery.