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In the present work, we have reported a facile and large-scale synthesis of TiO2 nanoparticles (NPs) through urea-assisted thermal decomposition of titanium oxysulphate. We have successfully synthesized TiO2 NPs by using this effective route with different weight ratios of titanium oxysulphate: urea. The structures and properties of TiO2 NPs were confirmed by scanning electron microscope) (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FT-IR), ultra violet–visible spectroscopy (UV-vis), and photoluminescence (Pl) techniques. XRD demonstrated that TiO2 NPs holds of anatase crystal phase with crystallizing size 14–19 nm even after heating at 600 °C. TGA, SEM, and TEM images reveal urea’s role, which controls the size, morphology, and aggregation of TiO2 NPs during the thermal decomposition. These TiO2 NPs were employed for photodegradation of Methyl Orange (MO) in the presence of ultraviolet (UV) radiation. An interesting find was that the TiO2 NPs exhibited better photocatalytic activity and excellent recycling stability over several photodegradation cycles. Furthermore, the present method has a great perspective to be used as an efficient method for large-scale synthesis of TiO2 NPs.

Carbon dots, very tiny carbon material with various surface passivations, have emerged as a new class of nanomaterials for various applications. Herein, we describe a simple, economical, and green approach for the synthesis of colloidal luminescent carbon dots (C-dots) by solvothermal method from fruit juice of Citrus limetta, an abundantly available plant in Asian countries. The existence of C-dots was confirmed by X-ray Diffraction and High Resolution Transmission Electron Microscopy studies. The C-dots size was observed to be 2-4 nm. We further evaluated the efficacy of C-dots to inhibit the attachment of Candida albicans MTCC 227, and biofilm formation on the polystyrene surfaces. The C-dots have effectively inhibited the attachment and formation of biofilm in Candida albicans at very low concentrations, which is hitherto unattempted. The ability of C-dots to inhibit biofilm formation may contribute to diverse applications of C-dots in biomedical field.

The preparation of nanostructured hierarchical Mn1−xNixCo2O4 metal oxides as efficient supercapacitors of different structures and configurations especially for the miniaturized electronics is still a challenge. In this context, we report template free facile hydrothermal synthesis of hierarchical nanostructured Mn1−xNixCo2O4 with excellent supercapacitive performance. Significantly, the morphology of pure MnCo2O4 transformed from 3D microcubes to 1D nanowires with incorporation of Ni. The electrochemical study shows highest specific capacitance i.e. 1762 F/g for Mn0.4Ni0.6Co2O4 with high cycling stability of 89.2% which is much higher than pristine MnCo2O4 and NiCo2O4. Later, asymmetric capacitor has been fabricated successfully using Mn0.4Ni0.6Co2O4 nanowires as positive electrode and activated carbon (AC) as negative electrode in a KOH aqueous electrolyte. An asymmetric cell could be cycled reversibly in the high-voltage range of 0–1.5 V and displays intriguing performances with a specific capacitance of 112.8 F/g (6.87 F/cm3) and high energy density of 35.2 Wh/kg (2.1 mWh/cm3). Importantly, this asymmetric capacitor device exhibits an excellent long cycle life along with 83.2% specific capacitance retained after 2000 cycles.