Synthesis, Characterization, and Supercapacitor Performance of a Mixed-Phase Mn-Doped MoS2 Nanoflower.

The fascinating features of 2D nanomaterials for various applications have prompted increasing research into single and few-layer metal dichalcogenides nanosheets using improved nanofabrication and characterization techniques. MoS2 has recently been intensively examined among layered metal dichalcogenides and other diverse transition metal-based materials, that have previously been studied in various applications. In this research, we report mixed-phase Mn-doped MoS2 nanoflowers for supercapacitor performance studies. The confirmation of the successfully prepared Mn-doped MoS2 nanoflowers was characterized by XRD, SEM-EDS, RAMAN, and BET research techniques. The mixed-phase of the as-synthesized electrode material was confirmed by the structural changes observed in the XRD and RAMAN studies. The surface area from the BET measurement was calculated to be 46.0628 m2/g, and the adsorption average pore size of the electrode material was 11.26607 nm. The electrochemical performance of the Mn-doped MoS2 electrode material showed a pseudo-capacitive behavior, with a specific capacitance of 70.37 Fg-1, and with a corresponding energy density of 3.14 Whkg-1 and a power density of 4346.35 Wkg-1. The performance of this metal-doped MoS2-based supercapacitor device can be attributed to its mixed phase, which requires further optimization in future works.

Fluorescent carbon nanoparticles from Citrus sinensis as efficient sorbents for pollutant dyes.

Here, we report a simple, green and economic process for the synthesis of highly fluorescent carbon nanoparticles (CPs) through low-temperature carbonization of a fruit waste, Citrus sinensis peel. This approach allows the large-scale production of aqueous CPs dispersions without any additives and post-treatment processes. The as-prepared CPs were of small particle size, exhibited bright blue fluorescence under UV irradiation (λmax  = 365 nm) with excellent colloidal stability in water. The chemical composition, structure and morphology of the as-prepared CPs were analyzed using various spectroscopic techniques such as X-ray diffraction, transmission electron microscopy and raman spectroscopy. The formed CPs were turbostratic in nature, with a large number of functional groups on the surface. We explored the adsorption characteristics of the formed CPs for wastewater treatment. Because of the negative surface of the CPs, as evident from the zeta value, it is possible to use them for selective adsorption of the cationic dye methylene blue from a mixture of dyes. The equilibrium adsorption isotherm revealed that the Langmuir model better describes the adsorption process than the Freundlich model. As-prepared CPs rapidly adsorbed ~84% of the methylene blue within 1 min and can be regenerated and used repeatedly. Copyright © 2016 John Wiley & Sons, Ltd.