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In the recent years, phase transitions in MoS2 from 2H to 1T has gained considerable research interest that finds significant technological applications. This paper describes the development of active 1T MoS2 exhibiting metallic behavior from the semiconducting 2H MoS2 by simple two-step hydrothermal method without adding any additional atoms. This strain induced synthesis method allows the modification of the crystal phase and facilitate the electron transfer with reduced resistance of 89 Ω . We studied the formation of 1T MoS2 nanostructures using X-ray diffraction, spectroscopic and microscopic scientific tools. The metallic 1T phase is found to exhibit markedly high optoelectronic properties demonstrating an excitation wavelength dependent down-conversion and up-conversion photoluminescence. The large surface area, tunable bandgap, high electron mobility and increased active sites of 1T MoS2 elucidates a viable designing of optical photoluminescence ammonia sensing. Finally, we investigated the integration of 1T polymorph into an efficient electrocatalytic hydrogen evolution system to compare their catalytic activity with that of 2H MoS2. 1T MoS2 is found to exhibit a low onset potential of 240 mV vs RHE than the 2H phase with a comparatively high onset potential of 550 mV vs RHE. The superior activity of 1T MoS2 owing to the abundant catalytic edge sites are critical for global production of clean and renewable energy sources. [ABSTRACT FROM AUTHOR]

A random copolymer of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and N-hydroxymethyl acrylamide (NHMA) was prepared by solution polymerization using ceric ammonium nitrate as an initiator. A grade of poly(AMPS)- co-poly(NHMA) (PAMPS- co-PNHMA) random copolymer was synthesized with AMPS and NHMA. The homopolymerization of AMPS and NHMA was also carried out by the same way as that of random copolymer. PAMPS- co-PNHMA and homopolymers of AMPS and NHMA were characterized by FTIR, rheology, FT-NMR, scanning electron microscope, thermal analysis, and X-ray diffaractometry. Cyclic voltammetry is used to explain the ion exchange properties of PAMPS- co-PNHMA and its possible application in the trace analysis. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

Due to exceptional electronic, optoelectronic and catalytic properties, MoS 2 has attracted extensive research interest in various applications. In the present scenario, the exploitation of noble-metal-free catalysts for hydrogen evolution is of great interest. Herein, we report the structural, optical, magnetic and electrocatalytic properties of pure and nickel-substituted MoS 2 nanostructures synthesized by the hydrothermal method. X-ray diffraction (XRD) analysis reveals that all samples exhibit the hexagonal structure of MoS 2 and the formation of NiS 2 at higher concentrations of nickel. Vibrating sample magnetometer (VSM) measurements of the Mo 1- x Ni x S 2 nanostructures show a hysteresis loop at room temperature with a higher saturation magnetization for 1% Ni-substituted MoS 2 nanostructures, confirming the ferromagnetic behaviour of the sample. The indirect-to-direct band gap transition of few-layered nanostructures was confirmed by the optical absorption spectrum showing bands in the 600-700 nm and 350-450 nm regions. This study also highlights the excitation wavelength-dependent down- and up-conversion photoluminescence of the as-synthesized samples, providing new horizons for the design of MoS 2 -based optical and spintronic devices. The electrocatalytic effect of 3% Ni-substituted MoS 2 nanostructures has been found to be higher than that of other deposit concentrations as it corresponds to the efficient hydrogen evolution reaction (HER)., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)