Search

A good bifunctional electrocatalyst can effectively drive water splitting to produce hydrogen gas. In this paper, NiMoO4an nanomaterial was prepared and combined with black phosphorus (BP) in a one-step method. Used as a bifunctional electrocatalyst, the composite demonstrated outstanding electrochemical performance with 162.7 mV and 137.6 mV achieving current densities of 20 mA cm−2 and 10 mA cm−2 for the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER), respectively. For overall water splitting, the potential was just 1.55 V to achieve 10 mA cm−2, and, especially, the value only rises by0.05 V after 2000 cycles of CV. Here, the one-step synthesis method favors the dispersion of NiMoO4 nanomaterial on the BP surfaces, and facilitates a combination between the nickel molybdate and the BP. Also, the excellent performance of the samples should benefit from the synergistic action between the components. [ABSTRACT FROM AUTHOR]

In this paper, α-Fe2O3 was prepared by hydrothermal and chemical precipitation methods, respectively, and its gas sensing properties toward CH4 were systematically studied. The larger specific surface area of the materials provided them potential and considerable gas adsorption abilities. The results of gas-sensing measurements indicated the synthesized α-Fe2O3 materials presented a p-type conductive nature. The sensitivities of the devices based on the different material fabrication methods were measured to be 195% and 214%, respectively, at 370°C for the concentration of 2000 ppm CH4. In addition, the sensing mechanism was discussed and simulated by first-principles calculation. The results revealed the higher surface adsorption energy of α-Fe2O3, which verified the experimental conclusions of our work. Our research suggests that α-Fe2O3 is a promising candidate for CH4 gas sensing in many fields such as mining safety and environmental monitoring. [ABSTRACT FROM AUTHOR]

Four different mediums have been developed for the synthesis of PbSe nanostructures, with different size and morphology. The particles were obtained in solid state medium with size of only 60 nm on average which are much smaller than those gained in liquid and molten state mediums. The growth mechanisms of these PbSe nanostructures were discussed. Results show that the state of medium have a direct impact on the size of PbSe nanostructures and the alkalinity of environment plays a key part in the formation of PbSe nanocubes. On the other hand, the electrochemical property of two typical nanostructures was studied. In the CV curves, there are four reaction peaks corresponding to oxidation of the PbSe and Pb(OH), and the reduction of PbO and Pb(OH). Otherwise, nanorods with size of only 60 nm have greater structural stability than nanocubes. [ABSTRACT FROM AUTHOR]