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Supercapacitors suffer either from low capacitance for carbon or derivate electrodes or from poor electrical conductivity and electrochemical stability for metal oxide or conducting polymer electrodes. Transition metal nitrides possess fair electrical conductivity but superior chemical stability, which may be desirable candidates for supercapacitors. Herein, niobium nitride, Nb4N5, is explored to be an excellent capacitive material for the first time. An areal capacitance of 225.8 mF cm−2, with a reasonable rate capability (60.8% retention from 0.5 to 10 mA cm−2) and cycling stability (70.9% retention after 2000 cycles), is achieved in Nb4N5 nanochannels electrode with prominent electrical conductivity and electrochemical activity. Faradaic pseudocapacitance is confirmed by the mechanistic studies, deriving from the proton incorporation/chemisorption reaction owing to the copious +5 valence Nb ions in Nb4N5. Moreover, this Nb4N5 nanochannels electrode with an ultrathin carbon coating exhibits nearly 100% capacitance retention after 2000 CV cycles, which is an excellent cycling stability for metal nitride materials. Thus, the Nb4N5 nanochannels are qualified for a candidate for supercapacitors and other energy storage applications. [ABSTRACT FROM AUTHOR]

Abstract: To explore new series of high-T c superconductors, Cu-based ternary pnictides of SrCu2 Pn 2 (Pn=P, As, Sb) with La doping were synthesized at 1073K from the stoichiometric reaction of the elements. The electrical and magnetic properties as well as the electronic structure were systematically investigated. Absence of superconductive transition was observed over the temperature range from room temperature down to 2K, and these materials show p-type metal-like conductivity and Pauli paramagnetic behavior. The near E F bands mainly originate from Cu 3d and Pn np states and the value of total densities of states (DOS) becomes higher as Pn goes from P to Sb. The results provides us with considerable information for a better understanding of the transport properties in pnictides. [Copyright &y& Elsevier]

Abstract: Visible-light-responsive composite photocatalysts SnS2/TiO2 and SnS/TiO2 with different mass ratios were prepared by in-situ synthesis technology in solution with commercial TiO2. The junction-based materials SnSx (x=1, 2)/TiO2 were found to have high visible-light photocatalytic performance and possess much better activity than the single-phase SnS x or TiO2. The greatly enhanced photocatalytic activity of the SnS x /TiO2 composites was mainly attributed to the matching band potentials and efficient charge transfer and separation at the tight-bonding interface between SnS x and TiO2. The fact was confirmed by the comparison of photocatalytic activities of the SnS2/TiO2 samples prepared by physical mixing method and in-situ synthesis technique. [Copyright &y& Elsevier]

Hexagonal phase ZnIn2S4 nanocrystalline thin films are deposited by spin-coating method using an air-stable precursor solution. In the process, metal oxide and hydroxide are used as Zn and In sources to avoid the introduction of any anion impurity in ZnIn2S4 thin films. The rod-like nanocrystalline grains with width and length about 13 ± 3 nm and 26 ± 5 nm grow along c-axis after annealing in sulfur vapor at 500 °C for 2 h. Smooth and compact thin films with different In/Zn ratios are fabricated by controlling the ratio of two metal sources in precursor solution. The flat-band potentials of these n-type ZnIn2S4 thin films are in the range of −0.55 to −0.45 V vs. normal hydrogen electrode. The photoelectrochemical measurement demonstrates the excellent visible light response of ZnIn2S4 thin films. The light current under visible light illumination occupies almost 60% of the light current under full spectrum illumination. The facile solution-based method provides a novel thought to fabricate high-quality thin films of multi metal chalcogenides with excellent photoelectric properties via solving the other metal oxide and hydroxide in the solution. [ABSTRACT FROM AUTHOR]

Supercapacitors suffer either from low capacitance for carbon or derivate electrodes or from poor electrical conductivity and electrochemical stability for metal oxide or conducting polymer electrodes. Transition metal nitrides possess fair electrical conductivity but superior chemical stability, which may be desirable candidates for supercapacitors. Herein, niobium nitride, Nb 4 N 5 , is explored to be an excellent capacitive material for the first time. An areal capacitance of 225.8 mF cm -2 , with a reasonable rate capability (60.8% retention from 0.5 to 10 mA cm -2 ) and cycling stability (70.9% retention after 2000 cycles), is achieved in Nb 4 N 5 nanochannels electrode with prominent electrical conductivity and electrochemical activity. Faradaic pseudocapacitance is confirmed by the mechanistic studies, deriving from the proton incorporation/chemisorption reaction owing to the copious +5 valence Nb ions in Nb 4 N 5 . Moreover, this Nb 4 N 5 nanochannels electrode with an ultrathin carbon coating exhibits nearly 100% capacitance retention after 2000 CV cycles, which is an excellent cycling stability for metal nitride materials. Thus, the Nb 4 N 5 nanochannels are qualified for a candidate for supercapacitors and other energy storage applications.