•Ni3B and Ni3B/C were prepared via a direct solution method.•Their catalytic performance for hydrolysis of ammonia borane was investigated.•Ni3B/C with 34.25 wt% Ni3B loading exhibited the highest catalytic activity.We report the preparation of Ni3B and carbon-supported Ni3B (denoted as Ni3B/C) nanoparticles, and their catalytic performance for hydrogen generation from hydrolytic dehydrogenation of ammonia borane (NH3BH3, AB). Ni3B and Ni3B/C were prepared via a chemical reduction and crystallization in tetraethylene glycol solution. The obtained Ni3B catalysts are in well-defined crystalline state and Ni3B/C catalysts have a high dispersion in the carbon. The hydrogen generation measurement shows that the carbon-supported Ni3B presents enhanced catalyst activity during hydrolytic dehydrogenation of AB. Among the as-prepared Ni3B/C catalysts, Ni3B/C with 34.25 wt% Ni3B loading displays the best catalytic activity, delivering a high hydrogen release rate of 1168 mL min−1 g−1 and the lower activation energy of 46.27 kJ mol−1. The kinetic results show that the hydrolysis is a first-order reaction in catalyst concentration, while it is a zero-order in AB concentration. Furthermore, the Ni3B/C is a recyclable catalyst under mild reaction conditions, indicating that the carbon-supported Ni3B is a promising catalyst for AB hydrolytic dehydrogenation.

In this paper, we report on the preparation of a Li2MnSiO4@C nanocomposite and its application as a high-capacity cathode material for rechargeable Li-ion batteries. Li2MnSiO4@C was synthesized via a hydrothermal-assisted solution route by using ascorbic acid as a carbon source and reductant. Based on the characterization by XRD, SEM, TEM, BET, elemental analysis and Raman analysis, it was found that the as-obtained homogenous Li2MnSiO4@C nanocomposite was composed of a Li2MnSiO4 core in a high-purity phase and a graphitized carbon shell. The electrochemical measurement results showed that Li2MnSiO4@C with an average particle size of 22.8 nm exhibited enhanced electrochemical properties, with initial discharge capacities of 281.5 mA h g−1 at 25 °C and 321.4 mA h g−1 at 45 °C, suggesting two lithium ions per formula unit.

We report on the synthesis of porous MnO2 hollow cubes via a microemulsion method and their application as new nanoscaffold materials to confine ammonia borane (AB) for enhancing the dehydrogenation process. Different loading levels of AB loaded in MnO2 are investigated. The results show that porous MnO2 hollow cubes have a high surface area of 297.9 m2/g and AB is uniformly loaded in the porous MnO2. It is also found that in the examined system, MnO2/AB with the mass ratio of 3:1 (3MnO2/AB) displays the best dehydrogenation properties. The onset temperature of the dehydrogenation of 3MnO2/AB sample is as low as 60 °C with the peak temperature at 97 °C, while the byproducts such as borazine, diborane and NH3 are completely suppressed. Furthermore, 3MnO2/AB sample can release about 0.9 equivalent H2 within 90 min at 85 °C. This study indicates that AB loaded in porous MnO2 is an effective approach in modifying the properties of AB with favorable dehydrogenation.Graphical abstractHighlights► Porous MnO2 hollow cubes have been synthesized. Different loading levels of AB loaded in MnO2 were considered. ► The dehydrogenation performance of the MnO2/AB system was investigated. ► MnO2/AB with the mass ratio of 3:1 showed the best dehydrogenation properties.

Chalcopyrite ternary CuInS2 semiconductor nanocrystals have been synthesized via a facile one-pot chemical approach by using oleylamine and oleic acid as solvents. The as-prepared CuInS2 nanocrystals have been characterized by instrumental analyses such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM)/high-resolution TEM (HRTEM), energy-dispersive X-ray spectroscopy (EDS), UV-vis absorption spectroscopy (UV-vis) and photoluminescence (PL) spectroscopy. The particle sizes of the CuInS2 nanocrystals could be tuned from 2 to 10 nm by simply varying reaction conditions. Oleylamine, which acted as both a reductant and an effective capping agent, plays an important role in the size-controlled synthesis of CuInS2 nanocrystals. Based on a series of comparative experiments under different reaction conditions, the probable formation mechanism of CuInS2 nanocrystals has been proposed. Furthermore, the UV-vis absorption and PL emission spectra of the chalcopyrite CuInS2 nanocrystals have been found to be adjustable in the range of 527–815 nm and 625–800 nm, respectively, indicating their potential application in photovoltaic devices.

In this paper, we report on the preparation of a Li2MnSiO4@C nanocomposite and its application as a high-capacity cathode material for rechargeable Li-ion batteries. Li2MnSiO4@C was synthesized via a hydrothermal-assisted solution route by using ascorbic acid as a carbon source and reductant. Based on the characterization by XRD, SEM, TEM, BET, elemental analysis and Raman analysis, it was found that the as-obtained homogenous Li2MnSiO4@C nanocomposite was composed of a Li2MnSiO4 core in a high-purity phase and a graphitized carbon shell. The electrochemical measurement results showed that Li2MnSiO4@C with an average particle size of 22.8 nm exhibited enhanced electrochemical properties, with initial discharge capacities of 281.5 mA h g−1 at 25 °C and 321.4 mA h g−1 at 45 °C, suggesting two lithium ions per formula unit.