Gallium Nitride Based Electrode for High-Temperature Supercapacitors.

Gallium nitride (GaN) single crystal, as the representative of wide-band semiconductors, has great prospects for high-temperature energy storage, of its splendid power output, robust temperature stability, and superior carrier mobility. Nonetheless, it is an essential challenge for GaN-based devices to improve energy storage. Herein, an innovative strategy is proposed by constructing GaN/Nickel cobalt oxygen (NiCoO2  ï¼‰heterostructure for enhanced supercapacitors (SCs). Benefiting from the synergy effect between the porous GaN network as a highly conductive skeleton and the NiCoO2 with massive active sites. The GaN/NiCoO2 heterostructure-based SCs with ion liquids electrolyte are assembled and delivered an impressive energy density of 15.2 µWh cm-2 and power density, as well as superior service life at 130 °C. The theoretical calculation further explains that the reason for the energy storage enhancement of the GaN/NiCoO2 is due to the presence of the built-in electric fields. This work offers a novel perspective for meeting the practical application of GaN-based energy storage devices with exceptional performance capable of operation under high-temperature environments.

Selenium-rich yeast counteracts the inhibitory effect of nanoaluminum on the formation of porcine neutrophil extracellular traps.

Aluminum is widely used in daily life due to its excellent properties. However, aluminum exposure to the environment severely threatens animal and human health. Conversely, selenium (Se) contributes to maintaining the balance of the immune system. Neutrophils exert immune actions in several ways, including neutrophil extracellular traps (NETs) that localize and capture exogenous substances. Despite the recent investigations on the toxic effects of aluminum and its molecular mechanisms, the immunotoxicity of aluminum nanoparticles on pigs and the antagonistic effect of selenium on aluminum toxicity are poorly understood. Here, we treated porcine peripheral blood neutrophils with zymosan for 3 h to induce NETs formation. Then, we investigated the effect of nanoaluminum on NETs formation in pigs and its possible molecular mechanisms. Microscopy observations revealed that NETs formation was inhibited by nanoaluminum. Using a multifunctional microplate reader, the production of extracellular DNA and the burst of reactive oxygen species (ROS) in porcine neutrophils were inhibited by nanoaluminum. Western blot analyses showed that nanoaluminum caused changes in amounts of cellular selenoproteins. After Se supplementation, the production of porcine NETs, the burst of ROS, and selenoprotein levels were restored. This study indicated that nanoaluminum inhibited the zymosan-induced burst of ROS and release of NETs from porcine neutrophils, possibly through the selenoprotein signaling pathway. In contrast, Se supplementation reduced the toxic effects of nanoaluminum and restored NETs formation.

Regulating Phase Conversion from Ni3 Se2 into NiSe in a Bifunctional Electrocatalyst for Overall Water-Splitting Enhancement.

Phase engineering has been demonstrated as an efficient method for the enhancement of catalytic activity. This study concerns the phase and morphology modulation of Ni3 Se2 /NiSe nanorod arrays through a hydrothermal process. Partial phase conversion can effectively enhance the electrical conductivity and yield more active sites through atom rearrangement during phase transformation. Quite low optimal overpotentials of 166 mV for the hydrogen evolution reaction (HER) and 370 mV for the oxygen evolution reaction (OER) are obtained in a sample containing 32.4 % of NiSe phase and 67.6 % of Ni3 Se2 phase. The performance is superior to the samples with only one phase. Furthermore, a water electrolyzer was assembled by using two symmetrical NiSe/Ni foam electrodes as the anode and cathode, which can deliver 10 mA cm-2 at a low voltage of 1.61 V. More significantly, the water electrolyzer can be operated at 10 mA cm-2 over 10 h without noticeable degradation, showing extraordinary operational stability. This phase conversion control strategy provides a new way to improve the catalytic activity of NiSe and may have potential use in the design of other selenide electrocatalysts.