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Porous Ni electrodes with different textures have been fabricated by a facile electro-deposition method. The additives ammonium chloride (NH4Cl) and ammonium sulfate ((NH4)2SO4) in supporting electrolytes play a vital role in the texture of porous electrodes. Porous Ni electrodes prepared with the NH4Cl additive present a (111) plane preferred orientation. However, with the additive (NH4)2SO4, as its concentration increases, the preferred orientation changes from the (111) plane to the (200) plane. In addition, we studied the texture of the porous Ni electrodes and their influence on the hydrogen evolution reaction (HER) and sodium borohydride (NaBH4) electrooxidation. Porous Ni electrodes with the (111) preferential orientation promote the electrooxidation of NaBH4. Meanwhile, optimum catalytic activity can be obtained when both the (111) and (220) planes are preferentially oriented. In contrast, porous Ni electrodes with the (200) preferential orientation facilitate NaBH4 hydrolysis. Interestingly, the porous Ni electrode with both the (200) and (220) preferential orientations exhibits the best HER catalytic activity. This work provides new insights into the relationship between the texture and the electrocatalytic properties of porous Ni electrodes, which is desirable to design nickel electrodes more reasonably for HER or sodium borohydride electrooxidation. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries are strongly expected to be the next-generation energy storage technology due to their superior theoretical specific capacity and energy density. However, the low conductivity of sulfur and the discharge species (Li2S2, Li2S), the “shuttle” issue of soluble intermediates, and the large volume change hinder their further practical application. In this study, vanadium dioxide (VO2) was successfully grown on reduced graphene oxide (rGO) surface via a one-step rapid and facile solvothermal method, and named as the VO2@rGO binary host. In this structure, the VO2 nanoflakes displayed intensive chemical adsorption for polar lithium polysulfide species (LiPSs), accelerating the conversion of long-chain LiPSs to Li2S2/Li2S discharge products and thus suppressing the shuttling of soluble LiPSs. Additionally, rGO could ensure good electronic conductivity of the sulfur cathode and significantly enhanced the electrochemical reaction kinetics. Particularly, the VO2@rGO/S cathode demonstrated a high initial discharge capacity of 1358 mA h g−1 at 0.2C and retained a stable cycling performance with a reversible capacity of 1049 mA h g−1 over 370 cycles (low capacity decay of 0.06% per cycle). Such excellent performance revealed its good potential for use in advanced lithium–sulfur batteries. [ABSTRACT FROM AUTHOR]

Multi-layer black phosphorus (m-BP) has been successfully incorporated in zinc oxide (ZnO) hollow spheres, thus forming hetero-structured ZnO-BP composites; a study performed on their properties reveals that the BP environmental stability can be significantly enhanced by the introduction of ZnO, and the sensors based on ZnO-BP composites exhibit high response, fast response behavior, outstanding selectivity, and ultralow detection limit of 1 ppb towards NO 2 gas molecules. The ultrasensitive sensing performance is suggested to be due to the large surface area, excellent carrier mobility, and enhanced charge transfer of ZnO-BP in the presence of BP. Moreover, the mechanism of NO 2 sensing with ZnO-BP is confirmed by the calculations obtained from the first-principle studies.