A direct and effective approach is proposed to fabricate bimetallic phosphide Ni 2 P−Cu 3 P with controllable phase composition and distribution for catalytic hydrogen evolution reaction (HER). Unlike previously reported precursors, a porous Ni−Cu alloy incorporated with graphitic carbon (NiCuC) prepared via powder metallurgy is employed herein, and the generated Ni 2 P−Cu 3 P@NiCuC possesses a hierarchical porous structure and controllable phase composition due to the high porosity and tunable Ni/Cu ratio of the precursor. With an optimal Cu content of 30.0 wt %, the catalyst demonstrates the highest catalytic activity due to a synergistic interaction between different metallic phosphide sites and the facilitated mass transport. Meanwhile, density functional theory (DFT) calculation reveals that the atomic interaction of Ni 2 P− Cu 3 P substantially lower the activation barrier for enhanced HER catalytic activity. The powder metallurgy provides an approach for the design of bimetallic phosphide electrocatalysts for HER and other catalytic applications.

Ru/RuO2 composites with unique metal/metal oxide interface are proposed and work to pursue efficient HER performance in pH-universal media.

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Crystalline manganese oxides have attracted the most attention in aqueous zinc-ion batteries due to their diverse nanostructures and low cost. However, extensive studies on amorphous manganese oxides are lacking. Herein, we report a mesoporous amorphous manganese oxide (UCT-1-250) as a cathode material with high capacity (222 mAh g–1), good cyclability (57% capacity retention after 200 cycles), and an acceptable discharge plateau (between 1.2 and 1.4 V). An approach to mechanistic studies was performed by comparison of UCT-1-250 and other crystalline manganese oxides through electrochemical, elemental, and structural analyses. An in situ conversion to ZnMn2O4 spinel phase after initial cycling contributes to the high performance. The irreversible capacity fading is due to the formation of the woodruffite phase.

Electrocatalysis of water is a scalable and easily available source of the production of hydrogen (H2), the future energy carrier. This drive for clean energy inspired us to develop an inexpensive, readily producible, highly active, and stable catalyst to replace current state of the art platinum catalysts. Building on the promising hydrogen evolution reaction (HER) activity of many pyrites, their structural tuning by different metals and nonmetals has been found to be effective in several instances. We present here one such effort by partial surface selenization of mesoporous cobalt sulfide material, which displayed long-term operational stability (for at least 25 h) besides attaining a current density of 100 mA cm–2 at an overpotential of 160 mV versus the reversible hydrogen electrode (RHE) (in acidic media). A low Tafel slope (of 52 mV dec–1) and high exchange current density (j 0) (of 70 μA cm–2) make our catalyst better to most existing systems. More importantly, using a variety of analytical techniques, electrochemical measurements, and theoretical calculations, we have analyzed the morphology of the material and rationalized the key to the enhanced intrinsic activity (as compared to the meso-CoS2) per active site. This study is expected to explain similar systems and modify approaches to enhancing the electrochemical activity of metal chalcogenides.