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Hydrogen production via water splitting has been extensively explored over the past few decades, and considerable effort has been directed toward finding more reactive and cost-effective electrocatalysts by engineering their compositions, shapes, and crystal structures. In this study, we developed hierarchical cobalt phosphide (Co-P) nanosphere assemblies as non-noble metal electrocatalysts via one-step electrodeposition. The morphologies of the Co-P nanostructures and their electrocatalytic activities towards the hydrogen evolution reactions (HER) were controlled by the applied potentials during electrodeposition. The physicochemical properties of the as-prepared Co-P nanostructures in this study were characterized by field-emission scanning electron microscopy, X-ray photoemission spectroscopy and X-ray diffraction. Linear sweep voltammetry revealed that the Co-P grown at −0.9 V showed the best HER performance exhibiting the highest electrochemical active surface area and lowest interfacial charge transfer resistance. The Co-P electrocatalysts showed superior long-term stability to electrodeposited Pt, indicating their potential benefits. [ABSTRACT FROM AUTHOR]

Carbon capture, utilization and storage techniques have been studied extensively to reduce atmospheric carbon dioxide. However, CO2 conversion technologies are not widely proposed due to sluggish conversion rate, high energy consumption and need for precious metals as catalysts. Therefore, novel metal‐CO2 electrochemical cell has been proposed to utilize CO2 to produce electricity and H2 gas continuously. Electrochemical hydrogen evolution reaction under neutral condition has demanded the overall device performance. Herein, we have developed non‐precious NiMo‐carbon nanofiber‐based catalyst with unique matchstick‐like morphology using low temperature CVD technique and demonstrated in aqueous Zn−CO2 system. The NiMo alloy offers excellent activity by promoting hydrogen adsorption/desorption and chemically bonded carbon nanofiber assists catalytic activity by providing charge transfer. Due to superior characteristics, NiMo‐carbon nanofiber exhibits significant HER activity (over‐potential of 268 mV at 10 mA cm‐2) in CO2‐saturated 1 M KOH and superior cell performance in aqueous Zn−CO2 system (peak power density of 25 mW cm−2). In addition, the stability of the catalysts has also been investigated using chronopotentiometry and the results have compared with commercial Pt/C catalysts. We are hopeful that the present study will provide insights into developing non‐precious electrocatalysts, particularly for metal‐CO2 electrochemical conversion devices. [ABSTRACT FROM AUTHOR]

The advancement of cost‐effective, efficient, and durable catalysts to replace high cost Pt‐based electrocatalysts are of recent interest, especially to enhance the sluggish oxygen reduction reaction (ORR) in fuel cells and metal−air batteries. Herein, we report self‐assembled Co−Ni based nitrogen doped carbon structures (Co−Ni/NC) derived from zeolitic imidazolate frameworks as a highly efficient and durable ORR catalyst for rechargeable zinc−air batteries (ZAB). An effective three‐phase boundary is recognised with a well‐organized interconnected porous carbon framework of the Co−Ni/NC catalyst. The developed catalyst exhibited much improved onset and half‐wave potentials (0.93 V and 0.86 V vs. RHE, respectively) in alkaline electrolyte, especially in the limiting current region, which was credited to the porous structure. Furthermore, excellent durability was found for the catalyst operated using continuous potential cycles for 5,000 times and chronoamperometric measurements for 50 h. Finally, the optimised Co−Ni/NC catalyst was successfully utilised as a cathode catalyst and delivered substantial power density in ZAB configuration under ambient operating conditions. Substantial battery durability was also observed over 1000 h by periodically replacing the anodic zinc electrode. Hence, the present investigation offers the prospect of the development of new non‐precious, highly active, and durable oxygen reduction catalysts for zinc air battery applications. Self‐assembled Co−Ni particles embedded in nitrogen doped carbon structures derived from zeolitic imidazolate frameworks (Co−Ni/NC) are synthesised as durable catalysts for the oxygen reduction reaction (ORR) in rechargeable zinc‐air batteries. The effect of Ni concentration in the catalyst on ORR activity is analyzed and the optimised catalyst delivers a peak power density of 199 mW cm−2 at a load current density of 207 mA cm−2. [ABSTRACT FROM AUTHOR]

Abstract: Development of cost‐effective and efficient electrocatalysts for the oxygen reduction reaction (ORR) is one of the most important topics in the polymer electrolyte membrane fuel cells (PEMFCs). Herein, we suggested the enhanced electrochemical catalyst with nanoscale platinum anchored on iron (Fe) and nitrogen (N) co‐doped graphene nanoplatelets (Pt/FeN‐GnPs) with low content of Pt. The nanoscale platinum particles are uniformly anchored on the surface of FeN‐GnPs and result in excellent oxygen reduction activity and stability in acidic media. The fascinating interaction between Pt particles and FeN−GnPs substrate contributed to advanced oxygen reduction activity, outstanding cell performance, and remarkable high stability for acidic PEM fuel cells. [ABSTRACT FROM AUTHOR]

The Cover Feature illustrates the morphology of the binder‐free electrode (bf‐PPy+Co3O4@CF) and its reactions in seawater. The binder‐free (bf) air electrode is structured with Co oxide (Co3O4) anchored on carbon fiber (CF) tissues with the assistance of polypyrrole‐doped carbon (PPy/C) by using a simple infiltration technique. The bf‐PPy+Co3O4@CF electrode exhibits excellent bifunctional stability for seawater batteries, presenting a comparable performance to the binder‐included Pt/C+IrO2 electrode. More information can be found in the Article by G. Kim and co‐workers on page 136 in Issue 1, 2019 (DOI: 10.1002/celc.201801219). [ABSTRACT FROM AUTHOR]