The development of highly active and durable inexpensive electrocatalysts for hydrogen evolution reaction (HER) is still a formidable challenge. Herein, an ordered hexagonal-closed-packed (hcp)-Ru nanocrystal coated with a thin layer of N-doped carbon (hcp-Ru@NC) was fabricated through the thermal annealing of polydopamine (PDA)-coated Ru nanoparticle (RuNP@PDA). As an alternative to Pt/C catalyst, the hcp-Ru@NC nanocatalyst exhibited the small overpotential of 27.5 mV at a current density of 10 mA cm −2 , as well as long-term stability for HER in acid media. Interestingly, the HER performance of hcp-Ru is highly dependent on its crystallinity. The calculation from density functional theory (DFT) revealed that the difference in HER activity over various exposed surface causes the crystallinity-dependent property of hcp-Ru. The results provided clues to guide the design of Ru-based inexpensive HER electrocatalyst.

3D N-doped graphene crosslinked by covalent bonds is fabricated through thermal treatment of graphene oxide with a nitrogen-contained resin. The material possesses a hierarchical porous architecture, robust mechanical stability, and abundant N-doped properties. As an electrode material for supercapacitors, this multifunctional material exhibits an unprecedented specific capacitance, high rate capability, and excellent long-term cycle stability.

Layer double hydroxide (LDH) has been widely applied to electrocatalysis, especially toward the oxygen evolution reaction (OER), owing to its flexible layered structure and multifunctionality. Herein, FeNi LDH nanosheet arrays are directly synthesized on various metal foils by a facile hydrothermal method. Compared with single Fe or Ni substrates, the obtained FeNi LDH/ FeNi foil exhibited an ultrasmall onset overpotential of ∼90 mV, high catalytic activity (overpotential of 130 mV @ 10 mA/cm 2 ), and durable stability in 0.1 M KOH electrolyte. We also demonstrate, by utilizing density functional theory calculations, that the growth of the hydroxide interfacial layer between LDH and FeNi foil makes the LDH possess more favorable adsorption to the OH intermediate during OER than the pure LDH. This reveals that the vertical FeNi LDH arrays on the FeNi alloy substrate are prone to be an efficient catalyst toward OER.

Cuprous oxide (Cu(2)O) nanoparticles dispersed on reduced graphene oxide (RGO) were prepared by reducing copper acetate supported on graphite oxide using diethylene glycol as both solvent and reducing agent. The Cu(2)O/RGO composite exhibits excellent catalytic activity and remarkable tolerance to methanol and CO in the oxygen reduction reaction.

Oxygen reduction reaction (ORR) is of paramount importance in polymer electrolyte membrane fuel cells due to its sluggish kinetics. In this work, a plasmon-induced hot electrons enhancement method is introduced to enhance ORR property of the silver (Ag)-based electrocatalysts. Three types of Ag nanostructures with differently localized surface plasmon resonances have been used as electrocatalysts. The thermal effect of plasmonic-enhanced ORR can be minimized in our work by using graphene as the support of Ag nanoparticles. By tuning the resonance positions and laser power, the enhancement of ORR properties of Ag catalysts has been optimized. Among these catalysts, Ag nanotriangles after excitation show the highest mass activity and reach 0.086 mA/μgAg at 0.8 V, which is almost 17 times that of a commercial Pt/C catalyst after the price is accounted. Our results demonstrate that the hot electrons generated from surface plasmon resonance can be utilized for electrochemical reaction, and tuning the resonance positions by light is a promising and viable approach to boost electrochemical reactions.

A new catalyst, P-3G simultaneously exhibited outstanding multifunctional catalytic activities for the ORR, OER, and HER. The synergistic effects between perovskite oxides and 3DNG was firstly proposed by DFT calculations.

Fabricating perovskite oxide/carbon material composite catalysts is a widely accepted strategy to enhance oxygen reduction reaction/oxygen evolution reaction (ORR and OER) catalytic activities. Herein, synthesized, porous, perovskite-type Sm Sr CoO hollow nanofibers (SSC-HF) are hybridized with cross-linked, 3D, N-doped graphene (3DNG). This rationally designed hybrid catalyst, SSC-HF-3DNG (SSC-HG), exhibits a remarkable enhancement in ORR/OER activity in alkaline media. The synergistic effects between SSC and 3DNG during their ORR and OER processes are firstly revealed by density functional theory calculations. It suggests that electron transport from 3DNG to O and SSC increases the activity of electrocatalytic reactions (ORR and OER) by activating O , increasing the covalent bonding of lattice oxygen. This electron transfer-accelerated catalysis behavior in SSC-HG will provide design guidelines for composites of perovskite and carbon with bifunctional catalysts.

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