An efficient manner to produce strained atomic structures, is fabricating catalysts with defect-rich atomic structures, including surface defects (such as surface vacancy, doping,) and bulk defects (such as dislocations and grain boundary). [3] Traditional methods to synthesize strain-effected structures, including polyol synthesis, seed-mediated growth, galvanic replacement, electrochemical dealloying, and thermal annealing-induced segregation, [2i,4] are complex and time-consuming processes, which hinder the manufacturing efficiency and limit the wide application of strain-effected catalysts. In addition, strain-induced high-energy surface structures arising from bulk defects, such as dislocations or grain boundary, are more likely to be resistant to surface restructuring during catalysis. [5] It is generally accepted that non-equilibrium conditions tend to induce plentiful defects, so we seek to employ a synthesis method in an extreme environment to realize bulk-defect-strained structures of electrocatalysts. Recently, our group developed a thermal shock nanomanufacturing method which showed enormous potential and achieved great progresses in ultrafast fabrication of nanoparticles, nanowires, graphene, and more. [6] Since the thermal shock process was invented, the method has been widely used in nanomaterials production. [6a-e,7] However, few studies focused on how Designing high-performance and low-cost electrocatalysts is crucial for the electrochemical production of hydrogen. Dislocation-strained IrNi nanoparticles loaded on a carbon nanotube sponge (DSIrNi@CNTS) driven by unsteady thermal shock in an extreme environment are reported here as a highly efficient hydrogen evolution reaction (HER) catalyst. Experimental results demonstrate that numerous dislocations are kinetically trapped in self-assembled IrNi nanoparticles due to the ultrafast quenching and different atomic radii, which can induce strain effects into the IrNi nanoparticles. Such strain-induced highenergy surface structures arising from bulk defects (dislocations), are more likely to be resistant to surface restructuring during catalysis. The catalyst exhibits outstanding HER activity with only 17 mV overpotential to achieve 10 mA cm −2 in an alkaline electrolyte with fabulous stability, exceeding state-of-the-art Pt/C catalysts. These density functional theory results demonstrate that the electronic structure of as-synthesized IrNi nanostructure can be optimized by the strain effects induced by the dislocations, and the free energy of HER can be tuned toward the optimal region. Hydrogen, as a clean energy source with a high energy density, opens up the opportunities of renewable energy and traditional fossil energy, increasing the diversification of energy sources. [1] Nevertheless, the improvement of hydrogen production is limited toward overpotential and stability due to the intrinsically sluggish kinetics of the hydrogen evolution reaction (HER). Strain engineering, which can optimize the electronic structure and chemical activity of the ...

Development of efficient non-precious catalysts for seawater electrolysis is of great significance but challenging due to the sluggish kinetics of oxygen evolution reaction (OER) and the impairment of chlorine electrochemistry at anode. Herein, we report a heterostructure of Ni 3 S 2 nanoarray with secondary Fe-Ni(OH) 2 lamellar edges that exposes abundant active sites towards seawater oxidation. The resultant Fe-Ni(OH) 2 /Ni 3 S 2 nanoarray works directly as a free-standing anodic electrode in alkaline artificial seawater. It only requires an overpotential of 269 mV to afford a current density of 10 mA•cm −2 and the Tafel slope is as low as 46 mV•dec −1. The 27-hour chronopotentiometry operated at high current density of 100 mA•cm −2 shows negligible deterioration, suggesting good stability of the Fe-Ni(OH) 2 /Ni 3 S 2 @NF electrode. Faraday efficiency for oxygen evolution is up to ~ 95%, revealing decent selectivity of the catalyst in saline water. Such desirable catalytic performance could be benefitted from the introduction of Fe activator and the heterostructure that offers massive active and selective sites. The density functional theory (DFT) calculations indicate that the OER has lower theoretical overpotential than Cl 2 evolution reaction in Fe sites, which is contrary to that of Ni sites. The experimental and theoretical study provides a strong support for the rational design of high-performance Fe-based electrodes for industrial seawater electrolysis.

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Low molecular weight alcohols, such as ethanol, are clean, economical and sustainable energy sources which can be easily obtained, stored, and transported. [1] At present, the platinum-based noble metal catalysts are considered as highly efficient electrocatalysts for alkaline alcohols oxidation reactions. [4-6] Nevertheless, vulnerable CO poisoning effect, sluggish kinetics of anodic oxidation as well as high price of noble metal catalysts seriously hampered their development. Therefore, the research interests in developing high efficiency and low cost anodic electrocatalysts are activated to facilitate the largescale commercialization of fuel cell in the future. Non-noble metal materials which have made great progress to date are regarded as suitable and promising alternative electrocatalysts for alcohols electrooxidation. [7-9] Among them, nickel-based materials have been introduced as a kind of active electrocatalysts in the oxidation of methanol and other alcohols. [10-13] Despite considerable progress, the high onset potential and the inferior catalytic activity for alcohols electrooxidation severely hinder the further applications of nickelbased materials. In this case, it is necessary to design catalysts Construction of active and durable non-noble-metals based electrocatalysts is one of important requirements for the practical application and development of fuel cells, which are presently inhibited by relative sluggish charge transport and reaction kinetics. Herein, highly dispersed ultrathin carbon-coated nickel oxide nanoparticles settled on carbon cloth (NiO@C/CC) as efficient catalysts for alkaline fuels oxidation are synthesized via an air-assisted transient thermal shock strategy. This NiO@C/CC catalyst induces an outstanding catalytic activity (up to 119.1 mA cm −2) and durability (a little current decay during tests) in electrooxidation for ethanol, even for methanol and ethylene glycol, which outperforms most of the reported non-noble metal catalysts. The excellent catalytic performance of NiO@C/CC is essentially attributed to the oxygen vacancies, high concentration, high-valence-state Ni, and carbon layers of NiO@C NPs, which contribute to regulate the surface properties and electronic structure, enhance charge transfer, and provide abundant active sites, promoting adsorption capacity of reactant molecules on its surface. The facile and promising air-assisted transient thermal shock strategy can be extended to guide rational design and rapid synthesis of transition metal compounds as advanced catalysts for alkaline direct alcohol fuel cells.

Crystal structure engineering of nanomaterials is crucial for the design of electrocatalysts. Inducing dislocations is an efficient approach to generate strain effects in nanomaterials to optimize the crystal and electronic structures and improve the catalytic properties. However, it is almost impossible to produce and retain dislocations in commercial mainstream catalysts, such as single metal platinum (Pt) catalysts. In this work, a non‐equilibrium high‐temperature (>1400 K) thermal‐shock method is reported to induce rich dislocations in Pt nanocrystals (Dr‐Pt). The method is performed in an extreme environment (≈77 K) created by liquid nitrogen. The dislocations induced within milliseconds by thermal and structural stress during the crystallization process are kinetically frozen at an ultrafast cooling rate. The high‐energy surface structures with dislocation‐induced strain effects can prevent surface restructuring during catalysis. The findings indicate that a novel extreme environmental high‐temperature thermal‐shock method can successfully introduce rich dislocations in Pt nanoparticles and significantly boost its hydrogen evolution reaction performance.