Preparation And Electrochemical Properties Of Two-Dimensional Amorphous Ru-Based Alloy Catalysts

As an attractive technology for hydrogen production,electrochemical water splitting(EWS),including anodic oxygen evolution reaction(OER)and cathodic hydrogen evolution reaction(HER),depends largely on the availability of efficient electrocatalysts.Therefore,much effort has been devoted to developing various electrocatalysts with excellent performance and reduced cost in the past few years.Among them,ruthenium(Ru)-based materials for OER and HER are very promising due to their outstanding catalytic activity and the cheapest price in the noble metal family.Alloying noble metal ruthenium with transition metal elements has been a hot research topic in recent years.On the one hand,alloying can increase the density of active sites and form heteroatom bonds to optimize surface chemical and electronic properties,thereby triggering the redistribution of host metal charges to improve electrochemical performance.On the other hand,it can reduce the use of noble metals,thereby saving costs.From the perspective of morphology,twodimensional(2D)materials are also favored by researchers due to their large specific surface area,which can expose more atoms as active sites.From a structural point of view,studies have shown that amorphous materials generally have higher electrochemical activity than crystalline structured materials,because amorphous materials contain a large number of randomly oriented bonds,which make the surface of amorphous materials rich in coordination saturation site.The above all provide new inspiration for researchers to better explore effective electrochemical catalysts.Combining the above advantages,we propose a common approach to prepare amorphous noble metal alloy nanosheets as advanced bifunctional catalysts to drive the efficient electrochemical water splitting by rapidly annealing metal acetylacetonate(metal=Ru,Co,Fe,Ni)and alkali salts,which allows to optimize their catalytic properties by tuning the introduction of transition metals.Especially in alkaline electrolyte,when the current density was 10 mA cm-2,the as-prepared ternary alloy RuCoFe NSs showed a low overpotential of 180 mV for OER.Under the same conditions,it exhibited 2.04 mV for HER.In addition to the excellent electrochemical performance,it tests proved that RuCoFe NSs also have good stability.Furthermore,it achieves high performance and stable overall water splitting with a potential of only 1.56 eV.Considering the advantages of multimetal-amorphous nanosheet electrocatalysts,our proposed synthetic strategy is versatile and suitable for further development of other functional alloy nanomaterials for energy generation,storage,and conversion.