Preparation And Electrochemical Performance Of Ruthenium-Doped Transition Metal Oxide Nanosheet Catalysts

As one of the most promising green energy sources in the 21st century,hydrogen has many advantages such as high calorific value of combustion and no pollution of products.The advantages of hydrogen production from electrolyzed water are environmentally friendly,renewable,efficient and flexible,which can be applied to energy systems of various scales,and is a potential renewable energy hydrogen production technology.In order to improve the efficiency of hydrogen production and reduce the cost of hydrogen production,it is essential to develop a cheap,efficient and stable catalyst.At present,we can roughly divide into precious metal catalysts and non-precious metal catalysts.Among them,precious metals refer to platinum metals(Pt,Ru,Ir,Rh,etc.),which are characterized by strong catalytic activity,but their high cost and scarce stock greatly limit their large-scale application.Non-noble metal catalysts,such as transition metal oxide catalysts,have abundant reserves and low prices,but low catalytic activity.A common and effective strategy is to incorporate small amounts of precious metals into non-noble catalysts to increase catalytic activity and keep costs low.Pt-based catalysts stand out among all electrocatalysts due to their excellent catalytic properties,but are limited in large-scale utilization due to their scarcity and high cost,thus promoting the development of inexpensive alternatives with high activity and durability.Ruthenium(Ru)has a hydrogen bond strength similar to platinum(Pt),and the price is only 4%of Pt,which is gradually attracting the attention of more and more researchers.At present,various structural design and engineering strategies have been reported for the study of highly active Ru-based catalysts,and heteroatom doping is widely used as an auxiliary control strategy,which can effectively adjust the structural electron cloud of the target product and induce lattice distortion,greatly improving the active state of the atoms in the material and bringing more HER active centers.In addition,twodimensional nanosheets are able to carry more active material due to their larger specific surface area,which facilitates rapid electrocatalytic reaction kinetics.Adjusting the morphology of catalysts by changing the preparation conditions and methods is also a commonly used strategy to improve the performance of catalysts.In this project,a series of two-dimensional nanosheet catalysts were synthesized by doping ruthenium into transition metal oxides(Fe,Co,Ni)through a simple rapid heating strategy.In 1 M KOH solution,the prepared Ru/Fe2O3 nanosheet catalysts exhibited low catalytic activity,while Ru/NiO and Ru/Co3O4 nanosheets showed high catalytic activity,and their overpotentials at 10 mA cm-2 current density were 30.6 mV and 28.8 mV,respectively,which were better than commercial Pt/C(30.8 mV),and the stability performance of Ru/Co3O4 nanosheets is much better than that of commercial Pt/C,too.