Cu₂O@C Nanoparticles And Multi-metal Complex As Electrocatalysts For Oxygen Evolution Reaction

Nowadays,hydrogen production from the renewable energy sources,then stored as hydrogen energy,is being the trend of new energy research.Putting water as the source of hydrogen is a recyclable production method.Water will split into hydrogen and oxygen,which are used as fuels for energy supplying and then recombined to generate water.This cycle does not have any by-products and pollution links.So if the solar-drived water splitting would be achieved,it will be a kind of energy saving,efficient,cheap,large-scale hydrogen production technology.As a half-reaction of water splitting,water oxidation is the key step of the whole process of energy conversion,for the low speed and thermodynamic difficulty of water oxidation directly control and affect the process of water decomposition.Therefore,the development of high performance oxygen evolution catalysts is critical to dealing with the primary problem,at the same time,improving the development of hydrogen economy.In the case of oxygen evolution,the noble metal catalysts have the best catalytic activities,but their rare distribution and costly cost limit the large-scale industrial utilization of the noble metal catalysts.Therefore,the development of oxygen evolution catalysts should focus on the study of non-precious metals that are abundant on the planet.For this reason,this paper aims to develop the new non-precious metal catalysts,through a green and convenient method of synthesis,and obtain the efficient and stable electrocatalytic oxygen evolution catalysts.?1?Cu₂O@C nanoparticles were synthesized in situ by UV irradiation.This simple and inexpensive preparation method results the nanoparticles with good electrocatalytic activity and electrocatalytic stability.The overpotential is 330 mV at the current density of 10 mV·cm-2,and the Tafel slope is only 63 mV·dec-1.In studying the factors which affect the catalytic activity,the effects of different synthesis conditions on the activity were studied.The fundamental reason for the high catalytic activity is the promotion of the conductivity by the suitable carbon shell and the central cuprous oxide was protected by the suitable carbon shell.Our work provides the evidence about Cu₂O@C as a promising oxygen evolution catalyst,and it can also be extended to the development and preparation of other catalysts.?2?Through the simple method of solvent dissolution and substrate soaking,without any additional conditions,in situ on the substrate to form a kind of solid material.The initial electrochemical test of the material showed that when the element Ce added into Fe-/Co-/Ni-based catalytic system,the metal complex exhibits excellent electrochemical properties with an overpotential as low as 230 mV at a current density of 10mV·cm-2.And its stability is up to 85 hours.Experiments show that its stability may be more durable.Although the La element into the multi-metal system for oxygen evolution performance is inferior to the introduction of Ce,the overpotential is about 260 mV at a current density of 10mV·cm-2,but also showed a good activity comparable of traditional non-precious metal catalyst.This result shows that the system is a catalytic system with great potential for oxygen evolution.And the synthetic method is of green,convenient,non-polluting.This also provides a new way for the synthesis of catalysts in the future.