Metal-organic framework derived NiFe_(2)O_(4)/FeNi_(3)@C composite for efficient electrocatalytic oxygen evolution reaction

Reducing the cost and improving the electrocatalytic activity are the key to developing high efficiency electrocatalysts for oxygen evolution reaction(OER).Here,bimetallic NiFe-based metal-organic framework(MOF)was prepared by solvothermal method,and then used as precursor to prepare NiFe-based MOF-derived materials by pyrolysis.The effects of different metal ratios and pyrolysis temperatures on the sample structure and OER electrocatalytic performance were investigated and compared.The experimental results showed that when the metal molar ratio was Fe:Ni=1:5 and the pyrolysis temperature was 450℃,the sample(FeNi_(5)-MOF-450)exhibits a composite structure of Ni Fe_(2)O_(4)/FeNi_(3)/C and owns the superior electrocatalytic activity in OER.When the current density is 100 mA·cm^(-2),the overpotential of the sample was 377 mV with Tafel slope of 56.2 mV·dec^(-1),which indicates that FeNi_(5)-MOF-450 exhibits superior electrocatalytic performance than the commercial RuO_(2).Moreover,the long-term stability of FeNi_(5)-MOF-450 further promotes its development in OER.This work demonstrated that the regulatory methods such as component optimization can effectively improve the OER catalytic performance of NiFe-based MOF-derived materials.

Recent progress of two-dimensional metal-organic-frameworks:From synthesis to electrocatalytic oxygen evolution

High-performance electrocatalysts for oxygen evolution reaction(OER)are crucial for water splitting and metal-air batteries.Twodimensional(2D)metal-organic framework(MOF)has become a new class of efficient OER electrocatalysts due to the rich coordination unsaturated metal nodes,large specific surface area,and adjustable structures.In addition,because inheriting the original microstructure of MOFs and having stronger chemical and mechanical stability,metal/alloy/oxide,metal sulfide/selenide/phosphide,and other compounds derived from 2D MOFs have also shown their unique OER catalytic ability.Here,we briefly introduced the existing reaction mechanism and evaluation parameters of catalyst performance of OER,introduced the synthesis methods and corresponding characterization techniques of 2D MOFs and their derivatives,and summarized the latest progress of 2D MOFs and their derivatives as OER catalysts.Finally,we put forward some views and suggestions on the existing problems hindering the development of 2D MOFs as OER for advancing the field.