Preparation And Modification Of Photo/Electrocatalytic Composite Materials Based On MIL-88B

With the severe challenges of energy crisis and environmental degradation caused by the use of fossil fuels,people have started to seek new green and sustainable energy sources.Hydrogen（H₂）as a high energy density and sustainable energy fuel with non-pollution,no carbon emission and renewable features has attracted the attention and favor of researchers,among which hydrogen production from cracked water has received the key attention of the academic community.In addition to the conversion and utilization of solar energy is also a major hot topic.And semiconductor materials have been the core of energy conversion.MIL-88B(C₂₄H₁₂Fe₃O₁₃),a typical metal-organic framework material,is a promising electrocatalyst and photocatalyst due to its narrow band gap and easy preparation.In this paper,MIL-88B was grown on nickel foam and modified using a solvothermal method.In the experiments,the electrocatalytic efficiency of bi-metallic organic framework compounds grown on nickel foam（NF）has been enhanced by adjusting the amount of iron and cobalt precursors.A unique wedge-like morphology was observed in Fe-1-Co-1-MOF.The optimized Fe-1-Co-1-MOF（1:1 of molar ratio of iron to cobalt）exhibits superior catalytic activity to oxygen evolution reaction（OER）performance with a lowest overpotential of only 233 m V at a current density of 10 m A·cm^-2and the higher current density of 400m A·cm^-2can be provided at overpotential of 264 m V.The Tafel slope in alkaline aqueous solutions was 24.4m V·dec^-1.After 10 hours of continuous operation,the catalyst showed only a slight loss of current density at 50 m A·cm^-2.This success may be attributed to synergy between the bi-metallic organic framework catalyst and the large pores of conductive nickel foam,as well as the synergistic effect between the two phases molecules of the bi-metallic organic framework metal.Metal organic frameworks（MOFs）have attracted great interest from scientific researchers in the field of photocatalysis due to their large specific surface area and semiconducting properties.In this paper,we investigated the growth of MIL-88B（Fe）by solvothermal method on conductive glass FTO,and then the novel MIL-88B（Fe）/Bi VO₄photocatalyst was successfully synthesized by secondary hydrothermal.The morphology and structure of the samples were characterized by XRD,SEM,EDX and XPS,in which3-BV/MIL-88B（Fe）showed the optimal photocatalytic performance.The degradation of 10mg/L tetracycline hydrochloride solution under xenon light irradiation was 85.6%in 180minutes.Compared to MIL-88B（Fe）or X-BV/MIL-88B（Fe）,3-BV/MIL-88B（Fe）exhibited showed the best photocatalytic activity,providing more active sites.Through cycling experiments,the 3-BV/MIL-88B（Fe）composites showed good stability and degradation efficiency,indicating their potential application in the degradation of pollutants.