| Spinel metal oxides are a kind of promising electrocatalytic materials due to their flexible composition and remarkable activity,among which cobalt-containing spinel oxides have attracted special attention because of their high catalytic activity and stability.The catalytic performance of spinel catalysts is complicated due to the interaction of tetrahedron structure and octahedron structure of crystals.The ordered mesoporous metal oxides have high specific surface area and large pore size microstructure,which can increase the number of active sites of the catalyst and promote the diffusion of materials,thus improving the electrocatalytic performance of the catalyst.In this paper,a series of cobalt-based spinel metal oxides with high specific surface area,large mesoporous and different element composition were designed and synthesized.The effects of adjusting the framework size and chemical composition of the catalysts on the electrocatalytic performance of the catalysts were studied.In this paper,a series of ordered mesoporous cobalt based oxides were synthesized by our improved hard template method using KIT-6 as hard template.The chemical composition of the tetrahedron and the octahedron of the spinel structure metal oxides was controlled by changing the type and mass of the precursors.By changing the mesoscopic morphology of KIT-6,the mesoscopic parameters such as specific surface area,pore size and pore volume of metal oxides can be adjusted.After testing,the material’s OER catalytic performance results show that:the change order of electrocatalytic performance from high to low is CuCo2O4,NiCo2O4,Co3O4 and ZnCo2O4,and the overpotential at the current density of 10 mA·cm-2 is 322 mV,333 mV,343 mV and 348 mV,respectively;Adjust the proportion of Fe replacing Co in the octahedron position,ZnFe0.6Co1.4O4 had the best electrocatalytic performance,and the overpotential was as low as 327 mV,which was better than that of ZnCo2O4 catalyst(348 mV).A series of ordered mesoporous ZnMxCO2-xO4(M=Fe,Ni)materials with low proportion of doping were synthesized by a similar synthesis strategy.and the octahedral position composition of ZnMxCO2-xO4 materials was adjusted in the range of low doping.(1)By adjusting the doping proportion of iron ions.the glucose electrochemical sensing performance of ZnFexCO2-xO4 material was tested.It was found that 2.5%Fe/Voct(the proportion of iron ions in the number of the octahedron position)had the best sensing performance.and the sensitivity was 3370 μA·mm-1·cm-2.It was better than ZnCo2O4(1574 μA·mm-1·cm-2).(2)By adjusting the doping proportion of nickel ions.the glucose electrochemical sensing performance of ZnNixCO2-xO4 was tested.When the doping amount of Ni/Voct was 2.5%,the catalytic performance was the best,and the sensitivity was increased to 5966 μA·mm-1·cm-2.A series of ordered mesopore octahedron doped CuMxCo2-xO4(M=Cr,Mn,Fe,Ni,Ga)materials were synthesized by changing the type and proportion of metal ion doing,at the same time,a series of CuGa0.05Co1.95O4-X(X=40,100,140)materials were synthesized by changing the framework size.It was found that the synthesized CuMxCo2-xO4-40 had ordered mesoscopic structure with high specific surface area and large pore size(specific surface area is about 130 m2·g-1,pore size is about 11 nm,pore volume greater than 0.6 cm3·g-1).Small amount of doping can not destroy the ordered mesoscopic structure of the material,which can realize the adjustment of the framework chemical composition without destroying the mesoscopic structure of the material.Testing glucose electrical sensing performance can be found:(1)The CuGa0.05Co1.95O4-40 which has the largest specific surface area and pore size(specific surface area 133 m2·g-1,pore size 12 nm,pore volume 0.87 cm3·g-1)had the best electrochemical sensing performance in a series of materials with different framework sizes.The glucose electrical sensing performance was 12366μA·mm-1·cm-2 within the linear range of 0.01～0.683 mM.(2)Among a series of CuMxCo2-xO4-40(M=Cr,Mn,Fe,Ni,Ga)materials with different doping types and ratios,it is found that the M/Voct is 2.5%,which has the best catalytic performance.Among them,the material is CuGao.05Co1.95O4 and CuCr0.05Co1.95O4 have the best electrochemical sensor performance for glucose.The sensitivity is 1 2366 μA·mm-1·cm-2 and 12823 μA·mm-1·cm-2 in the linear range of 0.01～0.683 mM.On the one hand,it proves that the material has the advantages of high specific surface area and large mesopores in the mesoscopic structure.On the other hand,it proves that the composition of the octahedron position of the spinel structure material has a strong correlation with its glucose electrochemical sensing performance.The glucose non-enzymatic electrocatalyst synthesized in this work has good stability,antiinterference ability and commercial application prospects. |
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