Research Of The Electrocatalysts Based On Carbon Nanomaterials

As the population increasing and the progress of science and technology level,the global energy shortage and environmental pollution problem more and more become the two obstacles which block the development of the society today. The development of new energy has become a scientific problem which must be solved urgently. Nowadays, the hydrogen and the microbial fuel cell are two big trends in the development of new energy. The hydrogen is considered to be the most ideal of the ideal energy, meanwhile the electrolysis of water hydrogen production technology is the most efficient hydrogen production technology, but excessive anode oxygen evolution potential limits the development of hydrogen production by electrolysis of water. Microbial fuel cell is a new clean energy technology, but it is difficult to find the alternative that can replace precious metal Pt cathode catalysts. Two kinds of new energy technology need to develop low cost and high performance electrode materials.Carbon nano materials with larger specific surface area, higher electrical conductivity,etc. are widely used in the fuel cells, hydrogen production by electrolysis of water,super capacitor and a lot of electrochemical fields. In this paper, we study the anode oxygen evolution and cathodic oxygen reduction performance of carbon nanomaterials which are loaded different types of catalysts. And the results are as follows:(1) H-TiO2/MnOx NWs supported on carbon cloth have been successfully prepared by hydrothermal method and electrodeposition method. The entire surface of the H-Ti O2 NWs is covered uniformly by amorphous Mn Ox, which forms a core-shell structure. At the anode oxygen evolution performance tests, H-Ti O2/Mn Ox NWs exhibits a low onset potential and high current density and good stability. As can be seen from the XPS test results, the percentage of Mn2+ increases and the percentage of Mn3+ and Mn4+ decreases after 30 min chronopotentiometry test at0.7 V, which prove the assume that electronic transmission is the key to the oxygen evolution reaction.(2) Porous type of graphene carbon nanomaterials are synthesized by acrylic acid type anion exchange resin. Ni Co2O4 are loaded on 3D HPG by a simple hydrothermal method. And then Au-Ni Co2O4/HPG, Pt-Ni Co2O4 /HPG and Pd-Ni Co2O4/HPG are prepared by the Na BH4 chemical reduction of precious metals salt.Au-Ni Co2O4/HPG is found to show best performance in OER. By seeking the different proportion of Au and Ni Co2O4, the Au-Ni Co2O4(wt 1:5)/HPG is find out with lower peak potential and higher current density. XPS data also shows Ni and Co 2p peak shift positively after loading with Au. The results show that Au is high electronegative which facilitate to generate Co4+ and Ni3+ cations as the active centres for the OER. As a result, the activity and stability of the composite material have been improved.(3) Co0.85 Se is loaded on 3D HPG by an one step hydrothermal method,and at the same time traditional catalysts Co3O4 is load on 3D HPG. As compared with Co3O4/HPG, Co0.85Se/HPG is found to show better performance in OER. This work provids new insight into using transition metal selenide as high performance electrocatalyst for OER in water electrolysis, and breaks the tradition of using only oxide as a catalyst.(4) NiCo2O4 are loaded on 3D HPG and MWCNTs by a simple hydrothermal method.Moreover, the different proportions of Ni Co2O4 and carbon nanomaterials are synthesized to study the oxygen reduction performance and equipped in microbial fuel cell to produce electric properties. In the application of MFC, Ni Co2O4/HPG and Ni Co2O4/MWCNTs show better power density and open circuit voltage.Ni Co2O4/MWCNTs exhibit the most superior performance. These two kinds of catalysts are expected to replace Pt/C because of with their simple preparation and low cost. And they can be used as the cathode catalyst to improve prospects for microbial fuel cell field.