The Preparation Of Nanoporous Gold Ribbon Composite Metal Oxide Electrode And Their Oxygen Evolution Properties Research

With the increase of energy consumption and environment polution, it has become imperative for us to find out effective approaches to producing environment- friendly energy source on large scale at low cost. Hydrogen, as secondary energy, is the best clean energy in the 21 st century. Electrolysis of water is an imporment way to produce hydrogen, but high overpotential and low reaction kinetics of oxygen evolution reaction seriously restricted its development. Therefore, developing high efficient and low-cost oxygen evolution catalyst is the key factor for large scale application of hydrogen.Although noble metal-based catalysts exhibit excellent catalytic activity, the high cost and scarce resources hinder the large scale application. So to improvement the catalytic activity further and low consumption is the key of developing noble metal-based catalysts. On the other hand, non-noble metal-based catalysts, as the first row transition metal oxides, caused more and more attention, because of the low cost, abundant and relatively good catalytic activity. Howere, the intrinsic low conductivity of transition metal oxides infuenced the catalytic properties of electrode materials. Thus, the researchers, in order to solve these problems, put forward various methods, such as reducing catalyst size into nanometer scale, increasing high index facet on catalyst surface, and loading/assembling the nanosized catalyst on the supports of large sueface areas, to enhance its catalytic activity as well as to reduce its consumption. Taking advantages of high surface area and conductivity of nanoporous gold and electroplating method, self- standing, flexile and intergrated solid/nanoporous gold/metal oxide composite electrode structure with stable and efficient catalytic properties are obtained. The main results are divided into two parts as following:1、Cobalt oxide, because of abundant element and good O ER activity, can be used as low cost electrochemical oxygen evolution catalysts instead of noble metal oxides in alkaline electrolyte. Adherent cobalt oxide layers were galvanostatically deposited on S/NP Au ribbon, obtaining integrating S/NP Au/Co oxide composite electrode. On one hand, S/NP Au composite structure can enhance transports of the electron and ion in whole electrode; on the other hand, the most electronegative metal Au creates a tronger filed for the adsorption of O to Co species to make the generation of high valence state of Co species easier. Therefore, S/NP Au/Co oxide composite electrode showed good catalytic performance: obtaining 10 m A cm-1 of current density only requiring 320 m V ove rpotential, and the decay of current density being small after stability of 24 hours.2、Iridium oxide is among the best electrochemical oxygen evolution catalysts, but is expensive and scarce. Iridium oxide film deposited on NP Au ribbon by cyclic voltammetry to prepare NP Au/Ir O2 composite electrode, showing excellent oxygen evolution catalytic activity, 10 m A cm-1 of current density only requiring 276 m V overpotential. This research show that the unique integrating electrode structure is a promising avenue to take full use of noble metal-base catalysts and improve the catalytic performance.