Study The Adsorption Reaction Of H~+or OH~-on Electrode Surface With A Hamiltonian-Based Electron Transfer Model

Studying the mechanism of electrochemical reaction plays a vital role in solving the problems in industrial processes like material selection,potential control and so on.The adsorption reaction on the electrode surface is a special phenomenon in the electrochemical process,reactions of this kind are usually quick steps in electrode reactions.The existing calculation method based on density functional theory(DFT)can be helpful to study some fast reactions which are difficult to detect experimentally.Besides,the application of some theoretical models can also make DFT calculation more accurate.In this paper,the Hamiltonian based ET model is combined with theoretical calculation results to study different single ET reactions through analyzing the density of states(DOS)of adsorbate,and it is modified in different solid system.In the first part,the ET model is applied to metal-water interface to study the mechanism of water dissociation on Ru(0001),two possible surface water structure,H-down and half-dissociated,are applied in constructing solid-liquid interface model to perform molecular dynamics(MD)simulation,the hexatomic ring is stable in the half-dissociated structure and the water dissociation can also be found,using the ET model,it is known that water dissociation on Ru(0001)is spontaneous.In the second part,the ET model is applied on the semiconductor-water interface,in order to study the process of the OH-oxidative adsorption on rutile TiO2(1 10)to generate·OH.In the analysis of the existing model,the DOS expressions of adsorbates at different adsorption distances were corrected.In DFT calculation,the cause of hole formation is analyzed and the method of calculating hole state by DOS expression is deduced.Finally,the total free energy expression of the whole reaction is proposed and the potential energy surface diagram of the reaction is obtained.