First-Principles Study Of Oxygen Formation Over NiFe(Al)- Layered Double Hydroxides

The oxygen evolution reaction (OER) is recognized as one of the crucial process in achieving efficient water splitting. In the process, the high overpotentials on the oxygen-evolving anode8 would lead to the energy loss which limits the overall efficiency of the OER system. So, To minimize the energy lose, it’s very important to find the catalytic active site.In the present research, the OER catalyst contains the transition metal, such as RuO2, PtO2,IrO2 �'�Co3O4, the front three are very scarce and precious, and the last one’s catalytic activity is lower than that three. So, many researchers devoted to find high active catalysts and studied the mechanism of oxygen evolution. The contents are summarized as below:1、Using Material Studio to build the NiⅡFeⅢ-LDH (Ni:Fe=2:1) structures with CO32-, NO3- and Cl- anions setting in the interlayer, designing the reaction species of different OER mechanisms, studying the energy profile of the system, using CI-NEB method to find the transition state of NiFe-CO3-LDH,the OER barrier is 182.27kJ/mol and the oxygen adsorption energy is-93.55 kJ/mol。2、Through the DOS analysis to know the effect of Fe in the system, it can accelerate the electron transportation speed, and improve the OER catalytic activity. The OER catalytic activity order of the three different anions is that NiFe-CO3-LDH>NiFe-NO3-LDH>NiFe-Cl-LDH.3、Using Material Studio to build the NiⅡAlⅢ-LDH (Ni:Al=2:1) structures with CO32-, NO3- anions setting in the interlayer, through the DOS analysis, different atomic orbital have a high degree of overlap, the structures have good stability. The OER catalytic activity are equal between CO32- and NO3- anions systems.