Synthesis of Monodispere Au@Co_3O_4 Core-Shell Nanocrystals and Their Enhanced Catalytic Activity for Oxygen Evolution Reaction

摘要

The hydrogen economy can provide an efficient energy system that is free from environmental issues related to the combustion of coal, oil, and natural gas. However, such a system requires a clean and sustainable source of hydrogen, which can be provided by splitting of water either electrochemically or photoelectrochemicaHy. One of the key problems in splitting water is the kinetically sluggish anode reaction, i.e., oxygen evolution reaction (OER, 40H~- → 2H_2O + 4e~- + O_2 in base). An overpotential of several hundred millivolts is often required to achieve a current density of 10 A g_(catalyst)~(-1). Recent studies have shown that spinel-type Co_3O_4 has relatively good OER activities. Hybrid materials have been proposed to further promote the OER activity of Co_3O_4, such as doping Co_3O_4 with other metals to make substituted cobaltites or growing Co_3O_4 on a special substrate.