Component-Tunable Rutile-Anatase TiO2/Reduced Graphene Oxide Nanocomposites for Enhancement of Electrocatalytic Oxygen Evolution

As an earth-abundant and environment-friendly material, the potential of TiO2 in many field, including oxygen evolution reaction (OER), has not yet been fully developed. Here, we fabricate component tunable rutile-anatase TiO2/reduced graphene oxide (RGO) nanocomposites with high OER activity which exhibit a current density of 10 mA cm(-2) at an overpotential of 283 mV. The performance is superior to the previous reported TiO2 (600 mV) and comparable with the leading results of other active materials. The catalytic mechanism is suggested according to our experimental results that the interactions between rutile and anatase, as well as RGO and TiO2 result in the enhancement of adsorption of hydroxyl. Such an adsorption is advantageous to provide a surface reaction environment and reduce the activation energy of the electrochemical process, resulting in the best OER performance. This work should stimulate the design of more materials for the improvement of OER activity.