Title : Parallelization of electrocatalytic oxygen evolution reactions as a new breakthrough
For the commercial application of water splitting, the development of efficient electrocatalysts for water oxidation, which is a key half-reaction because of sluggish reaction kinetics, is a huge challenge. Currently, novel metal-based catalysts such as IrO2 and RuO2 are widely used for boosting water oxidation kinetics. However, the scarcity and rareness of these metals hinder practical applications of water splitting. In this regard, exploring high-performance non-noble metal catalysts to replace IrO2 and RuO2 is highly desired, but remains a challenge. Although various strategies including alloying and morphology control have been developed to enhance the catalytic activity of non-noble metal-based electrocatalysts, there still remain large gaps to be resolved. In this research, we report novel interface (crystalline and amorphous phase boundary) engineering strategies using surface selective doping in order to significantly enhance the water oxidation properties of non-noble metal catalysts. Experiments demonstrated that the proposed interface engineering can induce high-density of crystalline and amorphous (c-a) phase boundaries on the surface. In addition, density functional theory (DFT) revealed that the c-a interface parallelizes the reaction pathway for water oxidation, efficiently facilitating reaction kinetics. These findings can provide a facile and unique strategy for designing high-performance noble-metal-free catalysts for water splitting. In this work, we developed a new and facile strategy for designing high-performance transition metal borides for water splitting by inducing the formation of high-density crystalline/amorphous phase boundaries via surface fluorination. The computational simulation was firstly conducted to test our material design principle, followed by experimental verification for optimization. The material design principle proposed in this work is a facile and cost-effective way to considerably enhance the water oxidation activity of metal-metalloids for electrocatalyst applications.