Sultan Siraj, Ha Miran, Kim Dong Yeon, Tiwari Jitendra N, Myung Chang Woo, Meena Abhishek, Shin Tae Joo, Chae Keun Hwa, Kim Kwang S
Center for Superfunctional Materials, Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan, 689-798, Korea.
Department of Energy and Chemical Engineering, UNIST, Ulsan, Korea.
Nat Commun. 2019 Nov 15;10(1):5195. doi: 10.1038/s41467-019-13050-3.
For efficient water splitting, it is essential to develop inexpensive and super-efficient electrocatalysts for the oxygen evolution reaction (OER). Herein, we report a phosphate-based electrocatalyst [FeCo(PO)@reduced-graphene-oxide(rGO)] showing outstanding OER performance (much higher than state-of-the-art Ir/C catalysts), the design of which was aided by first-principles calculations. This electrocatalyst displays low overpotential (237 mV at high current density 100 mA cm in 1 M KOH), high turnover frequency (TOF: 0.54 s), high Faradaic efficiency (98%), and long-term durability. Its remarkable performance is ascribed to the optimal free energy for OER at Fe sites and efficient mass/charge transfer. When a FeCo(PO)@rGO anodic electrode is integrated with a Pt/C cathodic electrode, the electrolyzer requires only 1.45 V to achieve 10 mA cm for whole water splitting in 1 M KOH (1.39 V in 6 M KOH), which is much smaller than commercial Ir-C//Pt-C electrocatalysts. This cost-effective powerful oxygen production material with carbon-supporting substrates offers great promise for water splitting.
为了实现高效的水分解，开发用于析氧反应（OER）的廉价且超高效的电催化剂至关重要。在此，我们报道了一种基于磷酸盐的电催化剂[FeCo(PO)@还原氧化石墨烯（rGO）]，其表现出出色的析氧反应性能（远高于目前最先进的Ir/C催化剂），其设计借助了第一性原理计算。这种电催化剂具有低过电位（在1 M KOH中高电流密度100 mA cm时为237 mV）、高周转频率（TOF：0.54 s）、高法拉第效率（98%）以及长期耐久性。其卓越性能归因于Fe位点上析氧反应的最佳自由能以及高效的质量/电荷转移。当将FeCo(PO)@rGO阳极电极与Pt/C阴极电极集成时，该电解槽在1 M KOH中实现全水分解析出10 mA cm仅需1.45 V（在6 M KOH中为1.39 V），这比商业Ir-C//Pt-C电催化剂小得多。这种具有碳支撑基底的高性价比的高效产氧材料在水分解方面具有巨大潜力。
