An Efficient Three-Dimensional Oxygen Evolution Electrode

摘要

The challenges of meeting the rapidly increasing global energy demand and developing carbon-neutral economy require untiring efforts to exploit and store abundant but diffuse renewable energy sources. Among many innovative approaches, the efficient production of hydrogen serving as fuel, through electricity-driven water splitting, seems promising and appealing. However, the overall efficiency of the reaction is largely impeded by the kinetically sluggish oxygen evolution reaction (OER), imposing serious overpotential requirement. Although precious metal oxides, such as RuO2 and IrO2, are considered to be the most active OER electrocatalysts, they are not suitable for large-scale applications because of their scarcity and high costs. In response, non-noble transition-metal-based catalysts, especially nickel (Ni), are becoming focus of growing research interests because of their earth-abundant nature and theoretically high catalytic activityCurrently, these non-noble transition-metal-based OER catalysts are usually prepared as thin films from precursor solution containing metal cations by electrodeposition, sputtering, dip-coating, and spin-coating methods on two-dimensional (2D) planar substrates.71 Although significant improvements have been achieved, the activity and stability of the catalyst layer should be further enhanced by optimizing the structural, mechanical, and electrical contact between the catalyst and the substrates.