Promoting Plasmonic Hot Hole Extraction and Photothermal Effect for the Oxygen Evolution Reactions.

Boosting oxygen evolution reaction by local surface plasmon resonance (LSPR) provides breakthrough opportunities for the promotion of solar energy conversion; the potential of LSPR, however, has rarely been tapped and investigated. Here, we report the precise regulation of commercial Au nanoparticles plasmonic nanomaterial and OER electrocatalysts, viz. the NiCoOx electrocatalytic layer with hole transport ability and photothermal effect is prepared on the surface of Au nanoparticles by photoelectrodeposition. The NiCoOx layer not only increases the transmission distance of holes generated by plasmonic Au nanoparticles, but also reduce the agglomeration of plasmonic Au nanoparticles during long‐time OER reaction, which greatly improves the OER catalytic ability. The current density of NiCoOx/Au anode achieves 16.58 mA cm−2 at 2.0 V versus RHE, which is about 6.5 times of pristine NiCoOx anode (2.56 mA cm−2) and 47 times of pristine Au anode (0.35 mA cm−2). More importantly, with the LSPR and photothermal effect of plasmonic Au nanoparticles, the NiCoOx/Au anode provides additional current density of 7.01 mA cm−2 after illumination, and maintains no attenuation for more than 2000 s. Benefiting from the solution of agglomeration problem of plasmonic Au nanoparticles in the long‐time OER process and the effective utilization of generated holes of plasmonic Au nanoparticles, this design can provide guidance for the application of plasmonic materials in the field of electrocatalysis. [ABSTRACT FROM AUTHOR]