Photo-promoted rapid reconstruction induced alterations in active site of Ag@amorphous NiFe hydroxides for enhanced oxygen evolution reaction

Abstract

The dynamic surface self-reconstruction behavior in local structure correlates with oxygen evolution reaction (OER) performance, which has become an effective strategy for constructing the catalytic active phase. However, it remains a challenge to understand the mechanisms of reconstruction and to accomplish it fast and deeply. Here, we reported a photo-promoted rapid reconstruction (PRR) process on Ag nanoparticle-loaded amorphous Ni-Fe hydroxide nanosheets on carbon cloth for enhanced OER. The photogenerated holes generated by Ag in conjunction with the anodic potential contributed to a thorough reconstruction of the amorphous substrate. The valence state of unsaturated coordinated Fe atoms, which serve as active sites, is significantly increased, while the corresponding crystalline substrate shows little change. The different structural evolutions of amorphous and crystalline substrates during reconstruction lead to diverse pathways of OER. This PRR utilizing loaded noble metal nanoparticles can accelerate the generation of active species in the substrate and increase the electrical conductivity, which provides a new inspiration to develop efficient catalysts via reconstruction strategies.