Efficient overall water splitting in acid with anisotropic metal nanosheets.

ABSTRACT: Water is the only available fossil-free source of hydrogen. Splitting water electrochemically is among the most used techniques, however, it accounts for only 4% of global hydrogen production. One of the reasons is the high cost and low performance of catalysts promoting the oxygen evolution reaction (OER). Here, we report a highly efficient catalyst in acid, that is, solid-solution Ru?Ir nanosized-coral (RuIr-NC) consisting of 3 nm-thick sheets with only 6?at.% Ir. Among OER catalysts, RuIr-NC shows the highest intrinsic activity and stability. A home-made overall water splitting cell using RuIr-NC as both electrodes can reach 10?mA?cm^-2_geo at 1.485?V for 120?h without noticeable degradation, which outperforms known cells. Operando spectroscopy and atomic-resolution electron microscopy indicate that the high-performance results from the ability of the preferentially exposed {0001} facets to resist the formation of dissolvable metal oxides and to transform ephemeral Ru into a long-lived catalyst.

SUBMITTER: Wu D 

PROVIDER: S-EPMC7887272 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature