All-Surface-Atomic-Metal Chalcogenide Sheets for High-Efficiency Visible-Light Photoelectrochemical Water Splitting

摘要

Artificial all-surface-atomic2Dsheets can trigger breakthroughs in tailoring the physical and chemical properties of advanced functional materials. Here, the conceptually new all-surface-atomic semiconductors of SnS and SnSe freestanding sheets are realizedusing a scalable strategy. As an example, all-surface-atomic SnS sheets undergo surface atomic elongation and structural disordering, which isrevealed by X-ray absorption fine structure spectroscopy and first-principles calculations, endowing them with high structural stability andan increased density of states at the valence band edge. These exotic atomic and electronic structures make the all-surface-atomic SnS sheet-based photoelectrode exhibit an incident photon-to-current conversion efficiency of 67.1% at 490 nm, much higher than the efficiencies of other visible-light-driven water splitting. A photocurrent density of 5.27 mA cm-2,which is twoorders of magnitude higher than that of the bulk counterpart, is also achieved for the all-surface-atomic SnS sheets-based photoelectrode. Thiswill allow the manipulation of the basic properties of advanced materials on the atomic scale, thus paving the way for innovative applications.