Versatile Synthesis of Hollow Metal Sulfides via Cation Exchange Reactions for Photocatalytic CO2 Reduction.

Herein, we explore a general Cu 2-x S nanocube template-assisted and reverse cation exchange-mediated growth strategy for fabricating hollow multinary metal sulfide . Impressively, different from the traditional cation exchange method controlled by the metal sulfide constant, the introduction of tri-n-butylphosphine (TBP) can reverse cation exchange to obtain a series of hollow metal sulfides. A variety of hollow multinary metal sulfide cubic nanostructure has been demonstrated while preserving anisotropic shapes to the as-synthesized templates, including binary compounds (CdS, ZnS, Ag 2 S, PbS, SnS), ternary compound (CuInS 2 , Zn x Cd 1-x S), and quaternary compound ( single-atom platinum anchored Zn x Cd 1-x S; Zn x Cd 1-x S-Pt 1 ). Experimental and density functional theory (DFT) calculations showed that the hollow metal sulfide semiconductor obtained by stepwise reverse cation exchange can significantly improve the separation and migration of photogenerated electron-hole pairs. Owing to the efficient charge transfer, the Zn x Cd 1-x S-Pt 1 exhibited outstanding photocatalytic performance of CO 2 to CO, with the highest CO generation rate of 75.31 μmol h -1. Collectively, these versatile post-synthetic techniques demonstrate the wide-ranging applicability of sequential reverse cation exchange reactions to controllably access a vast variety of previously intractable hollow compositions for photocatalysis and another energy catalysis.