Photocatalytic and Photocurrent Responses to Visible Light of the Lone-Pair-Based Oxysulfide Sr 6 Cd 2 Sb 6 S 10 O 7 .

We present a combined experimental and computational study on the recently reported oxysulfide Sr 6 Cd 2 Sb 6 S 10 O 7 . Our spectroscopy and photoelectrochemical measurements and tests for photocatalytic activity indicate the potential of Sr 6 Cd 2 Sb 6 S 10 O 7 for photocatalytic applications. In particular, the transient photocurrent response shows a reproducible photogenerated current which depends on light intensity and which indicates an efficient electron-hole separation upon visible light illumination. Density functional theory calculations, combined with crystal orbital Hamiltonian population analysis, give insights into the electronic structure of Sr 6 Cd 2 Sb 6 S 10 O 7 and the origin of its physical properties. Our comprehensive investigation into Sr 6 Cd 2 Sb 6 S 10 O 7 reveals the roles of its polar structure, polar Sb 3+ coordination environments, and the 5s 2 lone pair in making this compound a potential candidate for solar water splitting photocatalysis.