Fig. 1: Structural and electronic characterizations of Sb³⁺-based OIHHs.

a Schematic diagram of the introduction of water molecules in CP2 crystals; b Crystal structures of CP1 and c CP2; d PXRD of CP1 and CP2; e XPS of CP2; f Electronic band structure and g DOS of CP2; h VBM (left) and CBM (right) of CP2