Three Metal Complex-Decorated Halobismuthates: Syntheses, Structures, Semiconducting Behaviors and Theoretical Investigations

Abstract

Employing metal complex cations as the structural modifiers, three new numbers of hybrid halobismuthates family, namely [NH₄][Co(phen)₃]BiI₆ (phen=1,10-phenanthroline; 1), [Zn(phen)₂Br][Bi(phen)Br₄] ⋅ H₂O (2) and [Cu(2,2′-bipy)₂Br][Cu(2,2′-bipy)₂Bi₂Br₉] ⋅ H₂O (2,2′-bipy=2,2′-bipyridine; 3) have been solvothermally constructed and structurally characterized. X-ray crystallography analyses show that all compounds characteristic of abundant weak interactions feature the discrete anionic motifs. The obtained hybrid materials possess the semiconducting nature, with the visible light responding optical band gaps of 2.13–2.71 eV. Under the alternating light irradiation, they exhibit excellent photoelectric switching properties, whose photocurrent densities (0.85, 0.24, and 0.43 μA/cm² for compounds 1–3, respectively) compare well with some high-performance halobismuthate competitors. Further theoretical calculations of compound 1 reveal that the photosensitive [Co(phen)₃]²⁺ cations contribute greatly to the bottom of conduction bands (CBs) and the top of valence bands (VBs), which may be the important reason for its excellent photoelectric behavior. The analyses of Hirshfeld surface, thermal stability, and X-ray photoelectron spectroscopy were also discussed detailedly in this paper.