Syntheses, structures and efficient visible light-driven photocatalytic properties of layered cuprous halides based on two types of building units

Abstract

Three novel hybrid cuprous halides, [Me₃TPT][Cu₅I₈] (1, Me₃TPT = N,N′,N′′-trimethyl-2,4,6-tris(4-pyridyl)-1,3,5-triazine), [Et₃TPT][Cu₅I₈] (2, Et₃TPT = N,N′,N′′-triethyl-2,4,6-tris(4-pyridyl)-1,3,5-triazine), and [Me₃TPT][Cu₅Br₈] (3), were solvothermally prepared by using in situ N-alkylated 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT) derivatives as structure-directing agents. All the compounds feature layered structures extended by two types of building units, i.e. the chain-like Cu₃I₆/Cu₃Br₇ ({Cu₃}) cluster and ribbon-like Cu₄I₁₀/Cu₄Br₁₀ ({Cu₄}) cluster. UV-Vis spectra analyses indicate that they are potential semiconductor materials with narrow energy gaps of 1.05, 1.02, and 1.30 eV, respectively. These materials exhibit stable catalytic activity in the sunlight-driven degradation of organic dyes. Theoretical studies revealed that the N-alkylated TPT moieties contributed to the narrow semiconducting behavior, which results in the excellent visible light-driven photocatalytic activity.