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.

Tripyridine‐Derivative‐Derived Semiconducting Iodo‐Argentate/Cuprate Hybrids with Excellent Visible‐Light‐Induced Photocatalytic Performance

“…Thesem aterials, asw ell as the reported [(Me) 3 (4-TPT)] 2 [Cu 12 I 18 ], [63] [65] possess narrow band gaps of 1.02-2.19 eV.T he values are comparable to those of organic ammoniumso rm etal complex templated halide hybrids, [13, 15-19, 50, 71] which feature small band gaps and exhibit attractive optoelectronic properties. Therefore, we are delighted to discover that introducing N-alkylation TPT-derivatives as SDAs in halides may be an effective synthetic strategy for regulating electronic band structures,w hich can decrease the band gap and accordingly increase visible-light absorption.…”

“…It is noteworthy that they possess smaller band gaps and show red‐ shifts with respect to the bulk β‐AgI (2.81 eV) and CuI (3.10 eV) owing to the contribution of the organic cations to conduction bands. The values are compared with those of other hybrid halides directed by conjugated organic cations, such as [MC][Ag 2 I 3 ] (2.35 eV, MC= N ‐methyl‐4‐cyanopyridinium), [(Me) 3 TPT] 2 [Cu 12 I 18 ] (1.35 eV), [Me 3 TPT][Cu 5 Br 8 ] (1.30 eV), which display the properties of semiconductor materials.…”

“…The absorption spectra, calculated from the diffuser eflectance data, are shown in Figure 4. The band gaps (Eg) of 1-4 resultedb ye xtrapolationo ft he linear portion of the absorption edges are estimated to be 1.27, 1.61, 2.19 and 1.72 eV,r e-spectively.I ti sn oteworthyt hat they possess smaller band gaps and show red-shifts with respectt ot he bulk b-AgI (2.81 eV) [18] and CuI (3.10 eV) [67] owing to the contribution of the organic cations to conduction bands.T he values are compared with those of other hybrid halidesd irected by conjugated organic cations, such as [MC][Ag 2 I 3 ]( 2.35 eV,M C = Nmethyl-4-cyanopyridinium), [18] [(Me) 3 TPT] 2 [Cu 12 I 18 ]( 1.35 eV), [63] [Me 3 TPT][Cu 5 Br 8 ]( 1.30 eV), [65] which display the properties of semiconductor materials.…”

“…TPT molecules were reactedw ithm ethanolt og enerate methylated cations, which take an important effect in the self-assembly processo f the novel halides (Scheme 1). While as eries of metal halides are prepared by our team in the presence of Me 3 (4-TPT), [63][64][65] Me 3 (3-TPT) is first introduced in halidesi nt his work. Me 3 (4-TPT) andM e 3 (3-TPT) derive from in situ N-alkylation reaction of initial reactant 4-TPT and 3-TPT under solvothermal condition, respectively.F irstly,t he in situ reaction between methanol and HI form the intermediate product of iodomethane (CH 3 I).…”

A 3D Iodoplumbate Semiconducting Open Framework with Visible‐light‐induced Photocatalytic Performance

“…[42,43] Recently,o ur research focusingo nt he systematic exploration of halometallates using the conjugated polypyridine derivatives as SDAs has made some progress. [44][45][46][47] These previous study indicated that N-alkylation conjugated polypyridinec ations as SDAs ande lectron acceptors can effectively decrease the band gap and accordingly increaset he absorption of the visible light of the resultant materials. For example, the tripyridine-derivatives derived iodoargentates and iodocuprates, [Me 3 (4-TPT)][M 5 I 8 ], [Me 3 (3-TPT)][M 5 I 8 ]( M= Ag, Cu;4 -TPT = 2,4,6tris(4-pyridyl)-1,3,5-triazine,3 -TPT = 2,4,6-tris(3-pyridyl)-1,3,5-triazine), possess narrow band gaps of 1.05-2.19 eV ande xhibit excellent photodegradation activity.H ence, to further investigate the impact of different conjugated organic cations on the crystal structure and band structure on halometallates, we select the conjugated bpanth (bpanth = 9,10-bis(4-pyridyl)anthracene) as cation templates,t hrough the in situ N-alkylation synthesis, achieving a3 Di norganic-organic hybrid iodoplumbate, [Me 2 (bpanth)][Pb 4 I 10 ]( 1), which possessess mall band gap and exhibits efficient photocatalytic performance in visiblelight induced degradation.Compound 1 is synthesized by an in situ solvothermalr eaction.…”