Thermally-induced single-crystal-to-single-crystal transformations from a 2D two-fold interpenetrating square lattice layer to a 3D four-fold interpenetrating diamond framework and its application in dye-sensitized solar cells

Abstract

In this work, a rare 2D → 3D single-crystal-to-single-crystal transformation (SCSC) is observed in metal-organic coordination complexes, which is triggered by thermal treatment. The 2D two-fold interpenetrating square lattice layer [Cd(IBA)2]n (1) is irreversibly converted into a 3D four-fold interpenetrating diamond framework {[Cd(IBA)2(H2O)]·2.5H2O}n (2) (HIBA = 4-(1H-imidazol-1-yl)benzoic acid). Consideration is given to these two complexes with different interpenetrating structures and dimensionality, and their influence on photovoltaic properties are studied. Encouraged by the UV-visible absorption and HOMO-LUMO energy states matched for sensitizing TiO2, the two complexes are employed in combination with N719 in dye-sensitized solar cells (DSSCs) to compensate absorption in the ultraviolet and blue-violet region, offset competitive visible light absorption of I3(-) and reducing charge the recombination of injected electrons. After co-sensitization with 1 and 2, the device co-sensitized by 1/N719 and 2/N719 to yield overall efficiencies of 7.82% and 8.39%, which are 19.94% and 28.68% higher than that of the device sensitized only by N719 (6.52%). Consequently, high dimensional interpenetrating complexes could serve as excellent co-sensitizers and have application in DSSCs.

Finely Controlled Stepwise Engineering of Pore Environments and Mechanistic Elucidation of Water‐Stable, Flexible 2D Porous Coordination Polymers

“…This is especially pertinentf or 2D frameworks, because the high flexibility of 2D PCPs result in layer exfoliation and eventual degradation in the presence of water. [5] We are interested in the synthesis of water-stable and func-tionalP CPs. [6] Herein, we report the utilization of two Cu II -basedP CPs with different topologies (sql and dia,r espectively)a nd thiophene-functionalized ligand (5-(thiophen-2-yl)isophthalic acid, H 2 ttip)i nt he stepwise engineering of porous, water-stable and flexible kgm lattice (NTU-22:2 D) in water.T he electron-donating nature of the thiophenew ill provide H-bonding and extra p-interaction to preorganize segment distortion and crystallization.…”

“…However, to our knowledge, there is no example of employing a crystal conversion strategy to engender significant improvements in water stability of PCP materials. This is especially pertinent for 2D frameworks, because the high flexibility of 2D PCPs result in layer exfoliation and eventual degradation in the presence of water …”

Size Control through Scan Rate Modulation: Mapping Water Splitting Efficiency of Micro to Nano Size Cuboidal Copper Oxide Particles

“…It is presumed here that the sample formed at higher scan rate possesses high defect density and that resulted in the low lifetime of the carriers. 24,25 This argument is supported by the Hall data showing a higher carrier concentration for S100 sample than S20.…”

Two-Dimensional Metal-Organic Framework Materials: Synthesis, Structures, Properties and Applications

“…Change in the coordination sphere during the SCSC transformation of 2D MOF, [Cd­(iba) 2 ], to 3D MOF, [Cd­(iba) 2 (H 2 O)]·2.5H 2 O, with different interpenetration and dimensionality. Adapted with permission from ref . Copyright 2016 Royal Society of Chemistry.…”

“…The yellow blocks of two-fold interpenetrated 2D MOF [Cd­(iba) 2 ] (iba = 4-(1 H -imidazol-1-yl)­benzoate) with (4,4) connectivity were obtained in a hydrothermal reaction at 80 °C in 6 days (Figure ), while yellow platy crystals of four-fold interpenetrated 3D MOF [Cd­(iba) 2 (H 2 O)]·2.5H 2 O with dia topology were formed when the single crystals of 2D MOF were heated in a Teflon-lined stainless steel autoclave at 200 °C for 24 h. Obviously, water in the 3D MOF were picked up from moist air. In this 2D MOF, the Cd­(II) center acts as four connecting node formed by two chelating carboxylates and two N atoms from four different iba ligands.…”