Screening metal-dicorrole-based dyes with excellent photoelectronic properties for dye-sensitized solar cells by density functional calculations

The dye molecules behaving as photosensitizers in dye-sensitized solar cells are the most critical factors to determine the power conversion efficiency. Therefore, ways to design dye molecules with excellent photoelectric properties has been the focus of dye-sensitized solar cells research. Here, we selected four representative different metal-corrole monomers to characterize their structures and photoelectronic properties. Then based on these metal-corrole monomers, six different architectures of metal-dicorroles were designed by varying the linking forms. The most stable architecture [Formula: see text] was screened out by binding energy calculations. A further two types of metal-dicorrole-based dyes were constructed by incorporating different bridge groups with the cyanoacry acceptor into the stable metal-dicorroles. A large number of density functional theory calculations and photoelectric properties analysis indicate that among these different metal-dicorrole-based dyes, Ga-dicorrole dyes have two strong and wide absorption bands in the visible region corresponding to Soret and Q bands, respectively, and have high charge separation efficiency under optical excitation. Especially for Ga-SN dye, by incorporating a [Formula: see text]-bridge-conjugated group, its Soret absorption band is greatly enhanced, broadened and red-shifted, resulting in its merging with the Q band into one absorption band. Moreover, its charge transfer efficiency is up to 76.86%, which will facilitate its coupling with semiconductor materials and transfer its electrons to the semiconductor materials.

Theoretical investigation on the photoelectrochemical anticorrosion mechanism of SnO2–TiO2nanotube

In this work, the calculated electron density difference, Bader charge analysis and the density of states (DOS) of SnO2–TiO2-nanotubes (NTs) indicate that the electrons are transferred from the Ti atoms of TiO2into the O atoms of (SnO[Formula: see text] in SnO2–TiO2-NTs and the supported (SnO[Formula: see text] cluster acts as the role of storage for photogenerated electrons excited from TiO2-NTs, which is in good agreement with experimental results that the SnO2–TiO2-NTs composite films have higher photocurrent density for photocathodic protection of 304 stainless steel (304SS). The theoretical investigations provide a plausible explanation for the photoelectrochemical anticorrosion mechanism of SnO2–TiO2-NTs using periodic density functional theory (DFT).

Theoretical investigation on the electronic structure of one dimensional infinite monatomic gold wire: insights into conducting properties

Mixed-valence metal–organic nanostructures show unusual electronic properties. In our pervious investigation, we have designed and predicted a unique one-dimensional infinite monatomic gold wire (1D-IMGW) with excellent conductivity and the interesting characteristic of mixed valency (Au_c³⁺ and Au⁰_i). For further exploring its conduction properties and stability in conducting state, here we select one electron as a probe to explore the electron transport channel and investigate its electronic structure in conducting state. Density functional theory (DFT) calculations show the 1D-IMGW maintains its original structure in conducting state illustrating its excellent stability. Moreover, while adding an electron, 1D-IMGW is transformed from a semiconductor to a conductor with the energy band mixed with Au_c (5d) and Au_i (6s) through the Fermi level. Thus 1D-IMGW will conduct along its gold atom chain demonstrating good application prospect in nanodevices.

The electron transport is along the energy band mixed with Au_c (5d) and Au_i (6s) through the Fermi level for [1D-IMGW]⁻.

Facile Generation of A2B Corrole Radical Using Fe(III) Salts and Its Spectroscopic Properties

A carboxyphenyl-substituted corrole, 5,15-dimesityl-10-(4'-carboxyphenyl)corrole (1), has been synthesized and characterized by UV-vis, fluorescence, ¹H NMR spectroscopy, and electrospray ionization (ESI)-mass spectrometry (MS) techniques. An air-stable corrole radical (1^•) was obtained with the addition of the Fe(III) salt to 1 in dimethyl sulfoxide (DMSO) and characterized by UV-vis, fluorescence, electron paramagnetic resonance (EPR), ESI-MS techniques, and density functional theory studies. The neutral corrole radical (1^•) exhibited a sharp EPR signal at g = 2.006 in DMSO. The reduced bipyrrolic (N-C-C-N) dihedral angle (χ) of 1 from 19.11 to 7.07° leads to the release of angle strain, which is the driving force for the generation of 1^•. Notably, trans-dimesityl groups prevent the dimerization or aggregation of the corrole radical. Further, 1^• was converted to 1 by excess addition of Fe(II) salts in DMSO at 298 K.

Theoretical investigation of an ultrastable one dimensional infinite monatomic mixed valent gold wire with excellent electronic properties

A one-dimensional monatomic gold wire with mixed-valent Au³⁺ and Au⁰ exhibits excellent conductivity and strong visible absorption.