A series
of Zn–porphyrin dyes was prepared and anchored
onto a TiO2 surface to complete a dye-sensitized photocatalyst
system, Zn–porphyrin-|TiO2|-Cat, and tested as lower
energy photosensitizers for photocatalytic CO2 reduction.
Three major synthetic modifications were performed on the Zn–porphyrin
dye to obtain a lower energy sensitization and improve the catalyst
lifetime. We found that incorporating acetylene and linear hexyl groups
into the Zn–porphyrin core allowed facile lower energy sensitization,
and the addition of the cyanophosphonic acid as an anchoring group
gave the long-term dye stability on the TiO2 surface. Under
irradiation with red light of >550 nm and a light intensity of
207
mW/cm2, the hybrid ZnP
CNPA
catalyst showed a TONRe of ∼800 over an
extended time period of 90 h. The photocatalytic activities of porphyrin
hybrids differ greatly with the binding strength of the anchoring
groups of dye and spectral range of the irradiated light and its intensity.
Moisture-delicate and water-unstable organic-inorganic halide perovskites (OI-HPs) create huge challenges for the synthesis of highly efficient waterstable light-emitting materials for optoelectronic devices. Herein, a simple acid solution-assisted method to synthesize quantum confined 2D lead perovskites through Mn doping is reported. The efficient energy transfer between host and dopant ions in orange light-emitting Mn 2+ -doped OI-HPs leads to the most efficient integrated luminescence with a photoluminescence quantum yield over 45%. The Mn 2+ substitution of Pb 2+ and passivation with low dielectric constant molecules such as phenethylamine, benzylamine, and butylamine enhance water resistivity, leading to water stability. The dual emission process of this water-stable 2D Mn-doped perovskite will help in developing highly efficient 2D water-stable perovskites for practical applications.
We report, for the first time, the solid-phase gram-scale synthesis of two lead-free, zero-dimensional (0D) fluorescent organic–inorganic hybrid compounds, [Bu4N]2[MnBr4] (1) and [Ph4P]2[MnBr4] (2).
Rotaxane-based molecular shuttles are often operated using low-symmetry axles and changing the states of the binding stations. A molecular shuttle capable of directional shuttling of an acid-responsive cone-like macrocycle on a single-state symmetric dumbbell axle is now presented. The axle contains three binding stations: one symmetric di(quaternary ammonium) station and two nonsymmetric phenyl triazole stations arranged in opposite orientations. Upon addition of an acid, the protonated macrocycle shuttles from the di(quaternary ammonium) station to the phenyl triazole binding station closer to its butyl groups. This directional shuttling presumably originates from charge repulsion and an orientational binding preference between the cone-like cavity and the nonsymmetric phenyl triazole station. This mechanism for achieving directional shuttling by manipulating only the wheels instead of the tracks is new for artificial molecular machines.
White organic light‐emitting diode (WOLED) technology has attracted considerable attention because of its potential use as a next‐generation solid‐state lighting source. However, most of the reported WOLEDs that employ the combination of multi‐emissive materials to generate white emission may suffer from color instability, high material cost, and a complex fabrication procedure which can be diminished by the single‐emitter‐based WOLED. Herein, a color‐tunable material, tris(4‐(phenylethynyl)phenyl)amine (TPEPA), is reported, whose photoluminescence (PL) spectrum is altered by adjusting the thermal annealing temperature nearly encompassing the entire visible spectra. Density functional theory calculations and transmission electron microscopy results offer mechanistic understanding of the PL redshift resulting from thermally activated rotation of benzene rings and rotation of 4‐(phenylethynyl) phenyl)amine connected to the central nitrogen atom that lead to formation of ordered molecular packing which improves the π–π stacking degree and increases electronic coupling. Further, by precisely controlling the annealing time and temperature, a white‐light OLED is fabricated with the maximum external quantum efficiency of 3.4% with TPEPA as the only emissive molecule. As far as it is known, thus far, this is the best performance achieved for single small organic molecule based WOLED devices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.