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Dual-state (solution and solid) highly emissive three-arm star polymethacrylates were synthesized via ATRP using TPA-BKI-3Br as initiator. [Display omitted] • Three-arm star polymethacrylates with bright luminescence in both solution and solid state were prepared and studied efficiently. • The photophysical characteristics of the polymethacrylates were notably impacted by the space charge transfer between the TPA-BKI unit and polymer chains. Organic/polymeric fluorescent materials with bright emission both in solution and in the solid state have garnered growing interest in biological and optoelectronic fields. Herein, triphenylamine-derived boron ketoimine (TPA-BKI-3Br) was utilized as the initiator for atom transfer radical polymerization (ATRP) to prepare dual-state emission three-arm star polymethacrylates. Due to the intramolecular charge transfer (ICT) effect and highly distorted structure of the TPA-BKI unit, as well as the polymer arms constraining intramolecular motions, the resultant polymers displayed significant emission in solution. In the aggregated and solid states, the photophysical characteristics of the resultant polymethacrylates were notably impacted by the space charge transfer between the TPA-BKI unit and polymer chains. In addition, the TPA-BKI-based poly(2-(dimethylamino)ethyl methacrylate) (TPA-BKI-(PDMAEMA)3) exhibited fluorescence responses to temperature variations owing to the presence of dimethylamino group. This study presents an approach for the advancement of dual-state emission polymeric materials. [ABSTRACT FROM AUTHOR]

Emulation of photonic synapses through photo‐recordable devices has aroused tremendous discussion owing to the low energy consumption, high parallel, and fault‐tolerance in artificial neuromorphic networks. Nonvolatile flash‐type photomemory with short photo‐programming time, long‐term storage, and linear plasticity becomes the most promising candidate. Nevertheless, the systematic studies of mechanism behind the charge transfer process in photomemory are limited. Herein, the physical properties of APbBr3 perovskite quantum dots (PQDs) on the photoresponsive characteristics of derived poly(3‐hexylthiophene‐2,5‐diyl) (P3HT)/PQDs‐based photomemory through facile A‐site substitution approach are explored. Benefitting from the lowest valance band maximum and longest exciton lifetime of FAPbBr3 quantum dot (FA‐QDs), P3HT/FA‐QDs‐derived photomemory not only exhibits shortest photoresponsive characteristic time compared to FA0.5Cs0.5PbBr3 quantum dots (Mix‐QDs) and CsPbBr3 quantum dots (Cs‐QDs) but also displays excellent ON/OFF current ratio of 2.2 upon an extremely short illumination duration of 1 ms. Moreover, the device not only achieves linear plasticity of synapses by optical potentiation and electric depression, but also successfully emulates the features of photon synaptic such as pair‐pulse facilitation, long‐term plasticity, and multiple spike‐dependent plasticity and exhibits extremely low energy consumption of 3 × 10−17 J per synaptic event. [ABSTRACT FROM AUTHOR]

Achieving a large dissymmetry factor (glum) is a challenge in the field of circularly polarized luminescence (CPL). A chiral charge‐transfer (CT) system consisting of chiral electron donor and achiral electron acceptor shows bright circularly polarized emission with large glum value. The chiral emissive CT complexes could be fabricated through various approaches, such as grinding, crystallization, spin coating, and gelatinization, by simply blending chiral donor and achiral acceptor. The structural synergy originating from π–π stacking and strong CT interactions resulted in the long‐range ordered self‐assembly, enabling the formation of supramolecular gels. Benefiting from the large magnetic dipole transition moment in the CT state, the CPL activity of CT complexes exhibited large circular polarization. Our design strategy of the chiral emissive CT complexes is expected to help the development of new molecular engineering strategies for designing highly efficient CPL‐active materials. [ABSTRACT FROM AUTHOR]

Achieving a large dissymmetry factor (glum) is a challenge in the field of circularly polarized luminescence (CPL). A chiral charge‐transfer (CT) system consisting of chiral electron donor and achiral electron acceptor shows bright circularly polarized emission with large glum value. The chiral emissive CT complexes could be fabricated through various approaches, such as grinding, crystallization, spin coating, and gelatinization, by simply blending chiral donor and achiral acceptor. The structural synergy originating from π–π stacking and strong CT interactions resulted in the long‐range ordered self‐assembly, enabling the formation of supramolecular gels. Benefiting from the large magnetic dipole transition moment in the CT state, the CPL activity of CT complexes exhibited large circular polarization. Our design strategy of the chiral emissive CT complexes is expected to help the development of new molecular engineering strategies for designing highly efficient CPL‐active materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Complexes 1 , 2 and 3 exhibit reversible photochromic behavior. • Complexes 1 , 2 and 3 exhibit long-lived persistent phosphorescence. • Complex 2 exhibits excitation wavelength dependent fluorescence. • Three complexes show great potential in data encryption and anticounterfeiting. • 2 was fabricated in inkless printing performance and information transmission. Long persistent luminescence materials have wide application prospects in the fields of optical communication, sensors, and anticounterfeiting. Recently, some researchers have proved the feasibility of charge transfer effect in the construction of visible light excited room temperature phosphorescence (RTP) materials. However, materials with electronic effects require elaborate design to exhibit long-lived phosphorescence. Herein, a series of coordination compounds based on viologen ligand HL⋅Cl (4-carboxybenzyl)-4,4′-bipyridinium chloride) and Zn2+ with benzoic acid derivatives (o- , m- , p- phthalic acid) were reported. They exhibit not only reversible photochromic properties, but also long-lived persistent phosphorescence. Three complexes possess different structures through different auxiliary ligands with different optical physical properties. Complex 1 exhibits dynamic phosphorescence emission at low temperatures. Interestingly, we synthesized the first viologen complex (complex 2) with excitation wavelength dependent fluorescence, and the emission color gradually changed from blue to red with the increase of excitation wavelength. In addition, the applications of three complexes in data encryption and anticounterfeiting are further demonstrated. This work not only presents coordination compounds with dynamic afterglow materials, excitation wavelength- and time-dependent emission properties, but also provides a new strategy for the charge transfer effect in visible light-excited RTP materials. [ABSTRACT FROM AUTHOR]

In recent years, assembling 2D layered materials into three-dimensional (3D) architectures has become the research focus in catalysis fields. In this study, 3D porous g-C 3 N 4 @carbon (CN@C) microflowers composed of carbon-coated g-C 3 N 4 nanosheets were prepared by a facile bio-inspired method. At first, cyanuric acid-melamine (CAM) supermolecules were assembled into 3D microflowers with the mediation of sucrose molecules through a hydrothermal process, and then isomorphically converted into 3D CN@C microflowers upon calcination. By varying the saccharide species, it was found that the formyl groups of saccharide molecules and their self-polycondensation behavior could govern the CAM assembly and subsequent formation of microflower structure. The resultant CN@C microflowers exhibit high oxygen evolution reaction (OER) activity with a potential of 1.68 V at a current density of 10 mA cm −2 due to efficient mass and charge transfer, which is close to the reported value for the state-of-the-art metal catalyst IrO 2 /C (1.60 V, 0.1 mol L −1 KOH) and much superior to that of pure g-C 3 N 4 . [ABSTRACT FROM AUTHOR]

Solution‐processable organic–inorganic hybrid perovskite materials have been applied to a variety of optoelectronic devices due to its long exciton lifetime and small binding energy. It has emerged as promising front‐runners for next‐generation non‐volatile flash photomemory devices. However, the effect of crystal orientation of perovskite on the performance of photomemory still has not fully developed. Herein, non‐volatile flash photomemory with quasi‐2D perovskite/polystyrene‐block‐poly(ethylene oxide) (PS‐b‐PEO) as photoactive floating‐gate and p‐type semiconductor poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) as the chare‐transporting layer is successfully demonstrated. By adding phenylethylammonium bromide (PEABr) in formamidinium lead bromide perovskite (FAPbBr3), the crystal orientation of quasi‐2D perovskite is highly improved, which results in raised charge transfer efficiency from 76% to 90% compared to the pure FAPbBr3. Furthermore, ON/OFF current ratio of 104, low photo‐programming time of 5 ms under light intensity of 0.85 mW cm−2, charge transfer rate of 0.063 ns−1, and data storage capacity of over 7 bits (128 levels) in one cell can be achieved. In addition, the correlation between photo‐responsive current and photoluminescence (PL) is first examined by in operando PL measurement, which provides a new platform to explore the charge transfer process in photomemory. [ABSTRACT FROM AUTHOR]

Abstract: This study examined the effects of the addition of ZnO and Y2O3 on the electrochemical characteristics of a Ni(OH)2 electrode in nickel–metal hydride (Ni–MH) secondary batteries. The discharge capacity of the electrode was less affected by the addition of ZnO and Y2O3 at a 0.2 C-rate and 25°C. However, the addition of Y2O3 deteriorated the discharge capacity and the cycle life of the electrode by increasing the charge transfer resistance of the electrode at an increased C-rate of 1 C and 25°C. Under severer conditions at 1 C-rate and 60°C, the electrode materials were separated from the current collector and, accordingly, the discharge capacity was abruptly degraded with cycling for the electrodes comprising only 4wt% ZnO or 4wt% Y2O3. In contrast, the electrodes containing both 2wt% ZnO and 2wt% Y2O3 exhibited stable discharge capacity with cycling and excellent cycle life due to the high overvoltage for oxygen evolution. The present results indicate that the addition of ZnO and Y2O3 with an optimum composition suppresses oxygen evolution in the interfaces between active materials and the current collector and improves the cycle life of the electrode. [ABSTRACT FROM AUTHOR]

• Highlights: Porous N-deficient g-C3N4 was fabricated with acetic acid-treated melamine as precursor. • Acetic acid plays a key role in the formation of porous structure and N deficiency. • PNCN can degrade almost 100 % RhB within 2.0 h and generate 257.5 μmol g−1 h−1 H2. • DFT calculation indicates that N deficiency can lead to bandgap narrowing and activity elevating. • This study affords a facile and scalable strategy to fabricate efficient g-C3N4 photocatalysts. Porous nitrogen-deficient graphic carbon nitride (PNCN) was fabricated by using acetic acid (HAc)-treated melamine as precursor via one-pot method. The as-prepared PNCN photocatalysts possess a loose porous structure with nitrogen deficiencies due to the decomposition of HAc during calcination process. The PNCN photocatalyst exhibits the rate constant of RhB degradation (1.92 h−1) and H 2 evolution rate (257.5 μmol g−1 h−1) for ∼4.6 and ∼2.5 times of pristine g-C 3 N 4 under visible light irradiation, respectively. The mesoporous structure can increase the specific surface area of PNCN (19.24 m2 g-1), thereby rendering ample active sites and facilitating visible-light utilization. The moderate nitrogen deficiencies can not only substantially enhance photocurrent density and interfacial charge transfer, but also restrain the recombination of photo-generated carriers. In addition, the density functional theory (DFT) calculation further provides insight into the photocatalytic mechanism over PNCN. This study may present a facile and scalable method to fabricate PNCN with superior photocatalytic performance, which may hold great promise in practical applications. [ABSTRACT FROM AUTHOR]

• NM@NHM hetero-framework photocatalysts are designed and constructed. • The optimal photocatalyst exhibits a H 2 evolution rate of 2.25 mmol g−1 h−1 under visible light. • Both dual-ligand push-pull effect and heterojunction structure promote the electron transfer. • This study provides a new strategy to intensify the electron transfer in photocatalysis. The efficient transfer of photogenerated carriers is essential to the photocatalytic H 2 evolution. Herein, we designed and synthesized a kind of novel NH 2 -MIL-125@NH 2 /H-MIL-125 hetero-frameworks with nanopore structure to drive efficient charge transfer for photocatalytic H 2 evolution. Single-ligand NH 2 -MIL-125 (NM) and dual-ligand NH 2 /H-MIL-125 (NHM), which have similar composition, structure and well-matched energy band, were selected as the core and shell to prepare the NM@NHM hetero-framework as a proof-of-principle system. The hetero-framework strategy is proposed to intensify the charge transfer and thus enhance the photocatalytic activity. The H 2 evolution rate of optimal NM@NHM hetero-framework can reach 2.25 mmol g−1 h−1 under visible light, much higher than pristine NM (0.726 mmol g−1 h−1) and NHM (1.27 mmol g−1 h−1). Such high performance can be attributed to the hetero-framework structure consisting of NM and NHM with similar composition and structure, which reduces the interfacial resistance in the charge transfer, thus facilitating the photocatalytic H 2 evolution. Our work may provide a new strategy for the rational design of high-performance photocatalysts. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Low-cost FVC photocatalysts were successfully prepared using two-step hydrothermal method. • The prepared FVC photocatalysts exhibited a narrow bandgap of 2.0 eV and a wide light absorption range of 400 ∼ 700 nm. • Rapid transfer of photogenerated electrons through carbon media in FVC photocatalysts. • CSB, FV, and PMS had synergistic effect on promoting OFX degradation under visible light. • Gradual decrease in the toxicity of OFX intermediates. Biochar is recognized as a good medium for promoting photogenerated charge separation in photocatalysts. In this study, the FeVO 4 /coconut shell biochar (CSB) composites (FVC) were prepared through a cost-effective hydrothermal approach to activate peroxymonosulfate (PMS) for the degradation of ofloxacin (OFX). Incorporated CSB expanded the light absorption range of FVC by approximately 100 nm, and the band gap energy of FVC was reduced to 2.00 eV. Measurements through linear scanning voltammetry (LSV) and current–time (IT) chronoamperometric further confirmed that the accelerated electron transmission rate boosted PMS oxidation, which was attributed to the role of CSB acting as a mediator. Importantly, OFX degradation was significantly boosted by CSB, FV, and PMS synergistically. FVC had a significant OFX degradation efficiency under visible light irradiation (95.2 %) compared to FV (70.9 %), CSB (57.8 %) and PMS (30.5 %). Moreover, the h+, 1O 2 , ·O2–, ·OH, and SO 4 ·− were the main active species, whose degradation pathways were explored and the toxicity of the intermediates was assessed. Furthermore, the as-obtained FVC exhibited a remarkable stability and reusability. This work provides new insights into the mechanism of biochar-mediated charge transfer for antibiotic degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nitrogenase-inspired modular synthesis is designed to construct bimetallic UiO-66. • Zr-Hf clusters are constructed to coordinate the electron transfer and utilization. • U(0.5Hf)-2SH with TPA-2SH as the ligand can absorb and utilize the visible light. • A tandem ligand-to-metal-to-metal charge transfer mechanism (LMMCT) is proposed. • The resultant bimetallic UiO-66 yields 116.1 μmol h−1 g−1 NH 3 under visible light. Inspired by nitrogenase, we designed a kind of metal-organic framework (MOF) photocatalysts, U(Zr-Hf)-X, composed of bimetallic Zr-Hf nodes and different functional ligands. In the Zr-Hf bimetallic cluster, the Zr species serves as the active site of nitrogen fixation, while the Hf species acts as electron buffer tank to optimize electron transfer and utilization. In the organic ligands, the light absorption and utilization of MOFs is improved via introducing target functional groups to efficiently generate electrons. Notably, the organic ligand containing two thiol groups (-SH) can extend the absorption edge to the visible region. The optimal U(0.5Hf)-2SH (metal nodes: 0.5Zr: 0.5Hf; linkers: TPA-2SH) photocatalyst exhibits nitrogen fixation rate up to 116.1 μmol g−1 h−1 under visible-light, attributed to the ligand-to-metal-to-metal electron transfer (LMMET) pathway and Zr-based π-backbonding mechanism. Our nitrogenase-inspired strategy establishes a novel paradigm for rational design of visible-light-driven nitrogen fixation catalysts. [ABSTRACT FROM AUTHOR]

In organic light-emitting devices (OLEDs), the high performance of devices depends on balanced charge transfer in emitting layer (EML). However, the balance charge transfer is hard to achieve in the single host material-based EML. In this work, a high luminance co-host based OLEDs is printed. In detail, green phosphorescent material tris[2-(p-tolyl)pyridine]iridium(III) (Ir (mppy) 3) is used as dopant, and a hole-transporting material 4 , 4 ′ , 4 ″ -tris[3-methy-lphenyl(phenyl)amino]-triphenylamine (m-MTDATA) blended with an electron-transporting material 1,3,5-tris(phenyl-2-benzimidazolyl)-benzene (TPBi) as co-host. As a result, the optimized printing co-host OLEDs with 10 wt.% Ir (mppy) 3 shows a maximum luminance of 1 3 2 4 0 cd m − 2 , which is much higher than the CDBP counterpart. [ABSTRACT FROM AUTHOR]