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High-entropy oxides (HEOs) are considered promising electrode materials as they have great potential to provide much higher energy density and cyclability than their conventional electrode counterparts such as graphite. In the present work, nanostructured HEOs were fabricated on the surface of conductive carbon black using laser beam irradiation, which generally implements the rapid bottom-up carbothermal process. Furthermore, electrochemical performances of Co-free and Co-incorporated HEO nanoparticles in comparison with bulk-HEO counterparts were investigated. In particular, the Co-free (LiFeNiMnCuZn)3O4 nanoparticle electrode showed the best capability presenting both the highest cycling value of 866 mA h g−1 (100% capacity retention) after 800 cycles at 0.5 A g−1 and rate performances of 585 at 2.0 A g−1 and 436 mA h g−1 at 5.0 A g−1 without decay. The long cycling performance of Co-free HEOs could be derived from the reversible spinel structure, according to the in situ X-ray diffraction (XRD) results, as well as the strong thermal stability of high-entropy mixing phases, as indicated by a large positive decomposition enthalpy according to density functional theory (DFT) calculations. Additionally, the assembled full cell (LiFeNiMnCuZn)3O4‖LiNi0.6Co0.2Mn0.2O2 delivered a power density of 670 W h kg−1 with a high discharge voltage around 3.7 V based on the 0.1C discharge profile. As manifested by the DFT calculations, the low anode voltage of HEOs measured here is due to the electron-sufficient Zn, which favors the Ni2+/Ni3+ redox couple. This work is expected to provide a guideline for the development of advanced high-entropy nanostructured electrode materials for efficient batteries. [ABSTRACT FROM AUTHOR]

Low discharge capacity and rapid capacity decay are the main causes that hinder the commercialization of lithium–sulfur (Li–S) batteries. A feasible strategy is to modify electrolytes which aims at accelerating sulfur conversion reactions and restraining side reactions on both electrodes. However, simultaneously increasing the reactivity of sulfur and reducing the reactivity of Li poses great challenges. Herein, an electrolyte additive of 6-bromoxoindole (BOD) was introduced into Li–S batteries. Through a systematic study, it is found that the BOD can dissolve in electrolytes, undergo partial deprotonation, and react with LiTFSI/LiPSs to form BOD-Li-TFSI/BOD-Li-PS solvation structures. The Li+ transfer kinetics and sulfur conversion reactions were significantly enhanced with 0.5 wt% BOD addition, and meanwhile, the Li anode maintained stable plating/stripping behavior. As a result, the cell delivered a high discharge capacity of 811 mA h g−1 at a sulfur loading of 5 mg cm−2 and E/S ratio of 8 μL mg−1 at ambient temperature and could also work stably at a low temperature of −20 °C. [ABSTRACT FROM AUTHOR]

Targeted imaging is playing an increasingly important role in the early detection and precise diagnosis of cancer. This need has motivated research into sensory nanomaterials that can be constructed into imaging agents to serve as biosensors. Graphene quantum dots (GQDs) as a valuable nanoprobe show great potential for use in two-photon biological imaging. However, most as-prepared GQDs exhibit a low two-photon absorption cross-section, narrow spectral coverage, and "one-to-one" signal conversion mode, which greatly hamper their wide application in sensitive early-stage cancer detection. Herein, a versatile strategy has been employed to fabricate an aptamer Sgc8c-functionalized hybrid as a proof-of-concept of the signal amplification strategy for targeted cancer imaging. In this study, GQDs with two-photon imaging performance, and silica nanoparticles (SiO2 NPs) as nanocarriers to provide amplified recognition events by high loading of GQD signal tags, were adopted to construct a two-photon hybrid-based signal amplification strategy. Thus, the obtained hybrid (denoted SiO2@GQDs) enabled extremely strong fluorescence with a quantum yield up to 0.49, excellent photostability and biocompatibility, and enhanced bright two-photon fluorescence up to 2.7 times that of bare GQDs (excitation at 760 nm; emission at 512 nm). Moreover, further modification with aptamer Sgc8c showed little disruption to the structure of the SiO2@GQDs-hybrid and the corresponding two-photon emission. Hence, SiO2@GQDs–Sgc8c showed specific responses to target cells. Moreover, it could be used as a signal-amplifying two-photon nanoprobe for targeted cancer imaging with high specificity and great efficiency, which exhibits a distinct green fluorescence compared to that of GQDs–Sgc8c or SiO2@GQDs. This signal amplification strategy holds great potential for the accurate early diagnosis of tumors and offers new tools for the detection a wide variety of analytes in clinical application. [ABSTRACT FROM AUTHOR]

Rare-earth doped phosphors have received growing interest in the luminescence field, and hold great potential for lighting and display backlight applications. Nonetheless, the practical implementation of white light-emitting diodes requires the development of a cost-effective and high-performance red phosphor, which is still a significant challenge. In this paper, Eu3+ doped Ba3Na0.32Nb6O12(Si2O7)2 red phosphors were prepared using a high-temperature solid-state method. The structure and phase purity of the samples were analyzed in detail by powder X-ray diffraction (XRD), structure refinement and energy dispersive spectroscopy analysis. Under 395 nm excitation, the phosphor exhibited an intense red emission due to the 5D0 → 7FJ (J = 1, 2, 3, 4) transitions. Through decay curve measurements, it is found that the decay time corresponding to the double-exponential equation decreased with the increase of activator concentration. Theoretical calculations showed that the quadrupole–quadrupole interaction played a dominant role in concentration quenching. The CIE chromaticity coordinates of the phosphor were (0.6436, 0.3556) and the color purity reached 92.07%, indicating that the sample has high color purity. In addition, the temperature-dependent intensity was investigated in detail. The results demonstrated that Ba3Na0.32Nb6O12(Si2O7)2:Eu3+ is a potential red-emitting phosphor for near-ultraviolet based white light-emitting diodes. [ABSTRACT FROM AUTHOR]

Full-dimensional, ab initio-based many-body potential energy surfaces and dipole moment surfaces constructed using the neural network method for SO2(H2O)n (n = 1,2) complexes are reported. The database of the SO2 1-body PES, SO2(H2O) 2-body PES and SO2(H2O)2 3-body PES consists of 11 952, 79 882 and 84 159 ab initio energies, respectively. All 1-body energies were calculated at the CCSD(T)/CBS(AVTZ:AVQZ) level and all 2,3-body energies were calculated at the DSD-PBEP86/AVTZ level. The database of DMSs is the same as that of PESs and all dipole moments were calculated at the MP2/AVTZ level. Harmonic frequencies and dissociation energies of SO2(H2O) and SO2(H2O)2 were calculated on these PESs and compared with ab initio results to examine the fidelity of these PESs. [ABSTRACT FROM AUTHOR]

With the development of solid-state lighting, full-spectrum lighting has gradually received extensive attention. Until now, Bi3+-doped narrow-band blue phosphors have been widely reported, but broadband green-yellow Bi3+-doped luminescent materials generated by metal-to-metal charge transfer have been rarely reported. In this study, a Bi3+ ion doped germanate luminescent material CsAlGe2O6:x%Bi3+ (1 ≤ x ≤ 11) is synthesized by a high-temperature sintering method. The phosphor can generate a broad green-yellow band peaking at 535 nm with a full width at half maximum of 165 nm under ultraviolet radiation. Through the analysis of the coordination environment, photoluminescence spectra and decay curves, the broadband emission spectra of Bi3+ ions are proved to be generated by the metal-to-metal charge transfer state and the 3P1 → 1S0 transition. By using theoretical research, luminescence kinetics, and Gaussian fitting, the luminescence mechanism of Bi3+ is examined. Meanwhile, the high quantum efficiency and superior thermal stability prove that the phosphor can be used as an efficient luminescent material in the field of full-spectrum LED devices. [ABSTRACT FROM AUTHOR]

In this work, a series of Eu3+ doped double perovskite phosphors Ba9La2W4O24:xEu3+ (0.2 ≤ x ≤ 1.0) were synthesized by a high temperature solid-state method. The phase purity and morphology features of phosphors were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Rietveld refinement was also executed and the results indicated that the cation site could provide a relative symmetrical environment, which will induce a large orange/red emission ratio. When excited by n-UV light, the phosphors could emit bright orange-red light with the strongest peak at 592 nm corresponding to the 5D0–7F1 transition. The optimal doping concentration of Eu3+ ions was x = 0.8 and the photoluminescence quantum yield could reach 82.9%. The concentration quenching effect was calculated to be dominated by the dipole–dipole interaction and transient spectrum results also gave direct evidence of the concentration quenching. At the operating temperature of the LED (145 °C), the photoluminescence emission intensity can still reach 97.16% at room temperature. The abnormal thermal quenching behavior was demonstrated to be compensated by electrons captured by traps. The satisfactory CIE coordinates, high color purity and strong emission intensity indicated that BLWO:0.8Eu3+ was a potential red phosphor for WLEDs with broad application prospects. [ABSTRACT FROM AUTHOR]

Currently, modulating the charge transfer (CT) process poses a major challenge for many organic solar cells (OSCs) and monitoring the CT dynamics demands further research. The surface-enhanced Raman spectroscopy (SERS) technique was successfully used herein to monitor the CT process, which was strongly dependent on the carrier density in the Ag–polymer–fullerene system. However, the carrier density can be controlled by the acceptor and donor concentrations. As the acceptor and donor concentrations were changed, significant frequency shifts in the SERS peaks were observed. The donor and acceptor concentration changes exhibited the opposite effects on the frequency shift due to donor-to-acceptor and acceptor-to-donor CT. In addition, the peak intensity at 1450 cm−1 increased significantly owing to the CT contribution. Thus, the CT process induced the Raman frequency shift and monitoring the peak intensity increase can elucidate the interaction mechanism between the acceptor and donor in OSCs. This study provides a novel insight into the theoretical foundation of CT dynamics in metal–polymer–fullerene systems. [ABSTRACT FROM AUTHOR]

Red phosphors often play a crucial role in enhancing the lighting quality of WLEDs. However, it remains difficult to develop a red phosphor that shows high efficiency, outstanding thermal stability, and high color purity. The struggle against "thermal stability" is always an inevitable task for photoluminescent materials. In this work, we propose a method inspired by nonlinear optical materials to synthesize a novel red-emitting pyrophosphate phosphor Cs2MgZn2(P2O7)2:Eu3+. The phase purity and morphology features are clearly investigated using X-ray diffraction and scanning electron microscopy. The emission spectra show that Cs2MgZn2(P2O7)2:20%Eu3+ can emit bright red light with a high color purity (84.68%) under ultraviolet light excitation. Rietveld refinement of the XRD pattern and luminescence kinetics as a function of the Eu3+ doping concentration were used to obtain information about the crystal structure and determine the Eu3+ site occupation preference. In particular, the sample exhibited excellent thermal stability (100%@170 °C) due to zero thermal quenching behavior, and the mechanism is described in detail. The present work provides a new possibility for the research and application of zero-thermal quenching phosphors. In addition, the fabricated WLED device was characterized via its satisfactory CIE coordinates (0.3508, 0.3233), outstanding correlated color temperature (CCT = 4608 K) and strong emission intensity, which demonstrates its potential for application in the field of WLED solid-state lighting. [ABSTRACT FROM AUTHOR]

To realize early fire identification in cotton harvesting operations, a mid-infrared carbon monoxide (CO) sensor system was developed. To match the broadband light source with a 15° divergence angle, a multipass gas cell (MPGC) with an effective path length of 180 cm was designed to improve sensor sensitivity, leading to a limit of detection (LoD) of 0.83 parts-per-million by volume (ppmv). A damping module with springs at the bottom and front/back sides was fabricated, which can effectively reduce the vibration intensity by >80%. The sensor system can operate normally from −40 °C to 85 °C by stabilizing the temperature of the optical module through heating or cooling as well as using automotive electronic components. An adaptive early fire identification algorithm based on a dual-parameter threshold alarming method was proposed to avoid false and missing alarms. Field deployments on a harvester verified the good practicability of the sensor system. [ABSTRACT FROM AUTHOR]

One-dimensional nanotube heterostructures with IrO2-stabilized La2IrO6 is obtained by an electrospinning approach. The La2IrO6/IrO2 catalyst exhibits superior catalytic activity and strong stability for the oxygen evolution reaction. The synergistic cooperation between the two types of Ir as the active sites in La2IrO6/IrO2 is demonstrated by in situ Raman spectrum and DFT calculation. [ABSTRACT FROM AUTHOR]

Fe–N–C catalysts can be used as a substitute for expensive and scarce platinum-based catalysts in proton exchange membrane fuel cells (PEMFCs). However, the durability of MEAs worsens as the performance loss increases after the first few hours of operation. To gain better insight into the degradation mechanism, a cesium salt of phosphotungstic acid is employed as a proton conductor to replace the Nafion ionomer in MEAs. The experimental data reveals improved performance stability. Except for degradation of the catalyst itself, the faster growth of proton resistance of MEAs confirms the degradation of solid electrolyte Nafion as the primary reason leading to fast performance degradation. By contrast, changes in the structure and morphology of the cathode catalyst layer (CCL) are not the primary reasons for the performance degradation of the Fe–N–C MEA. Furthermore, the 19F NMR peak assigned to a SCF2-linked SO3H group decreases by about 20%, providing direct evidence for the deactivation of the Nafion ionomer. The quantitative results provide a better in situ understanding of the fast degradation of the Fe–N–C based CCL attributed to the decomposition of the Nafion ionomer. In sum, these data look promising for future optimization of CCLs to match the commercialized requirement of the Fe–N–C MEA. [ABSTRACT FROM AUTHOR]

Fluorescent organic nanoparticles (FONs) with intriguing features have emerged as a kind of inspiring contrast reagent for various biomedical applications. However, the formation of preassembled nanoparticles requires stimuli (such as light, pH, heat, etc.), which hampers their application in all circumstances. The challenge lies in understanding and then exploring a simple and feasible method to prepare FONs without any external stimuli. Herein, we designed a novel in situ strategy to fabricate cobalt oxyhydroxide (CoOOH) nanoflake-loaded pyrene-based fluorescent organic nanoparticles (PyFONs), enabling sensitive monitoring and precision imaging of ascorbic acid (AA) in living cells. The pyrene-based FONs were constructed via a facile one-step co-precipitation method and used as the signal output. The π–π stacking-directed self-assembly process provides a brightness at 468 nm of the pyrene excimer emission accompanied by an almost disappeared monomer peak around 370–400 nm. The CoOOH nanoflakes were then in situ grown on the surface of PyFONs to serve as both an effective quencher and a recognition unit for AA. The as-synthesized PyFONs@CoOOH showed weak fluorescence signals via Förster resonance energy transfer (FRET). Subsequently, the turn-on fluorescence responses were triggered during CoOOH nanoflake reduction to Co2+ by AA, which resulted in the decomposition and collapse of the CoOOH nanoflakes. Owing to the specific oxidation–reduction reaction between the enediol group of AA and CoOOH on the surface of the PyFONs@CoOOH nanoprobe, excellent sensitivity and selectivity for AA detection was obtained with a wide linear relationship from 2.0 μM to 500 μM. The detection limit was calculated to be as low as 0.21 μM (S/N = 3). More importantly, the PyFONs@CoOOH nanoprobe also presented excellent sensitivity and selectivity for AA analysis in biological fluids, as well as for bioimaging of endogenous AA in living cells. Consequently, the proposed sensing systems can serve as a powerful tool to monitor and image AA and show broad potential applications in clinical diagnostics and drug screening. [ABSTRACT FROM AUTHOR]

Effective methods are required to quantify the organochlorine pesticide procymidone due to its potentially harmful effects toward human health and the environment. Here, hydrophilic hollow imprinted microspheres were prepared via a simple method as fluorescent sensors (@MIH-prm) for the sensitive and selective detection of PRM in ginseng. A new method of adsorption efficiency evaluation for @MIH-prm was subsequently introduced (EBS%), the effective binding site, which provided a comprehensive evaluation of the performance compared with conventional methods. The results showed that @MIH-prm could detect PRM in filtered and diluted ginseng juice with high sensitivity (LOD, 0.569 nM) and a rapid detection rate (quantitative detection of PRM within 18 min). Good selectivity was observed in the presence of combinations of different pesticides, and the adsorption of PRM could be described by the pseudo-second-order kinetic model. PRM concentrations exhibited good linearity over 1–40 nM, and the accuracy (recovery rates, 99.2 to 103.1%) and precision (RSD at 1.0 × 10−9 M, 3.14%) indicated that @MIH-prm could be used for the quantitative analysis of PRM in complex matrices. Hence, @MIH-prm has good application potential in pollution control monitoring and enforcement. [ABSTRACT FROM AUTHOR]

The construction of the cyclopropyl quaternary carbon center can afford a series of 1,1-olefin bioisosteres. Here, we report tertiary cyclopropyl carbagermatranes, which can be easily obtained by the zinc-mediated decarboxylation of NHP esters. In addition, they exhibit efficient reactivity in the palladium-catalyzed cross-coupling reaction and orthogonal reactivity with boron reagents, therefore acting as robust nucleophiles for the synthesis of tertiary cyclopropane and efficient intermediates for the formation of quaternary centers. [ABSTRACT FROM AUTHOR]

Tunable oxygen vacancies of LaNiO3 (LNO–Vo) are realized by theoretical prediction and the NaBH4-reduction approach. The LNO2.7 catalyst exhibits superior catalytic activity and long-term stability for water oxidation. Direct evidence of the active site center and the intermediates is observed from in situ Raman spectra and DFT calculations. [ABSTRACT FROM AUTHOR]

A high-performance catalyst, O-doped Sb2S3 nanosheets (SS–O NSs), is synthesized and introduced into lithium–sulfur batteries. Owing to their good conductivity, strong adsorbability/catalytic effect to polysulfides and fast Li+ diffusion, the SS–O NSs-modified cathodes can effectively mitigate the shuttle effect, thus achieving outstanding electrochemical performance. [ABSTRACT FROM AUTHOR]

Donor–acceptor (D–A) copolymers are a type of prototypical conducting conjugated polymers with remarkably high mobility approaching 100 cm2 V−1 s−1, making them potential thermoelectric (TE) candidates. However, only limited pioneering experimental studies have been devoted to obtaining a microscopic understanding of the relationship between the atomic structure and TE properties of D–A copolymers, which hampered the effort to enhance their TE performance. As such, our work seeks to establish a comprehensive understanding of the intrinsic electronic, geometric, and TE properties of a series of D–A copolymer chains. By using density functional theory methods combined with Boltzmann transport and deformation potential theories, we found the strong intra-chain superexchange (SE) coupling to be a key indicator for high mobility and TE performance. Strong SE couplings induce not only small hole effective mass but also weak electron–phonon couplings, resulting in high mobility and high power factors. Furthermore, we provide a route to establish strong SE coupling and optimize the TE performance by minimizing the energy difference between the frontier molecular orbitals of the donor and acceptor moieties. Our work thus provides strong indications that D–A copolymers represent a class of systems with high potential in TE applications. [ABSTRACT FROM AUTHOR]

A mild copper-catalyzed alkylarylation of vinylarenes with cycloalkylsilyl peroxides and boronic acids is described. This three-component protocol provides a straightforward approach to the remote keto-functionalized 1,1-diarylmethane derivatives. A radical pathway initiated by C–C bond cleavage is proposed for this tandem reaction. [ABSTRACT FROM AUTHOR]

Thermoelectric (TE) polymers have unique advantages in converting heat into electricity. But their Seebeck coefficient is lower than that of inorganic TE materials by about one order of magnitude. Here, surface energy filtering is proposed to significantly enhance the Seebeck coefficient of TE polymers. The as-prepared poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS, the most popular TE polymer) films from aqueous solution have a low Seebeck coefficient of 15–18 μV K−1 and a power factor of ∼0.008 μW m−1 K−2. Depositing Rhodamine 101, a zwitterion, on PEDOT:PSS films can enhance the Seebeck coefficient to 47.2 μV K−1 and the power factor to 401.2 μW m−1 K−2. The Rhodamine 101 effect on the Seebeck coefficient is consistent with its effect on the work function of PEDOT:PSS. The enhancement in the Seebeck coefficient is ascribed to the dipole moment of Rhodamine 101 and the interfacial dipole moment formed at the surface of the PEDOT:PSS films. This is confirmed by theoretical simulations. We call this mechanism surface energy filtering. Surface energy filtering can increase the mean energy of the transporting carriers and thus the Seebeck coefficient of the PEDOT:PSS films while only slightly affecting the electrical conductivity. It can thus significantly enhance the Seebeck coefficient and the power factor simultaneously. [ABSTRACT FROM AUTHOR]

Here, the carrier dynamics of a π-conjugated polymer is monitored by voltage-dependent surface-enhanced Raman scattering (SERS). The conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is employed as a metal-free SERS substrate. Under different voltage conditions, the SERS performance of the semiconductors' rectification characteristic is discussed. Our results open an unprecedented regime for conducting polymer-based SERS. [ABSTRACT FROM AUTHOR]

Herein, a new electropolymerized (EP) film named poly-triphenylcarbazole fluoranthene (p-TPCF) has been in situ synthesized by an electrochemical cyclic voltammetry method and applied to tune the work-function (WF) of the PEDOT:PSS hole-transporting layer (HTL) in organic solar cells (OSCs). Multiple techniques, including Kelvin probe force microscopy (KPFM), light intensity dependent solar cell characterization, Mott–Schottky analysis, and transient photovoltage (TPV) and transient photocurrent (TPC) measurements, have been explored to provide insights into the mechanism. Benefiting from the deeper work-function (WF), larger built-in voltage (Vbi), decreased recombination, and longer carrier lifetime, the devices with EP films exhibited superior device performance with simultaneously enhanced Voc, Jsc and FF. [ABSTRACT FROM AUTHOR]

Mahan and Sofo proved that the best thermoelectric performance could be found in materials with a sharp peak in the density-of-states (DOS) near the chemical potential, which may come from a localized electronic state. However, such a state usually results in a poor electrical conductivity. Therefore, such an idealized model leads to this question: is there a material which naturally possesses a narrow DOS peak near the band edge without a localized state? The answer is yes. From a number of covalent organic frameworks (COFs), we identified poly(tetrathienoanthracene) (PTTA), a purely organic 2D COF possessing such a DOS and subsequently achieves a significant thermoelectric performance with an enhanced Seebeck coefficient such that the peak n- and p-type power factors can reach up to 14.9 and 21.9 μW cm−1 K−2, respectively. This provided a feasible prototype of the Mahan–Sofo model and demonstrated for the first time that a purely organic 2D COF could exhibit high thermoelectric performance for functional applications. [ABSTRACT FROM AUTHOR]

In this study, we constructed bioconjugates of targeting immune checkpoint B7-H3 antibody and chlorin e6 to treat non-small cell lung cancer under the guidance of spectroscopic photoacoustic and fluorescence imaging. The B7-H3–Ce6 conjugates could display effective tumor diagnosis and therapy and provide a novel approach for immunotherapy. [ABSTRACT FROM AUTHOR]

The cathode interlayer plays a key role in the photovoltaic performance in organic solar cells. In this work, we demonstrate that polydopamine/ZnO can be used as efficient electron transport layers (ETL) in inverted non-fullerene organic solar cells. In comparison to the devices with the ZnO ETL, the power conversion efficiency of inverted PBDBT:ITIC solar cells with the PDA/ZnO ETL can be boosted from 10.15% to 11.14%, due to the simultaneously enhanced open-circuit voltage, short-circuit current and fill factor. The increased photovoltaic performance is mainly attributed to a faster charge extraction ability at the cathode interface and longer carrier lifetime, confirmed by transient optoelectrical analyses. Revealed by conductive-AFM and KPFM coupled with absorption spectroscopy, high optical transmittance and vertical electrical conductivity with a suitable low work function and a doping effect induced by PDA were observed in the PDA modified ZnO, which makes it a good ETL material for inverted solar cells and indicated universal applicability. This work provides a new approach to modify the cathode interfacial properties towards high efficiency organic solar cells with non-fullerene acceptors. [ABSTRACT FROM AUTHOR]

π–d conjugated transition-metal coordination polymers have been rapidly emerging as one of the most attractive polymer-based thermoelectric materials in the past decade. However, the relationship between these polymers' geometric structures, orbital characteristics and their thermoelectric properties remains unclear, which has seriously hindered the development of a straightforward design strategy for π–d conjugated coordination polymer-based thermoelectric materials. Herein, taking poly(nickel-benzene-1,2,4,5-tetrathiolate) and its five derivatives as specimen models, we have studied the effect of ligand chemistry modulation on the thermoelectric properties and elucidated the structure–property relationship based on density functional calculations, and Boltzmann transport and deformation potential theories. Our theoretical results indicate that the thermoelectric power factor is governed by the frontier molecular orbital alignment between the square planar metal-tetrasulfide fragment and the organic π-conjugated spacers. Specifically, a better frontier molecular orbital alignment results in a weaker electron–phonon coupling. Consequently, higher mobility can be achieved, which leads to a higher thermoelectric power factor. This finding provides a screening rule for the rationalization and design of high performance p-type π–d conjugated transition-metal coordination thermoelectric materials. [ABSTRACT FROM AUTHOR]

Conjugated microporous polymers (CMPs) are a unique class of polymers that consist of an extended π-conjugated backbone and reactive side groups. Owing to the non-planar configuration of the monomer, these polymers form a solid 3D crosslinked framework that facilitates charge transport in the polymers. Herein, we report the synthesis of CMP films polymerized by electrochemical deposition and their use as hole transporting layers in organic photovoltaics (OPVs). With this strategy, the thickness could be precisely controlled by the scan cycle. The pH neutral CMP film avoids the acidity of the commercial PEDOT:PSS, which is the most commonly used hole transporting material in OPVs. With CMP films, we achieve comparable device performances with PEDOT:PSS containing devices based on PTB7-Th:PC71BM. Afforded by the described electrochemical approach, the amounts of materials needed to reach a target film thickness can be favorably saved with respect to those with spin-casting, which provides an opportunity for reducing the cost of OPVs. [ABSTRACT FROM AUTHOR]

Conductive polymers have been attracting attention for decades due to their promising applications in photovoltaic cells and thermoelectrics. Among them, poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is the most extensively studied one with the features of high water dispersibility, transparency and thermal stability as well as having relatively high electrical conductivity (EC). Nevertheless, the EC of as-prepared PEDOT:PSS is still unsatisfactory for real applications. Experimental studies on PEDOT:PSS have showed that its low EC could be elevated by more than 3 to 4 orders of magnitude by polar solvent treatment. However, the mechanism of this enhancement remains unclear. In this work, dimethyl sulfoxide (DMSO) treated PEDOT:PSS polymers are studied using multiscale molecular modeling, including density functional theory (DFT) calculations and molecular dynamics (MD) simulations. We elucidate the mechanism of EC enhancement at the molecular level, demonstrating that DMSO dissolves the PSS shell to release the conductive PEDOT in the core for self-aggregation, leading to subsequent phase separation of PEDOT and PSS by charge screening. These findings are important for the selection of alternative solvents for further EC enhancement of PEDOT:PSS in thermoelectric applications. [ABSTRACT FROM AUTHOR]

Self-assembled DNA nanostructures have attracted significant research interest in biomedical applications because of their excellent programmability and biocompatibility. To develop multifunctional drug delivery from DNA nanostructures, considerable key information is still needed for clinical application. Traditional fixed endpoint assays do not reflect the dynamic and heterogeneous responses of cells with regard to drugs, and may lead to the misinterpretation of experimental results. For the first time, an integrated time-lapse live cell imaging system was used to study the cellular internalization and controlled drug release profile of three different shaped DNA origami/doxorubicin (DOX) complexes for three days. Our results demonstrated the dependence of DNA nanostructures on shape for drug delivery efficiency, while the rigid 3D DNA origami triangle frame exhibited enhanced cellular uptake capability, as compared with flexible 2D DNA structures. In addition, the translocation of released DOX into the nucleus was proved by fluorescence microscopy, in which a DOX-loaded 3D DNA triangle frame displayed a stronger accumulation of DOX in nuclei. Moreover, given the facile drug loading and auto fluorescence of the anti-cancer drug, DOX, our results suggest that the DNA nanostructure is a promising candidate, as a label-free nanocarrier, for DOX delivery, with great potential for anticancer therapy as well. [ABSTRACT FROM AUTHOR]