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Considering the strong intermolecular interaction in all-polymer solar cells, 1-chloronaphthalene assisted layer-by-layer deposition was used to fabricate all-polymer solar cells with a P–i–N heterojunction and favorable crystallinity.

Due to the combination of ordered pores, TFSI− confined in the pores and continuous oxygen-containing functional groups, fast and homogeneous Li-ion transportation during repeated cycles was realized.

Photo- or electroreduction of carbon dioxide into highly valued products offers a promising strategy to achieve carbon neutrality. Here, a series of polyoxometalate-based metal-organic frameworks (M-POMOFs) were constructed by metalloporphyrins [tetrakis(4-carboxyphenyl)-porphyrin-M (M-TCPPs)] and reductive POM for photo- and electrocatalytic carbon dioxide reductions (PCR and ECR, respectively), and the mysteries between the roles of single metal site and cluster in catalysis were disclosed. Iron-POMOF exhibited an excellent selectivity (97.2%) with high methane production of 922 micromoles per gram in PCR, together with superior Faradaic efficiency for carbon dioxide to carbon monoxide (92.1%) in ECR. The underlying mechanisms were further clarified. Photogenerated electrons transferred from iron-TCPP to the POM cluster for methane generation under irradiation, while the abundant electrons flowed to the center of iron-TCPP for carbon monoxide formation under the applied electric field. The specific multielectron products generated on iron-POMOF through switching driving forces to control electron flow direction between single metal site and cluster catalysis.

1,2-Dimethoxyethane (DME) has been considered as the most promising electrolyte solvent for Li-metal batteries (LMBs). However, challenges arise from insufficient Li Coulombic efficiency (CE) and poor anodic stability associated with DME-based electrolytes. Here, we proposed a rational molecular design methodology to tailor electrolyte solvation for stable LMBs, where shortening the middle alkyl chain of the solvent could reduce the chelation ability, while increasing the terminal alkyl chain of the solvent could increase the steric hindrance, affording a diethoxymethane (DEM) solvent with ultra-weak solvation ability. When serving as a single solvent for electrolyte, a peculiar solvation structure dominated by contact ion pairs (CIPs) and aggregates (AGGs) was achieved even at a regular salt concentration of 1 m, which gives rise to anion-derived interfacial chemistry. This illustrates an unprecedentedly high Li||Cu CE of 99.1% for a single-salt single-solvent (non-fluorinated) electrolyte at ∼1 m. Moreover, this 1 m DEM-based electrolyte also remarkably suppresses the anodic dissolution of Al current collectors and significantly improves the cycling performance of high-voltage cathodes. This work opens up new frontiers in engineering electrolytes toward stable LMBs with high energy densities.

Two narrow bandgap conjugated polymers, PTT-EFQX and PT-DFBT-T-EFQX, comprising a novel bis(2-alkyl) 5,8-dibromo-6,7-difluoroquinoxaline-2,3-dicarboxylate (EF-Qx) unit, are designed and synthesized through palladium-catalyzed Stille coupling reaction. The ester groups and difluorine substituents are introduced into the EF-Qx unit to improve the electron affinity. The polymers containing EF-Qx unit exhibit a relatively narrow bandgap of around 1.6 eV. To optimize the effects of solubility and molecular packing, D-A structure and D-A1-D-A2 structure synthesis strategies are adopted in this work and the structure-property relationship is systematically studied. The results morphology characterizations indicate that the active layer based on D-A structure polymer PTT-EFQX has a superior morphology compared to active layer based on D-A1-D-A2 structure polymer PT-DFBT-T-EFQX, which helps PTT-EFQX-based polymer solar cells (PSCs) to obtain better PCEs of up to 5.4%. Our work demonstrates that the effective design strategy for development of quinoxaline-based polymer donor is necessary for controlling the morphology and thus achieving high-performance PSCs.

Silicon-based materials have been regarded as the most promising anodes for high-energy batteries, when combined with high- voltage/capacity nickel-rich layered cathodes. However, challenges arise ...

Typically, conjugated polymers are composed of conjugated backbones and alkyl side chains. In this contribution, a cost-effective strategy of tailoring the length of alkyl side chain is utilized to design high-performing thieno[3,4-c]pyrrole-4,6-dione (TPD)-based large bandgap polymer donors PBDT-BiTPD(Cχ) (χ = 48, 52, 56), in which χ represents the alkyl side chain length in term of the total carbon number. A combination of light absorption, device, and morphology examinations make clear that the shorter alkyl side chains yield (i) higher crystallinity and more predominant face-on crystallite orientation in their neat and BHJ blend films, (ii) higher charge mobilities (6.7 × 10−4 cm2 V−1 s−1 for C48 vs. 3.2 × 10−4 cm2 V−1 s−1 for C56), and negligible charge recombination, consequently, (iii) significantly improved fill-factor (FF) and short current (JSC), while almost the same open circuit voltage (VOC) of ca. 0.82 V in their corresponding BHJ devices. In parallel, as alkyl side chain lengths decrease from C56 to C48, power conversion efficiencies (PCEs) increased from 7.8% for C56 to 11.1% for C52, and further to 14.1% for C48 in their BHJ solar cells made with a narrow bandgap non-fullerene acceptor Y6. This systematic study declares that shortening the side chain, if providing appropriate solubility in device solution processing solvents, is of essential significance for developing high-performing polymer donors and further improving device photovoltaic performance.

Due to the low vapor pressure of aniline, it is challenging to develop a specific rapid fluorescence detection material for low concentrations of aniline gas, which is suspected to result in carcinogenicity when people are exposed by ingestion, inhalation, and skin contact. Herein, the easy-preparing Schiff base ligands were employed to construct the binuclear cadmium(II) compounds featuring a good plane and fine luminescent property, and then, the end groups were changed, making the compounds metalloligands to further build the 3D metal-organic frameworks (MOFs), named

The Li dendrite issue is the major barrier that limits the implement of Li metal anode practically, especially at high current density. From the perspective of the nucleation and growth mechanism of the Li dendrite, we rationally develop a novel Prussian blue analogues (PBA)-derived separator, where tuning the metal ions bestows the PBAs with open metal site to confine anion movement and thereby afford a high Li

The practical applications of Li metal batteries (LMBs) have long been limited by the obstacles of low Coulombic efficiency (CE) and formation of dendrites on Li metal electrode. Herein, we demonstrated the synthesis of a novel three-dimensional (3D) nanostructured skeleton substrate composed of nitrogen-doped hollow carbon fiber/carbon nanosheets/ZnO (NHCF/CN/ZnO) using 2-methylimidazole (2-MIZ)-coated 3D cloth as a scaffold. The mechanism of formation of this novel hierarchical structure was investigated. The multilayered hierarchical structure and abundant lithiophilic nucleation sites of the substrate provide a stable environment for the deposition and stripping of lithium metal, thus preventing the generation of lithium dendrites. Consequently, the lithium anode based on the NHCF/CN/ZnO current collector demonstrated an excellent Coulombic efficiency of 96.47% after 400 cycles at 0.5 mA cm-2. The prepared NHCF/CN/ZnO/Li electrode also showed outstanding cycling performance of over 800 h and an ultralow voltage hysteresis of less than 30 mV in a symmetric cell at 5 mA cm-2 and 5 mAh cm-2. Even at a high loading of the cathode with 10.4 mg cm-2, the full cell of NHCF/CN/ZnO/Li anode with LiFePO4 can also work very well. Our work offers a path toward the facial preparation of 3D hierarchical structure for high-performance lithium metal batteries.

The design of a powerful heterojunction structure and the study of the interfacial charge migration pathway at the atomic level are essential to mitigate the photocorrosion and recombination of electron-hole pairs of CdS in photocatalytic hydrogen evolution (PHE). A temperature-induced self-assembly strategy has been proposed for the syntheses of Prussian blue analogue (PBA)/CdS nanocomposites with beaded structure. The specially designed structure had evenly exposed CdS which can efficiently harvest visible light and inhibit photocorrosion; meanwhile, PBA with a large cavity provided channels for mass transfer and photocatalytic reaction centers. Remarkably, PB-Co/CdS-LT-3 exhibits a PHE rate of 57 228 μmol h-1 g-1, far exceeding that of CdS or PB-Co and comparable to those of most reported crystalline porous material-based photocatalysts. The high performances are associated with efficient charge migration from CdS to PB-Co through CN-Cd electron bridges, as revealed by the DFT calculations. This work sheds light on the exploration of heterostructure materials in efficient PHE.

Hydrolysis of benzonitrile to benzoate was realized for constructing a zero-dimensional dinuclear europium complex [Eu2(pip)2(PhCOO)6] via a hydrothermal reaction, where pip denotes 2-phenylimidazo[4,5-f][1,10]phenanthroline. This complex is very insoluble and stable in water from pH 3 to 10. It exhibits strong characteristic Eu(III) red photoluminescence, which could be significantly quenched by clinafloxacin without remarkable disturbance by other common salts or fluoroquinolone antibiotics. The luminescence quenching might be the result of photoinduced electron transfer from excited pip or benzoate to clinafloxacin. This complex is the first convenient luminescent sensor for clinafloxacin and the limit of detection is determined to be 0.21 μM.

The vertical composition distribution and crystallinity of photoactive layers are considered to have critical roles in photovoltaic performance. In this concise contribution, the layer-by-layer (LB...

The lithium–sulfur (Li–S) battery has drawn tremendous interest because of its superior theoretical specific capacity, while the shuttle effect of lithium polysulfides (LPSs) has greatly hindered i...

The vertical component distribution of bulk heterojunction (BHJ) active film shows a significant impact on determining the device performance in polymer solar cells (PSCs). Processing solvent additives are well known for regulating the BHJ active layer morphology; however, there are few reports regarding the quantitative evaluation of the effect. Herein, a study of the quantitative determination of the vertical segregation in combination of molecular ordering of PBDB-T/ITIC blend films with various 1,8-diiodooctane (DIO) contents is provided. A 0.5% (volume ratio) DIO-added blend film achieves the highest power conversion efficiency of 10.75%. The reduced performance of the PSCs resulted from the excessive vertical component segregation and overcrystallization investigated by various techniques. X-ray photoelectron spectroscopy indicates that DIO aggravates the PBDB-T enrichment region at the air side. Neutron reflectivity further quantitatively figures out the phase separation effect. Although increased crystallinity of ITIC and a higher face-on ratio of PBDB-T in active layer were obtained with increased DIO content approved by grazing-incidence wide-angle X-ray scattering (GIWAXS), the enhanced vertical distribution along with the enhanced crystal size of ITIC leads to the reduced performance of the PSCs due to the reduced carrier transportation paths between donor and acceptor.

In this work, a new design of a zeolitic imidazolate framework-derived CoF2/Fe2O3 hybrid structure is reported via a simple copyrolysis strategy. The in situ generated C/N doped framework effective...

Herein, a synthetic strategy for growing trimetallic zeolitic imidazolate framework (ZIF) polyhedrons on copper foam (CF) and interweaving with copper nanowires (CNWs) is proposed. Subsequently, in situ annealing under N2 atmosphere leads to the formation of multi-doped CNWs/Cu0.39Zn0.14Co2.47O4-ZnO/CF (CNWs/CZCOZ/CF). The unique structural characteristics of CNWs/CZCOZ/CF allow it to be directly assembled as a working electrode, without additional conductive additives or binders. When it's used as the lithium-ion battery (LIB) anode, this electrode exhibits a significantly high capacity of 2305 mAh g-1 at 0.1 A g-1 after 500 cycles. More importantly, kinetic analysis on the basis of cyclic voltammograms (CVs) indicates that the pseudocapacitive effect is the primary contributor to the high lithium storage capacity and also accounts for the exceptionally high rate capacity of 713 mAh g-1 even if the current density is at a maximum of 10 A g-1. Moreover, the superior battery performance originates from their advantageous structural diversity and unique compositional features, including synergistic effects among polymetallic components and two highly conductive substrates (CNWs and CF), forming unhindered paths for fast charge transfer.

The carbon layer with good electrical conductivity and outstanding mechanical stability are essential in designing high-performance silicon/carbon (Si/C) anodes to replace the commercial graphite in lithium-ion batteries (LIBs). In terms of solving the two inherent defects of poor conductivity and big volume change of silicon, we fabricate a spongy carbon matrix derived from ZIF-8 to anchor saclike silicon synthesized by molten salt magnesiothermic reduction method. This spongy matrix can anchor saclike silicon to provide a stable reaction interface and support fast electronic transmission. At the same time, buffer space in saclike Si nanoparticles and spongy matrix can synergistically accommodate the volume change of Si to maintain the integrity of the electrode. The resulting composite with a high Si content of 77.58% exhibits good capacities of 1448 mAh g−1 at 2 A g−1 and 848 mAh g−1 at 4 A g−1 after 500 cycles. High initial coulombic efficiency of 84% at 0.2 A g−1 is also exhibited in the first three activation cycles. Therefore, this novel multifunctional N-doped spongy matrix can supply multifaceted benefits in accommodation of volumetric variation, enhancement of conductivity, and integrity of structure during cycling.

Transition-metal sulfide is a good kind of material for supercapacitors because of the large capacity. Nevertheless, the low electroconductivity, slow reaction kinetics, and limited active centers lead to poor electrochemical properties such as long-term cycling stability. In the present work, nano nickel metal–organic framework (Ni-MOF) was constructed by using the nitrogen-rich functional group ligand 2,4,6-tris(3,5-dicarboxylphenylamino)-1,3,5-triazin and compounded with carbon nanotubes (CNTs) to prepare Ni-MOF/CNTs composite, which was used as a precursor to prepare the MOFs-derived NC/Ni–Ni3S4/CNTs composite with the Ni3S4 uniformly distributed in the three-dimensional (3D) conductive network. The rich nitrogen doping and 3D conductive network constructed by CNTs improved the conductivity, prompted the rapid entry of electrolyte, and improved the reaction kinetics of NC/Ni–Ni3S4/CNTs, thus obtained excellent specific capacitance, coulomb efficiency, and cyclic stability. The specific capacitance of ...

State-of-the-art non-fullerene bulk-heterojunction (BHJ) polymer solar cells outperform the more extensively studied polymer-fullerene BHJ solar cells in terms of efficiency, thermal-, and photostability. Considering the strong light absorption in the near-infrared region (600-1000 nm) for most of the efficient acceptors, the exploration of high-performing large band gap (LBG) polymer donors with complementary optical absorption ranging from 400 to 700 nm remains critical. In this work, the strategy of concurrently incorporating fluorine (-F) and unsaturated nitrogen (-N) substituents along the polymer backbones is used to develop the LBG polymer donor PB[N][F]. Results show that the F- and N-substituted polymer donor PB[N][F] realizes up to 14.4% efficiency in BHJ photovoltaic devices when paired with a benchmark molecule acceptor Y6, which largely outperforms the analogues PB with an efficiency of only 3.6% and PB[N] with an efficiency of 11.8%. Systematic examinations show that synergistic effects of polymer backbone fluorination and nitrogenation can significantly increase ionization potential values, improve charge transport, and reduce bimolecular recombination and trap-assisted recombination in the PB[N][F]:Y6 BHJ system. Importantly, our study shows that the F- and N-substituted conjugated polymers are promising electron-donor materials for solution-processed non-fullerene BHJ solar cells.

The two key problems for the industrialization of Li-S batteries are the dendrite growth of lithium anode and the shuttle effect of lithium polysulfides (LiPSs). Herein, we report the Janus separator prepared by coating anionic Bio-MOF-100 and its derived single-atom zinc catalyst on each side of the Celgard separator. The anionic metal-organic framework (MOF) coating induces the uniform and rapid deposition of lithium ions, while its derived single-atom zinc catalyzes the rapid transformation of LiPSs, thus inhibiting the lithium dendrite and shuttle effect simultaneously. Consequently, compared with other reported Li-S batteries assembled with single-atomic catalysts as separator coatings, our SAZ-AF Janus separator showed stable cyclic performance (0.05% capacity decay rate at 2 C with 1000 cycles), outstanding performance in protecting lithium anode (steady cycle 2800 h at 10 mAh cm-2), and equally excellent cycling performance in Li-SeS2 or Li-Se batteries. Our work provides an effective separator coating design to inhibit shuttle effect and lithium dendrite.

Solution-processed nonfullerene bulk-heterojunction (BHJ) polymer solar cells (PSCs), which are composed of polymer donors and organic acceptors, are proven to manifest promising performance and lo...

Photocatalytic light-driven micro/nanomotors have exhibited great potential in various applications ranging from environmental to biomedical fields. However, in order to expand the practicality of synthetic micromotors, overcoming the challenges of efficiently converting visible light energy to mechanical propulsion energy in fully-biocompatible environments has become critically important. Here, we firstly introduce oxygen vacancies into micromotors by a one-pot method without any additional modification and report a highly efficient Cu2+1O light-driven micromotor with simple fabrication, low cost, and excellent motion performance under low intensity, multi-wavelength visible light (from blue to red) and with biocompatible fuels. Under visible light (1/3 light intensity of sunlight), such oxygen vacancy-based micromotors can reach a maximum speed of 18 body length s−1 in pure water which is comparable to that of conventional Pt-based catalytic micromotors fueled by toxic H2O2. In addition, the motors show over 100 body length s−1 at very low concentrations of additional biocompatible fuels (0.2 mM tannic acid) which is comparable to the speed of bubble-driven microrockets. Even under blue light with only 1/44 of the intensity of sunlight, the motors can be propelled at speeds of 10 body length s−1 in water, indicating that they are the most efficient visible-light driven micromotors fueled by pure water to date. These exceptionally high speeds set new records for photocatalytic micromotors operated in fully green environments, and the proposed novel fabrication approach may pave a new way for designing and mass-producing highly efficient, smart micromachines for on-demand operations, motion-based sensing, and enhanced cargo transportation.

Two isostructural MOFs with coordination of different halogen ions (Cl− and Br−), namely NNU-17 and NNU-18, were utilized to reveal the influence of different electron-withdrawing halogen anions on ECR performance. The performance difference between them mainly originates from the different abilities of adsorption and activation of CO2 by halogen ions.

The vertical composition distribution of a bulk heterojunction (BHJ) photoactive layer is known to have dramatic effects on photovoltaic performance in polymer solar cells. However, the vertical composition distribution evolution rules of BHJ films are still elusive. In this contribution, three BHJ film systems, composed of polymer donor PBDB-T, and three different classes of acceptor (fullerene acceptor PCBM, small-molecule acceptor ITIC, and polymer acceptor N2200) are systematically investigated using neutron reflectometry to examine how donor-acceptor interaction and solvent additive impact the vertical composition distribution. Our results show that those three BHJ films possess homogeneous vertical composition distributions across the bulk of the film, while very different composition accumulations near the top and bottom surface were observed, which could be attributed to different repulsion, miscibility, and phase separation between the donor and acceptor components as approved by the measurement of the donor-acceptor Flory-Huggins interaction parameter χ. Moreover, the solvent additive 1,8-diiodooctane (DIO) can induce more distinct vertical composition distribution especially in nonfullerene acceptor-based BHJ films. Thus, higher power conversion efficiencies were achieved in inverted solar cells because of facilitated charge transport in the active layer, improved carrier collection at electrodes, and suppressed charge recombination in BHJ solar cells.