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Nitrogen‐containing heterocyclic molecules feature metal resource‐independence, flexible conjugation structure and fast charge storage kinetics, making them promising to be used as the electrode material in lithium‐ion batteries. However, an insufficiently high capacity (<400 mAh g−1) seriously threatens their practical application. Herein, a novel molecule, viz. 3,6‐bis(2‐pyrimidinyl)‐1,2,4,5‐tetrazine (DPmT), is developed by inserting an electron‐withdrawing π‐bridge unit of s‐tetrazine between two pyrimidine rings, in which a dense assembly of multiple active sites is realized. The DTmP exhibits a remarkable atom economy of 40 g (mol e)−1, which refers to the molecule mass per unit of charge transferred. The cathode material of DPmT yields a high capacity of 653 mAh g−1 and an energy density of 1188 Wh kg−1 at 50 mA g−1 at 70 °C. And 80% capacity retention is achieved after 500 cycles at 500 mA g−1, confirming its superior cyclability. Spectroscopy studies and theoretical calculations are performed to investigate the charge storage process. First, the C═N and N═N are claimed as plausible binding sites for the lithium ions. Second, the introduction of s‐tetrazine significantly enhances molecular planarity, thereby promoting charge delocalization and molecular stability. This work provides a novel strategy for designing atom‐economic multi‐charge electrode materials with high capacity. [ABSTRACT FROM AUTHOR]

The pulley structure has been widely employed to improve mechanical properties. Polyrotaxane‐based waterborne polyurethane (WPU) typically exhibits good tensile strength and Young's modulus. However, achieving outstanding self‐healability of polyrotaxane‐based WPU under mild conditions generally proves insufficient solely relying on host‐guest interactions. Herein, a strategy that constructs a triple synergy of host‐guest interaction, hydrogen bonds, and metal coordination bonds by sequentially introducing tannic acid (TA) and Fe3+ is proposed to prepare polyrotaxane‐based WPU with excellent mechanical performance and high self‐healable capability. Besides the reversible non‐covalent bonding contributing to intrinsic self‐healing, the unique sliding motion of WPU's molecule chain acts as a driving force, promoting efficient contact among reversible bonds. Notably, benefiting from the sliding motion of β‐cyclodextrin (β‐CD) along a chain, the dynamic reconstruction of hydrogen bonds and metal coordination bonds, the resulting supramolecular WPU exhibited a tensile strength of 46.05 MPa and a toughness of 130.30 MPa, with satisfactory self‐healing performance (tensile strength healing efficiency of more than 95%). This work enriches the self‐healing mechanism and expands the concepts for the design of resilient self‐healing environmentally friendly supramolecular WPU. [ABSTRACT FROM AUTHOR]

Poor miscibility with the most popular n-dopants of polar 1H-benzimidazolyl molecules and limited doping efficiency have severely retarded the development of highly efficient n-doped organic semiconductors for organic thermoelectrics (OTE) applications. One effective strategy to enhance miscibility involves introducing hydrophilic triethylene-glycol-type (TEG-type) side chains into n-type organic semiconductors. In this contribution, an alternative strategy is introduced for miscibility modulation by replacing the dimethylaniline group of the representative n-dopant of 4-(1,3-dimethyl-2,3-dihydro-1H-benzoimidazol-2-yl)phenyl)dimethylamine (N-DMBI-H) with julolidine; 9-(1,3-dimethyl-2,3-dihydro-1H-benzoimidazol-2-yl)-julolidine (JLBI-H) was attained with more lipophilicity. JLBI-H was found to modulate its miscibility with three representative n-type fullerene derivatives: PC61BM, PTEG-1, and PTEG-2 with increasing hydrophilicity in an opposite trend to N-DMBI-H. The optimal PC61BM film doped with 15 mol% JLBI-H exhibited a remarkably high conductivity (σ) of 1.25 S cm−1 at 100 °C, one of the highest values reported so far for solution-processed PC61BM films. The optimized PTEG-1 film doped with 15 mol% JLBI-H achieved a room-temperature σ of approximately 2.0 S cm−1, comparable to that doped with 30 mol% N-DMBI-H. In contrast, the σ of the PTEG-2 film doped with 15 mol% JLBI-H is only one-tenth of the one doped with 22 mol% N-DMBI-H. The doping efficacy of JLBI-H on the three fullerene derivatives is significantly influenced by the initial microstructure of the host films, the miscibility level between the dopant and the hosts and the unique thermal annealing treatment to trigger doping, as evidenced by a collaborative analysis on electrical behaviors, GIWAXS and AFM. This study demonstrates the effectiveness of tailoring the structure of molecular n-dopants to modulate the miscibility between host–dopant pairs and achieve high electrical performance. [ABSTRACT FROM AUTHOR]

Rational design and construction of bifunctional electrocatalysts with excellent activity and durability is imperative for water splitting. Herein, a novel top‐down strategy to realize a hierarchical branched Mo‐doped sulfide/phosphide heterostructure (Mo‐Ni3S2/NixPy hollow nanorods), by partially phosphating Mo‐Ni3S2/NF flower clusters, is proposed. Benefitting from the optimized electronic structure configuration, hierarchical branched hollow nanorod structure, and abundant heterogeneous interfaces, the as‐obtained multisite Mo‐Ni3S2/NixPy/NF electrode has remarkable stability and bifunctional electrocatalytic activity in the hydrogen evolution reaction (HER)/oxygen evolution reaction (OER) in 1 m KOH solutions. It possesses an extremely low overpotential of 238 mV at the current density of 50 mA cm−2 for OER. Importantly, when assembled as anode and cathode simultaneously, it merely requires an ultralow cell voltage of 1.46 V to achieve the current density of 10 mA cm−2, with excellent durability for over 72 h, outperforming most of the reported Ni‐based bifunctional materials. Density functional theory results further confirm that the doped heterostructure can synergistically optimize Gibbs free energies of H and O‐containing intermediates (OH*, O*, and OOH*) during HER and OER processes, thus accelerating the catalytic kinetics of electrochemical water splitting. This work demonstrates the importance of the rational combination of metal doping and interface engineering for advanced catalytic materials. [ABSTRACT FROM AUTHOR]

The organic molecular nanotubes, nanotube junctions, and nanorods are prepared form organic compound powders through the combination of thermal evaporation and the self-assembly technique. A simple method through thermal evaporation of 9,10-anthrapuinone (AQ) powders in the presence of zinc catalyst is developed to produce nanotubes, nanotube junctions and nanorods.

A novel hydrogen-bonded supramolecular system of a [60]fullerene derivative with perylene bisimide is synthesized and characterized. The photocurrent response of the film is measured, and a steady and rapid anodic photocurrent response is obtained.

The ladder‐type nonacyclic arene (bis(thieno[3,2‐b]thieno)cyclopentafluorene (BTTF)) has been designed and synthesized through fusing thienothiophenes with the fluorene core from the synthon of dimethyl 9,9‐dioctyl‐2,7‐bis(thieno[3,2‐b]thiophen‐2‐yl)fluorene‐3,6‐dicarboxylate. With BTTF as the central donor unit, a novel acceptor–donor–acceptor (A‐D‐A) type non‐fullerene small‐molecule acceptor (BTTFIC) was prepared with 1,1‐dicyanomethylene‐3‐indanones (IC) as the peripheral acceptor units. The energy level of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of BTTFIC locate at −5.56 and −3.95 eV, respectively, presenting a low optical band gap of 1.58 eV. Encouragingly, polymer solar cells based on the blends of BTTFIC with both the representative wide‐ and low‐bandgap polymer donors (PBDB‐T, 1.82 eV. PTB7‐Th, 1.58 eV) offer power conversion efficiencies over 8 % (8.78±0.18 % for PBDB‐T:BTTFIC and 8.18±0.29 % for PTB7‐Th:BTTFIC). These results highlight the advantage of ladder‐type BTTF on the preparation of nonfullerene acceptors with extended conjugated backbones. [ABSTRACT FROM AUTHOR]

Conjugated polymers in thin films tend to orient their backbones with respect to substrates through self-assembly when processed from a solution. The molecular packing orientation and crystallinity of polymer crystals have been found to play a critical role in terms of their electrical performance. Taking advantage of the shorter bond length and the smaller rotation energy of the CH2–O bond than those of the CH2–CH2 bond in an alkyl chain, a side-chain engineering strategy is reported, which involves sequential oxygen-substitution of the carbon atoms from the γ position outwards along the hexyls in regioregular poly(3-hexylthiophene) (RR-P3HT). The subtle disparity between the CH2–O and CH2–CH2 bonds is found to enable fine tuning of the solid-state organization of the corresponding RR-P3HT analogues, namely poly(3-(2-propoxyethyl)thiophene) (P3POET), poly(3-(3-ethoxypropyl)thiophene) (P3EOPT) and poly(3-(4-methoxybutyl)thiophene) (P3MOBT). The evolution of film microstructures is observed when doping with FeCl3 in nitromethane at room temperature, and so is their thermoelectric performance. The highest power factor of 19 μW m−1 K−2 was observed for the doped P3POET film, which presents a dominant edge-on orientation with the strongest crystallinity and the closest π–π stacking. At the doping time corresponding to the optimized power factors (PFs) for each polymer, the doped P3POET film maintains both relatively high Seebeck coefficient (S) and electrical conductivity (σ) close to their maximum values, while the other polymers show either higher S and much lower σ (P3HT) or higher σ but much lower S (P3EOPT and P3MOBT). The square dependence of the PFs on S together with higher σ amplifies the power factor value of P3POET, which is almost 2 times those of the other polymers (11–13 μW m−1 K−2). [ABSTRACT FROM AUTHOR]