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The combination of p‐type NiOx and self‐assembled monolayers (SAMs) has recently emerged as an optimal structure for hole transport layer (HTL) structure in wide‐bandgap perovskite solar cells (WBG PSCs). However, the unique requirements for NiOx in this cascade HTL system differ significantly from those of neat NiOx. Specifically, the tendency of NiOx to agglomerate can lead to poor film morphology and inadequate interfacial contact with SAMs, resulting in significant open‐circuit voltage (Voc) loss in PSCs. Herein, these issues are addressed by incorporating sodium hexametaphosphate (SHMP) into NiOx ink. This approach enhances the dispersibility of NiOx nanoparticles, improving the morphology and conductivity of the NiOx films through interactions between the P = O and P‐O groups and Ni ions. Additionally, SHMP promotes better contact between the NiOx and Me‐4PACz interface by increasing the number of hydroxyl groups on the uniform surface of NiOx films. Consequently, a high power conversion efficiency (PCE) of 21.02% is achieved for WBG (1.79 eV) PSCs with the smallest relative Voc loss of 24.69%. The encapsulated devices exhibit excellent stability under high humidity and elevated temperatures. Furthermore, when combined with Sn‐Pb narrow‐bandgap perovskite, a PCE of 27.66% is attained for the 2‐terminal tandem solar cells (TSCs). [ABSTRACT FROM AUTHOR]

Exploration of significantly active functional materials is highly valued for designing efficient electrochemical energy devices. 2D‐covalent organic frameworks (2D‐COF) have attracted significant interest in the context of important electrochemical applications due to their tunable structural and electronic properties, high thermal/chemical stability, and their carbon‐based motifs. The present review highlights the strategies and properties of modifying 2D‐COF electronically in detail and their prospects in electrochemical devices. The review clearly explains the electronic actuation methods of the COF skeletons by various synthetic and post‐synthetic strategies. The review crucially elucidates the importance of electroactive 2D‐COF as emerging functional materials in practical applications of electrochemical energy conversion devices. The review concludes by summarizing the effective strategies of 2D‐COF in improving electrocatalytic applications and suggests future research scope. The review orients the electroactive 2D‐COFs for critical analysis as advanced functional materials for a sustainable and reliable future. [ABSTRACT FROM AUTHOR]

Electrical conductivity and piezoresistivity of carbon nanotube (CNT) nanocomposites are analyzed by nodal analysis for aligned and random CNT networks dependent on the intrinsic CNT conductivity and tunneling barrier values. In the literature, these parameters are assigned with significant uncertainty; often, the intrinsic resistivity is neglected. We analyze the variability of homogenized conductivity, its sensitivity to deformation, and the validity of the assumption of zero intrinsic resistivity. A fast algorithm for simulation of a gauge factor is proposed. The modelling shows: (1) the uncertainty of homogenization caused by the uncertainty in CNT electrical properties is higher than the uncertainty, caused by the nanocomposite randomness; (2) for defect-prone nanotubes (intrinsic conductivity ~104 S/m), the influence of tunneling barrier energy on both the homogenized conductivity and gauge factor is weak, but it becomes stronger for CNTs with higher intrinsic conductivity; (3) the assumption of infinite intrinsic conductivity (defect-free nanotubes) has strong influence on the homogenized conductivity. [ABSTRACT FROM AUTHOR]

Nickel oxide (NiOx) is a promising hole transport material in inverted organic‐inorganic metal halide perovskite solar cells. However, its low intrinsic conductivity hinders its further improvement in device performance. Here, we employ a trimercapto‐s‐triazine trisodium salt (TTTS) as a chelating agent of Ni2+ in the NiOx layer to improve its conductivity. Due to the electron‐deficient triazine ring, the TTTS complexes with Ni2+ in NiOx via a strong Ni2+‐N coordination bond and increases the ratio of Ni3+:Ni2+. The increased Ni3+ concentration adjusts the band structure of NiOx, thus enhancing hole density and mobility, eventually improving the intrinsic conductivity of NiOx. As a result, the device with TTTS modification displays a champion power conversion efficiency (PCE) of 22.81%. The encapsulated device based on a modified‐NiOx layer maintains 94% of its initial power output at the maximum power point and continuous one‐sun illumination for 1000 h at 45 °C. In addition, the unencapsulated target devices also maintain 92% at 60 ± 5% relative humidity and 25 °C in the air for 5000 h; and 91% at 85 °C in a nitrogen atmosphere for 1000 h. The research provides an effective strategy to enhance PCE and stability of inverted PSCs via modifying NiOx films with triazine molecule. [ABSTRACT FROM AUTHOR]

The poor intrinsic conductivity and serious aggregation of MnO 2 has limited its further application in capacitive deionization (CDI). In the present work, GO was introduced as the growth substrate to alleviate the aggregation behavior of MnO 2 , while oxygen vacancies were created in the MnO 2 crystal by calcination to improve the intrinsic conductivity of MnO 2. The uniform dispersion and the expanded layer spacing of δ-MnO 2 provide larger specific surface area and more active sites for ion adsorption and storage, while the abundant oxygen vacancies in the crystal enhance the intrinsic conductivity and provide convenient ion transport channels for ion movement and transport. The electrochemical tests show that the rGO@MnO 2−x electrode presents higher specific capacitance (284 F g−1) and lower equivalent series resistance (1.11 Ω) than those of MnO 2 electrode (128 F g−1 and 1.25 Ω). Meanwhile, the desalination tests display that the hybrid GO||rGO@MnO 2−x cell demonstrates prominent desalination capacity (58.75 mg g−1) and ultrahigh charge efficiency (95.01%) compared to GO||MnO 2 cell (38.25 mg g−1 and 83.81%) in 500 mg L−1 NaCl solution at 1.2 V. The proposed design offers an optional strategy to improve the intrinsic conductivity of MnO 2 and enables synthesis of a novel composite to achieve efficient desalination. [Display omitted] • Oxygen vacancies introduced by calcination enhances intrinsic conductivity of MnO2. • Layered GO as a substrate assists uniform growth and alleviates aggregation of MnO2. • rGO@MnO2-x has excellent specific capacitance and low equivalent series resistance. • rGO@MnO2-x shows prominent desalination capacity and ultrahigh charging efficiency. [ABSTRACT FROM AUTHOR]

• The ultra-fine stainless-steel fibers into mesh as conductive stretchable base. • SSM has excellent mechanical properties and negative resistance effects. • The sensor has high sensitivity, wide detection range and good repeatability. • It is expected to be applied to robots performing tasks at extreme temperatures. The sensors used in extreme environments has broad application prospects. Herein, the ultra-fine stainless-steel fibers are knitted into a stainless-steel mesh (SSM) by warp knitting. Through the simple plate coating method, the SSM@silicone composite strain sensors are prepared. The sensor shows obvious negative resistance effects, meanwhile, it has the advantages of high sensitivity (GF = 14.9), wide detection range (30 %), good repeatability, and can be used at 300 ℃ and −20 ℃. It is anticipated to be applied on robots that perform tasks in extreme temperature environments. [ABSTRACT FROM AUTHOR]

Nanoscale Li 2 FeSiO 4 cathode material is successfully prepared using a ball-milling assisted hydrothermal method with inorganic precursors. Structures, morphologies, and thermal stabilities of the samples are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric-differential scanning calorimetry (TG-DSC). The prepared Li 2 FeSiO 4 samples are well crystallized and have an irregular cuboid morphology with particle sizes in the range of 50–300 nm. The crystal structure of pure Li 2 FeSiO 4 is stable in air at room temperature, and no distinct new phase is observed for the sample annealed at 300 °C in argon. The temperature-dependent intrinsic transport properties of nanoscale Li 2 FeSiO 4 are obtained using dynamic potential scanning (DPS) and electrochemical impedance spectroscopy (EIS); the ionic conductivity and electronic conductivity are 1.32 × 10 −8  S/cm and 2.8 × 10 −8  S/cm, respectively, at 20 °C. Nanoscale Li 2 FeSiO 4 exhibits stable cycle performance at different rates from 0.1C to 2C, and at 0.1C its specific charge and discharge capacity remain 144.1 mAh/g and 138.8 mAh/g, respectively, after 50 cycles. [ABSTRACT FROM AUTHOR]

Abstract: Metallic phase molybdenum disulfide (MoS2) is well known for orders of magnitude higher conductivity than 2H semiconducting phase MoS2. Herein, for the first time, the authors design and fabricate a novel porous nanotube assembled with vertically aligned metallic MoS2 nanosheets by using the scalable solvothermal method. This metallic nanotube has the following advantages: (i) intrinsic high electrical conductivity that promotes the rate performance of battery and eliminates the using of conductive additive; (ii) hierarchical, hollow, porous, and aligned structure that assists the electrolyte transportation and diffusion; (iii) tubular structure that avoids restacking of 2D nanosheets, and therefore maintains the electrochemistry cycling stability; and (iv) a shortened ion diffusion path, that improves the rate performance. This 1D metallic MoS2 nanotube is demonstrated to be a promising anode material for lithium‐ion batteries. The unique structure delivers an excellent reversible capacity of 1100 mA h g−1 under a current density of 5 A g−1 after 350 cycles, and an outstanding rate performance of 589 mA h g−1 at a current density of 20 A g−1. Furthermore, attributed to the material's metallic properties, the electrode comprising 100% pure material without any additive provides an ideal system for the fundamental electrochemical study of metallic MoS2. This study first reveals the characteristic anodic peak at 1.5 V in cyclic voltammetry of metallic MoS2. This research sheds light on the fabrication of metallic 1D, 2D, or even 3D structures with 2D nanosheets as building blocks for various applications. [ABSTRACT FROM AUTHOR]

• Improve intrinsic electronic conductivity of MnO 2 via decreasing its bandgap. • Accelerate reaction kinetics by weakening the strong electrostatic interactions. • Zn/B-MnO 2 batteries exhibit a significantly enhanced rate performance. • B-MnO 2 cathodes show superior performance even at high mass-loading of 30 mg cm−2. • Developing a molecular tailoring strategy for ultra‑high mass‑loading cathode. Manganese dioxide (MnO 2) is a promising cathode for aqueous zinc-ion batteries (ZIBs) because of its low cost, high energy density and environmental friendliness. However, the intrinsic poor electrical conductivity and sluggish reaction kinetics lead to inferior rate capability, especially under high mass loading, which hinders its commercialization. Herein, we report a molecular engineering strategy that can enhance the intrinsic electrical/ionic conductivity of MnO 2 and accelerate reaction kinetics. Electrochemical analysis reveals that boron-modified MnO 2 (B-MnO 2) delivers improved reaction kinetics since the tailored boron atoms with lower electronegativity can abate the strong electrostatic interactions between the cations and cathode. Theoretical calculations demonstrate that B-MnO 2 possesses a smaller bandgap than MnO 2 , which can enhance its electrical conductivity. As a result, the developed Zn/B-MnO 2 batteries display a high specific capacity (325.3 mAh/g at 200 mA g−1) and remarkable rate capability (99.4 mAh/g at 10 A/g). More importantly, at high mass loadings of 25 and 30 mg cm−2, the B-MnO 2 cathodes can still deliver high specific capacity of 197.2 and 176.5 mAh/g, respectively. This work will pave a way toward the commercial applications of Mn-based cathodes. [ABSTRACT FROM AUTHOR]

The electrical sensing zone (ESZ) particle counting method has been in use for decades. It records a change in resistance when a particle flows in a conducting fluid from a large reservoir through a narrow aperture into another reservoir, where the flow direction is aligned with an applied electric field and the particle is assumed to be much less conductive than the fluid. The measured resistance of the entire system goes through a peak as the particle flows through the aperture, at the center of the aperture, and the height of the peak is assumed to be a measure of particle volume. In this paper, the sensitivity of the ESZ particle counting method is shown to be directly related to the particle intrinsic conductivity, which depends only on particle shape and conductivity relative to the matrix fluid. The intrinsic conductivity is the main parameter that influences the change in conductivity, in the dilute limit, when a particle is added to a conducting matrix. A simple finite element model of an ESZ particle counter, built from cubic voxels, along with a sphere (calibration particle), cube, and ellipsoid of equal volumes, are used to show how particle shape affects the ESZ result. Even though the specific counter geometry can affect the resistance seen, it is shown that the intrinsic conductivity still explains the main influence on the resistance results in these numerical experiments, within certain geometric bounds. Finally, if the particle and fluid conductivity are close to each other, the measurement errors caused by particle shapes that are different from the calibration particle can be in principle be largely eliminated by exploiting the shape-independence of the intrinsic conductivity near this condition, which is analytically known. [ABSTRACT FROM AUTHOR]

• Single-phased high-entropy (Bi 2/3 Sb 1/3) 2 (Te 2/5 Se 2/5 S 1/5) 3 alloy was prepared. • Single-crystalline ingot was grown to prepare starting powder by grinding ingot. • Bi, Sb, Te, Se and S are homogeneously distributed within the ingot. • Specific features in thermoelectric properties due to intrinsic conductivity observed. • With increasing T , thermoelectric figure-of-merit of alloy increases to 0.3 at 570 K. Single-phased high-entropy (Bi 2/3 Sb 1/3) 2 (Te 2/5 Se 2/5 S 1/5) 3 alloy with homogeneous distribution of various elements was prepared by way, based on preliminary growing single-crystalline precursor that was after grinding applied as starting powder for spark plasma sintering. Thermoelectric properties of the alloy were analyzed in comparison with medium-entropy BiSbTe 1.5 Se 1.5 alloy. For both alloys, specific features in the properties due to intrinsic conductivity were observed. Owing to narrow energy gap (∼0.083 eV), these features for (Bi 2/3 Sb 1/3) 2 (Te 2/5 Se 2/5 S 1/5) 3 are remarkably shifted to low temperatures. With growing temperature, thermoelectric figure-of-merit of high-entropy alloy increases to ∼0.3 at 570 K. [ABSTRACT FROM AUTHOR]

An approach towards the expansion of Rh(I)-containing single-chain polymer nanoparticles (SCNPs) using linear polymers and μ -halo(diene)Rh(I) dimers as cross-linkers in high dilution was explored. Initially, the effects of utilizing different anionic ligands, i.e. , halides, together with various labile alkene ligands, such as ethylene, 1,5-cyclooctadiene and 1,5-hexadiene, on the stability and activity of the resulting Rh(I) cross-linking complexes were examined. While the ethylene complexes for bromide and iodide bridges resulted too unstable and the 1,5-cyclooctadiene ligand produced inert complexes, the 1,5-hexadiene ligands provided the proper equilibrium of stability and lability to achieve efficient polymer folding. Thus, a range of new organometallic nanoparticles could be obtained via a direct exchange between the 1,5-hexadiene labile ligands of the Rh(I) complexes, and the corresponding 1,5-hexadiene elements present in ROMP derived 1,5-polycyclooctadiene (PCOD) and 1,4-polybutadiene (PBD). Notably, SEC analysis of the single-chain nanoparticles both for PCOD and PBD revealed the expected decrease in the hydrodynamic radius (R h) of the parent polymer, indicating that other anions can also be used as elements in the cross-linking moieties to form these organometallic nanoparticles. Moreover, all of the Rh-SCNPs displayed intrinsic semi-conductivities in the range of similar undoped organic conjugated polymers, expanding the possible uses of this methodology for many applications. [Display omitted] • Chloride, Bromide or Iodide bridges can generate organometallicSCNPs. • Conductivity of polymers is enhanced by intramolecular cross-linking with metals. • 1,5-hexadiene ligands are optimal, displaying both stability and required lability. [ABSTRACT FROM AUTHOR]