Explore the vast range of titles available.

The intercalation strategy has become crucial for 2D layered materials to achieve desirable properties, however, the intercalated guests are often limited to metal ions or small molecules. Here, we develop a simple, mild and efficient polymer-direct-intercalation strategy that different polymers (polyethyleneimine and polyethylene glycol) can directly intercalate into the MoS 2 interlayers, forming MoS 2 -polymer composites and interlayer-expanded MoS 2 /carbon heteroaerogels after carbonization. The polymer-direct-intercalation behavior has been investigated by substantial characterizations and molecular dynamic calculations. The resulting composite heteroaerogels possess 3D conductive MoS 2 /C frameworks, expanded MoS 2 interlayers (0.98 nm), high MoS 2 contents (up to 74%) and high Mo valence (+6), beneficial to fast and stable charge transport and enhanced pseudocapacitive energy storage. Consequently, the typical MoS 2 /N-doped carbon heteroaerogels exhibit outstanding supercapacitor performance, such as ultrahigh capacitance, remarkable rate capability and excellent cycling stability. This study offers a new intercalation strategy which may be generally applicable to 2D materials for promising energy applications. Methods to fabricate layered materials are often associated with harsh conditions and complicated manipulations. Here the authors report a polymer-direct-intercalation strategy to synthesize composite heteroaerogels consisting of molybdenum sulfide/carbon nanosheets for high-capacitance supercapacitors.

The development of stable Ru-based anodes for acidic proton exchange membrane water electrolysis is promising, but strictly limited by Ru over-oxidation and structural collapse due to lattice oxygen participation under high current densities. Rational design of competitive Ru-based catalyst is, thereby, highly desired. Here, by exploring a customized self-assembly route, we report a type of mesoporous Ru-Ti-O solid solution catalyst delivering competitive performance (1 A cm -2 for over 450 h at 0.4mg Ru cm -2 ). Mechanistic investigations reveal that the enhanced performance arises from the integration of atomic-scale electronic structure tuning and mesoscopic triple phase interface engineering. The electron delocalization forms a conductive network and suppresses Ru overoxidation through electron donation. Atomically dispersed Ru-O-Ti motifs favor the oxygen pathway mechanism over the lattice oxygen mechanism, suppressing lattice oxygen release and enhancing structural stability. Simultaneously, the ordered mesoporous architecture and radially aligned nanorod bundles establish a robust, super-hydrophilic triple phase interface, enabling effective water and gas exchange and mitigating concentration overpotentials. This cross-scale design strategy offers a possible route to non-Ir catalysts with measurable activity and long-term durability for scalable acidic water electrolysis. Developing robust anode catalysts that can operate at industrial-level current densities is essential for efficient hydrogen production. Here, the authors report a mesoporous ruthenium–titanium oxide solid solution with an engineered three-phase reaction interface for stable water electrolysis.

Even though organic molecules with well-designed functional groups can be programmed to have high electron density per unit mass, their poor electrical conductivity and low cycle stability limit their applications in batteries. Here we report a facile synthesis of π-conjugated quinoxaline-based heteroaromatic molecules (3Q) by condensation of cyclic carbonyl molecules with o-phenylenediamine. 3Q features a number of electron-deficient pyrazine sites, where multiple redox reactions take place. When hybridized with graphene and coupled with an ether-based electrolyte, an organic cathode based on 3Q molecules displays a discharge capacity of 395 mAh g −1 at 400 mA g −1 (1C) in the voltage range of 1.2–3.9 V and a nearly 70% capacity retention after 10,000 cycles at 8 A g −1 . It also exhibits a capacity of 222 mAh g −1 at 20C, which corresponds to 60% of the initial specific capacity. Our results offer evidence that heteroaromatic molecules with multiple redox sites are promising in developing high-energy-density, long-cycle-life organic rechargeable batteries. Organic compounds can be used as electrode materials for Li-ion batteries, but problems such as facile dissolution and low electrical conductivity hinder their application. Here the authors report π-conjugated quinoxaline-based heteroaromatic molecules with multiple redox sites to tackle the problems.

The intercalation strategy has become crucial for 2D layered materials to achieve desirable properties, however, the intercalated guests are often limited to metal ions or small molecules. Here, we develop a simple, mild and efficient polymer-direct-intercalation strategy that different polymers (polyethyleneimine and polyethylene glycol) can directly intercalate into the MoS interlayers, forming MoS -polymer composites and interlayer-expanded MoS /carbon heteroaerogels after carbonization. The polymer-direct-intercalation behavior has been investigated by substantial characterizations and molecular dynamic calculations. The resulting composite heteroaerogels possess 3D conductive MoS /C frameworks, expanded MoS interlayers (0.98 nm), high MoS contents (up to 74%) and high Mo valence (+6), beneficial to fast and stable charge transport and enhanced pseudocapacitive energy storage. Consequently, the typical MoS /N-doped carbon heteroaerogels exhibit outstanding supercapacitor performance, such as ultrahigh capacitance, remarkable rate capability and excellent cycling stability. This study offers a new intercalation strategy which may be generally applicable to 2D materials for promising energy applications.

Even though organic molecules with well-designed functional groups can be programmed to have high electron density per unit mass, their poor electrical conductivity and low cycle stability limit their applications in batteries. Here we report a facile synthesis of π-conjugated quinoxaline-based heteroaromatic molecules (3Q) by condensation of cyclic carbonyl molecules with o-phenylenediamine. 3Q features a number of electron-deficient pyrazine sites, where multiple redox reactions take place. When hybridized with graphene and coupled with an ether-based electrolyte, an organic cathode based on 3Q molecules displays a discharge capacity of 395 mAh g-1 at 400 mA g-1 (1C) in the voltage range of 1.2-3.9 V and a nearly 70% capacity retention after 10,000 cycles at 8 A g-1 . It also exhibits a capacity of 222 mAh g-1 at 20C, which corresponds to 60% of the initial specific capacity. Our results offer evidence that heteroaromatic molecules with multiple redox sites are promising in developing high-energy-density, long-cycle-life organic rechargeable batteries.

Confined ion transport is involved in nanoporous ionic systems. However, it is challenging to mechanistically predict its electrical characteristics for rational system design and performance evaluation using electrical circuit model due to the gap between the circuit theory and the underlying physical chemistry. Here we demonstrate that machine learning can bridge this gap and produce physics-based nano-circuitry, based on equation discovery from the modified Poisson-Nernst-Planck simulation results where an anomalous constructive diffusion-migration interplay of confined ions is unveiled. This bridging technique allows us to gain physical insights of ion dynamics in nanoporous electrodes, such as the non-ideal cyclic voltammetry.