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Electrochemical reduction reaction is an important approach to utilize CO 2 and convert it into valuable products. Exceptional reaction kinetics at a high temperature of solid oxide electrolysis cells (SOECs) attracts particular attention. In this work, we propose to investigate CO 2 -RR kinetics using a new theoretical method based on the electrical conductivity relaxation (ECR) technique on a typical mixed-conducting Sr 2 Fe 1.5 Mo 0.5 O 6-δ (SFM) electrode. Three kinetic parameters that are commonly adopted in the typical electrochemical test experiments consisting of overpotential, current density and area-specific resistance (ASR) are derived. The overpotential resulted from the difference in the oxygen partial pressure is caused by the change of CO 2 partial pressure, while current density from the surface reaction rate constant. Accordingly, area-specific resistance, as well as overpotential-current density relationship, can be derived. We believe that this work brings a new method to study the kinetic process of CO 2 electrolysis and to evaluate the electrocatalyst activity of developed new electrode materials as well as to benefit the designing of novel electrode electrocatalysts for highly efficient solid oxide electrolysis cells. • A new theoretical method of investigating CO 2 reduction kinetics is proposed. • The electrical conductivity relaxation technique is applied to CO 2 -SOEC cathode. • The formulations of η , i and ASR are derived by k chem. [ABSTRACT FROM AUTHOR]

The role of exciton dissociation in charge separation dominated by in-plane crystallinity has been rarely addressed, although it is the decisive step of polymeric carbon nitride (CN) photocatalysis. Here, taking ten kinds of crystalline carbon nitride (CCN) as examples, the relationship between exciton dissociation, carrier mobility, conductivity, charge separation and photocatalytic activity under different in-plane crystallinity has been investigated. Although the in-plane crystallinity dominates charge separation and photocatalytic activity, it does not significantly reduce excitons binding energy (EBE) or improve exciton dissociation efficiency (EDE), only decreasing by 1.5 meV and increasing by 2.3 %, respectively. It is the greatly improved carrier mobility and conductivity that are more responsible for the increased charge separation and photocatalytic activity than the slight change in EDE. To our knowledge, this is the first reported case of overall water splitting in CCN of poly(heptazine imide) structure, resulting from the optimized in-plane crystallinity. [Display omitted] • Demonstrating the role of exciton dissociation in charge separation dominated by in-plane crystallinity. • Providing modification strategies for layered photoelectric conversion materials. • The first reported case of overall water splitting in CCN of poly(heptazine imide) structure. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) is a promising anode material for sodium‐ion batteries (SIBs) due to its low cost, natural abundance, nontoxicity, and excellent electrochemical stability. Oxygen vacancies, the most common point defects in TiO2, can dramatically influence the physical and chemical properties of TiO2, including band structure, crystal structure and adsorption properties. Recent studies have demonstrated that oxygen‐deficient TiO2 can significantly enhance sodium storage performance. Considering the importance of oxygen vacancies in modifying the properties of TiO2, the structural properties, common synthesis strategies, characterization techniques, as well as the contribution of oxygen‐deficient TiO2 on initial Coulombic efficiency, cyclic stability, rate performance for sodium storage are comprehensively described in this review. Finally, some perspectives on the challenge and future opportunities for the development of oxygen‐deficient TiO2 are proposed. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous zinc‐ion batteries (AZIBs) have attracted extensive attention and are considered to be promising energy storage devices, owing to their low cost, eco‐friendliness, and high security. However, insufficient energy density has become the bottleneck for practical applications, which is greatly influenced by their cathodes and makes the exploration of high‐performance cathodes still a great challenge. This review underscores the recent advances in the rational design of advanced cathodes for AZIBs. The review starts with a brief summary and evaluation of cathode material systems, as well as the introduction of proposed storage mechanisms. Then, fundamental problems associated with ion and electron transport behaviors inside the electrode will be pointed out and followed by potential solutions, aiming to reveal the correlation between cathode architecture design and efficient transport kinetics through structural engineering. Afterward, the structural engineering for designing advanced cathodes, including interlayer intercalation, doping effects, defect engineering, surface coatings, composite formation, and morphology control, are summarized and discussed from the view of experimental and theoretical results. Finally, the critical research challenges and future perspectives on advanced cathode materials as well as the potential developing directions of AZIBs are also given. [ABSTRACT FROM AUTHOR]

Previous density‐functional theory (DFT) calculations show that sub‐nanometric Cu clusters (i.e. 13 atoms) favorably generate CH4 from the CO2 reduction reaction (CO2RR), but experimental evidence is lacking. Herein, a facile impregnation‐calcination route towards Cu clusters, having a diameter of about 1.0 nm with about 10 atoms, was developed by double confinement of carbon defects and micropores. These Cu clusters enable high selectivity for the CO2RR with a maximum Faraday efficiency of 81.7 % for CH4. Calculations and experimental results show that the Cu clusters enhance the adsorption of *H and *CO intermediates, thus promoting generation of CH4 rather than H2 and CO. The strong interactions between the Cu clusters and defective carbon optimize the electronic structure of the Cu clusters for selectivity and stability towards generation of CH4. Provided here is the first experimental evidence that sub‐nanometric Cu clusters facilitate the production of CH4 from the CO2RR. [ABSTRACT FROM AUTHOR]

Previous density‐functional theory (DFT) calculations show that sub‐nanometric Cu clusters (i.e. 13 atoms) favorably generate CH4 from the CO2 reduction reaction (CO2RR), but experimental evidence is lacking. Herein, a facile impregnation‐calcination route towards Cu clusters, having a diameter of about 1.0 nm with about 10 atoms, was developed by double confinement of carbon defects and micropores. These Cu clusters enable high selectivity for the CO2RR with a maximum Faraday efficiency of 81.7 % for CH4. Calculations and experimental results show that the Cu clusters enhance the adsorption of *H and *CO intermediates, thus promoting generation of CH4 rather than H2 and CO. The strong interactions between the Cu clusters and defective carbon optimize the electronic structure of the Cu clusters for selectivity and stability towards generation of CH4. Provided here is the first experimental evidence that sub‐nanometric Cu clusters facilitate the production of CH4 from the CO2RR. [ABSTRACT FROM AUTHOR]

With the impetus to accelerate worldwide market adoption of electrical vehicles and afford consumer electronics with better user experience, advancing fast-charging technology is an inevitable trend. However, current high-energy lithium-ion batteries are unable to support ultrafast power input without any adverse consequences, with the capacity fade and safety concerns of the mainstream graphite-based anodes being the key technological barrier. The aim of this review is to summarise the fundamentals, challenges, and solutions to enable graphite anodes that are capable of high-rate charging. First, we explore the complicated yet intriguing graphite–electrolyte interface during intercalation based on existing theories. Second, we analyse the key dilemmas facing fast-charging graphite anodes. Finally, some promising strategies proposed during the past few years are highlighted so as to outline current trends and future perspectives in this field. [ABSTRACT FROM AUTHOR]

The ability to develop bifunctional electrocatalysts for concurrent CO2 reduction reaction (CO2RR) and oxygen evolution reaction (OER) is the key to the practical application of CO2 splitting to produce CO. However, this remains a grand challenge. Herein, a robust strategy to rationally craft hierarchical structured bifunctional electrocatalysts composed of 3D CoS2 nanocages interconnected on 2D CoS2 nanosheet arrays (denoted hierarchical CoS2 nanocages) for high‐performance CO2 splitting is developed. The subsequent calcination removes the partial S edges of CoS2, thereby strongly suppressing the hydrogen evolution reaction (HER) of CoS2. By combining theoretic and experimental results, for the first time, it is discovered that the plane S of CoS2, instead of S edges, are highly active for CO2RR but inactive for HER, rendering the plane S as ideal active sites for CO2RR. Intriguingly, the composition tuning via calcination and the presence of a hierarchical architecture confer hierarchical CoS2 nanocages respective outstanding CO2RR and OER performance. Notably, the hierarchical CoS2 nanocages can be exploited as bifunctional electrocatalysts for overall CO2 splitting to yield the current density of 1 mA cm−2 at a small cell voltage of 1.92 V, much lower than the widely reported values (>2.5 V). [ABSTRACT FROM AUTHOR]

Electrochemical reduction of CO2 may provide a promising method to mitigate the concentration of CO2 in the atmosphere, and simultaneously convert this greenhouse gas into value‐added fuels or chemicals. However, electrocatalysts for CO2 reduction are mostly powder based; therefore, polymer binders are always employed to make these catalysts useful as working electrodes. As a consequence, plenty of active sites are embedded inside without catalytic performance, causing a relatively low efficiency. On the contrary, self‐supported electrocatalysts do not involve the typical powdering and drop‐coating procedure with the aid of polymer binders or additives, avoiding the weak contact between active materials and current collector. Moreover, the superior self‐supported structure can also provide an accelerated electron transfer, guarantee ample electrolyte access to the active sites, offer large electrochemical surface areas, and increase CO2 adsorption capacity around the active sites, finally leading to the excellent efficiency and long‐term stability in CO2 reduction. In this manuscript, recent advances regarding CO2 reduction by self‐supported electrocatalysts are comprehensively reviewed, including the synthesis methods, chemical compositions, nanostructures, and catalytic efficiencies. Furthermore, the existing challenges and perspectives on the research and development of self‐supported electrocatalysts for CO2 reduction are discussed. [ABSTRACT FROM AUTHOR]

Superhydrophobic surfaces based on non‐fluorinated materials and facile fabrication techniques are of great practical value with respect to environmental friendliness and industrial applications. In this work, a fluorine‐free, superhydrophobic coating with hierarchical surface structure and low surface energy is successfully fabricated on various substrates through a recently developed dip coating combined with non‐solvent induced phase separation (dip‐coating‐NIPS) method. A bio‐based polymer, poly(l‐lactic acid), and commercially available hydrophobic SiO2 nanoparticles, are used. The fabricated coating exhibits superhydrophobicity, with a static water contact angle (WCA) of 155.7° ± 1.4° and contact angle hysteresis (θHys) of 5.2° ± 0.4°. The results from stability tests demonstrate excellent mechanical durability and chemical stability of the superhydrophobic coating. Finally, the fabricated coating is successfully applied in water–oil separation with superior efficiency. This simple, cost‐effective, and time‐efficient method may provide an effective way for the design of nonfluorine‐based environmentally friendly membranes for separation applications. [ABSTRACT FROM AUTHOR]

Bioinspired unidirectional porous materials have emerged as a unique class of scaffolds for the fabrication of macroscopic nanomaterial assemblies. However, these scaffolds usually serve simply as mechanical carriers to support various building blocks. Here, we report that the unidirectional silk fibroin scaffold can not only act as a carrier, but also serve as a controllable multiscale reactor to achieve the in situ synthesis of a Ag3PO4 nanowire network anchored to ordered channels. Both the silk fibroin matrix and the interface play important roles in the nucleation and growth of the Ag3PO4 nanowires. This unidirectional composite scaffold can be used for efficient water disinfection. Furthermore, the facile chemical transformation of Ag3PO4 in the composite scaffold into Ag2S provided an analogous unidirectional composite silk scaffold that displays both efficient solar water evaporation effect and antibacterial activity. It is expected that this method can be extended to fabricate a series of silk‐based unidirectional composite scaffolds with varying functionalities. [ABSTRACT FROM AUTHOR]

Bioinspired unidirectional porous materials have emerged as a unique class of scaffolds for the fabrication of macroscopic nanomaterial assemblies. However, these scaffolds usually serve simply as mechanical carriers to support various building blocks. Here, we report that the unidirectional silk fibroin scaffold can not only act as a carrier, but also serve as a controllable multiscale reactor to achieve the in situ synthesis of a Ag3PO4 nanowire network anchored to ordered channels. Both the silk fibroin matrix and the interface play important roles in the nucleation and growth of the Ag3PO4 nanowires. This unidirectional composite scaffold can be used for efficient water disinfection. Furthermore, the facile chemical transformation of Ag3PO4 in the composite scaffold into Ag2S provided an analogous unidirectional composite silk scaffold that displays both efficient solar water evaporation effect and antibacterial activity. It is expected that this method can be extended to fabricate a series of silk‐based unidirectional composite scaffolds with varying functionalities. [ABSTRACT FROM AUTHOR]

• The Fe-doped cathode exhibited superior catalytic activity for CO 2 reduction compared to pristine La 0.5 Sr 0.5 MnO 3. • The incorporation of Fe into the unit cell increased its size and facilitated the CO 2 reduction activity. • Fe substitution improves CO 2 adsorption and decreased the energy barrier of the rate-determining step. • The Fe-doped cathode resulted in an increased maximum power density in the Zn-CO 2 battery. Aqueous Zn-CO 2 batteries are a new technology for reducing carbon dioxide emissions and converting CO 2 into valuable products. The development of high-performance catalysts is crucial for improving the efficiency of the CO 2 reduction reaction(CO 2 RR) in these batteries. The technical challenges of CO 2 RR catalysts include high cost, complicated synthesis and low Faraday efficiency. In this study, we developed an efficient and cost-effective CO 2 RR perovskite catalyst, by partially substituting Fe to the B site of precious metal-free La 0.5 Sr 0.5 MnO 3 (LSM) perovskite. Comprehensive investigation into the Structure, morphology, coordination information and electrochemical performance of pristine La 0.5 Sr 0.5 MnO 3 (LSM) and substituted La 0.5 Sr 0.5 Fe 0.6 MnO 3 (LSF 0.6 M) catalysts were conducted, LSF 0.6 M catalyst shows enhanced electrochemical performance, Faraday efficiency, battery durability and battery power density than LSM. Specifically, the Fe-doped catalyst shows a significant improvement in CO 2 reduction reaction (CO 2 RR) performance, with an 80% increase in current density, an 82% Faraday efficiency, and a 50% increase in power density of Zn-CO 2 battery. Characterization experimental results and DFT calculation reveal that Fe substitution can increase the perovskite lattice size to favor CO 2 absorption and *COOH formation, thus the improved CO yields. These analyses provided insights into the underlying mechanisms of the catalyst's performance in CO 2 RR within the battery system. These results highlight LSF 0.6 M perovskite as a very promising CO 2 RR electrocatalyst for Zn-CO 2 battery. [ABSTRACT FROM AUTHOR]

• Facile synthesis of amorphous VO 2 –crystalline NiS 2 heterostructures. • Identifying the different co-catalytic function of VO 2 for boosting the HER and OER. • VO 2 tunes the binding energy of NiS 2 with hydrogen intermediates to enhance the HER activity. • VO 2 alters the electrochemical reconstruction behavior of NiS 2 during the process of OER. • The obtained VO 2 / NiS 2 requires a low voltage of 1.53 V at10 mA cm−2 for overall water splitting. The rational design of bifunctional electrocatalysts is essential to achieve efficient hydrogen production from water splitting. Here, inspired by cocatalysts widely utilized in photocatalysis, we designed a heterostructure comprising amorphous VO 2 and crystalline NiS 2 , aiming at using VO 2 cocatalyst to boost activity of NiS 2 for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Intriguingly, we found that VO 2 displayed different co-catalytic function in boosting the OER and HER. Specifically, the VO 2 optimized the binding energy of hydrogen intermediate on NiS 2 and thus improved the HER activity. As for the OER, the amorphous VO 2 was easily dissolved in the KOH electrolyte, resulting in the generation of abundant oxygen vacancies in the in-situ generated active phase of NiOOH from NiS 2 , thereby drastically enhancing the OER activity. Consequently, the obtained VO 2 –NiS 2 @CC displayed excellent performance for overall water splitting, with a low voltage of 1.53 V at 10 mA cm−2. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • LSFT is used as anode electrocatalyst for hydrocarbon fueled SOFC. • LSFT shows good electro-activity toward CH 4 direct oxidation. • LSFT keeps stable in H 2 fuel with different H 2 S contents up to 750 ppm for 24 h. • LSFT presents a good carbon deposition tolerance. Abstract Efficient and direct utilization of hydrocarbon fuel in a solid oxide fuel cell (SOFCs) is highly desirable. However, the carbon deposition and contaminants poisoning issue should be overcome. In this work, we developed a titanium-doped (La,Sr)FeO 3 ceramic oxide (LSFT) anode which integrates the advantage of high durability of titanate perovskite and super electrocatalytic activity of ferrite-based perovskite for methane-fueled SOFCs with H 2 S impurity. Its electrocatalytic activity and operational durability in H 2 with various H 2 S contents and humidified CH 4 fuel were systematically investigated. We found that the LSFT perovskite oxide anode showed acceptable activity and durability toward methane direct oxidation, and excellent coke and sulfur tolerance up to 750 ppm, making it a promising electrocatalyst for direct use of hydrocarbon fuels such as natural gas in high-temperature SOFCs. [ABSTRACT FROM AUTHOR]

Recently, metal‐free, heteroatom‐doped carbon nanomaterials have emerged as promising electrocatalysts for the oxygen evolution reaction (OER), but their synthesis is a tedious process involving energy‐wasting calcination. Molecular electrocatalysts offer attractive catalysts for the OER. Here, phytic acid (PA) was selected to investigate the OER activity of carbons in organic molecules by DFT calculations and experiments. Positively charged carbons on PA were very active towards the OER. The PA molecules were fixed into a porous, conductive hydrogel with a superhydrophilic surface. This outperformed most metal‐free electrocatalysts. Besides the active sites on PA, the high OER activity was also related to the porous and conductive networks on the hydrogel, which allowed fast charge and mass transport during the OER. Therefore, this work provides a metal‐free, organic‐molecule‐based electrocatalyst to replace carbon nanomaterials for efficient OER. Positively charged carbons on organic molecules (i.e. phytic acid, denoted PA) can participate in the oxygen evolution reaction (OER), as shown by DFT calculations and experiments. Moreover, doping of PA into a porous and conductive hydrogel is a robust strategy for stabilizing PA, as well as boosting the charge and mass transport of PA during the OER. [ABSTRACT FROM AUTHOR]

Recently, metal‐free, heteroatom‐doped carbon nanomaterials have emerged as promising electrocatalysts for the oxygen evolution reaction (OER), but their synthesis is a tedious process involving energy‐wasting calcination. Molecular electrocatalysts offer attractive catalysts for the OER. Here, phytic acid (PA) was selected to investigate the OER activity of carbons in organic molecules by DFT calculations and experiments. Positively charged carbons on PA were very active towards the OER. The PA molecules were fixed into a porous, conductive hydrogel with a superhydrophilic surface. This outperformed most metal‐free electrocatalysts. Besides the active sites on PA, the high OER activity was also related to the porous and conductive networks on the hydrogel, which allowed fast charge and mass transport during the OER. Therefore, this work provides a metal‐free, organic‐molecule‐based electrocatalyst to replace carbon nanomaterials for efficient OER. [ABSTRACT FROM AUTHOR]

A facile route to scalable production of N and S co‐doped, hierarchically porous carbon nanofiber (NSHCF) membranes (ca. 400 cm2 membrane in a single process) is reported. As‐synthesized NSHCF membranes are flexible and free‐standing, allowing their direct use as cathodes for efficient electrochemical CO2 reduction reaction (CO2RR). Notably, CO with 94 % Faradaic efficiency and −103 mA cm−2 current density are readily achieved with only about 1.2 mg catalyst loading, which are among the best results ever obtained by metal‐free CO2RR catalysts. On the basis of control experiments and DFT calculations, such outstanding CO Faradaic efficiency can be attributed to the co‐doped pyridinic N and carbon‐bonded S atoms, which effectively decrease the Gibbs free energy of key *COOH intermediate. Furthermore, hierarchically porous structures of NSHCF membranes impart a much higher density of accessible active sites for CO2RR, leading to the ultra‐high current density. An effective method was developed for scalable production of N, S co‐doped hierarchically porous carbon nanofiber membranes. These membranes are flexible and self‐supporting, and they could be directly used as a cathode for electrochemical CO2 reduction. With a circa 1.2 mg catalyst loading, a 94 % Faradaic efficiency and −103 mA cm−2 current density was obtained, which are among the best results for metal‐free CO2RR catalysts. [ABSTRACT FROM AUTHOR]

A facile route to scalable production of N and S co‐doped, hierarchically porous carbon nanofiber (NSHCF) membranes (ca. 400 cm2 membrane in a single process) is reported. As‐synthesized NSHCF membranes are flexible and free‐standing, allowing their direct use as cathodes for efficient electrochemical CO2 reduction reaction (CO2RR). Notably, CO with 94 % Faradaic efficiency and −103 mA cm−2 current density are readily achieved with only about 1.2 mg catalyst loading, which are among the best results ever obtained by metal‐free CO2RR catalysts. On the basis of control experiments and DFT calculations, such outstanding CO Faradaic efficiency can be attributed to the co‐doped pyridinic N and carbon‐bonded S atoms, which effectively decrease the Gibbs free energy of key *COOH intermediate. Furthermore, hierarchically porous structures of NSHCF membranes impart a much higher density of accessible active sites for CO2RR, leading to the ultra‐high current density. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • MoS ` -NiS x electrocatalysts are prepared by scalable mechanical ball milling method. • NiS x addition exposes edge sites of MoS 2 and creates active hetero-interfaces. • Synergistic effect takes place in the heterostructure MoS 2 -NiSx. • Ni-Mo-S (1:1:10) give the best HER activity (Tafel slope 66 mV dec−1 and η 10 83 mV), better than literature. Abstract Hydrogen generation by electrochemical water splitting with the renewable power source is one of the most promising pathways for green and sustainable society. The challenge is to explore a simple and cost-effective method to synthesize earth-abundant and noble-metal-free electrocatalysts with reliable hydrogen evolution reaction (HER) activity. Herein, we report a facile and scalable method to synthesize hybrid MoS 2 and nickel sulfides (NiS/NiS 2 /Ni 3 S 4) nanosheets (Mo-Ni-S NSs) with highly efficient HER activity in alkaline media. The hybrid phase and NSs allow large exposure of edge sites of MoS 2 and construct highly active hetero-interfaces between MoS 2 and NiS x and sufficient durability in alkaline solution. Mo-Ni-S NSs with optimal composition presents a low overpotential of 83 mV to reach a current density of 10 mA cm−2 in 1.0 M KOH, which is comparable to the performance of recent reported highly active MoS 2 based electrocatalysts. This work sheds light on the facile synthesis of multiple heterostructures as efficient electrocatalysts for scalable application in energy chemistry. [ABSTRACT FROM AUTHOR]

Fabricating heterointerfaces with optimized electronic structures is a robust strategy to boost the activity of electrocatalysts. Herein, for the first time, we demonstrate that the heterointerfaces of metallic Ag and NiFe-oxides on hierarchical nanoarrays facilitate the charge transfer during the OER and optimize the electronic state of NiFe-oxides, thereby significantly boosting the activity for the OER. [ABSTRACT FROM AUTHOR]

The efficient and sustainable production of high-purity hydrogen gas through electrochemical water splitting calls for robust and bifunctional catalysts to accelerate the two half reactions of water splitting. Herein, we in-situ craft ultrathin CoNi-sulfides nanosheet (∼2.2 nm in thickness) arrays-anchored MnO 2 nanoparticles (∼3.2 nm in diameter) (denoted U-CoNi-S-NSA/MnO 2 ) via a spontaneous redox process between CoNi-sulfides nanosheet and MnO 4 − anions at ambient temperature. The hierarchical U-CoNi-S-NSA/MnO 2 nanocomposites are then directly employed as self-supported catalysts for the two half reactions of water splitting, showing excellent activity with small overpotentials of 170 mV for oxygen evolution reaction and 67 mV for hydrogen evolution reaction to achieve 10 mA cm −2 , respectively. Moreover, an efficient water electrolyzer through using U-CoNi-S-NSA/MnO 2 as both anodic and cathodic catalysts is fabricated, which achieves current density of 10 mA cm -2  at a small voltage of 1.51 V over a long-time operation of 20 h. This outstanding performance is markedly superior than that of precious Pt/C//RuO 2 counterpart (1.61 V). Therefore, the as-synthesized hierarchical nanocomposites are promising candidates for cheap and efficient water splitting. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting by electricity from the renewable power sources is one of the most promising pathways for green and sustainable hydrogen production. The key is to synthesize earth-abundant and noble-metal-free electrocatalysts with outstanding hydrogen evolution reaction (HER) activity and durability in wide-pH electrolytes by simple and cost-effective methods. Herein, we reported a one-step synthesis of uniform, ultrafine molybdenum carbide (Mo 2 C) and molybdenum nitride (Mo 2 N) hybrid [together as Mo 2 (CN)] inserted carbon nanosheets as efficient electrocatalyst for HER. The as-synthesized catalyst showed an excellent HER activity in acid medium, and even superior performance was obtained in the alkaline medium. The optimal Mo 2 (CN) annealed at 750 °C showed an overpotential of −80 mV at 10 mA cm −2 and a Tafel slope of 40 mV dec −1 ; the former strikingly outperforms commercial 20% Pt/C materials (−112 mV). Moreover, Mo 2 (CN) gave an onset voltage of −33 mV and overpotential of −202 mV at 100 mA cm −2 with merely a mass loading of 0.2 mg cm −2 , which are, to date, among the best records for Mo-based catalysts in both media. The nanosheet structure providing large active area and quick charge transfer, and the synergistic effects between Mo 2 C and Mo 2 N toward HER are ascribed to the outstanding electrocatalytic activity according to the capacitive current and turnover frequency analysis. The remarkable catalytic activity and operational durability in wide pH ranges guarantee their potential for highly efficient hydrogen production. [ABSTRACT FROM AUTHOR]

Highly efficient, cost-effective and environmental-friendly electrocatalysts play a crucial role in oxygen reduction reaction (ORR) for fuel cells and metal-air batteries. Herein, a series of hybrids comprising of NiCo alloy, metal oxides and carbon black were readily prepared by a one-pot pyrolysis approach and employed as efficient ORR electrocatalysts in the alkaline media. Different amounts of Ketjen Black EC 300J (EC) with a large mesoporous area and exceptional electrical conductivity were directly added to synthesize the hybrids. Among the hybrids tested, the NC-MMO-EC-3 (where NC stands for NiCo alloy and MMO for mixed metal oxides) with an appropriate amount of EC displayed the best ORR electrochemical activity. The enhanced activity of the NC-MMO-EC-3 could be attributed to the conductivity improved by EC, the high dispersion of MMO and NC on EC support, and the beneficial interaction among those three components. [ABSTRACT FROM AUTHOR]

Highly conductive ceria-carbonate composite represents one type of most promising electrolyte materials for low temperature solid oxide fuel cells (SOFCs). Composites with large oxide-carbonate interface and homogeneous element/phase distribution are desirable to further enhance electrical properties and to study the ionic conduction mechanism. In this work, we report the successful synthesis of element/phase well-distributed, interfacial strongly coupled Sm 0.2 Ce 0.8 O 2 -Na 2 CO 3 (NSDC) nanocomposite with different residual carbonate contents by an in-situ one-pot one-step citric acid-nitrate combustion method. Interestingly, NSDC shows distinct properties over those prepared by conventional methods and improved ionic conductivity. In particular, NSDC9010 nanocomposite displays a proton conductivity of 0.044 S cm −1 at 650 °C, which is 3–5 times higher than the oxide proton conductors. Electrolyte supported SOFCs based on the resultant nanocomposite electrolyte, NSDC9010, give the best power output of 281.5 mW cm −2 at 600 °C with LiNiO 2 symmetric electro-catalysts. The excellent ionic conductivity and fuel cell performance are correlated with the unique core-shell structure, good phase distribution and large interfacial area induced by the one-step fabrication method, the strong coupling between oxide and carbonate as verified by the differential thermal and Raman spectroscopy characterization results and the optimal interfacial carbonate layer thickness by intentionally adjusting of carbonate contents. [ABSTRACT FROM AUTHOR]

The intrinsic or acquired cisplatin resistance of cancer cells frequently limits the final therapeutic efficacy. Detoxification by the high level of intracellular glutathione (GSH) plays critical roles in the majority of cisplatin-resistant cancers. In this report, we designed an amphiphilic diblock copolymer composed of poly(ethylene glycol) (PEG) and polymerized phenylboronic ester-functionalized methacrylate (PBEMA), PEG- b -PBEMA, which can self-assemble into micelles in aqueous solutions to load hydrophobic cisplatin prodrug (Pt(IV)). Pt(IV)-loaded PEG- b -PBEMA micelles (PtBE-Micelle) reverse cisplatin-resistance of cancer cells through improving cellular uptake efficiency and reducing intracellular GSH level. We found that the cellular uptake amount of platinum from PtBE-Micelle was 6.1 times higher than that of free cisplatin in cisplatin-resistant human lung cancer cells (A549R). Meanwhile, GSH concentration of A549R cells was decreased to 32% upon treatment by PEG- b -PBEMA micelle at the phenyl borate-equivalent concentration of 100 μM. PtBE-Micelle displayed significantly higher cytotoxicity toward A549R cells with half maximal inhibitory concentration (IC 50 ) of cisplatin-equivalent 0.20 μM compared with free cisplatin of 33.15 μM and Pt(IV)-loaded PEG- b -poly( ε -caprolactone) micelles of cisplatin-equivalent 0.75 μM. PtBE-Micelle can inhibit the growth of A549R xenograft tumors effectively. Accordingly, PEG- b -PBEMA micelles show great potentials as drug delivery nanocarriers for platinum-based chemotherapy toward cisplatin-resistant cancers. [ABSTRACT FROM AUTHOR]

The ability to develop low-cost highly efficient electrocatalyst for oxygen evolution reaction (OER) is key to the overall water splitting device that represents a viable and promising source of alternative energy. Herein, we crafted three-dimensional (3D) network comprising nitrogen-doped graphitic carbon-coated heterojunctions (denoted NC-Ni 0.36 Fe 0.64 /MnO x ) via one-step calcination of hybrid precursors containing ternary Prussian blue analogues and polymers. The NC-Ni 0.36 Fe 0.64 /MnO x nanocomposites were then exploited as catalysts for OER, displaying exceptional performance with a small overpotential of 300 mV to reach 10 mA cm −2 , a low Tafel slope of 43 mV/dec and an outstanding stability without deactivation over a 10-h OER. Notably, compared to commercial RuO 2 catalysts, NC Ni 0.36 Fe 0.64 /MnO x catalysts demonstrated much lower overpotential and Tafel slope. The excellent OER performance can be attributed to the presence of high-valence oxidized metal species (Ni 2+ , Fe 2+ and Mn 2+ ) at the heterostructured interface as well as pyridinic N-doped carbon species on highly conductive graphitic carbon network, thus greatly facilitating the electron-withdrawing from OH − and thus charge transfer during OER. This simple yet effective strategy may open new possibilities for creating a wide range of low-cost, high-efficiency, non-precious transition metal OER catalysts for the overall water splitting. [ABSTRACT FROM AUTHOR]

Glutathione (GSH), cysteine (Cys), and homocysteine (Hcy) are three major biothiols, which play key roles in various biological systems. Accordingly, the development of phosphorescent probe of biothiols has attracted great attention in clinical applications. Here we report a ruthenium polypyridyl complex ( 1 ), which shows large phosphorescence quenching with 2.0 equivalents of Cu 2+ ions. The non-phosphorescent 1 −Cu ensemble sensor is formed and further applied to detect biothiols in living cancer cells. Among the various amino acids, GSH, Cys and Hcy induce distinct turn-on phosphorescence with high selectivity and insensitivity to biological relevant pH range and other proteins. As we know, this is the first report that Ru−Cu ensemble is used for probing endogenous thiols in the living cells. [ABSTRACT FROM AUTHOR]

Block copolymer prodrugs (BCPs) have attracted considerable attentions in clinical translation of nanomedicine owing to their self-assembly into well-defined core-shell nanoparticles for improved pharmacokinetics, stability in blood circulation without drug leakage, and optimized biodistribution. However, a cascade of physiological barriers against specific delivery of drugs into tumor cells limit the final therapeutic efficacy. Herein, we report a robust and facile strategy based on thiolactone chemistry to fabricate well-defined BCPs with sequential tumor pH-promoted cellular internalization and intracellular stimuli-responsive drug release. A series of BCPs were prepared through one-pot synthesis from clinically used small molecule anticancer drugs. The ring-opening reaction of drug-conjugated thiolactones releases mercapto groups via aminolysis by N -(3-aminopropyl)-imidazole, which further react with poly(ethylene glycol)- block -poly(pyridyldisulfide ethylmethacrylate) (PEG-PDSEMA) to produce imidazole and disulfide bonds-incorporated BCPs. Taking paclitaxel (PTX) for example, PTX BCPs exhibited high drug-loading content (>50%) and low critical micellization concentration (5 × 10 −3 g/L), which can self-assemble into micellar nanoparticles in aqueous solution with a small size (∼40 nm). The nanoparticles showed high tumor accumulation and uniform distribution in hypopermeable tumors via systemic administration. Meanwhile, imidazole moieties endow nanoparticles tumor pH-sensitive charge transition from nearly neutral to positive, which promoted cellular internalization. Disulfide bonds can be cleaved by intracellular glutathione (GSH) of cancer cells, which accelerate the release of active PTX drug inside cells. Finally, highly aggressive murine breast cancer 4T1 tumor and hypopermeable human pancreatic adenocarcinoma BxPC3 tumor were completely ablated after treatment by PTX BCP nanoparticles. Consequently, the robust and facile preparation strategy based on thiolactone chemistry represents an efficient approach to construct multifunctional BCPs for better therapeutic efficacy via addressing multiple physiological barriers. [ABSTRACT FROM AUTHOR]

Two isomeric ruthenium(II) complexes, [Ru- m -OH] 2+ and [Ru- o -OH] 2+ with two hydroxyl substituents at different positions of ligands, had been designed and synthesized. We found that the cellular uptake efficiency of Ru- o -OH] 2+ was much better than Ru- m -OH] 2+ , and it exhibited higher toxicity toward cancer cell (BEL-7402) than its isomeric compound, [Ru- m -OH] 2+ . Importantly, [Ru- o -OH] 2+ showed great selectivity between cancer cells and human normal cell (HBMEC). Confocal microscopy and inductively coupled plasma mass spectrometry (ICP-MS) indicated that [Ru- o -OH] 2+ mainly accumulated in mitochondria. It could up-grade the expression of Bax and down-grade the level of Bcl-2, which trigger in mitochondrial apoptotic pathway. This study suggests that isomeric metal complexes might make differences in the field of medicine for anti-cancer. [ABSTRACT FROM AUTHOR]

A novel bifunctional organic sponge photocatalyst can enable the efficient coupling of tertiary amines with ketones in water. The asymmetric transformation can be also achieved by using this sponge photocatalyst. [ABSTRACT FROM AUTHOR]

A novel near infrared (NIR) phosphorescent osmium complex (Os1) was developed for lysosome tracking and photodynamic therapy. Owing to its NIR photophysical properties, cellular imaging ability and phototoxicity, it has advantages over its ruthenium analogue (Ru1). [ABSTRACT FROM AUTHOR]

Rational designing of efficient bifunctional oxygen electrocatalysts is significantly important but rather challenging for rechargeable zinc-air batteries. Herein, a novel high-performance bifunctional oxygen electrocatalyst for rechargeable zinc–air batteries are constructed based on bimetal Mn@Co-N-C encapsulated in in situ grown N,S-doped graphitic carbon framework with within a porous three-dimensional (3D) structure. The final catalyst shows a high half-wave potential of 0.89 V for oxygen reduction reaction, and a low operating overpotential of 0.38 V to achieve a 10 mA cm−2 current density for oxygen evolution reaction. The physical characterizations reveal that a strong synergetic coupling between bimetal Mn@Co-N-C and S dopant can effectively increase the active sites, meanwhile achieve a rational manipulation of the active site configuration toward a favorable electronic structure. Impressively, the assembled zinc–air batteries using liquid electrolytes and the all-solid-state batteries with this catalyst exhibit excellent charging–discharging performance, long lifetime, and high flexibility. [Display omitted] • The second metal source is Mn, which utilizes a controlled self-assembly method to orient on N, S-doped carbon-based materials generated from MOFs. • The synthesized Mn@Co-NS catalyst exhibits excellent bifunctional electrocatalytic activity. • The reasons for the superior performance of Mn@CO-NS catalysts are revealed. • Mn@Co-NS has good performance and long-term stability in the field of zinc-air batteries. • It provides direction guidance for the qualitative landing of various metals on carbon substrates, bringing the application of zinc-air batteries to a new level. [ABSTRACT FROM AUTHOR]

The coordination environment of Li+ is adjusted by introducing FEC and the solvation structure of Li+ in the flame-retardant electrolyte is reshaped simultaneously. Furthermore, the higher LUMO energy level of FEC facilitates the formation of firm and dense SEI on the surface of the Gr electrode. The in-situ induced stable interface of this novel solvated structure not only suppresses the co-intercalation effect of TMPa solvent, but also enhances the even Li+ transport, contributing to the stable cycling of Li|Gr cells. [Display omitted] • A flame-retardant electrolyte with FEC involved in Li+ solvated structure is proposed. • In-situ induced LiF-rich SEI promotes structural integrity of graphite electrodes. • The modified Li|Gr cell delivers an excellent cycling performance for 300 cycles with 97.48% capacity retention. Conventional electrolytes with flammability and volatility may incur severe safety issues, which are impeding the application of lithium batteries on a large scale. Flame-retardant solvents are introduced into the electrolytes to enhance the security performance, while the battery electrochemical performance is compromised due to incompatibility between these solvents and graphite (Gr) anode. In this work, a flame-retardant electrolyte prepared by trimethyl phosphate (TMPa), lithium difluoro(oxalato)borate (LiDFOB) and fluoroethylene carbonate (FEC) could be expected to solve the dilemma via regulating the solvation structure of Li+ to suppress the co-intercalation effect of TMPa with Li+ and alleviate the compatibility issues of interface caused by the continuous reduction of LiDFOB. The formation mechanism of the solid electrolyte interface (SEI) at the graphite electrode was analyzed to explore the intrinsic reaction of the electrolyte at the electrode interface. The 300-cycle capacity retention of Li|Gr cell at 0.5C reaches 97.48 %, and the deposition and stripping performance of the Li|Li symmetric cell is also significantly improved. Such Li+ solvation structure modification provides a new idea for fire-extinguishing electrolyte design and helps to promote the industrialization of safe and eco-friendly electrolytes. [ABSTRACT FROM AUTHOR]

The successfully developed polydimethylsiloxane (PDMS, a green and highly transparent polymer material) sponge photocatalyst can catalyze cross-dehydrogenative coupling (CDC) of tertiary amines and various nucleophiles with high efficiency and reusability under visible light irradiation. Through an easy-to-build continuous flow reactor, the sponge photocatalytic reaction can be facilely scaled up. [ABSTRACT FROM AUTHOR]

Active cathode materials for low temperature solid oxide fuel cells (SOFC) below 600 °C are urgently required due to the sluggish oxygen reduction reaction (ORR) kinetics at reduced temperature. In this work, a detailed experimental fabrication and characterization of silver modified Pr 2 NiO 4 composite material for low temperature SOFC cathode catalyst with superior ionic conducting ceria-carbonate composite electrolyte was carried out. Pr 2 NiO 4 was prepared by a co-precipitation method with NaOH as precipitant, and it was composited with silver to improve the electrode activity toward ORR through three various methods of impregnation, solid-state mixing and freeze-drying, respectively. Effects of Ag loading on the electrochemical activity were systematically investigated. It was found that composite materials originated from impregnation method presented the optimal material microstructure, and 15% Ag loaded composite gave the lowest area specific resistance of 0.45 Ω cm 2 at 600 °C, which is reduced by around 300% compared with previous work, indicating that impregnated Pr 2 NiO 4 -15Ag composite is a promising cathode catalyst for low temperature SOFC with ceria-carbonate composite electrolyte. [ABSTRACT FROM AUTHOR]

Li 4 Ti 5 O 12 particles are synthesized coated with very thin graphene-like sheets in situ using liquid-polyacrylonitrile (LPAN) as the carbon source and added utilized conductivity additives to improve the conductivity of the electrode materials. The crystalline structures of Li 4 Ti 5 O 12 with 20% LPAN and different conductivity additives composites were examined by XRD. The structure and electrochemical performance of the graphene-like sheets coated Li 4 Ti 5 O 12 , with conductivity additives added, was systematically investigated. The electrochemical performance also revealed that the graphene-like sheets significantly improved the discharge capacity and cycling stability of Li 4 Ti 5 O 12 . In particular, the coated Li 4 Ti 5 O 12 with 20 wt% LPAN and 1% acetylene black (CB) reached 166.2 mAh g −1 at 10C. The performance improvement is a result of the graphene-like nanosheet conformal coating, which creates an electrically conductive network for the electrode. [ABSTRACT FROM AUTHOR]

The vanadium oxides with classical high-capacity materials as well as high operating voltage have been regarded as appealing electrodes for aqueous zinc-ion batteries (AZIBs) owing to their multiple valences and adjustable ion-diffusion channels. However, the developed AZIBs cathodes have always suffered from sluggish Zn2+ diffusion kinetics and less stable layered structure, thus resulting in the inadequate electrochemical performance. In this work, unique organometallic (ferrocene) reintercalated inorganic (vanadium oxide) cathodes (Fec/O d -VO) with defective crystal structure were firstly synthesized via a redox intercalation method for ultrahigh-rate and ultralong-life aqueous ZIBs. The unique organometallic can not only enlarge interlayer distances between the V-O layers, with expediting channels for fast Zn2+ diffusion, but also introduce the rich oxygen vacancies to facilitate the surface reversible Zn2+ adsorption. The resulting Fec/O d -VO displays a high discharge capacity (411.7 mAh g−1 at 0.5 A g−1) and superior long-term cycling stability (86.5% retention over 3000 cycles at 20 A g−1). This enlightened design combining interlayer regulation with oxygen defect engineering proves to be a new modus operand toward advanced AZIBs by redox intercalation of unique organometallic. [ABSTRACT FROM AUTHOR]

Non-noble-metal catalysts have shown promising oxygen reduction reaction (ORR) activity in proton exchange membrane fuel cells (PEMFCs). Herein, by using sulfur-terminated fluidic acrylonitrile telomere (ANT) as precursor, an N and S dual-doped Co/ANT/C catalyst was prepared via a facile heat treatment of the mixture of Co salt, ANT and carbon black, in which cobalt salt was uniformly-dispersed and interacted with ANT. As such, the increasing contact area between ANT and cobalt salt leads to a highly catalytic activity toward oxygen reduction reaction. Most importantly, by using ANT as precursor, the catalyst showed a remarkable improvement in the onset potential and current density as compared with those prepared from pure carbon black, cobalt salt/C or catalyst using high molecular weight polyacrylonitrile as precursor. Besides, the as-made Co/ANT/C catalyst demonstrated a comparable catalytic activity with commercial expensive Pt/C at high loading. In addition, the catalyst participated promotes a direct four-electron reduction of O 2 to H 2 O and long term operation stability in an alkaline medium. Owing to its superb ORR performance, low cost and facile synthesis approach, such prepared Co/ANT/C catalyst has great potential applications in PEMFCs. [ABSTRACT FROM AUTHOR]

The built-in electric field kinetically controlled by in-situ polarization of the battery's inherent electric field and extra piezoelectric potential induced by volume expansion effectively accelerate Na+ transport, just 1 min to charge 99% at 10 A·g−1. Such outstanding tolerance and high-rate sodium storage capacity have implications for sodium-ion battery fast charging technologies. [Display omitted] • Three-dimensional core–shell BTO@SnO 2 @P-C composites are designed. • BTO@SnO 2 @P-C delivers excellent cycle tolerance and high-rate Na+ storage capacity. • The BIEF and extra piezoelectric potential effectively accelerates Na+ transport. • Confirms kinetically reversible BIEF and irreversible piezoelectric potential. Batteries with high storage capacity, durable cycle lifetime and fast charging are extremely rare but meaningful. Herein, the three-dimensional core–shell structure with tin dioxide coated barium titanate (BTO) and the outermost layer covered with phosphorus doped carbon (BTO@SnO 2 @P-C) is designed as an anode for sodium-ion batteries (SIBs), which shows remarkable cycle tolerance and high-rate sodium storage capacity. It exhibits rapid kinetics at 10 A·g−1 with a powerful life of 10,000 cycles, just 1 min to charge 99%. Such advanced electrochemical performance is primarily attributed to the built-in electric field (BIEF) generated by the in-situ dynamic polarization of BTO from the battery's inherent electric field. Additionally, ensuring the piezoelectric potential through the core–shell structure intensifies the BIEF. The BIEF effectively accelerates sodium ions transport and greatly improves tin dioxide anode reaction kinetics and sodium storage capacity, which is of constructive significance for realizing SIBs with high energy density and fast charging capability. [ABSTRACT FROM AUTHOR]

The introduction of TMP changes the coordination environment of Zn2+ to reshape the hydrogen bond network of water. A novel strategy is established to regulate Zn2+-solvation shell, restraining vanadium dissolution, suppressing Zn dendrite formation and contributing to uniform deposition of Zn2+. [Display omitted] • A novel Zn2+-solvation shell is formed via trimethyl phosphate. • Zn symmetrical battery exhibits an ultralong cyclic lifespan for 7000 h at 1 mA cm−2. • The cathode dissolution and self-discharge of battery are efficiently suppressed. • Zn|VO 2 (B) cell possesses 97.86% capacity retention after 1200 cycles at 1 A·g−1 (0 °C). The wide-scale application of zinc-ion batteries (ZIBs) is largely restricted by dendrite formation, hydrogen evolution corrosion and capacity fading, caused by the coordinated H 2 O within the Zn2+-solvation shell as well as reactive active water in the bulk electrolyte. Here, one green and flame-retardant additive, trimethyl phosphate (TMP) is introduced into aqueous electrolyte systems, contributing to Zn2+-solvation shell reshaping and promoting the stability hydrogen bonding network of H 2 O. The strategy is significant in suppressing water-induced side reactions and dendrite growth, enabling an ultralong cycling lifespan of 7000 h at 1 mA·cm−2 and 0.5 mAh·cm−2 in Zn symmetrical cell. In addition, Zn|VO 2 (B) full cells with TMP addition exhibit an ultralong cyclic performance for 1200 cycles at 1 A·g−1 with 97.86% capacity retention even at 0 °C, which contributes to taking a step closer to commercial application. This work demonstrates the feasibility of developing electrolytes for practical ZIBs that integrate safety, sustainability and wide-temperature applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Identifying that the surface-supported electrocatalysts are actually not stable under harsh condition towards the practical applications. • A lattice-confined approach is developed to concurrently enhance the stability and intrinsic activity of Ru. • Lattice-confined Ru delivers both outstanding activity and stability for HER under harsh conditions. • Both experimental and theoretical results reveal that the lattice-confined strategy significantly enhances the interaction of Ru/TiO 2. Ru-based nanomaterials are among the best electrocatalysts for hydrogen evolution reaction (HER) in alkaline media, however their stability is still questionable, especially under harsh conditions towards practical applications (i.e., 80 °C, 6 M KOH). We demonstrate that the conventionally surface-supported Ru electrocatalysts are actually not stable under harsh conditions due to the weak interaction between Ru and supports, although they are stable under mild conditions. Here, we report a lattice-confined approach to concurrently enhance the stability and intrinsic activity of Ru via confining ultrafine Ru clusters into TiO 2 lattice frameworks. Impressively, such confined Ru delivers outstanding performance for HER under harsh conditions, such as a small overpotenital of 116 mV at 800 mA cm−2, and long-time stability for 200-h continuous HER at 300 mA cm−2. As uncovered by both computational and experimental results, the lattice-confined strategy can significantly enhance the interaction between Ru and TiO 2 for promoting the electron transfer from Ru to TiO 2 , thereby strongly stabilizing Ru for avoiding the dissociation and aggregation of Ru during the stability test. Therefore, the lattice-confined strategy may stand out as a robust approach for boosting the activity and stability of electrocatalysts. [ABSTRACT FROM AUTHOR]

• PEO-based polymer electrolyte with KPF 6 additive was developed for improving the performance. • KPF 6 can reduce the crystallinity of PEO, and promote dissociations of LiTFSI. • KPF 6 can increase the ionic conductivity of PEO-based polymer electrolyte. • KPF 6 salt can regulate the formations of Li 2 S/LiF-rich SEI layer. • Li 2 S/LiF-rich SEI layer and K + electrostatic shielding led to a uniform Li deposition. High energy density all-solid-state lithium metal batteries (ASSLMBs) with flexible, low-cost solid polymer electrolytes (SPEs) have received extensive research attention, but the low ionic conductivity of SPEs and the rapid growth of lithium dendrite seriously limit their performance. Here, polyethylene oxide (PEO) based solid polymer electrolytes (SPEs) containing potassium hexafluorophosphate (KPF 6) salt additive are developed for lithium dendrite-free ASSLMBs. The results show that with the additive of KPF 6 , the dissociation of lithium salt is promoted, providing more free Li+ ions in SPEs and enhancing the ionic conductivity. KPF 6 additive also makes SPE more flexible and promotes the formation of Li 2 S and LiF-rich solid electrolyte interphase (SEI). Besides, the presence of K + is also expected to work as a shield to inhibit the lithium dendrite growth. With the synergistic effect of above advantages, lithium dendrite growth and interfacial side-reactions in ASSLMBs are prevented. Li/Li symmetric cell with SPE can achieve a stable cycling performance over 1500 h with low polarization potential. The all-solid-state LiFePO 4 /Li cell releases an initial capacity of 142.1 mAh g−1 with a capacity retention of 91.3% after 200 cycles at 0.5 C and 60 °C. This study provides a facile scheme for designing high performance ASSLMBs. [Display omitted] Solid-state lithium metal batteries with polyethylene oxide (PEO) based solid polymer electrolytes (SPEs) suffer from lithium dendrite problems. To address this challenge, KPF 6 is used as an additive to improve ionic conductivities and mechanical properties of SPEs. Moreover, KPF 6 is favorable to the formation of LiF-rich solid electrolyte interphase. K + also works to suppress the lithium dendrite through shielding effects. [ABSTRACT FROM AUTHOR]

This article describes a low-temperature thermal stabilization method, for the efficient preparation of polyacrylontrile (PAN)-based carbon fibers with improved mechanical properties. In this method, bundles of regular PAN precursor fibers were firstly heated and stored in air for 30 days at 120 °C to cyclise the nitrile groups and oxidize the PAN backbone. A further stabilization above 200 °C in air made the pretreated fibers fully stabilized. Structural changes of the as-made PAN fibers were observed by Fourier Transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, differential scanning calorimetry, thermogravimetry and dynamic mechanical analysis. Microvoid evolutions of the fibers during stabilization and carbonization process were studied by synchrotron small-angle X-ray scattering. Our results showed that the initiation of the cyclization and oxidation reaction at 120 °C not only restricts the disorientation of PAN molecules but also reduces the pyrolysis of molecular chains at higher temperatures in the carbonization process. Hence, preferred orientation of crystallites and char yield increased. Moreover, microvoid defects were significantly reduced, leading to a significant improvement of the mechanical properties (a 16% increment in the tensile strength). [ABSTRACT FROM AUTHOR]

Single-atom catalysts (SAC) stabilized by nitrogen in carbon support are promising candidates for oxygen reduction reaction (ORR). However, conventional preparation methods usually lead to encapsulation of metallic centers in matrix and thus the utilization efficiency (UE) is underexploited. Herein, we report a novel strategy to prepare an Fe-SAC with all Fe atoms anchored on the surface of carbon nanospheres, which exhibited an extraordinary UE of 80% for ORR. This efficiency was achieved by coating polydopamine spheres with silica, followed by the pyrolysis of their blend with FeCl 3. During thermal treatment, Fe migrates across the silica shell by atomic exchange with silicon, which inhibits the aggregation of Fe and allows Fe atoms to anchor on the surface. As such, it showed excellent ORR activity at a low Fe content. Zn-air batteries assembled using this catalyst showed a peak power density of 113 mW cm−2 and specific capacity of 710 mAh g Zn −1. [Display omitted] • A single atomic Fe catalyst anchored on carbon nanosphere was prepared. • All Fe species were single-atomic and fully exposed due to restriction of silica. • The method can be extended to prepare other single-atom catalysts. • The catalyst exhibited excellent catalytic performance at a low loading of Fe. [ABSTRACT FROM AUTHOR]

Ordered mesoporous carbon (OMC) was synthesized by nano-casting method using novel fluidic precursor – acrylonitrile telomer (ANT). By the penetration of mesoporous silica template with pure ANT, followed by the stabilization, carbonization and removal of the template, we obtained highly ordered mesoporous carbon rods (specific area 408 m 2 g −1 ). When an acetone solution of ANT (66 and 33 wt.%) was used instead of pure ANT, carbon materials with mesopore ranging from 2 to 7 nm were obtained (specific area 843 and 1012 m 2 g −1 respectively). Both nitrogen and sulfur atoms were doped into mesoporous carbon with 4 and 0.6 at.% using nitrogen containing monomer and sulfur containing chain transfer agent, without involving complicated synthetic technique and poisonous gaseous compounds. This method was proved to be a facile way to synthesize nitrogen and sulfur containing OMC with partially controllable pore distribution and morphology. More importantly, due to unique mesopore structure and heteroatom doping, Pt nano-particles deposited on the OMCs showed electrocatalytic activity as high as 508 mA mg −1 Pt in methanol oxidation which is 1.7-fold of activity of Pt deposited on commercial Vulcan carbon black. [ABSTRACT FROM AUTHOR]

This paper reveals a novel Li-rich layered cathode material Li[Li 0.1 Ni 0.45 Mn 0.45 ]O 2 in situ coated with graphene-like carbon prepared by using liquid-polyacrylonitrile (LPAN) as the carbon source. The structure and electrochemical performance of graphene-like carbon coated Li[Li 0.1 Ni 0.45 Mn 0.45 ]O 2 are investigated systematically. The results demonstrate that the graphene-like carbon are in situ coated tightly on the surface of Li[Li 0.1 Ni 0.45 Mn 0.45 ]O 2 particles. The in-situ coating of graphene-like carbon significantly improves the electrochemical properties of cathode materials. The discharge capacity of cell made of 12wt% LPAN-coated Li[Li 0.1 Ni 0.45 Mn 0.45 ]O 2 can reach 210 mAh g −1 and the capacity retention is close to 100% after 50 cycles at 0.1C. The cyclic voltammgram and electrochemical impedance spectra analyses further demonstrate that the improved electrochemical performance of LPAN-coated Li[Li 0.1 Ni 0.45 Mn 0.45 ]O 2 cathode materials is attributed to the graphene-like carbon in situ coating, which can protect the cathode directly contact with the electrolyte. Therefore, the Li-rich layered Li[Li 0.1 Ni 0.45 Mn 0.45 ]O 2 in situ coated with graphene-like carbon is a very good promise cathode material for advanced LIB with high capacity and good stability. [ABSTRACT FROM AUTHOR]

The precise design and controllable manufacture of electrocatalysts for efficient oxygen reactions (OER and ORR) based on the abundant elements of the earth are urgently required but challenging task. In this study, a CoS 2 /Cu 2 S heterostructured composite (CoS 2 /Cu 2 S-NF) supported by the porous carbon nanofibers is synthesized as a high-efficiency oxygen reaction electrocatalyst. As indicated from in-situ characterization methods (infrared, Raman and XRD) integrated with the density functional theory results, the heterostructures exhibited by CoS 2 and Cu 2 S could be regulated. The results show that the electron transfer/interaction between CoS 2 and Cu 2 S in the heterojunction were regulated, as well as the electronic structures of Co and Cu sites. As impacted by the structural engineering and the electronic modulation, the activity was enhanced, and the performance of electrocatalytic oxygen reactions was improved, which exhibited the lowest potential difference for (ΔE = 0.73 V) compared with commercial electrocatalysts. The liquid ZAB in accordance with on CoS 2 /Cu 2 S-NF exhibited a stable charge and discharge capacity up to 590 h and a great power density reaching 260.60 mW cm−2. Moreover, the flexible solid-state ZAB based on CoS 2 /Cu 2 S-NF exhibited a great competitive power density (92.06 mW cm−2), robust flexibility and an obvious integration. As compared with single metal sulfide-NF, the Density functional theory calculations (DFT) highlight the adsorption on CoS 2 /Cu 2 S-NF side surface in the heterojunction, which more specifically demonstrates the synergistic effect in the junction. This work presents a direction for designing heterostructured junctions as electrocatalyst and moreover its great application potential in rechargeable metal-solid batteries. [Display omitted] • Heterostructure CoS 2 /Cu 2 S-NF shows outstanding catalysis activity for OER and ORR. • The electrocatalytic mechanism is revealed by DFT calculation and in-situ techniques. • CoS 2 /Cu 2 S-NF employing Zn-air battery displays excellent performance. • The flexible Zn-air battery was fabricated by using CoS 2 /Cu 2 S-NF. [ABSTRACT FROM AUTHOR]