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Self-healing materials are widely used in flexible and stretchable electronic devices because of their capability to repair cracks or damages that occur during usage, thus extending their lifetime. In this work, self-healable polydimethylsiloxane-polyurea/carbon composite elastomers (CCF/PDMS) are prepared successfully via the design of multiple hydrogen bonds. The multiple hydrogen bonds formed between the urea groups of polymer chains and between the urea groups and the carboxyl/hydroxyl groups of the graphite/carboxylated carbon nanotube complex fillers (CCFs) endow CCF/PDMS with excellent recyclability, mechanical properties (687.9%, 1.02 MPa), and rapid ethanol-assisted self-healing properties (99.4% at room temperature for 3 h), which exceeds most of the reported polydimethylsiloxane-based composites. Besides, the mechanism of ethanol-assisted self-healing properties is investigated using in situ FTIR spectra, providing a new strategy for self-healing composites of hydrogen bonding systems. Significantly, CCF endows CCF/PDMS with impressive self-powered capability. The self-healing triboelectric nanogenerator (SH-TENG) with an area of 30 × 30 × 0.25 mm3 prepared from CCF/PDMS has a remarkable output (125 V, 11.9 μA) and can easily power 144 LEDs. The design strategy with excellent mechanical performance, ultrahigh self-healing properties, and remarkable self-powered capability can meet the wide applications of wearable flexible sensors, electronic skins, flexible robots, self-powered devices, etc. [ABSTRACT FROM AUTHOR]

The construction of bifunctional catalysts for the oxygen evolution reaction (OER) and urea oxidation reaction (UOR) is important for accelerating the development of the hydrogen economy. Herein, a novel three-dimensional core–shell heterostructure (Ni–Mo–S@NiFeLDH/NF) was prepared by vertically growing NiFe layered double hydroxide (NiFe LDH) nanosheets on nickel foam (NF)-supported arrays of Ni–Mo–S (Ni3S2, Ni0.96S, Mo2S3) nanorods via a hydrothermal–sulfide–hydrothermal process. Benefiting from the unique core–shell structure with numerous exposed active sites, the optimized Ni–Mo–S@NiFe LDH/NF shows excellent OER/UOR activity, with an overpotential of only 274 mV for OER to reach 100 mA cm−2 and 1.318 V for UOR to reach 10 mA cm−2. Moreover, the assembled Ni–Mo–S@NiFe LDH‖‖Pt/C urea electrolytic system requires only 1.348 V to achieve 10 mA cm−2, as much as 159 mV lower than pure water electrolysis. This work provides an idea for researching NiFe LDH-based OER/UOR bifunctional catalysts. [ABSTRACT FROM AUTHOR]

As a versatile and environmentally friendly chemical, hydrogen peroxide (H2O2) is in high demand. The current anthraquinone oxidation process suffers from high energy consumption in hydrogen production and the cumbersome alternating operations of hydrogenation and oxidation. The direct synthesis of H2O2 from H2 and O2 is constrained by the balance between safety and efficiency and heavy metal pollution from catalysts. Two-electron oxygen reduction reaction (2e− ORR) is an efficient, safe, and low-cost route for the production of H2O2. This 2e− ORR pathway has potential to become a supplement to the anthraquinone process because of fossil energy-free feature. The bottleneck of the industrialization of 2e− ORR is the lack of efficient catalysts. The 2e− ORR catalytic performance of noble metal electrode materials urgently needs to be significantly enhanced by smart design. However, the high price and limited reserves of these noble metal-based materials still severely limit their commercialization. Among many 2e− ORR catalysts, carbon-based catalysts have received much attention because of their low cost and diverse structures. This study reviews the research progress and the synthesis methods of carbon-based catalysts for 2e− ORR in recent years. First, this paper introduces the fundamental mechanism of H2O2 production by 2e− ORR through a combination of theory and experiment. Then, the synthesis methods and optimization strategies of various high-efficiency carbon-based catalysts are discussed. Finally, the various influencing factors (pH effect, pore structure, and carbon defects) and the practical applications for H2O2 production are analyzed. In addition, the future research direction is also proposed to promote the development of carbon-based catalysts for 2e− ORR toward industrialization. Although carbon-based catalysts display obvious advantages for electrocatalytic applications, there are still a few shortcomings that need to be overcome. The intrinsic activity and the long-term stability of carbon-based materials still require to be improved to a level that can be compared with those of noble metal-based catalysts. This review presents a comprehensive overview of the latest developments in the production of H2O2 by 2e− ORR on carbon-based catalysts, combining the most advanced theoretical and experimental literature available. The current state of the research on carbon-based catalysts in recent years indicates great promise for further advancement. [ABSTRACT FROM AUTHOR]

Notorious dendrite growth is the major cause of low coulombic efficiency and safety issues in Li metal batteries, which is highly related to the crystallographic features of Li crystals. Generally, Li dendrites tend to grow on the (110) crystal face with the lowest surface energy. However, the understanding of deposited Li morphology evolution is still unexplored in terms of the changes in the exposure possibility of various Li crystal faces. Herein, we report isotropic Li growth by minimizing the surface energy discrepancy of lithium crystal faces to induce homogeneous Li deposition. Using DFT calculations, the surface energy discrepancy decreased from 0.17 to 0.1 J cm−2 after manipulation. The yielded dendrite-free Li anode exhibited long-term cycling for 4000 hours at 3 mA cm−2 for 3 mA h cm−2 in symmetric cells and exhibited extraordinary performance of up to 10 mA cm−2 with a capacity of 10 mA h cm−2. Moreover, 91.5% capacity retention was achieved in LFP full cells cycled at 1C for about 650 times. [ABSTRACT FROM AUTHOR]

The large-scale applications of zinc–air batteries (ZABs) as vital energy storage devices have been limited by the sluggish kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in the air electrode. Herein, Mn-doped Co nanoparticles on cedarwood-derived carbon (CoMn-N@NCW) are fabricated as a bifunctional catalyst to boost the reaction kinetics. The as-prepared catalyst shows a half-wave potential of 0.885 V for the ORR and an overpotential of 335 mV at 10 mA cm−2 for the OER in alkaline electrolytes. ZABs based on the catalyst exhibit a high peak power density of 186 mW cm−2 and a robust lifetime of 600 h. The quasi-solid-state ZABs assembled with CoMn-N@NCW exhibit a splendid open-circuit voltage of 1.493 V and a long-term cycling stability of 70 h. Oxygen electrocatalytic kinetics are improved by the electronic modulation of cobalt from adjacent manganese and the rapid mass transfer of porous biomass carbon. This work provides a remarkable inspiration to prepare a practically applicable oxygen electrode for ZABs. [ABSTRACT FROM AUTHOR]

Cooperatively coupling efficient photocatalytic hydrogen (H2) evolution with simultaneous organic transformations into value-added chemicals is a promising strategy for addressing global energy and environmental challenges. Herein, a nitrogen-vacancy-rich Ti3C2Tx/g-C3N4 (TC/CN) Schottky junction is developed as an efficient photocatalyst for the simultaneous reduction of water to H2 and oxidation of furfuryl alcohol to furfural by utilizing photogenerated electrons and holes. Experimental results and density functional theory calculations demonstrate that the Schottky junctions created by interfacial N–Ti bonding between CN and TC facilitate efficient directional transfer of carriers while preventing electron backflow, thereby boosting separation of photogenerated electron–hole pairs. Further, the incorporation of nitrogen vacancies into TC/CN can provide active sites to enhance reactant adsorption and activation, thereby facilitating hole-mediated photooxidation activity towards furfuryl alcohol on the valence band of CN. As expected, the optimized TC/CN heterostructure exhibits a highly stable photocatalytic activity for H2 coupled furfural, with rates of 1.17 and 1.22 mmol g−1 h−1, respectively, which are 3.7 and 3.8 times higher than pure g-C3N4. The photocatalytic oxidation mechanism of the carbon-centered radical pathway was confirmed through control experiments, in situ EPR spectra, and theoretical studies. This ingenious work provides insightful guidance for the rational design of a dual-functional photocatalyst that can efficiently reduce water while selectively synthesizing organic compounds. [ABSTRACT FROM AUTHOR]

Diphenylamine (DPA) is a harmful pesticide widely used to control post-harvest scald of fruits. In this study, rapid and sensitive determination of DPA was realized by the development of an effective electrochemical sensor, which was fabricated by coupling La-doped NiWO4 nanoparticles (La/NiWO4) with reduced graphene oxide (rGO), and the obtained rGO/La/NiWO4 nanocomposite was modified on glassy carbon electrodes (GCEs). The morphologies, structures and compositions were well characterized, and the effects of La doping and the introduction of rGO on the crystal structure and electrochemical performance were discussed. The incorporation of both La and rGO was found to enhance the active surface area and improve conductivity, resulting in the enhanced electrocatalytic performance of rGO/La/NiWO4/GCE, including a wide linear range (0.01–500 μM), a low detection limit (0.0058 μM) and high sensitivity (1.778 μA μM−1 cm−2). The fabricated sensor was further used for DPA detection in fresh apple extract to evaluate its practicality and demonstrated excellent recoveries ranging from 99.52 to 104.70%. [ABSTRACT FROM AUTHOR]

Advances in rechargeable zinc–air batteries are hindered by the lack of efficient and economical oxygen electrocatalysts. Herein, a monolithic bifunctional catalyst is rationally constructed via an in situ growth of a FeNi3 alloy on nitrogen-doped wood-derived carbon (FeNi3@NWC). FeNi3 alloy nanoparticles coupled with nitrogen-doped carbon expedite the catalytic activity toward oxygen reduction reaction (ORR) by promoting proton generation on FeNi3 and transfer to nitrogen-doped carbon. The actual formation of Ni1–xFexOOH on the surface of the FeNi3 alloy effectively accelerates oxygen evolution reaction (OER) via the charge transfer with outstanding activity. The potential gap of only 0.68 V between ORR and OER of FeNi3@NWC is achieved. The liquid zinc–air batteries (ZABs) with FeNi3@NWC convey a robust lifetime of ∼266 h (800 cycles) with stable charging and discharging. Theoretical calculations manifest that the construction of double active sites through a synergistic mechanism between the FeNi3 alloy and catalytically active carbon ignites the prominent catalytic activity with superior stability. This work provides remarkable inspiration for the rational design of biomass-derived efficient electrocatalysts and will facilitate the practical application of energy storage and conversion devices. [ABSTRACT FROM AUTHOR]

3D N, S, P-doped rice-like C-Zn4Si2O7(OH)2·H2O (C-ZnSi-N2) and rose-like C-Zn2SiO4 (C-ZnSi-CO2) are derived from reed leaves and used for application in supercapacitors. The as-prepared C-ZnSi architectures with a large number of hierarchical pores and high specific surface area from reed leaves have outstanding electrochemical performance. The obtained C-ZnSi-N2 shows 341 F g−1 at the current density of 0.5 A g−1, while the C-ZnSi-CO2 exhibits 498 F g−1, and both of the C-ZnSi materials significantly retain above 99% of their capacitance after 10 000 cycles. Furthermore, the flexible solid-state asymmetric supercapacitors (ASCs) synthesized from C-ZnSi and activated carbon (denoted as C-ZnSi-N2//AC and C-ZnSi-CO2//AC) achieve a high capacitance (405 and 194 mF cm−2 at the current density of 2 mA cm−2, respectively). Besides, the ASC devices show good cycling stability for 7300 cycles with 73% and 77% capacitance retention. The results presented in this study indicate that the N, S, P-doped C-ZnSi architectures from natural reed leaves are promising and efficient materials for manufacturing high performance supercapacitors. [ABSTRACT FROM AUTHOR]

Due to their low cost and high safety, aqueous rechargeable Zn-ion batteries (ARZIBs) have attracted considerable attention for large-scale energy storage systems but the limited capacity and energy density hinder their wide application due to the lack of advanced cathode materials. Recently, ammonium vanadates have received huge interest as cathode materials for ARZIBs. However, all previously reported works have been usually focused on electrodes comprising ammonium vanadates, a conductive agent, and a binder. Herein, we report 2D hydrated ammonium vanadate nanosheets (NV NSs) grown on alkali-treated carbon cloth (denoted as NV NSs@ACC) as the free-standing cathode for high performance ARZIBs. This as-prepared cathode enables fast ion/electronic transport and reduces the aggregation of ultrathin NV NSs. The NV NSs@ACC cathode in coin-type batteries can deliver a high reversible capacity of 523 mA h g−1 at a current density of 0.1 A g−1 and a remarkable energy density of 343 W h kg−1 at 150 W kg−1 based on the mass weight of NV NSs. Furthermore, the quasi-solid-state flexible battery assembled with NV NSs@ACC as the cathode and Zn NSs@CC as the anode shows an outstanding cycling stability (93.4% capacity retention after 1000 cycles at 1 A g−1) with high coulombic efficiency. This work is expected to promote V-based nanomaterials on CC for the development of ARZIBs for large-scale applications and even for use in flexible energy storage devices. [ABSTRACT FROM AUTHOR]

Uneven growth of lithium dendrites and large volume expansion of Li–metal batteries based on a Li anode upon cycling cause low coulombic efficiency, fast capacity decay, and safety concerns. Herein, inspired by the hybrid concept we for the first time prepare a PCL–LAGP composite polymer electrolyte. The chemical interactions of PO43− and ester groups are revealed through a detailed investigation. Given the synergistic effect of organic–inorganic hybrids, the composite electrolyte achieves dendrite-free Li deposition, which is confirmed by long-term galvanostatic polarization tests over 4 mA cm−2 and in situ TEM observation of potentiostatic cycling. Moreover, the soft feature of PCL results in the formation of a stable interphase layer with low resistance to sustain the volume expansion. A LiFePO4/Li all-solid-state battery demonstrates a high coulombic efficiency close to 100%, superior cycling stability and a rate capability of over 10C. The PCL–LAGP composite is a promising solid electrolyte for practical applications at high current density. [ABSTRACT FROM AUTHOR]

Here, we report the synthesis of Cu-doped CeO2 nanorods (denoted as Cu-CeO2-x, x represents the mass content (wt%) of the doped Cu) by a facile hydrothermal method, followed by thermal treatment in an H2/Ar atmosphere. As the electrocatalyst, Cu-CeO2-3.9 with a large surface area of 95.2 m2 g−1 and mesoporous structure exhibits high electrocatalytic activity toward the N2 reduction reaction (NRR), delivering an NH3 yield rate of 5.3 × 10−10 mol s−1 cm−2 and a faradaic efficiency of 19.1% at −0.45 V (vs. RHE) in a 0.1 M Na2SO4 electrolyte (pH = 6.3), much higher than the NRR performance achieved with pure CeO2 nanorods. The Cu doping can effectively tune the concentration of multiple oxygen vacancies in CeO2, thus resulting in significantly improved NRR activity. [ABSTRACT FROM AUTHOR]

Large scale application of graphene is still facing a great challenge due to the lack of cost-effective methods for its production. Herein, we report a simple and cost-effective method for scalable production of few-layer graphene (FLG) with high quality and large size in only one step at room temperature. In this method, a novel binary-component system, which is composed of sodium percarbonate (SPC) and concentrated H2SO4, has been developed for the chemical exfoliation of graphite, where sodium percarbonate is used to exfoliate graphite for the first time, furthermore, the amount of the concentrated H2SO4 used as an intercalating agent is reduced dramatically by 83–85% in comparison to those in the other chemical exfoliation methods. It is found that SPC plays a key role in the exfoliation of graphite. Considering the analysis results, a possible mechanism for the exfoliation of graphite to FLG is proposed. The exfoliated graphene sheets exhibit a few-layer feature (average layer number ＜5 layers), and possess large areal sizes (the maximum areal size can be up to 538 μm2, and the average sheet area is 276.8 μm2) and few structural defects (the oxygen content is only 1.65%), thereby exhibiting an outstanding electrical conductivity of 1.90 × 105 S m−1. [ABSTRACT FROM AUTHOR]

Multimodal imaging can improve the accuracy of cancer diagnosis by combining two or more imaging modalities into one system. In this study, PEGylated BaGdF5 nanoparticles (NPs) were synthesized by a hydrothermal method, and the formed PEG-BaGdF5 NPs showed good X-ray attenuation properties and positive MR contrast effects in vitro. Considering that the overexpression of integrin αvβ3 in the endothelial cells of angiogenic tumor vasculature is universal, RGD peptide, which can recognize and bind integrin αvβ3 specifically, was connected to the surface of PEG-BaGdF5 NPs. The resulting RGD-PEG-BaGdF5 NPs had good biocompatibility and a long half-life in vivo. In VX2 tumor-bearing mice, the HU values and MR signal enhancement of tumor sites in the targeted group were both higher than that in the non-targeted group after intravenous injection of RGD-PEG-BaGdF5 NPs or PEG-BaGdF5 NPs, respectively. Therefore, the RGD-PEG-BaGdF5 NPs may be used as dual-modal CT/MR contrast agents of different types of solid tumors via an active RGD-mediated vasculature targeting pathway. [ABSTRACT FROM AUTHOR]

The construction of defects in two-dimensional ultrathin nanosheets will improve the activity of transition metal-based catalysts. CoSx-based electrocatalysts have attracted increasing attention because of their low cost. In this article, defect-rich, Co9S8-based ultrathin nanosheets were synthesized through direct pyrolysis of cobalt dibutyl dithiocarbamate in organic amine solvents. Edge, cavity and dislocation defects exist in the as-obtained nanosheets. The nanosheets with thickness of 4–6 nm are composed mainly of Co9S8, with small amounts of Co and CoS2. The defects on Co9S8-based nanosheets were controlled by tuning the coordination solvents and pyrolysis parameters. The optimized nanosheets with defective structures have superior catalytic activity for hydrogen evolution reaction in acid media, with a low onset potential of 228 mV and Tafel slope of 51.0 mV dec−1. The catalyst displays robust stability without obvious degradation after being employed over 16 h. The pyrolysis of monomolecular precursors in an organic system provides a new way to construct transition metal compound-based, defect-rich nanostructures for electrocatalysis and energy storage. [ABSTRACT FROM AUTHOR]

In recent decades, tremendous attention has been paid to the development of new electrode materials with high capacitance to meet the requirements of electrode materials in supercapacitors. Among vanadium oxides, VO2(A) has recently received increasing attention due to its unique layered structure, phase transformation and applications in Li-ion batteries. However, few studies have focused on the electrochemical properties of VO2(A) as electrochemical capacitors. Herein, we develop a facile hydrothermal method to prepare VO2(A)@C core–shell structured composites by carbonization of glucose in the presence of V2O5 nanowires. The electrochemical properties of the VO2(A)@C core–shell composites are investigated as a supercapacitor electrode material for the first time; the composites show excellent pseudocapacitive behavior and display a specific capacitance as high as 179 F g−1 at 1 A g−1. A flexible asymmetric supercapacitor device is fabricated using VO2(A)@C composites and activated carbon and delivers an excellent capacitance of 0.5 F cm−2 at a scan rate of 5 mV s−1. Replacing the aqueous electrolyte with a LiCl/PVA gel electrolyte can efficiently improve the cycling performance to 85% retention after 1600 cycles. The good electrochemical performance of the composites indicates their high potential as electrode materials for supercapacitors. [ABSTRACT FROM AUTHOR]

Based on its high Li-ion conductivity, argyrodite Li6PS5Br is a promising solid electrolyte for all-solid-state batteries. However, more understanding is required on the relation between the solid electrolyte conductivity and the solid-state battery performance with the argyrodite structure, crystallinity and particle size that depend on the synthesis conditions. In the present study, this relationship is investigated using neutron and X-ray diffraction to determine the detailed structure and impedance as well as 7Li solid state NMR spectroscopy to study the Li-ion kinetics. It is found that depending on the synthesis conditions the distribution of the Br dopant over the crystallographic sites in Li6PS5Br is inhomogeneous, and that this may be responsible for a larger mobile Li-ion fraction in the interfacial regions in the annealed argyrodite materials. Comparing the bulk and interfacial properties of the differently prepared Li6PS5Br materials, it is proposed that optimal solid-state battery performance requires a different particle size for the solid electrolyte only region and the solid electrolyte in the cathode mixture. In the electrolyte region, the grain boundary resistance is minimized by annealing the argyrodite Li6PS5Br resulting in relatively large crystallites. In the cathode mixture however, additional particle size reduction of the Li6PS5Br is required to provide abundant Li6PS5Br–Li2S interfaces that reduce the resistance of this rate limiting step in Li-ion transport. Thereby the results give insight into how to improve solid-state battery performance by controlling the solid electrolyte structure. [ABSTRACT FROM AUTHOR]

A series of ternary rare-earth metal aluminum germanides with the general formula REAl1−xGe3 (RE = Nd, Sm, Gd, Tb, Dy, and Ho; 0.6 ＜ x ＜ 0.9) have been synthesized by direct fusion of the corresponding elements. Their structures have been characterized by single-crystal X-ray diffraction and selected area electron diffraction methods. The average structure for all members is a representative of the orthorhombic SmNiGe3-type structure (Pearson symbol oS20, space group Cmmm), where the Al atoms occupy the Ni site, and the deep off-stoichiometry is due to statistical vacancies at this position. Considering long-range ordering of the vacancies, a monoclinic and a different orthorhombic structure, which represent idealized ordered variants, are possible, and the structural evolution depending on the nature of the rare-earth metals and the amount of vacancies at the aluminum site are discussed. Commensurate and incommensurate structural modulations based on these parent structures are also observed by electron diffraction, attesting to the great structural complexity in these systems. Magnetic susceptibility measurements are presented and discussed, along with the results from electronic band-structure calculations. [ABSTRACT FROM AUTHOR]

In this study, excellent full water splitting achieved with a rationally structured multimetallic Ni–Mo/Cu nanowire free-standing electrode prepared via scalable electrochemistry is reported. By combining a conductive nanostructured scaffold and highly active outer layers, the as-prepared Ni–Mo/Cu nanowires deliver superior hydrogen and oxygen evolution performance. To achieve a 20 mA cm−2 catalytic current in a 1 M KOH electrolyte, the NM-CNW requires an overpotential of only 152 mV for hydrogen evolution and 280 mV for oxygen evolution. When assembled into a full electrolyzer, the Ni–Mo/Cu nanowires can drive full water splitting at nearly 100% faradaic efficiency steadily up to 12 h without any significant performance decay, and afford a catalytic current close to that of the state-of-the-art Pt–RuO2 system over long-term operation. [ABSTRACT FROM AUTHOR]

In this paper, we present a novel route to prepare sulfur and nitrogen co-doped reduced graphene oxide, in which, two main procedures – the preparation of a sulfur doped graphite intercalation compound (S-GIC) and the construction of the sulfur and nitrogen co-doped reduced graphene oxide (SN-RGO) – are included. The loading of sulfur and nitrogen in SN-RGO, which is tracked by X-ray photoelectron spectroscopy, is 1.47 and 3.90 at%, respectively. SN-RGO possesses an almost two times higher specific surface area (SSA) than RGO and a narrow pore size distribution. Electrochemical investigations demonstrate that SN-RGO exhibits an outstanding capacitive performance, its specific capacitance at the scan rate of 5 mV s−1 in a 6 M KOH aqueous electrolyte being up to 402.4 F g−1, which is, to the best of our knowledge, among the highest values so far reported for S/N co-doped carbon materials. Furthermore, SN-RGO also exhibits an excellent cycling stability (almost 95% specific capacitance being retained even after 10 000 cycles). This work suggests that constructing doped graphene-based materials by using the intercalated substances among the graphite layers as the dopant sources can be considered as a promising strategy for the development of high performance electrodes for supercapacitors. [ABSTRACT FROM AUTHOR]

A series of Sm and Ca co-doped ceria, i.e. Ca0.04Ce0.96−xSmxO2−δ (x = 0, 0.09, 0.16, and 0.24) (SCDC), were synthesized by a co-precipitation method. Detailed morphology, composition, crystal structure and electrochemical properties of the prepared materials were characterized. The results revealed that Sm and Ca co-doping could enhance the ionic conductivity in comparison with that of single Ca-doped samples. The composition as Ca0.04Ce0.80Sm0.16O2−δ exhibited a highest ionic conductivity of 0.039 S cm−1 at 600 °C in comparison with the rest of the series, and the optimal ionic conductivity can be interpreted by the coupling effect of oxygen vacancies and mismatch between the dopant ionic radius and critical radius. Composite formation between the semiconductor La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) and the as-prepared SCDC contributed to a remarkable improvement in the ionic conductivity, an unexpectedly high ionic conductivity of 0.188 S cm−1 was obtained for LSCF–SCDC composites at 600 °C, which was four times higher than that of pure SCDC. Using transmission electron microscopy and spectroscopy approaches, we detected an enrichment of oxygen in the LSCF–SCDC interface region and a depletion of oxygen vacancies in LSCF–SCDC and LSCF–LSCF grain boundaries was significantly mitigated, which resulted in the enhancement of ionic conductivity of semiconductor–ionic LSCF–SCDC composites. The electrolyte-layer-free fuel cell (EFFC) fabricated from the LSCF–SCDC semiconductor–ionic membrane demonstrated excellent performances, e.g. 814 mW cm−2 at 550 °C for using the LSCF–Ca0.04Ce0.80Sm0.16O2−δ (SCDC2). [ABSTRACT FROM AUTHOR]