Search

Lack of fundamental understanding of the oxygen reduction reaction (ORR) hampers the development of effective metal oxide catalysts and advance low-temperature solid oxide fuel cells (LT-SOFCs). In this study, we report Ba0.5Sr0.5Fe1–xSbxO3–δ (BSFSb, x = 0, 0.05, and 0.1) cathodes designed from both theoretical and experimental aspects to study a good relationship between a material property and enhanced ORR activity. The BSFSb cathode exhibits a very low area-specific resistance (ASR) of 0.20 Ω cm2 and excellent power output of 738 mW cm−2 using the Sm0.2Ce0.8O2 (SDC) electrolyte at 550 °C. The Sb ions doping significantly enhances electrical conductivity and reduces its ORR activation energy. First-principles calculations screen the potential of designed perovskite by showing very low vacancy formation energy and shift in O-p and Fe3-d band centers near to fermi level by replacing Fe with Sb ions. Correspondingly, wide range coverage of distributed orbitals at the fermi level in BSFSb cathode promotes charge transfer with lower energy barrier. These results demonstrate that this design can impact the development of highly functional ORR electrocatalysts for LT-SOFCs and other electrocatalyst applications.

BaZr0.5Y0.5O3(BZY) electrolyte exhibited enormous potential for low temperature solid oxide fuel cell (SOFC) due to its proton dominant mobile carriers rather than oxygen ions during the electrochemical process. In order to enhance the ionic conductivity, triple conductor BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY) was composited with proton conductor BZY to form semiconductor-ionic conductor composite (SIM), which was applied as electrolyte to fabricate symmetrical fuel cell. The microstructural and electrochemical properties for BZY, BCFZY and BZY-BCFZY composites were studied. After optimizing the weight ratio of composite content, the ionic conductivity and electronic conductivity reached an equilibrium state to obtain the maximum cell performance, namely the highest output of 902.5 mW cm−2 and an open circuit voltage (OCV) of 1.043 V at 550 °C. The BZY-BCFZY cell also presented decent power output at low temperature, a power density of 265.625 mW cm−2 was received even at 500 °C, demonstrating that the BZY-BCFZY composite was a potential electrolyte for low temperature SOFCs.

Nowadays, lowering the operating temperature of solid oxide fuel cells (SOFCs) is a major challenge towards their widespread application. This has triggered extensive material studies involving the research for new electrolytes and electrodes. Among these works, it has been shown that CeO2 is not only a promising basis of solid oxide electrolytes, but also capable of serving as a catalytic assistant in anode. In the present work, to develop new electrolytes and electrodes for SOFCs based on these features of CeO2, a new type of functional composite is developed by introducing semiconductor CuO into CeO2. The prepared composites with mole ratios of 7:3 (7CeO2–3CuO) and 3:7 (3CeO2–7CuO) are assessed as electrolyte and anode in fuel cells, respectively. The cell based on 7CeO2–3CuO electrolyte reaches a power outputs of 845 mW cm−2 at 550 °C, superior to that of pure CeO2 electrolyte fuel cell, while an Ce0.8Sm0.2O2-δ electrolyte SOFC with 3CeO2–7CuO anode achieves high power density along with open circuit voltage of 1.05 V at 550 °C. In terms of polarization curve and AC impedance analysis, our investigation manifests the developed 7CeO2–3CuO composite has good electrolyte capability with a hybrid H+/O2− conductivity of 0.1–0.137 S cm−1 at 500–550 °C, while the 3CeO2–7CuO composite plays a competent anode role with considerable catalytic activity, indicative of the dual-functionalities of CeO2–CuO in fuel cell. Furthermore, a bulk heterojunction effect based on CeO2/CuO pn junction is proposed to interpret the suppressed electrons in 7CeO2–3CuO electrolyte. Our study thus reveals the great potential of CeO2–CuO to develop functional materials for SOFCs to enable low-temperature operation.

Materials are always among the first considerations to the development of low temperature solid oxide fuel cells (SOFCs). In this study, we investigate the multifunctionality of a layer-perovskite oxide La2-xCexCuO4 (LCCO) for its applications in SOFC as cathode, anode and electrolyte. The performances of the LCCO cathode and anode fuel cells are characterized by I–V–P and electrochemical impedance spectra (EIS). Results suggest that LCCO is a good cathode material and it can also deliver impressive anode performance. Though LCCO is noticed to be reduced by H2 in the anode, the cell performance is relatively stable under multiple times of operation. The existing of ceria and reduced Cu in it may be a reason for its anode catalytic activation. For the application in electrolyte, LCCO is mixed with ionic conductor Ce0.8Sm0.2O2-δ (SDC) in different weight ratios. Differences in power output and open circuit voltage for the cells containing various ratios of LCCO under normal and reverse operation conditions are highlighted. The electronic conductivity of LCCO doesn't bring in electronic leakage if it is kept in a certain range. The multifunctionality of LCCO would enable it to be potentially applied in single layer fuel cell to simplify the structure and fabrication process of SOFC.

Lithium-sulfur batteries (LSBs) are very promising for large-scale electrochemical energy storage. However, dissolution and shuttling of lithium polysulfides (LiPSs) intermediates have severely affected their overall electrochemical properties and limited their practical application. Designing polar cathode hosts that can effectively bind LiPSs and simultaneously promote their redox conversion is crucial for realizing high-performance LSBs. Herein, we report bronze TiO2 (TiO2-B) nanosheets (~5 nm in thickness) chemically bonded with carbon as a novel multifunctional cathode host for advanced LSBs. Experimental observation and first-principles density functional theory (DFT) calculations reveal that the TiO2-B with exposed (100) plane and Ti3+ ions exhibited high chemical affinity toward polysulfides and effectively confined them at surface. Meantime, Ti3+ ions and interface coupling with carbon promoted electronic conductivity of the composite cathode, leading to enhanced redox conversion kinetics of LiPSs during charge/discharge. Consequently, the as-assembled TiO2-B/S cathode manifested high capacity (1165 mAh/g at 0.2 C), excellent rate capability (244 mAh/g at 5 C) and outstanding cyclability (572 mAh/g over 500 cycles at 0.2 C). This work sheds insights on rational design and fabrication of novel functional electrode materials for beyond Li-ion batteries.

Recent research has shown that fuel cells using semiconductor–ionic conductor material (SIM) as electrolytes can achieve good performance due to the enhancement of ionic conductivity, and the Schot...

Electrolyte densification, which is often realized by high temperature sintering (i.e. >1000 °C), is an essential process for solid oxide fuel cell (SOFC). However, it is hard to achieve interfaces with high ionic conductivity because the interfaces between particles would be greatly eliminated during the sintering process. In this study, a novel interface engineering method is designed basing on capillary action to densify the electrolyte and at the meantime achieve ionic conductive interfaces at low temperature. A porous electrolyte layer is found to become dense during fuel cell operation when alkali metal hydroxide (AMH) is added to the NiO anode. The observation of improved open circuit voltage (OCV) indicates gas leakage has been eliminated after AMH modification. Raman images confirm that AMHs can be absorbed into the electrolyte layer when the operating temperature is higher than the melting point of AMH. In addition, using a lithiated metal oxide (i.e. LiNiO2) as the anode, cell performance is further improved. EIS proves that the existing of AMH in the cell may affect gas diffusion in the electrode, but it significantly reduces ohmic resistance due to better interfacial ionic conductivity of the electrolyte. This in-situ electrolyte densification method not only enables us to simplify fuel cell fabrication process and lower the fabrication temperature but also provides ways for maintaining interface conductivity.

High power density performance at intermediate (600 °C–450 °C) temperatures (IT) must be considered in the development of solid oxide fuel cell (SOFC). A niobium and tantalum co-doped perovskite material SCNT (SrCo0.8Nb0.1Ta0.1O3-δ) can be used as a cathode for IT-SOFC due to its (H+/O2−/e−) triple conduction and promising catalysis activity. In this work, the SCNT was composited with ionic conductor SCDC(Ce0.8Sm0.05Ca0.15O2-δ) and processed as electrolyte membrane into semiconductor-ionic membrane fuel cell (SIMFC), which delivered an appreciable performance at IT, i.e., a peak power output of 1016 mW/cm2 at 550 °C and 401 mW/cm2 at 450 °C, respectively. The high performance mainly originated from the (H+/O2−) dual-ion conduction of SCNT as well as the high oxygen ion conductivity of SCDC, the SCNT-SCDC electrolyte layer adjacent to cathode have promoted the oxygen reduction reaction (ORR) with some extent because of the excellent catalysis activity of SCNT. Moreover, the on-line generated carbonate suppressed the electronic conductivity and resulted in the attractive density of SCNT-SCDC electrolyte to further contribute to the desired cell performance.

Interface engineering holds huge potential for enabling exceptional physical properties in heterostructure materials via tuning properties at the atomic level. In this study, a heterostructure built by a new redox stable semiconductor SrFe0.75Ti0.25O3-δ (SFT) and an ionic conductor Sm0.25Ce0.75O2 (SDC) is reported. The SFT-SDC heterostructure exhibits a high ionic conductivity >0.1 S/cm at 520 °C, which is 1 order of magnitude higher than that of bulk SDC. When it was applied into the fuel cell, the SFT-SDC can realize favorable electrolyte functionality and result in an excellent power density of 920 mW cm-2 at 520 °C. The prepared SFT-SDC heterostructure materials possess both electronic and ionic conduction, where electron states modulate local electrical field to facilitate ion transport. Further investigations to calculate the structure and electronic structure/state of SFT and SDC are done using density functional theory (DFT). It is found that the reconstruction of the energy band at interfaces is responsible for such enhanced ionic conductivity and cell power output. The current study about the perovskite-based heterostructure presents a novel strategy for developing advanced ceramic fuel cells.

Recently, semiconductor-ionic materials (SIMs) have emerged as new functional materials, which possessed high ionic conductivity with successful applications as the electrolyte in advanced low-temperature solid oxide fuel cells (LT-SOFCs). In order to reveal the ion-conducting mechanism in SIM, a typical SIM pellet consisted of semiconductor La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) and ionic conductor Sm and Ca Co-doped ceria Ce0.8Sm0.05Ca0.15O2-δ (SCDC) are suffered from sintering at different temperatures. It has been found that the performance of LSCF-SCDC electrolyte fuel cell decreases with the sintering temperature, the cell assembled from LSCF-SCDC pellet sintered at 600 °C exhibits a peak power density (P max) of 543 mW/cm2 at 550 °C and also excellent performance of 312 mW/cm2 even at LT (500 °C). On the contrary, devices based on 1000 °C pellet presented a poor P max of 106 mW/cm2. The performance difference may result from the diverse ionic conductivity of SIM pellet through different temperatures sintering. The high-temperature sintering could severely destroy the interface between SCDC and LSCF, which provide fast transport pathways for oxygen ions conduction. Such phenomenon provides direct and strong evidence for the interfacial conduction in LSCF-SCDC SIMs.

Li+ plays a critically important role in layer-structured LiNiO2 family oxides in that it affects the oxidant state of Ni and catalyst's function. Layer-structured LixNi0.8Co0.15Al0.05O2-δ (LxNCA, x = 1, 1.2, 1.4) with different lithium content was prepared and applicated as both cathode and anode catalysts in symmetrical solid oxide fuel cell (SSOFC) that using samarium doped ceria (SDC) as electrolyte. Excess Li precursor resulted in the formation of Li2CO3 in L1.2NCA and L1.4NCA materials, whose influence on the performance of LxNCA was studied. Oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR) of LxNCA as well as its catalytic stability were investigated by impedance spectroscopy. Its ORR process was found to be greatly influenced by the amount of Li in LxNCA while HOR was less related to Li content. Accompanying the on-line reduction and oxidation of LxNCA, fuel cells tested under reverse operation condition revealed enormous improvement in Pmax, which was due to the significant improvement of ORR process and the reduction of interface resistance.

Background Infectious diseases caused by multidrug-resistant (MDR) bacteria, especially MDR Gram-negative strains, have become a global public health challenge. Multifunctional nanomaterials for controlling MDR bacterial infections via eradication of planktonic bacteria and their biofilms are of great interest. Results In this study, we developed a multifunctional platform (TG-NO-B) with single NIR laser-triggered PTT and NO release for synergistic therapy against MDR Gram-negative bacteria and their biofilms. When located at the infected sites, TG-NO-B was able to selectively bind to the surfaces of Gram-negative bacterial cells and their biofilm matrix through covalent coupling between the BA groups of TG-NO-B and the bacterial LPS units, which could greatly improve the antibacterial efficiency, and reduce side damages to ambient normal tissues. Upon single NIR laser irradiation, TG-NO-B could generate hyperthermia and simultaneously release NO, which would synergistically disrupt bacterial cell membrane, further cause leakage and damage of intracellular components, and finally induce bacteria death. On one hand, the combination of NO and PTT could largely improve the antibacterial efficiency. On the other hand, the bacterial cell membrane damage could improve the permeability and sensitivity to heat, decrease the photothermal temperature and avoid damages caused by high temperature. Moreover, TG-NO-B could be effectively utilized for synergistic therapy against the in vivo infections of MDR Gram-negative bacteria and their biofilms and accelerate wound healing as well as exhibit excellent biocompatibility both in vitro and in vivo. Conclusions Our study demonstrates that TG-NO-B can be considered as a promising alternative for treating infections caused by MDR Gram-negative bacteria and their biofilms.

An intrinsic flame retardant vinyl ester TGIC-AA-DOPO constructed by phosphaphenanthrene and triazine-trione groups was successfully synthesized via the reaction between 1,3,5-triglycidyl isocyanurate (TGIC), acrylic acid and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). The structure of TGIC-AA-DOPO was characterized in detail by fourier transform infrared spectroscopy (FTIR), 1 H and 31 P nuclear magnetic resonance (NMR) and liquid chromatography-high resolution mass spectrometry (LC-HRMS). The intrinsic P-N-containing flame retardant vinyl ester resin (IFR-VER) was prepared after diluting TGIC-AA-DOPO with styrene (st) and triallyl isocyanurate (TAIC). The flame retardancy, thermal properties and combustion behavior of IFR-VER were respectively investigated by a series of tests involving limited oxygen index (LOI) measurement, UL-94 vertical burning test, cone calorimeter test, thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The results showed that the as-obtained resin system exhibited a dramatic improvement in flame retardance. In the case of 40 wt% TAIC in resin system, the LOI value achieved 31%, leading to the UL-94 V-0 rating. In addition, compared with the 901-VER, the peak heat release rate (pk-HRR), average of heat release rate (av-HRR), total heat release (THR) and average effective heat of combustion (av-EHC) of the IFR-VER containing 40% TAIC diluent were decreased by 48%, 60%, 41% and 24% respectively. The diphase flame retardant effect of the prepared IFR-VER during combustion was demonstrated by the results of Py-GC/MS, FTIR, laser raman spectroscopy and scanning electron microscope (SEM).

In the past few years, triple (H+/O2−/e−) conducting materials have been regarded as one of the most promising electrode categories for solid oxide fuel cells (SOFCs). In this work, a layer-structured LiNi0.8Co0.15Al0.05O2-δ (LNCA) with triple conduction has been studied. The semiconductor-ionic conductor (SIC) LNCA-SDC composite has been fabricated by compositing the LNCA material with ionic conductor, i.e., samarium doped ceria (SDC). The electrochemical performance of the LNCA-SDC composite was studied by electrochemical impedance spectroscopy, while its electronic conductivity was confirmed by d.c. polarization method. It is found that the ionic conductivity of the composite is higher than the electronic conductivity by several orders of magnitude. The charge carriers and transportation properties of LNCA-SDC were studied using H+ and O2− blocking layer cells respectively. Results prove that the LNCA-SDC composite is a hybrid oxygen ion-proton conducting material. The oxygen ion conduction is dominated at low temperature (425–500 °C), however, it is comparable with H+ conduction at high temperature (550 °C). Additionally, the formation of Li2CO3 under fuel cell operation environment was observed and the mechanism of the hybrid conductivity of LNCA-SDC was studied.

In present work, we reported an novel oxide-salt Al2O3 NaAlO2 composite, which was prepared by mixing Al2O3 and Na2CO3 two phase materials in different weight ratio, and then sintering at 1100 °C. The X-ray diffraction pattern, scanning-electron microscope and impedance spectra are applied to characterize the crystal structure, morphology and electrical properties of the Al2O3 NaAlO2 composite. The Al2O3 NaAlO2 composite as electrolyte membrane was sandwiched by two pieces of Ni0.8Co0.15Al0.05Li-oxide (NCAL) electrode layer to construct advanced fuel cell. Optimizing the weight ratio of Al2O3 and NaAlO2, such cell delivered an highest power density of 789 mW/cm2 and an open circuit voltage (Voc) of 1.13 V at 575 °C. The superior performance is mainly due to the excellent ion-conducting of Al2O3 NaAlO2 composites and the outstanding catalysis activity of the NCAL eletrodes. The EIS results revealed that the Al2O3 NaAlO2 composite possessed superior ionic conductivity of 0.121 S/cm at 575 °C. The interfacial effects between oxide-salt two phase including space-charge and structural misfit at the interface region dominated the ion transport for Al2O3 NaAlO2 composite.

The semiconductor-ionic composite membrane has been recently developed for a novel solid oxide fuel cell (SOFC), i.e., the semiconductor-ion membrane fuel cell (SIMFC). In this work, the perovskite-type SrFeO3-δ (SFO) as semiconductor material was composited with ionic conductor Ce0.8Sm0.2O2-δ (SDC) to form the SFO-SDC composite membrane for SIMFCs. The SFO-SDC SIMFCs using the optimized weight ratio of 3:7 SFO-SDC membrane obtained the best performances, 780 mW cm−2 at 550 °C, compared to 348 mW cm−2 obtained from the pure SDC electrolyte fuel cell. Introduction of SFO into SDC can extend the triple phase boundary and provide more active sites for accelerating the fuel cell reactions, thus significantly enhanced the cell power output. Moreover, SFO was employed as the cathode, and a higher power output, 907 mW cm−2 was achieved, suggesting that SFO cathode is more compatible for the SFO-SDC system in SIMFCs. This work provides an attractive strategy for the development of low temperature SOFCs.

© 2018 Elsevier Ltd and Techna Group S.r.l. Stable and compatible cathode materials are a key factor for realizing the low-temperature (LT, ≤600 °C) operation and practical implementations of solid oxide fuel cells (SOFCs). In this study, perovskite oxides SrFe 1-x Ti x O 3-δ (x < = 0.1), with various ratios of Ti doping, are prepared by a sol-gel method for cathode material for LT-SOFCs. The structure, morphology and thermo-gravimetric characteristics of the resultant SFT powders are investigated. It is found that the Ti is successfully doped into SrFeO 3-δ to form a single phase cubic perovskite structure and crystal structure of SFT shows better stability than SrFeO 3-δ . The dc electrical conductivity and electrochemical properties of SFT are measured and analysed by four-probe and electrochemical impedance spectra (EIS) measurements, respectively. The obtained SFT exhibits a very low polarization resistance (R p ),.01 Ωcm 2 at 600◦C. The SFT powders using as cathode in fuel cell devices, exhibit maximum power density of 551 mW cm −2 with open circuit voltage (OCV) of 1.15 V at 600◦C. The good performance of the SFT cathode indicates a high rate of oxygen diffusion through the material at cathode. By enabling operation at low temperatures, SFT cathodes may result in a practical implementation of SOFCs.

In this paper, poly (tetrahydrofuranyl ether diol) and trimethylolpropane (TMP) were used respectively as chain extender and cross-linking agent to fabricate polyurethane resin. The morphol...

Polyphenol chemistry-based surface modification has received extensive attention in membrane science for its simplicity and low-cost. However, the limited molecular structures combined with the generally time-consuming process have largely restricted their further applications. Herein, we report an ultrafast and universal surface modification strategy based on the co-deposition of a macrocycle polyphenol molecule, Noria, and polyethyleneimine (PEI), for which only several seconds are required to obtain a uniform coating. Moreover, nanofiltration membranes were fabricated by traditional interfacial polymerization (IP) using the Noria–PEI co-deposited coating as the interlayer. Interestingly, the host–guest heterogeneous interaction between anchored Noria on the support surface and amine monomers in the aqueous phase could significantly alter the IP process and contribute to a unique nanostrand-hybrid morphology for piperazine and trimesoyl chloride-based membranes. Consequently, such novel morphology-based nanofiltration membranes exhibited a high permeance of up to 28 L m−2 h−1 bar−1 while still maintaining comparable divalent salt (Na2SO4, MgSO4, MgCl2 and CaCl2) rejections of above 96.0%, which are among the best performances for nanofiltration membranes. In addition to membrane science, this ultrafast surface modification strategy could arouse intense interest in host–guest chemistry at interfaces for fabricating multifunctional materials.

Due to the strong emulsion stability of alkaline/surfactant/polymer (ASP) produced water, its treatment and reuse constitute an urgent issue in the petroleum industry. This study presents an effective and economical method to decontaminate emulsified oil via in situ formed magnesium hydroxide (IFM). IFM was directly synthesized in ASP produced water by a wet precipitation method, which is simple for industrial production, and the emulsified oil was simultaneously removed during the precipitation process of IFM. The roles of contact time, pH, interface-active components, temperature, and initial oil concentration in oil removal were systematically investigated. Under optimal experimental conditions, the residue oil concentration could be reduced below 5.0 mg L−1 within 8 min. Even if the emulsion stability was enhanced by an increase in concentration of interface-active components, efficient oil removal could still be achieved. The adsorption capacity of IFM for oil was 10 959 mg g−1 at 293 K. MgOH+ played a significant role during treatment. The oil removal mechanism was mainly dominated by electrostatic attraction and the network structure of IFM. Crude oil could be recovered and the regenerated IFM maintained an oil removal efficiency of 91% in the fifth cycle. The results showed that the co-precipitation/adsorption process by IFM can be used as a promising technology for emulsified oil removal and recovery.

Open-circuit photovoltage (Voc ) is among the critical parameters for achieving an efficient light-to-charge conversion in existing solar photovoltaic devices. Natural photosynthesis exploits light-harvesting chlorophyll (Chl) protein complexes to transfer sunlight energy efficiently. We describe the exploitation of photosynthetic fucoxanthin-chlorophyll protein (FCP) complexes for realizing photoelectrochemical cells with a high Voc . An antenna-dependent photocurrent response and a Voc up to 0.72 V are observed and demonstrated in the bio-photovoltaic devices fabricated with photosynthetic FCP complexes and TiO2 nanostructures. Such high Voc is determined by fucoxanthin in FCP complexes, and is rarely found in photoelectrochemical cells with other natural light-harvesting antenna. We think that the FCP-based bio-photovoltaic conversion will provide an opportunity to fabricate environmental benign photoelectrochemical cells with high Voc , and also help improve the understanding of the essential physics behind the light-to-charge conversion in photosynthetic complexes.

A novel solid oxide fuel cell (SOFC) incorporating the semiconductor with the ionic conductor to replace the traditional electrolyte layer with improved performance has been recently reported. In the present work, we found that the redox stable electrode material La 0.7 Sr 0.3 Cr 0.5 Fe 0.5 O 3-δ (LSCrF) can be considered as a good candidate for such configuration, electrolyte layer-free fuel cells (EFFCs), due to its high ionic and electronic conductivities, excellent catalytic activity and good chemical stability. EFFCs based on the composite of perovskite oxide LSCrF and ionic conductor Ce 0.8 Sm 0.2 O 2-δ (SDC) offered promising performances, i.e., 1059 mW cm −2 at 550 °C without any electronic short circuiting problem. It even exhibited a highly promising result of 553 mW cm −2 at 470 °C in further low-temperature operation. These high performances can be attributed to the improved conductivity, more triple-phase boundaries (TPB) and accelerated oxygen reduction reaction (ORR) of LSCrF-SDC composite. The influence of the weight ratio between LSCrF and SDC on the EFFC electrochemical performance was investigated. This new discovery indicates a great potential for exploring multifunctional perovskites for the new SOFC technologies.

A novel semiconductor-ionic La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF)-Sm/Ca co-doped CeO2 (SCDC) nanocomposite has been developed as a membrane, which is sandwiched between two layers of Ni0.8Co0.15Al0.0 ...

Commercial double Perovskite Sr 2 Fe 1.5 Mo 0.5 O 6-δ (SFM), a high performance and redox stable electrode material for solid oxide fuel cell (SOFC), has been used for the electrolyte (layer) -free fuel cell (EFFC) and also as the cathode for the electrolyte based SOFC in a comprehensive study. The EFFC with a homogeneous mixture of Ce 0.8 Sm 0.2 O 2-δ (SDC) and SFM achieved a higher power density (841 mW cm −2 ) at 550 °C, while the SDC electrolyte based SOFC, using the SDC-SFM composite as cathode, just reached 326 mW cm −2 at the same temperature. The crystal structure and the morphology of the SFM-SDC composite were characterized by X-ray diffraction analysis (XRD), and scanning electron microscope (SEM), respectively. The electrochemical impedance spectroscopy (EIS) results showed that the charge transfer resistance of EFFCs were much lower than that of the electrolyte-based SOFC. To illustrate the operating principle of EFFC, we also conducted the rectification characteristics test, which confirms the existence of a Schottky junction structure to avoid the internal electron short circuiting. This work demonstrated advantages of the semiconductor-ionic SDC-SFM material for advanced EFFCs.

Low-temperature solid oxide fuel cell (LTSOFC) has shown great potentials for commercial applications in clean energy generation. Seeking for low cost and easy fabrication method is one of the most important issues for LTSOFC investigations. This paper introduces a new coating spray technology, namely Low-Pressure Plasma Spray (LPPS), for efficiently manufacturing different functional coatings of LTSOFC. By applying the LPPS technique, uniform and dense Ni0.8Co0.15Al0.05LiO2−δ (NCAL) coatings were made on both solid bipolar plates and porous nickel foams to perform as protecting coatings and electrode catalyst coatings respectively. Microstructure study showed that multi phases were formed and in-situ nano-micro crystallization occurred in the coatings during the LPPS process. Around 30 W output was achieved in a 4-cell stack indicating that the LPPS sprayed NCAL coatings on bipolar plates worked well. A fuel cell based on the NCAL-coated Ni foam reached an open circuit voltage (OCV) at 1.08 V and a maximum power density of 717 mW cm−2 at 550 °C. This study reveals that LPPS is a promising technology for fabricating coatings of LTSOFC.

A fuel cell based on a functional layer of perovskite Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) composited samarium doped ceria (SDC) has been developed. The device achieves a peak power density of 640.4 mW cm−2 with an open circuit voltage (OCV) of 1.04 V at 560 °C using hydrogen and air as the fuel and oxidant, respectively. A numerical model is applied to fit the experimental cell voltage. The kinetics of anodic and cathodic reactions are modeled based on the measurements obtained by electrochemical impedance spectroscopy (EIS). Modeling results are in well agreement with the experimental data. Mechanical stability of the cell is also examined by using analysis with field emission scanning electron microscope (FESEM) associated with energy dispersive spectroscopy (EDS) after testing the cell performance.

In this study，nanocomposites of LaCePr-oxide (LCP) and Ni 0.8 Co 0.15 Al 0.05 LiO 2-δ (NCAL) with different contents of polyvinylidene fluoride (PVDF) were prepared and applied to solid oxide fuel cells. The composite materials were characterized by X-ray diffraction analysis (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and electrochemical impedance spectrum (EIS). The effect of PVDF concentration on the conductivity and performance of the fuel cells was investigated. It was found that PVDF plays a template role of pore forming in the nanocomposites, and the changed microstructure by as-formed pores greatly influences the electrochemical property of the nanocomposites. The cell with 3 wt% PVDF heat-treated at 210 °C achieved the highest power density of 982 mW cm −2 at 520 °C, which enhanced performance by more than 57% than when no heat-treatment was implemented. It is 66% higher than the cell with no PVDF and no heat-treatment. Pores formed by PVDF after heat-treatment enlarged the triple phase boundary (TPB), which results in improved fuel cell performance.

Immunoglobulin G (IgG) is related to the occurrence of many diseases, such as measles and inflammatory. In this paper, IgG imprinted polymers (IgGIPs) were fabricated on the surface of nano Au/nano Ni modified Au electrode (IgGIPs/AuNCs/NiNCs/Au) via metal-free visible-light-induced atom transfer radical polymerization (MVL ATRP). The IgGIPs were prepared by IgG conjugated with fluorescein isothiocyanate (FITC-IgG) as both a template and a photocatalyst. After the templates were removed, the photocatalysts (FITC) would not remain in the polymer and avoided all the effect of catalysts on the electrode. The fabricated electrodes were examined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). Under the optimized conditions, IgGIPs/AuNCs/NiNCs/Au was prepared and used as an electrochemical biosensor. The biosensor could be successfully applied for the determination of IgG by differential pulse voltammetry (DPV) measurement. The results showed that the proposed biosensor displayed a broader linear range and a lower detection limit for IgG determination when it was compared to those similar IgG sensors. The linear range from 1.0 × 10−6 mg L−1 to 1.0 × 101 mg L−1 was obtained with a low detection limit (LOD) of 2.0 × 10−8 mg L−1 (S/N = 3). Briefly, the biosensor in this study introduced an easy and non-toxic method for IgG determination and also provided a progressive approach for designing protein imprinted polymers., Graphical abstract Image 1

This study reports a kind of single layer solid oxide fuel cell (SLSOFC) based on semiconductor-ionic conductor composite material which consists of Ce0.8Sm0.2O2-δ (SDC, ionic conductor), La0.25Sr0.75Ti1O3+δ (LST, n-type semiconductor) and Ni0.8Co0.15Al0.05LiO2-δ (NCAL, p-type semiconductor). It was found that the LST-SDC-NCAL composite based SLSOFC exhibited open circuit voltage (OCV) of more than 1 V and maximum power density of 222 mW cm−2 under 550 °C. In-situ Schottky junction in the device helps to prevent short circuiting as well as promote ion transport. Electrochemical impedance spectroscopy (EIS) analysis revealed that the ionic conductivity of the SLSOFC was about 0.09 S cm−1, and the corresponding activation energy is 0.7 eV. The cell performance was stable during 65 h without any significant degradation. Moreover, the SLSOFC possessed higher tolerance for temperature change than traditional three-layer SOFC due to the well match of thermal expansion coefficient between electrodes and electrolyte. This device is of great significance in preventing fuel cell delamination, simplifying manufacturing process and promoting its commercialization.

All-oxide solar cells are presently attracting extensive research interest due to their excellent stability, low-cost and non-toxicity. However, the band gap of metal oxides is lack of effective optimization and results in poor photovoltaic performance, thus hindering their practical applications. In this work, Co 3 O 4 was investigated for application as a photo-absorber in all-oxide solar cells, and its band gap was optimized by introducing Li dopant into the spinel structure. Li x Co 3−x O 4 nanoparticles, prepared via the hydrothermal method, were homogenously coated onto TiO 2 mesoporous films, which were then used to fabricate planar heterojunction TiO 2 /Li x Co 3−x O 4 solar cells (SCs). The effects of Li-doping on the heterojunction solar cell performance were further investigated. The findings revealed that the incorporation of Li ions into Co 3 O 4 led to a significant enhancement in short-circuit current density (J sc ). Remarkably, a high open-circuit voltage (V oc ) of 0.70 V was also achieved. Besides, reasons for the enhanced cell performance are the narrower band gap, reduced photogenerated carrier recombination and the more favorable energy band structure as compared with SCs assembled from pure Co 3 O 4 .

The mixture of ionic electrolyte Ce0.8Sm0.05Ca0.15O2−δ (SCDC) and semiconductor Ni0.8Co0.15Al0.05LiO2−δ (NCAL) layers was used for low temperature solid oxide fuel cell (LT-SOFC) applications. Using the as-prepared SCDC-NCAL semiconductor-ionic layer to replace the ionic SCDC electrolyte, following results have been obtained: the SCDC electrolyte fuel cell reached a lower voltage, 1.05 V, and lower power output, 415 mW cm−2, compared to that using the semiconductor-ionic layer, 1.06 V and 617 mW cm−2 at 550 °C. The electrochemical impedance spectroscopy (EIS) was applied to investigate the electrochemical processes of the device; X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM) for the microstructure and morphology of the as-prepared materials. The results have illuminated that the introduction of semiconductor into ionic electrolyte could make extended triple phase boundary (TPB) area, which can provide more active sites to accelerate the fuel cell reactions and enhance the cell performance. Furthermore, we also discovered that the ionic SCDC and electronic NCAL should be in an appropriate composition to achieve a balanced ionic and electronic conductivity, which is the key issue for high performance semiconductor-ionic fuel cells.

Single-layer fuel cells (SLFCs) are the product of recent advances in low-temperature solid-oxide fuel cell (SOFC) research and development. Conventional three-layer materials comprising an anode, ...

Multifunctional roles of La0.2Sr0.25Ca0.45TiO3 (LSCT) perovskite material as anode, cathode, and electrolyte for low temperature solid oxide fuel cell (LT-SOFC) are discovered for the first time, and have been investigated via electrochemical impedance spectroscopy (EIS) and fuel cell (FC) measurements. LSCT resistance decreases prominently in FC environment as shown in this study. An improved performance was observed by compositing LSCT with samaria doped ceria (SDC) at 550 °C when the FC power density increased from tens of mW cm−2 for the pure LSCT system up to hundreds of mW cm−2. The improved conductivity of LSCT–SDC composite is highlighted. The multifunctionality of LSCT as cathode, anode and electrolyte could be attributed to different conducting behavior at high and low oxygen partial pressures and ionic conduction at intermediate oxygen partial pressures. These new discoveries not only indicate great potential for exploring multifunctional perovskites for the next generation SOFC, but also deepen SOFC science and develop new technologies.

In the present work, we report a composite of industrial-grade material LaCePr-oxide (LCP) and perovskite La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ (LSCF) for advanced electrolyte layer-free fuel cells (EFFCs). The microstructure, morphology, and electrical properties of the LCP, LSCF, and LCP-LSCF composite were investigated and characterized by XRD, SEM, EDS, TEM, and EIS. Various ratios of LCP to LSCF in the composite were modulated to achieve balanced ionic and electronic conductivities. Fuel cell with an optimum ratio of 60 wt% LCP to 40 wt% LSCF reached the highest open circuit voltage (OCV) at 1.01 V and a maximum power density of 745 mW cm −2 at 575 °C, also displaying a good performance stability. The high performance is attributed to the interfacial mechanisms and electrode catalytic effects. The findings from the present study promote industrial-grade rare-earth oxide as a promising new material for innovative low temperature solid oxide fuel cell (LTSOFC) technology.

A novel fuel-to-electricity conversion technology resembling a fuel cell has been developed based on the perovskite solar cell principle using a perovskite, e.g. La0.6Sr0.4Co0.2Fe0.8O3-δ and an ionic nanocomposite material as a core functional layer, sandwiched between n- and p-conducting layers. The conversion process makes use of semiconductor energy bands and junctions properties. The physical properties of the junction and alignment of the semiconductor energy band allow for direct ion transport and prevent internal electronic short-circuiting, while at the same time avoiding losses at distinct electrolyte/electrode interfaces typical to conventional fuel cells. The new device achieved a stable power output of 1080mWcm-2 at 550°C in converting hydrogen fuel into electricity. QC 20160203. QC 20160304

The construction of multimodal targeting and therapeutic platforms is a promising strategy for combating multidrug-resistant (MDR) bacteria-associated infections. We report a dual-targeted antibacterial platform integrating a synergistic chemo-photothermal effect based on the boronic acid functionalized graphene-based quaternary ammonium salt (B-CG-QAS). When located at the sites of Gram-negative bacteria associated infections, B-CG-QAS was able to specifically bind to the bacteria and their biofilms via the dual effect of electrostatic adhesion (QAS) and covalent coupling (BA), resulting in a superior targeting ability over the single-targeted agents (B-CG or CG-QAS), improved bactericidal efficacy, a reduced dose of QAS and minimized chemotherapeutic/photothermal toxicity. In addition to the QAS-mediated antibacterial effects, NIR laser irradiation onto CG could further improve the antimicrobial effect via the synergy of hyperthermia. On the other hand, QAS could disrupt the bacterial cell membrane and improve its permeability and sensitivity to heat. Moreover, B-CG-QAS could be effectively utilized for synergistic chemo-photothermal therapy against the in vivo infections of MDR Gram-negative bacteria and their biofilms and accelerate bacteria-infected wound healing as well as exhibit outstanding biocompatibility both in vitro and in vivo. Therefore, our study demonstrates that B-CG-QAS has great potential to treat MDR Gram-negative bacterial infections and their biofilms.

Preparation of highly permeable and selective organic solvent nanofiltration (OSN) membranes is desired for precise chemical separations. Although the emerging nanomaterials and novel preparation methods have significantly boosted the membrane performance, it still requires much effort to drive them toward scale-up production with lower cost and easier preparation process. Herein, we constructed a polyarylate membrane from one kind of porous organic cage, namely Noria through traditional interfacial polymerization technique. Under the catalysis of triethylamine, Noria in aqueous phase would react with terephthaloyl chloride (TPC) in hexane to form a dense nano-film. The inner cavity of Noria molecule provided nano-channel for both polar and non-polar solvents to transport through the membrane. Specially, the Noria + TPC membrane exhibits a high permeance for methanol up to 18 L m−2h−1bar−1. This is resulted from the low interaction energy between methanol and Noria as revealed by the molecular dynamics (MD) simulation. In addition to the excellent performance, the simple preparation process with low-cost materials suggests the great potential of Noria + TPC membrane for practical application. Moreover, it would inspire the exploration of other molecules with tailored chemical structures for the assembly of high-performance membranes in future.

Long-term stability is of significant importance to energy conversion devices including solid oxide fuel cell (SOFC). In this work, we apply a layered perovskite oxide La1·85Sr0·15CuO4 (LSCO4) mixing with ionic conductor Ce0.8Sm0.2O2-δ (SDC) to get an ionic and electronic conductor composite (IECC) membrane SOFC for the sake of achieving a stable cell. The addition of proper ratio of LSCO4 in the membrane improves cell performance. The IECC fuel cell reaches a stability of over 75 h at 550 °C under 100 mAcm−2 and can resist multiple times of rapid heat-up and cool-down cycles. The factors that influence cell stability are investigated. The covalence states of the IECC are found to change firstly but stabilize after several hours of test. Resulting from anode Ni0·8Co0·15Al0·05LiO2-δ (NCAL) reduction, Li+ is found to migrate to the IECC membrane, leading to IECC membrane densifying and resultantly protecting the IECC from further reduction by hydrogen. However, the continuous online reaction of NCAL electrodes leads to the increase of charge transfer resistance as well as the decrease of gas diffusion pores in the electrode. This study provides important reference for designing stable IECC membrane fuel cell.

A novel composite was synthesized by mixing La0.1Sr0.9MnO3&minus, &delta, (LSM) with Ce0.8Sm0.2O2&minus, (SDC) for the functional layer of low temperature solid oxide fuel cell (LT-SOFC). Though LSM, a highly electronic conducting semiconductor, was used in the functional layer, the fuel cell device could reach OCVs higher than 1.0 V without short-circuit problem. A typical diode or rectification effect was observed when an external electric force was supplied on the device under fuel cell atmosphere, which indicated the existence of a junction that prevented the device from short-circuit problem. The optimum ratio of LSM:SDC = 1:2 was found for the LT-SOFC to reach the highest power density of 742 mW&middot, cm&minus, 2 under 550 &deg, C The electrochemical impedance spectroscopy data highlighted that introducing LSM into SDC electrolyte layer not only decreased charge-transfer resistances from 0.66 &Omega, &middot, cm2 for SDC to 0.47&ndash, 0.49 &Omega, cm2 for LSM-SDC composite, but also decreased the activation energy of ionic conduction from 0.55 to 0.20 eV.

Lowering the operating temperature of the solid oxide fuel cells (SOFCs) is one of the world R&D tendencies. Exploring novel electrolytes possessing high ionic conductivity at low temperature becomes extremely important with the increasing demands of the energy conversion technologies. In this work, perovskite La0.1SrxCa0.9-xMnO3-δ (LSCM) materials were synthesized and composited with the ionic conductor Sm0.2Ce0.8O1.9 (SDC). The LSCM-SDC composite was sandwiched between two nickel foams coated with semiconductor Ni0.8Co0.15Al0.05LiO2- δ (NCAL) to form the fuel cell device. The strontium content in theLSCM and the ratios of LSCM to SDC in the LSCM-SDC composite have significant effects on the electrical properties and fuel cell performances. The best performance has been achieved from LSCM-SDC composite with a weight ratio of 2:3. The fuel cells showed OCV over 1.0 V and excellent maximum output power density of 800 mW/cm2 at 550 ºC. Device processes and ionic transport processes were also discussed. QC 20190306

Surface morphology has been proven to significantly affect nanofiltration (NF) membrane performance. However, the morphology control in membrane fabrication remains a great challenge. Herein, based on interfacial manipulation, a new strategy was developed to fabricate NF membranes with tunable 3D surface nanostructures. The manipulation was achieved by forming aqueous template on the substrate surface during the membrane fabrication, which directly influenced the consequent membrane surface morphology. Based on this, a systematic transition of surface morphology from leaf-like shapes to ridges was achieved in a facile way. The representative NF membrane with ridged nanostructures exhibited water permeance of 21.3 Lm-2h-1bar-1 and Na2SO4 rejection of 99.4 % due to increased permeable area, reduced membrane thickness and low-resistance flow channel within the ridged nanostructures. The mechanism and detailed process of forming these 3D surface nanostructures were demonstrated by combining dissipative particle dynamics (DPD) simulations and experiments. In consideration of the simplicity, generality and controllability, this aqueous template-based interfacial manipulation strategy would be of importance to the fabrication of thin-film composite membranes.

In the present study, a novel composite was fabricated by incorporating the semiconductor Ni0.8Co0.15Al0.05LiO2-delta (NCAL) into the ionic electrolyte Ce0.8Sm0.2O2-delta-Na2CO3 (NSDC), and further developed as a mixed-conducting membrane for single layer fuel cell (SLFC) applications. Experimentally, the crystal structure, morphology, chemical composition and thermo-stability of the composite were characterized by XRD, SEM and TGA. The best cell performance was investigated when the NSDC-NCAL membrane was optimized at a weight ratio of 6:4. On this basis, a number of interesting findings were obtained: i) the mixed conducting membrane did not cause any short circuit; on the contrary, the cell reached a decent open circuit voltage (OCV) of similar to 1.0 V. a high power density of 1072 mW cm(-2) was achieved at 550 degrees C for the NSDC-NCAL membrane based cell, which was much better than that using a pure NSDC electrolyte membrane. Electrochemical impedance spectroscopy (EIS) showed that the NSDC-NCAL composite exhibited significantly improved grain boundary conduction and reduced electrode polarizations, contributing to the resultant performance. To consolidate the usefulness of the device, we also conducted the durability test. The above findings indicate the strategy of introducing mixed NSDC-NCAL membrane is feasible for high-performance SLFCs operating at low temperatures.

Perovskite solar cells (PSC) have attracted much attention in the recent years. It is important to understand their working principle in order to uncover the reasons behind their high efficiency. In this study, the carrier transport mechanism of PSC by controlling the structure of a scaffold is investigated. CeO2 is used as an electron blocking material in PSCs to study the electron transport behavior for the first time. The influence of light absorption can be excluded because CeO2 has a similar bandgap to TiO2. A variety of scaffolds are constructed using nano-TiO2 and CeO2. The results show that electrons can transport from light absober (perovskite) to FTO electrode (external circuit) through two kinds of channels. The energy band level, as well as the electronic conductivity of the scaffolds, is are key issues that affect electron transport. Although perovskites are able to transport both electrons and holes, it is still necessary to have effective electron transport channels (ETCs) between perovskite and external circuit for the sake of high efficiency. Electrochemical impedance spectroscopy analysis suggests that the lack of such channels will result in high recombination. The number of ETCs and effecient electron-hole separation are also proven to be important for cell performance.