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We designed and synthesized a series of sulfonated poly(arylene ether sulfone) (SPES) with different hydrophilic or hydrophobic oligomer ratios using poly-condensation strategy. Afterward, we fabricated the corresponding membranes via a solution-casting approach. We verified the SPES membrane chemical structure using nuclear magnetic resonance (1H NMR) and confirmed the resulting oligomer ratio. Field-emission scanning electron microscope (FE-SEM) and atomic force microscope (AFM) results revealed that we effectively attained phase separation of the SPES membrane along with an increased hydrophilic oligomer ratio. Thermal stability, glass transition temperature (Tg) and membrane elongation increased with the ratio of hydrophilic oligomers. SPES membranes with higher hydrophilic oligomer ratios exhibited superior water uptake, ion-exchange capacity, contact angle and water sorption, while retaining reasonable swelling degree. The proton conductivity results showed that SPES containing higher amounts of hydrophilic oligomers provided a 74.7 mS cm−1 proton conductivity at 90 °C, which is better than other SPES membranes, but slightly lower than that of Nafion-117 membrane. When integrating SPES membranes with proton-exchange membrane fuel cells (PEMFCs) at 60 °C and 80% relative humidity (RH), the PEMFC power density exhibited a similar increment-pattern like proton conductivity pattern. [ABSTRACT FROM AUTHOR]

Oxygen reduction reaction (ORR) stability and catalytic activity in high‐durability anion exchange membrane fuel cells (AEMFCs) can be improved using graphene‐supported spinel‐based Ni3O4 cathode catalysts. Here, we describe a simple and economical hydrothermal method for synthesizing reduced graphene oxide (rGO) supported on Ni3O4. The atomic‐level contribution of the Ni−Ni and Ni−O bonds to the chemical structure of nickel oxide was confirmed by X‐ray photoelectron and absorption spectroscopy studies. Due to the force of the void for oxygen created by nickel atoms, Ni3O4@rGO for the ORR exhibited enhanced stability and catalytic activity (E1/2=0.761 V and over 30,000 CV cycles). A single AEMFC cell achieved the greatest power density and long‐term durability using a Ni3O4@rGO cathode, suggesting improved endurance despite the minimal voltage decrease (power density 29.6 mW cm−2, endurance for 25 h). These findings offer insights and point to opportunities for developing metal oxide–based AEMFCs. [ABSTRACT FROM AUTHOR]

The composite structure, good porosity, and electrochemical behavior of proton exchange membranes (PEMs) are important characteristics, which can improve the performance of polymer electrolyte fuel cells (PEFCs). In this study, we designed and synthesized an XY block copolymer via a polycondensation reaction that contains sulfonated poly(ether ether ketone) (SPEEK) (X) as a hydrophilic unit and a fluorinated oligomer (Y) as a hydrophobic unit. The prepared XY block copolymer is composed of Fe3O4 nanoparticles to create composite architecture, which was subsequently treated with a 1 M H2SO4 solution at 70 °C for 1 h to eliminate Fe3O4 and generate a pores structure in the membrane. The morphological, physiochemical, thermomechanical, and electrochemical properties of bare XY, XY/Fe3O4-9 and XY(porous)-9 membranes were measured and compared in detail. Compared with XY/Fe3O4-9 composite, the proton conductivity of XY(porous)-9 membrane was remarkably enhanced as a result of the existence of pores as nano-conducting channels. Similarly, the XY(porous)-9 membrane exhibited enhanced water retention and ion exchange capacity among the prepared membranes. However, the PEFC power density of XY(porous)-9 membrane was still lower than that of XY/Fe3O4-9 membrane at 60 °C and 60% relative humidity. Also, the durability of XY(porous)-9 membrane is found to be lower compared with pristine XY and XY/Fe3O4-9 membranes as a result of the hydrogen crossover through the pores of the membrane. [ABSTRACT FROM AUTHOR]

In this contribution, sulfonated poly(ether ether ketone) (SPEEK) is inter-connected using a hydrophobic oligomer via poly-condensation reaction to produce SPEEK analogues as PEMs. Prior sulfonation is performed for SPEEK to avoid random sulfonation of multi-block copolymers that may destroy the mechanical toughness of polymer backbone. A greater local density of ionic moieties exist in SPEEK and good thermomechanical properties of hydrophobic unit offer an unique approach to promote the proton conductivity as well as thermomechanical stability of membrane, as verify from AC impedance and TGA. The morphological behavior and phase variation of membranes are explored using FE-SEM and AFM; the triblock (XYX) membranes exhibits a nano-phase separated morphology. Performance of PEFC integrated with blend and block copolymer membranes is determined at 60 °C under 60% RH. As a result, the triblock (XYX) membrane has a high power density than blend (2X1Y) membrane. [ABSTRACT FROM AUTHOR]

A series of anion exchange membranes composed of partially fluorinated poly(arylene ether sulfone)s (PAESs) multiblock copolymers bearing quaternary ammonium groups were synthesized with controlled lengths of the hydrophilic precursor and hydrophobic oligomer via direct polycondensation. The chloromethylation and quaternization proceeded well by optimizing the reaction conditions to improve hydroxide conductivity and physical stability, and the fabricated membranes were very flexible and transparent. Atomic force microscope images of quaternized PAES (QN-PAES) membranes showed excellent hydrophilic/hydrophobic phase separation and distinct ion transition channels. An extended architecture of phase separation was observed by increasing the hydrophilic oligomer length, which resulted in significant improvements in the water uptake, ion exchange capacity, and hydroxide conductivity. Furthermore, the open circuit voltage (OCV) of QN-PAES X10Y23 and X10Y13 was found to be above 0.9 V, and the maximum power density of QN-PAES X10Y13 was 131.7 mW cm−2 at 60 °C under 100% RH. [ABSTRACT FROM AUTHOR]

Sulfonated poly(arylene biphenylether sulfone)-poly(arylene ether) (SPABES-PAE) block copolymers by controlling the molar ratio of SPABES and PAE oligomers were successfully synthesized, and the performances of SPABES-PAE (1:2, 1:1, and 2:1) membranes were compared with Nafion 212. The prepared membranes including fluorinated hydrophobic units were stable against heat, nucleophile attack, and physio-chemical durability during the tests. Moreover, the polymers exhibited better solubility in a variety of solvents. The chemical structure of SPABES-PAEs was investigated by 1H nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FT-IR), and gel permeation chromatography (GPC). The membrane of SPABES-PAEs was fabricated by the solution casting method, and the membranes were very flexible and transparent with a thickness of 70–90 μm. The morphology of the membranes was observed using atomic force microscope and the ionic domain size was proved by small angle X-ray scattering (SAXS) measurement. The incorporation of polymers including fluorinated units allowed the membranes to provide unprecedented oxidative and dimensional stabilities, as verified from the results of ex situ durability tests and water uptake capacity, respectively. By the collective efforts, we observed an enhanced water retention capacity, reasonable dimensional stability and high proton conductivity, and the peak power density of the SPABES-PAE (2:1) was 333.29 mW·cm−2 at 60 °C under 100% relative humidity (RH). [ABSTRACT FROM AUTHOR]

Here, we present a series of organic-inorganic composite membranes using graphitic carbon nitride (gC 3 N 4) derivatives (porous (p-) gC 3 N 4) and F-doped porous (F-p-) gC 3 N 4) to improve the electrochemical properties and dimensional stability for anion exchange membranes (AEMs). The introduction of F-p-gC 3 N 4 onto a quaternized poly(phenylene oxide) (QPPO) matrix induced the expansion of the ion channel by promoting nanophase separation, and the composite membranes possess high ion conductivity (>142.1 mS cm−1 at 90 °C, i.e., 1.75 times as high as the pristine membrane) and suitable alkaline durability (>74% ion conductivity in 1 M KOH at 80 °C for 30 days) with enhanced dimensional change. Importantly, H 2 -O 2 fuel cell performance of QPPO/F-p-gC 3 N 4 -0.5 reached a maximum peak power density of 286.2 mW cm−2 at 60 °C. In addition, the QPPO/F-p-gC 3 N 4 -0.5-based membrane electrode assembly can be operated under 0.15 A cm−2 current density at 60 °C for 100 h. Thus, this strategy could be suitable for future work on AEM applications. [Display omitted] • The F-doped porous gC 3 N 4 (F-p-gC 3 N 4) was prepared for anion exchange composite membranes. • The composite membrane showed superior ion conductivity of 142.1 mS cm−1 with suitable dimensional stability. • The ion conductivity of composite membrane was well-retained after alkaline stability >30 days in 1 M KOH at 80 °C. • The H 2 -O 2 fuel cell performance exhibited the highest peak power density of 286.2 mW cm−2. • The prepared composite membrane exhibited long-term stability at 60 °C for 100 h. [ABSTRACT FROM AUTHOR]

The development of efficient and highly durable materials for renewable energy conversion devices is crucial to the future of clean energy demand. Herein, cage‐like quasihexagonal structured platinum nanodendrites decorated over the transition metal chalcogenide core (CoS2)‐N‐doped graphene oxide (PtNDs@CoS2‐NrGO) through optimized shape engineering and structural control technology are fabricated. The prepared electrocatalyst of PtNDs@CoS2‐NrGO is effectively used as anodic catalyst for alcohol oxidation in direct liquid alcohol fuel cells. Notably, the prepared PtNDs@CoS2‐NrGO exhibits superior electrocatalytic performance toward alcohol oxidation with higher oxidation peak current densities of 491.31, 440.25, and 438.12 mA mgpt–1 for (methanol) C1, (ethylene glycol) C2, and (glycerol) C3 fuel electrolytes, respectively, as compared to state‐of‐the‐art Pt‐C in acidic medium. The electro‐oxidation durability of PtNDs@CoS2‐NrGO is investigated through cyclic voltammetry and chronoamperometry tests, which demonstrate excellent stability of the electrocatalyst toward various alcohols. Furthermore, the surface and adsorption energies of PtNDs and CoS2 are calculated using density functional theory along with the detailed bonding analysis. Overall, the obtained results emphasize the advances in effective precious material utilization and fabricating techniques of active electrocatalysts for direct alcohol oxidation fuel cell applications. [ABSTRACT FROM AUTHOR]

Abstract: The synthesis and properties of densely sulfonated poly(arylene biphenylsulfone ketone) block copolymer and its composite membranes including phosphotungstic acid (PWA) were investigated. The chemical structure of the block copolymers was characterized by FT-IR, 1H-NMR, and GPC. The block copolymer composite membranes were prepared by mixing the block copolymer with a commercial PWA. The composite membranes have shown not only good thermal stability (decomposition temperature in nitrogen >250°C), but also lower water uptake than the unfilled membranes. Their crystalline phases and morphologies have been confirmed by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FSEM), respectively. The composite membranes displayed relevant ion exchange capacity (IEC), as well as good proton conductivity especially at elevated temperature. The proton conductivity of the Block-19/PWA-30 composite membrane (IEC 1.58meqg−1) reached the maximum of 97mScm−1 at 90°C under 100% relative humidity (RH), which is comparable to Nafion-117. The fabricated composite membrane exhibited a maximum fuel cell power density of 150mWcm−2, which was much higher that of Block-19 membrane and can be considered as a candidate for potential application in fuelcells. [Copyright &y& Elsevier]

Abstract: Organic–inorganic hybrid membranes based on poly(vinylidene fluoride-co-hexa fluoropropylene) (PVdF-HFP)/sulfosuccinic acid were fabricated with different nanometer sizes of silica particles. Morphological images reveal the embedded ceramic filler over the membrane. Structural characterizations were made by FT-IR and XPS, ensure the inclusion of sulfosuccinic acid and silica into the PVdF-HFP polymer matrix. Sulfonic acid groups promote the IEC values and greater swelling behavior. Silica content in the hybrid membranes had a great effect on crystalline character as well as thermal properties of the membranes. Decrease in the filler size creates an effective route of polymer–filler interface and promotes the protonic conductivity of the membranes. The high conductivities in the range of 10−2 to 10−3 Scm−1 were achieved through synergistic interactions between the organic and inorganic moieties of the hybrid membranes. Due to these splendid features, the prepared hybrid membranes can be a trademark in the field of fuel cells. [Copyright &y& Elsevier]

Herein, a proton exchange membrane fuel cell (PEMFC) equipped with phosphoric acid-doped polybenzimidazole (PA-PBI) membrane was exploited to determine the effects of changing type and stoichiometry of feed gas at operating temperature from 120 to 160 °C. Results show that maximum power density of proposed system increases as increasing temperature, and varying the type and stoichiometry of feed gas. For example, a typical power density of 0.254, 0.299 and 0.389 W/cm2 was obtained when operating PEMFC at 120, 140 and 160 °C respectively with pure hydrogen (H 2) as feed gas. By contrast, power density of only 0.128, 0.194 and 0.243 W/cm2 was achieved when operating the PEMFC under identical condition with reformed H 2 as feed gas. On the other hand, when varying oxygen (O 2) stoichiometry from 2 to 6, power density of PEMFC vary from 0.330 to 0.472 W/cm2 at 160 °C. At high temperature and high O 2 diffusion rate, reaction kinetics of electrodes and membrane were boosted, resulting lower mass-transfer resistance and higher PEMFC performance. In addition, we conducted long-term operation of PEMFC at 160 °C for 500 h to examine durability of PA-PBI. PA-PBI membrane was not lose open circuit voltage (OCV) significantly, indicating its good PEMFC durability. • HT-PEMFC equipped with PA-PBI membrane was developed and investigated. • Operating temperature and fuel type influenced the power density of PA-PBI. • O 2 stoichiometry influenced the performance of PA-PBI. • Only 0.02 V day observed from PA-PBI membrane after 500 h operation at 160 °C. [ABSTRACT FROM AUTHOR]

The adsorption of copper (II) ions with aqua ligands on a glassy carbon electrode was induced by electrochemically oxidizing the surface. Electrochemical characterizations of the adsorbed copper ions using cyclic voltammetry and chronocoulometry were performed. The adsorption kinetics and isotherm were estimated. The amount of adsorption was proportional to the background currents which increased with the degree of surface oxidation. To explain the adsorption of the copper ions onto the surface, an electrostatic interaction after the ion-exchange reactions was proposed. With increasing ionic strength or decreasing pH of the copper-containing solution for the adsorption, voltammograms with decreasing waves were obtained, which indicates that decreasing amounts of copper ions were adsorbed. From the sizes of the waves for the redox reactions of Cu2+ ions adsorbed in solutions containing some alkali metal cations, their relative adsorption strengths were estimated with the order of H+>Li+>Na+>K+. [Copyright &y& Elsevier]

In this work, quaternized poly(arylene ether ketone) (QPAEK)/functionalized TiO 2 (f -TiO 2) composite membranes were fabricated with different f -TiO 2 contents (1, 3, 5, 7, and 9 wt%), and the structure of the materials was characterized by 1H NMR, ATR-FT-IR, XRD, XPS, and FE-SEM. The addition of f -TiO 2 enlarges the ion cluster in the membrane due to enhancing the interaction between the functional groups, and SAXS analysis revealed an extension of the ion domain size with an increase in the filler content (up to 5 wt%). In particular, the composite membrane with 5 wt% f -TiO 2 displayed the highest ion conductivity (74.6 mS cm−1); such a result was attributed to the formation of water traps by the deliquescence of TiO 2 and enhanced interfacial interactions between the pure organic polymers and inorganic nanomaterials. This work proves that a composite membrane with an appropriate f -TiO 2 concentration is a promising candidate for application to anion exchange membranes. [Display omitted] • Anionic organic-inorganic composite membranes are prepared by introducing various amount of f -TiO 2. • The properties of composite membranes are optimized by changing the contents of f -TiO 2. • The prepared membranes show improved mechanical and dimensional stabilities. • The QPAEK/ f -TiO 2 composite membranes demonstrate superior oxidative/alkaline stabilities. [ABSTRACT FROM AUTHOR]

Novel anion conductive nanocomposite membranes with superb hydroxide conductivity and chemical durability in alkaline conditions were prepared by the introduction of quaternary ammonium functionalized graphene oxide (Q-GO) into quaternized poly(arylene ether) (QPAE) random copolymer. Q-GO containing amino silane units, which induce ion cluster formation in the polymer matrix, was synthesized using (3-aminopropyl)triethoxysilane (APTS) and (3-bromopropyl)trimethyl ammonium bromide (PTMA) as the main quaternization reagents. The chemical structures and morphologies of the polymers and inorganic nanofillers were characterized by 1H NMR, FT-IR, FE-SEM, XPS, and SAXS. GO-(APTS- c -PTMA), the so called Q-GO, was used to expand the ion transfer sites and improve the physicochemical stability of the membrane. The electrochemical properties, thermal/mechanical properties, and chemical stabilities of the anion exchange membranes (AEMs) were investigated in accordance with different contents of GO-(APTS- c -PTMA). The π-π bonds between the polymer matrix and the Q-GO resulted in improved dimensional stability and mechanical properties in the composite membrane. The QPAE/GO-(APTS- c -PTMA) 0.7 wt% membrane showed the highest hydroxide conductivity of 114.2 mS cm−1 at 90 °C with an ion exchange capacity of 1.45 mmol g−1, which is 2.07 times higher than the pristine membrane (55.1 mS cm−1 at 90 °C). Furthermore, the single-cell performance of the QPAE/GO-(APTS- c -PTMA) 0.7 wt% as an AEM showed an excellent maximum power density of 135.8 mW cm−2 at 70 °C. Image 1 • Cheap and easy method for crosslinked anion exchange membrane (AEM) preparation for anion exchange membrane fuel cells AEMFC. • The composite AEMs showed highest hydroxide conductivity. • The prepared composite AEMs exhibit long-term chemical stability (>20 days). • The cell was stably operated at 60 °C for 120 h. [ABSTRACT FROM AUTHOR]

The anion exchange membrane may have different physical and chemical properties, electrochemical performance and mechanical stability depending upon the monomer structure, hydrophilicity and hydrophobic repeating unit, surface form and degree of substitution of functional groups. In current work, poly(arylene ether sulfone) (PAES) block copolymer was created and used as the main chain. After controlling the amount of NBS, the degree of bromination (DB) was changed in Br-PAES. Following that, quaternized PAES (Q-PAES) was synthesized through quaternization. Q-PAES showed a tendency of enhancing water content, expansion rate, ion exchange capacity (IEC) as the degree of substitution of functional groups increased. However, it was confirmed that tensile strength and dimensional properties of membrane reduced while swelling degree was increased. In addition, phase separation of membrane was identified by atomic force microscope (AFM) image, while ionic conductivity is greatly affected by phase separation. The Q-PAES membrane demonstrated a reasonable power output of around 64 mW/cm2 while employed as electrolyte in fuel cell operation. [ABSTRACT FROM AUTHOR]

A series of sulfonated poly(arylene ether sulfone) block copolymers with aliphatic chains (SPAES-LA) to lend structural flexibility in the polymer backbone have been synthesized to prepare proton exchange membranes (PEMs) showing improved electrochemical performance and dimensional/oxidative stabilities. The SPAES-LAs, bearing different hydrophilic/hydrophobic segment lengths, are prepared via polycondensation and sulfonation reactions. The sulfonation reaction occurs in specific fluorenylidene units by using chlorosulfonic acid. The SPAES-LA membrane, fabricated by solvent casting method, exhibits remarkable dimensional/thermal stabilities. Moreover, proton conductivity of as-prepared SPAES-LA membranes demonstrates significant improvement with expansion of ion clusters which is due to the increased hydrophilic volume ratio. In particular, the SPAES-LA-X12Y28 membrane exhibited heightened proton conductivity of 158.4 mS cm−1 as well as suitable dimensional stability and durability towards radical oxidation, due to an effective well-defined hydrophilic-hydrophobic interface. Furthermore, H 2 /O 2 fuel cell performance using SPAES-LA-X12Y28 membrane achieves a maximum power density of 232.02 mW cm−2, a result which points out that SPAES-LA membranes show great potential for applications of polymer electrolyte membrane. Image 1 • The block copolymers are synthesized via controlling oligomer lengths. • The fabricated membranes show desirable thermo-oxidative stability. • The membranes showed high physio-chemical properties. • The as-prepared membranes exhibit high ionic conductivity and unit-cell performance. [ABSTRACT FROM AUTHOR]

We have investigated the impact of electronic structure modulation on the intrinsic performance of spinel catalysts (ZnCoX; X = O, S, Se) towards OER by using experimentally and theoretically. [Display omitted] • Design and synthesis of spinel catalysts (ZnCo 2 X 4 ; X = O, S, Se). • ZnCo 2 Se 4 shows improved activity of OER (Eη 10 = 302 mV) and Tafel slope (58 mV dec−1). • Zn and Co atoms electronic properties are modified by the counter anionic components. • The higher e g orbital mixing boosts catalytic activity. • The geometrical, chemical, and electronic states of atoms are determined by MO theory. Design, synthesis, and engineering of electrocatalysts for the oxygen evolution reaction (OER) are essential for attaining desirable electrocatalytic performance towards practical implementation. Emerging spinel-type OER catalysts have not reached the desirable activity and durability, thus demanding critical research to advance the field. To achieve enhanced OER performance for spinel-type OER catalysts, we present an efficient strategy of electronic structure modulation of central metal atoms. Modulation of the electronic properties of the Zn and Co atoms through the counter anionic components (O, S, and Se) regulates the adsorption of oxygen intermediates and thus enhances OER activity, which is systematically demonstrated using Density Functional Theory (DFT) calculation. Although the zinc cobalt selenide catalyst showed the less pronounced trigonal distortion, the mixing of e g orbitals with selenium accounts for the experimentally observed enhancement in OER activity. The result is, in contrast to the benchmark catalyst made of RuO 2 , ZnCo 2 Se 4 @rGO demonstrated lower OER overpotential (η 10 = 302 mV) and Tafel slope (58 mV dec−1) as well as greater durability at 10 mA cm−2 for 50 h. The implementation of this strategy in several spinel-type catalysts could improve their electrocatalytic performance. [ABSTRACT FROM AUTHOR]

An environmentally benign and cost efficient cysteine fluorescence sensor is constructed on the basis of nitrogen doped carbon nanodots (NCNDs) prepared by using citron fruit extract and human urine waste as carbon and nitrogen sources, respectively. The turn-off-on fluorescence technique is exploited for the sensing of cysteine, in which the initial fluorescence of NCNDs is quenched with Hg 2+ via an electron transfer process. Owing to the competitive binding of Hg 2+ with cysteine, the ‘turn-off’ fluorescence sensor is switched to the ‘turn-on’ state. Under optimized conditions, NCNDs-Hg 2+ assembly demonstrates a lower detection limit and a wide linear range toward cysteine detection. Furthermore, NCNDs display the discriminative detection of cysteine from the similar bioactive molecules and the co-existence of interference species does not influence the detection of NCNDs toward the interest of an analyte. Furthermore, the practical application of NCNDs based fluorescence sensor is validated with the good recovery in human urine samples, which explores the new avenues in the fluorescence sensing of biomolecules. [ABSTRACT FROM AUTHOR]

Abstract: Poly(styrene sulfonic acid)-grafted poly(vinylidene fluoride-co-hexafluoroproplyene)/tin oxide composite membranes were prepared for the direct methanol fuel cells applications. The interconnected pores of the PVdF-HFP membranes endorsed the higher poly(styrene sulfonic acid) grafting. The incorporation of tin oxide particles decreased the polymeric content volume which was available for the grafting reaction and reduced the grafting degree values. The obtained morphological and structural characterizations confirmed the polystyrene grafting and sulfonic acid functionalization of the fabricated membranes. The incorporated tin oxide particles promoted the thermal stability of the composite membranes via its ceramic filler property. Though the composite membranes exhibited lower grafting values, the structural, bonded, and physisorbed water molecules of the tin oxide particles governed the prompt ionic conductivity values even at higher temperature and lower humidity conditions. The lower grafting and methanol resistive behavior of tin oxide particles distorted the fuel transportation channels and reduced the fuel permeability. By the combined efforts of high ions and lower molecular transportation, fuel cell efficiency was facilitated for the fabricated composite membranes and geared its potential applications in direct methanol fuel cells field. [Copyright &y& Elsevier]

Abstract: Thermogravimetric analysis of LiAlH4 chemically mixed with different additives is reported for the application of hydrogen storage. Here, we illustrated the dehydrogenation properties of combined LiAlH4/LiNH2 (2:1) mixture and LiAlH4 wet-doped with different transition metals (Sc, Ti, and V) in their chloride forms. Thermal gravimetric analysis of LiAlH4/LiNH2 system released ∼7.9wt.% of hydrogen in three decomposition steps at temperatures between 75 and 280°C under a heating ramp of 5°Cmin−1. The LiAlH4 doped with transition metals showed the decrease of decomposition temperature down to 30–40°C for both 1st and 2nd dehydrogenation steps as compared to as-received LiAlH4. The catalytic activity in lowering the dehydrogenation temperature of LiAlH4 doped with transition metals increases in the order of pure LiAlH4

Constructing an electrocatalyst with highly durable active and cost-effective core-shell with a porous carbon nanosheet for the development of high efficiency energy conversion and storage devices. Herein, we developed core-shell nickel-iron oxide on a highly porous N-doped carbon nanosheet (CS-NFO@PNC) via a facile solvothermal calcination route. The optimized CS-NFO@PNC-700 showed remarkable electrocatalytic activity towards ORR (0.85 V vs RHE), OER ƞ 10 = 217 mV, and HER ƞ 10 = 200 mV with excellent durability towards the corresponding half-cell reactions. Further, we investigated the ORR, OER, and HER mechanistic pathways of the electrocatalyst using the density functional theory. Finally, we fabricated a rechargeable liquid electrolyte-based zinc–air battery with CS-NFO@PNC-700 as the cathode which displayed an improved power density of 130 mW cm−2 at 217 mA cm−2 with excellent durability of 180 h. The rechargeable flexible quasi-solid-state zinc–air battery with CS-NFO@PNC-700 air cathode, which exhibited excellent long term durability over 40 h at 5 mA cm−2. [Display omitted] • Novel core-shell NFO@PNC was fabricated by a facile solvothermal calcination route. • CS-NFO@PNC-700 shows better ORR activity with E 1/2 of 0.85 V vs. RHE than 20% Pt-C. • CS-NFO@PNC-700 shows improved activity of OER (Eη 10 =217 mV) and HER (Eη 10 =200 mV). • CS-NFO@PNC-700 based zinc-air battery shows high power density and long life cycle. • Water splitting driven by CS-NFO@PNC-700 based zinc–air battery devices. [ABSTRACT FROM AUTHOR]

Abstract: The power of nanomaterials has been hampered by the difficulty in controlling their size and morphology. Monodispersed silica particles with different nanometer sizes synthesized by a novel spray method remove the obstacles for the commercialization of nanomaterials at a global level. The size and shape of the silica particles were effectively controlled by simple hydrolysis and condensation reaction. Morphological images (SEM and TEM) reveal the smooth and spherical shaped silica particles with homogeneous distribution. Structural and luminescence properties of the silica particles were examined by FT-IR absorption spectroscopy and photoluminescence. A very low weight percentile loss of the silica particle ensures its high thermal stability. The high surface areas of about 55 and 25m2/g were achieved for 90 and 220nm particle sized silica particles, respectively. The resultant silica particles can be easily suspended in water and would be useful for variety of applications. [Copyright &y& Elsevier]

Abstract: Li[Li1/5Ni1/10Co1/5Mn1/2]O2 solid solutions were prepared by four different routes using a solid-state reaction method. All the prepared samples were of a layered manganese oxide structure. The prepared samples were subjected to XRD, Raman and charge–discharge studies. The addition of ethyl alcohol in the starting materials during the synthesis process has exhibited superior electro-chemical properties and offered higher discharge capacity than the samples calcinated in the form of pellets without solvent. The added ethyl alcohol not only assists to get a homogeneous mixing of reacting species, but also influences the chemical reaction during the synthesis process. The materials are found to be superior in terms of minimum capacity fading per cycle than the materials so far reported. The other electro-chemical properties like irreversible capacity and discharge capacity of the synthesized materials have also been discussed based on the experimental observations. [Copyright &y& Elsevier]

[Display omitted] • Pt@CoS 2 -NrGO was synthesized by using hydrothermal and chemical reflux method. • Pt@CoS 2 -NrGO shows a good ORR activity with E 1/2 of 0.85 V vs. RHE. • Pt@CoS 2 -NrGO shows excellent performances of HER (Eη 10 = 39 mV) and OER (Eη 10 = 235 mV). • Pt@CoS 2 -NrGO based zinc–air battery exhibits a peak power density of 114 mW cm−2. • Highly efficient water splitting driven by Pt@CoS 2 -NrGO based zinc–air batteries. Constructing more active and durable trifunctional electrocatalysts is key for boosting overall water splitting and metal–air battery efficiency. Herein, we developed a trifunctional electrocatalyst of ultrafine Pt nanoparticles anchored on CoS 2 -N-doped reduced graphene oxide (Pt@CoS 2 -NrGO). Owing to its more Pt active sites with rapid ion/electron transport ability, the Pt@CoS 2 -NrGO shows excellent trifunctional activities towards HER (ƞ 10 = 39 mV), OER (ƞ 10 = 235 mV) ORR (E 1/2 = 0.85 V vs. RHE) and water splitting device of Pt@CoS 2 -NrGO||Pt@CoS 2 -NrGO achieved cell voltage of 1.48 V at 10 mA cm−2, which is better than Pt-C||RuO 2. Finally, we employed Pt@CoS 2 -NrGO as air cathode for zinc–air battery to display a power density of 114 mW cm-2 and durability of 55 h, outperforming than Pt-C + RuO 2 based zinc–air batteries. For practical aspects, Pt@CoS 2 -NrGO based zinc–air batteries were connected to overall water splitting device to produce H 2 and O 2 gases for hydrogen fuel cell. [ABSTRACT FROM AUTHOR]

Numerous chemosensors have been developed for next-generation detection systems because of their ease of use and promising characteristics to distinguish signals between various analytes binding. However, given their typically poor emission response and arduous preparation methods, very few chemosensing probes have been commercialized to date. In this work, a simple, naphthoquinone-based mitochondria-targeting chemosensor (CIA) has been fabricated for the simultaneous detection of Cu2+ and GSSG (glutathione oxidized) through an "on-off" mode in a buffered semi-aqueous solution. Significantly, the CIA chemosensor showed a sensitive detection response towards Cu2+ and GSSG with low detection limits (0.309 μM, and 0.226 μM, respectively). In addition, the detection mechanism of CIA was thoroughly verified and confirmed using numerous analytical techniques. Furthermore, CIA was utilized as a sequential fluorescence biomarker to detect Cu2+ in human cervical cancer cell lines. These findings indicate that the chemosensor CIA can discriminate human cancer cells from normal cells. The CIA was also confirmed to possess the ability to target mitochondria. More importantly, the present CIA chemosensor detected Cu2+ in zebrafish larvae, indicating the probe has tissue penetration ability. [Display omitted] • A cheap and simple naphthoquinone-based sensing probe CIA was fabricated. • CIA exhibited good performance in semi-aqueous solution for Cu2+ and GSSG detection. • CIA displayed a quick response with a higher sensitivity. • CIA shows distinguishable detection of Cu2+ in human cancer cells. • CIA have mitochondria-targeted ability. [ABSTRACT FROM AUTHOR]

The goal of the present work was to fabricate a new low-cost, easy-to-prepare, dual-channel fluorescence chemosensor comprised of acridine-diphenylacetyl moieties (NDA) to enable remarkable Sn4+ detection in water and biological medium. The resulting NDA –Sn4+ complex was utilized for the distinguished identification of Cr 2 O 7 2- ions from other anions and biomolecules. These investigations involve the absorption, fluorescence, and electrochemical methods for the detection of Sn4+ and Cr 2 O 7 2- ions in pure water. The mechanism for NDA -mediated Sn4+ detection was experimentally determined by FT-IR, NMR titrations, mass (ESI) analyses, and DFT calculations. The obtained results indicate that the NDA chemosensor possessed excellent performance characteristics including good water solubility and compatibility, quick response time (less than 10 s), high sensitivity (Sn4+ = 0.268 μM and Cr 2 O 7 2- = 0.160 μM), and selectivity against coexisting metals, anions, amino acids, and peptides. The chemosensor NDA induced negligible toxicity in live cells and was successfully utilized as a biomarker for the tracking of Sn4+ in human normal and cancer cells. More importantly, NDA demonstrates distinguished recognition of Sn4+ in human cancer cells rather than in normal live cells. Additionally, NDA was shown to act as a mitochondria-targeted probe in FaDu cells. [Display omitted] • A new acridine-based chemosensor NDA for Sn4+ and Cr 2 O 7 2- ions was developed. • NDA displays higher selectivity over other coexisted ions and biomolecules. • NDA shows distinct superiority in real water samples and bioimaging analysis. • NDA demonstrated as a mitochondria-targeted chemosensor in FaDu cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • The chemosensor 4DBS synthesized via greener and simple synthetic methods. • The colorimetric and fluorescence recognition of Hg2+ ion was accomplished. • The LOD for 4DBS towards Hg2+ was 0.451 µM. • Bioimaging of 4DBS was accomplished in live cells and zebrafish larvae. • 4DBS showed the discriminative identification of Hg2+ in live cells. A new colorimetric and ratiometric fluorescence chemosensor 4-((3-(octadecylthio)-1,4-dioxo-1,4-dihydronaphthalen-2-yl)amino)benzenesulfonamide (4DBS) was synthesized and investigated for the selective detection of Hg2+ in DMSO-H 2 O (9:1, v/v) solution. The chemosensor was efficiently synthesized in two steps via Michael-like addition and nucleophilic substitution reactions. The ratiometric fluorescence turn-on response was obtained towards Hg2+, and its fluorescence emission peak was red-shifted by 140 nm with an associated color change from light maroon to pale yellow due to the intramolecular charge transfer effect. The formed coordination metal complex was further evaluated by FT-IR, 1H NMR, and quantum chemical analyses to confirm the binding mechanism. The detection process was sensitive/reversible, and the calculated limit of detection for Hg2+ was 0.451 µM. Furthermore, 4DBS was effectively utilized as a bioimaging agent for detection of Hg2+ in live cells and zebrafish larvae. Additionally, 4DBS showed distinguishing detection of Hg2+ in cancer cells in comparison with normal cells. Thus, 4DBS could be employed as an efficient bioimaging probe for discriminative identification of human cancer cells. [ABSTRACT FROM AUTHOR]

Several fluorescence and colorimetric chemosensory for Sn2+ detection in an aqueous media have been reported, but applications remain limited for discriminative Sn2+ detection in live human cells and zebrafish larvae. Herein, a mitochondria-targeted Sn2+ "turn-on" colorimetric and fluorescence chemosensor, 2CTA , with an aggregation-induced emission (AIE) response was developed. The sensing of Sn2+ was enabled by a reduction-enabled binding pathway, with the conversion of –C˭O groups to –C–OH groups at the naphthoquinone moiety. The color changed from light maroon to milky white in a buffered aqueous solution. The chemosensor 2CTA possessed the excellent characteristics of good water solubility, fast response (less than 10 s), and high sensitivity (79 nM) and selectivity for Sn2+ over other metal ions, amino acids, and peptides. The proposed binding mechanism was experimentally verified by means of FT-IR and NMR studies. The chemosensor 2CTA was successfully employed to recognize Sn2+ in live human cells and in zebrafish larvae. In addition, a colocalization study proved that the chemosensor had the ability to target mitochondria and overlapped almost completely with MitoTracker Red. Furthermore, a bioimaging study of live cells demonstrated the discriminative detection of Sn2+ in human cancer cells and the practical applications of 2CTA in biological systems. [Display omitted] • A mitochondria-targeted colorimetric/fluorescence chemosensor 2CTA was developed. • 2CTA showed excellent sensitivity to Sn2+ at a nanomolar level (79 nM). • 2CTA discriminatively detected Sn2+ in cancer cells than the normal live cells. • The probe was used as a mitochondria-targeted fluorescent marker. • The probe was used for the tracking of Sn2+ in live cells and zebrafish. [ABSTRACT FROM AUTHOR]

[Display omitted] • Successfully synthesized Fe 3 O 4 nanorods coated PPy/rGO by chemical reflux method. • Fe 3 O 4 @PPy/rGO/GCE effectively sensing dopamine molecules. • Fe 3 O 4 @PPy/rGO/GCE shows better repeatability, reproducibility and stability. • Photocatalytic studies reveal 84% ACP degradation by Fe 3 O 4 @PPy/rGO with persulfate. • ACP photodegradation studies shows rate constant of 9.13 × 10−4 M−1 s−1. The increase in the world's population has exerted tremendous pressure on the research community to solve the related health and environmental issues. Hence, it is an important and challenging task to design a multifunctional catalyst that both aids medical diagnostics and removes organic pollutants from aqueous environments. Herein, we developed iron oxide nanorods uniformly coated on the polypyrrole/reduced graphene oxide (Fe 3 O 4 @PPy/rGO) nanohybrids by the chemical reflux method. The optimized Fe 3 O 4 @PPy/rGO nanohybrids show better electrochemical detection of dopamine (DA) with a low detection limit (0.063 µM) and a better linearity range (0 to 100 µM), with a coefficient of determination of 0.994. The Fe 3 O 4 @PPy/rGO nanohybrids reveal an excellent DA recovery rate of 97– 98% during real sample analysis. In addition, photocatalytic studies reveal that 84% acetaminophen (ACP) degradation by Fe 3 O 4 @PPy/rGO nanohybrids was noticed with the persulfate. The effect of co-existing photocatalytic studies affirms that the higher ACP photodegradation rate constant of 9.13 × 10−4 M−1 s−1 was obtained in the presence of the Cl− ion. The present work provides a new pathway for the development of a metal oxide with a conducting polymer and graphene-based catalyst for multi-functional applications for the electrochemical sensing and photodegradation of organic pollutants. [ABSTRACT FROM AUTHOR]

• Novel core-shell FeCoMoS@NG was fabricated by simple and cost-effective method. • FeCoMoS@NG catalyst exhibits an excellent ORR activity with E 1/2 of 0.83 V vs. RHE. • FeCoMoS@NG shows better performances of OER (Eη 10 = 238 mV) and HER (Eη 10 = 137 mV). • FeCoMoS@NG based zinc-air battery shows a peak power density of 118 mW cm−2. • High efficient water splitting driven by FeCoMoS@NG based zinc–air battery devices. Emerging demands for the highly active, durable, and cost-effective trifunctional catalysts for overall water splitting and metal–air batteries in the scientific community. Herein, a novel strategy is demonstrated for the rational design of hierarchical iron cobalt molybdenum sulfide nanoflower encapsulated in nitrogen doped graphene (FeCoMoS@NG) through a facile, cost-effective, and single-step in-situ hydrothermal process. Owing to its hierarchical nanostructures, larger specific surface area, and exclusive porous networks, the optimal FeCoMoS@NG shows excellent catalytic activities for OER ƞ10 = 238 mV, HER ƞ10 = 137 mV, and ORR (0.83 V vs RHE). Most significantly, FeCoMoS@NG||FeCoMoS@NG water splitting device achieves a cell voltage of 1.58 V at 10 mA cm−2. Furthermore, FeCoMoS@NG based zinc–air battery endows a high power density of 118 mW cm−2, and overall water splitting was successfully driven by FeCoMoS@NG based zinc–air battery. This work provides new pathway for designing highly active and durable multifunctional catalysts for energy conversion and storage applications. [ABSTRACT FROM AUTHOR]

A series of novel blended anion exchange membranes (AEMs) were prepared with hyperbranched brominated poly(arylene ether sulfone) (Br-HB-PAES) and linear chloromethylated poly(phenylene oxide) (CM-PPO). The as-prepared blended membranes were fabricated with different weight ratios of Br-HB-PAES to CM-PPO, and the quaternization reaction for introducing the ionic functional group was performed by triethylamine. The Q-PAES/PPO-XY (quaternized-PAES/PPO-XY) blended membranes promoted the ion channel formation as the strong hydrogen bonds interconnecting the two polymers were maintained, and showed an improved hydroxide conductivity with excellent thermal behavior. In particular, the Q-PAES/PPO-55 membrane showed a very high hydroxide ion conductivity (90.9 mS cm−1) compared to the pristine Q-HB-PAES membrane (32.8 mS cm−1), a result supported by the morphology of the membrane as determined by the AFM analysis. In addition, the rigid hyperbranched structure showed a suppressed swelling ratio of 17.9–24.9% despite an excessive water uptake of 33.2–50.3% at 90 °C, and demonstrated a remarkable alkaline stability under 2.0 M KOH conditions over 1000 h. [ABSTRACT FROM AUTHOR]