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The X-ray diffraction internal standard method can quantitatively determine the ash content of paper, but the requirements for the experimental environment are high, the determination is not convenient and the cost is high, and it is difficult to be widely used in the papermaking enterprises. In order to determine the total ash and its components of the single filler paper samples, and meet the ash determination requirements of papermaking enterprises, the continuous X-ray method is proposed. In this paper, an X-ray tube is used as the radiation source and an ionization chamber is used as the detector. Through polynomial fitting of the total ash and voltage logarithm ratio of the single filler paper samples, the mathematical model of total ash is established; the total ash and its components content of paper are calculated according to the mathematical model of total ash and the Beer–Lambert law deformation formula; the total ash and its components content of paper are verified by the burning method. The research results show that the total ash error of the single filler paper samples is less than 4%, and the ash component error is less than 5%.

Lignin-based epoxy resins containing phosphorus (P) and nitrogen (N) elements were prepared by blending the epoxy resin (EP) with different amounts of lignin-based flame retardant additive (Lig-F). The thermal performance of EP thermosets was performed via thermogravimetric analysis coupled with Fourier transformation infrared spectroscopy (TG-FTIR). The results showed that the presence of Lig-F had significant influence on thermal stability (tested by TG) and flame retardancy (determined by limited oxygen index, vertical burning and cone calorimeter) of EP thermosets. 1H NMR and FTIR analyses confirmed the successful synthesis of flame retardant (DOPO-PA) and modification of lignin, and the evolution of gas produced by thermal decomposition was different with different quantities of Lig-F added. Finally, the activation energy (E) of cured 10% Lig-F/EP was measured by two different methods, namely Flynn–Wall–Ozawa and Kissinger-Akahira-Sunoe, which was obviously higher than that of neat EP.

A homogeneous α-cellulose film was prepared by regeneration method from ZnCl2/CaCl2/cellulose mixed system and was further combined with sodium lignosulfonate (SLS) by crosslinking through interaction hydrogen bonds and “bridge linkages”. The physicochemical and antibacterial performance of films were all investigated and results showed that modified films exhibited stronger tensile strength, higher thermal stability, lower hydrophilic effect, better UV shielding as compared with those of pure cellulose film, and especially, better antibacterial ability derived from the presence of phenolic and sulfonate groups in SLS. This study proposed a simple and sustainable method for fabricating a multifunctional and environmentally friendly composite film by using two main lignocellulose resources as raw materials.

This work focuses on the reactivation of fluid catalytic cracking (FCC) catalyst via mixed acid to leach out pollutant Ni and Fe oxides and reserve acidic sites provider Al2O3 in zeolite. The micro-structure, morphology and chemical composition of reactivated catalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive X-ray analysis (EDXA), respectively. The change of micro-structure and catalytic performance of the catalyst after reactivation were discussed. The blocked micro- and meso-pores in the spent catalyst are opened by acid leaching, and the specific surface area is doubled, which is close to that of fresh catalyst. The catalytic performance of the reactivated catalyst is evaluated in heavy oil micro-reactor. It results in 6.3% increase of conversion than the spent catalyst, and 2.31% increase of gasoline yield and 11.60% increase of diesel yield. This method for spent FCC catalyst reactivation has strong practicability and is of great significance for environment protection and resources recycling.

In this study, we reported the preparation of a conducting polymeric/inorganic nanohybrid consisting of multiwalled carbon nanotubes (MWCNT), N-doped graphene (NGr), and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and its electrochemical application in intelligent sensors and supercapacitors. The multilayer thin film of the PEDOT:PSS-supported MWCNT-NGr nanohybrid was prepared by a facile layer-by-layer assembly strategy. The obtained conducting polymeric/inorganic nanohybrid modified electrode displayed superior electron transfer ability and a high specific surface area, which was used for electrochemical applications in intelligent sensors and supercapacitors. Remarkably, the fabricated amaranth sensor exhibited a broad linear range of 0.05-10 μM with a limit of detection of 0.015 μM under the optimal conditions. With the help of the response surface methodology, multivariate optimization was used as a substitute for the traditional single variable optimization to reflect the complete real effects of multivariate optimization in a sensing platform. Machine learning implemented by hybrid genetic algorithm-artificial neural network was used as an intelligent analysis model to replace the traditional regression analysis model for realizing intelligent analysis and output of sensing system. The MWCNT-NGr/PEDOT:PSS modified electrode exhibited a considerable specific capacitance of 6.5 mF cm-2 at a current density of 2.0 mA cm-2. The proposed results provided a new thought for a nanosensing platform equipped with a supercapacitor as a self-powered electrochemical energy storage system and machine learning as an intelligent analysis and output system in the near future.

A nanozyme sensor consisted of both carbonylated multi-walled carbon nanotubes (COOH-MWCNT) and two-dimensional layered molybdenum disulfide (MoS2) nanosheets for the sensitive detection of 5-nitroguaiacol sodium (5-NG) in tomato and broiler feed under the optimal conditions was successfully developed. MoS2-COOH-MWCNT nanohybrid was simply obtained by ultrasonic preparation in presence of Nafion. The MoS2-COOH-MWCNT film was characterized, and parameters of their film electrodes such as pH, scan rates, the percentage content of Nafion (Nf), and the ratio between COOH-MWCNT and MoS2 were optimized. The MoS2-COOH-MWCNT nanohybrid was used to detect 5-NG in tomato and broiler feed, and their recoveries were 102.22 and 93.2%, respectively. The electrocatalytic oxidation mechanism of 5-NG and oxidase-like (nanozyme) kinetics of MoS2-COOH-MWCNT nanohybrid were investigated. The fabricated nanozyme sensor displayed good electrochemical responses, wide linear ranges of 0.1–70 μM with limit of detection (LOD) 0.02 μM, unique oxidase-like characteristics, and good practicability, which will provide a new sensing platform based on inorganic nanomaterials with enzyme-like (nanozyme) characteristics for the determination of 5-NG in plant-derived agro-products and/or plant-derived animal feeds.

The dielectric performance of ReCOB-type (Re: rare earth ions) crystals is vital for modulating their electro-elastic properties and improving the sensing capabilities of such high temperature piezoelectric sensors. It has been reported that the dielectric permittivity of ReCOB increases with increasing Re3+ ion radius, whereas LaCOB exhibits an abnormal drop in the dielectric permittivity, which presents an obstacle to the optimization of the properties of ReCOB crystals. By using first-principle calculations and combining these with experiments, we found that both electronic hybridization and bond vibrations contribute to the dielectric permittivity of ReCOB. A significant decrease in dielectric permittivity for LaCOB can be attributed to the distinct reduction in the ionic displacement polarization. Charged antisite LaCa+ defects play an important role in improving the dielectric properties of LaCOB by changing the polarization direction. This suggests that it would be useful to increase the concentration of LaCa antisite defects by partially replacing La3+ with smaller ions, such as Y3+, Er3+, and Tm3+.

The electrical conduction behavior of piezoelectric crystals is critical in the design of piezoelectric sensors for use at elevated temperatures. The electrical resistivity and dielectric properties of rare-earth calcium oxyborate crystals ReCa4O(BO3)3 (ReCOB, Re = Y, Gd and Pr) are investigated in this report. The relationships between the electronic structures and electrical properties are then determined using X-ray photoelectron spectra and first principle calculations. Among the ReCOB type crystals, YCOB is found to possess the highest electrical resistivity and lowest dielectric loss. Nonlinearity of the electrical resistivity as a function of temperature for ReCOB crystals is then confirmed, corresponding to different conduction mechanisms. It is also revealed that the electrical conductivity of ReCOB type crystals is heavily influenced by oxygen vacancy defects at relatively lower temperatures (below ∼600 °C), while both vacancy defects and band gap contribute to conductivity at elevated temperatures (above ∼600 °C).

Associative polysaccharides, decorated by multiple but short, side-chain hydrophobic stickers (typically 6–20 carbon long) that associate in solution, are used as thickeners for an extensive range of aqueous-based formulations. Characterizing and elucidating the influence of stickers on the response to extensional flows that spontaneously arise in pinching necks formed during spraying, jetting, or coating fluids have remained longstanding experimental and analytical challenges due to relatively low viscosity and elasticity of industrially relevant systems. In this contribution, we contrast the shear rheology as well as extensional rheology and pinching dynamics of hydrophobically modified hydroxyethyl cellulose (hmHEC, Mw = 300 kg/mol) as a sticky polymer with the bare chain of a higher molecular weight (hydroxyethyl cellulose (HEC), Mw = 720 kg/mol) using the recently developed dripping-onto-substrate (DoS) rheometry protocols. We show that sticker associations enhance zero shear viscosity and relaxation time (elasticity), and both quantities display stronger concentration-dependent variation for sticky polymers. Striking differences are observed in neck shapes, radius evolution profiles, and extensional viscosity plotted as a function of strain as well as strain rate. We present a comprehensive analysis of changes in pinching dynamics, concentration-dependent variation in steady, terminal viscosity as well as filament lifespan as a function of the sticky polymer concentration and describe the influence of multiple stickers on the macromolecular strain, relaxation, and dynamics of associative polysaccharides.

It is an urgent need to exploit a potentially green, cost efficient and eco-friendly strategy for the utilization of waste kudzu vine. We developed a one-step green preparation of kudzu vine biochar (BC) decorated graphene-like molybdenum selenide (MoSe2) with the oxidase-like activity as intelligent nanozyme sensing platform for voltametric detection of hesperetin (HP) in orange peel using the in-situ hydrothermal synthesis method. The structure and properties of MoSe2-BC was characterized, and found that BC significantly improved electrochemical cycle stability, electronic conductivity, electrochemical active area, and electrocatalytic activity of MoSe2. The oxidase-like activity of MoSe2-BC was confirmed by the oxidization of the colorless substrate 3,3′,5,5′-tetramethylbenzidine (TMB) to form blue products and the change of absorbance intensity of UV–vis absorption spectra. The MoSe2-BC exhibited excellent electrochemical sensing performance for the detection of HP in wide linear ranges from 10 nM to 9.5 μM with a low limit of detection of 2 nM using differential pulse voltammetric method. An emerging machine learning technique is used to realize the intelligent sensing of HP, and the performance evaluation of regression analysis was selected to evaluate this technique. This work will provide a guidance for the preparation and application of biochar decorated graphene-like nanomaterials with the oxidase-like activity and the development of intelligent nanozyme sensing platform.

A novel and simple strategy was proposed for the determination of ZEA in breakfast cereal, maize powder and rice flour using an electrochemical nanohybrid sensor based on copper-based metal-organic framework (Cu-MOF)/magnetic Fe3O4-graphene oxide (Fe3O4-GO) modified electrode fabricated by the layer-by-layer assembled technique. The synthesized Cu-MOF with high porosity favorably improved the effective surface area and the analytical performance of nanohybrid sensing electrode. The crafted sensor has large surface area, high electron transfer, and satisfactory efficiency. ZEA was electrochemically detected in a wide linear range from 159.2 to 2865.2 ng mL−1 with LOD of 23.14 ng mL−1 under the optimal conditions. Moreover, the electrocatalytic mechanism of ZEA oxidation was proposed by density functional theory (DFT). A favorable energetic interaction was presented when Cu-MOF adsorbed on Fe3O4-GO, and a small new band appeared on the Fermi level energy (Ef) that facilitated the electron transfer between bands.

Herein, a new approach of inducing oxygen vacancy in BiVO4/FeOOH nanostructures is designed, where metal trichalcogenide is introduced. The strategy involves integration of Bi2S3 quantum dots (QDs) in BiVO4/FeOOH to construct defect-rich BiVO4/FeOOH (denoted Vo-BiVO4/FeOOH) as high-performance photoanode for photoelectrochemical water oxidation. Both experimental and theoretical analysis confirm that the excellent PEC performance is due to the introduction of oxygen vacancies and FeOOH cocatalyst, which significantly improves the charge separation. As a result, the obtained Vo-BiVO4/FeOOH photoanode not only demonstrates an optimized Photoelectrochemical (PEC) performance for water oxidation, with photocurrent density of 4.71 mA cm−2 at 1.23 V versus RHE under AM 1.5 G illumination but the interaction of BiVO4 with FeOOH cocatlayst also significantly enhance the stability for Vo-BiVO4/FeOOH without any decrease after 11 h. The oxygen vacancy and FeOOH can effectively enhance the light conversion efficiency, charge transfer efficiencies and charge separation efficiency. This work highlights an effective strategy towards achieving efficient and stable BiVO4 photoanode for sustainable solar energy conversion.

Ultrasonic-assisted liquid-phase exfoliation is one of high-efficiency strategies for preparing two-dimensional (2D) materials. Herein, we report a facile and green synthesis of the phosphorene (BP) obtained from bulk black phosphorus crystal in the ionic liquid (IL) 1-ethyl-3-methylimidazoliumtetrafluoroborate ([EMIm]BF4) through ultrasonic-assisted liquid-phase exfoliation under the continuous nitrogen atmosphere. To gain more insight, the morphology and composition of the as-prepared BP were characterized. The prepared BP showed satisfactory stability in ambient condition containing oxygen and water. In the following, single walled carbon nanohorn (SWCNH) was selected to enhance electrocatalytic capacity and endow oxidase-like (nanozyme) characteristics, which was further applied for electrochemical sensing of 5-hydroxytryptamine (5-HT). Derivative techniques were employed for treating voltammograms to obtain sharper and narrower voltammetric peak, transform asymmetric peak into much more symmetrical peak, reduce background interference, eliminate personal error and directly read the accurate value. Machine learning (ML) model based on artificial neural network (ANN) algorithm as an artificial intelligence approach is adopted to establish smart sensing system via the relationship between concentrations and currents in comparison with traditional linear regression model. The BP-IL-SWCNH nanozyme sensor displayed excellent electrocatalytic ability for second-order derivative voltammetric smart analysis of 5-HT range from 0.3 to 115 µM under optimal conditions.

Given the self-stressing property of its matrix, textile reinforced self-stressing concrete (TRSSC) has excellent cracking resistance and is especially beneficial to the tensile position of the structure in enhancing cracking resistance and stiffness. In this research, the cracking resistance of TRSSC under bending is studied through the four-point bending test. Experimental results show that the cracking load of specimens increases by 33.39% due to self-stress, and the cracking resistance of the specimens increases by 55.23% due to the increase in the number of textile layers. The calculation method for cracking load and deflection is proposed based on the basic equation of elasticity and the finite difference method. The theoretical analytical solution is consistent with the experimental value.

A novel nanozyme sensor based on the electro-synthesized molecularly imprinted conducting poly(3,4-ethylenedioxythiophene) (PEDOT) nanocomposite with graphene-like two-dimensional layered molybdenum disulfide (MoS2) was successfully prepared for electrochemical detection and analysis of luteolin in Gnaphalium affine. MoS2-MIPs were prepared facilely by electrochemical polymerization of monomer 3,4-ethylenedioxythiophene in the presence of both modifier MoS2 and template molecule luteolin that can change the morphological structure and specific surface area of PEDOT, enhance electronic conductivity of MoS2, and improve the recognition capability and electrocatalytic capacity of electrode interface. The morphological structure of MoS2-MIPs was characterized by SEM, and its electrochemical performance and sensing parameters were investigated by voltammetry. The electrochemical response of luteolin was recorded by MoS2-MIPs in the linear concentration range from 3 × 10-7 to 3 × 10-5 Μ with limit of detection of 0.04 μΜ under the optimal conditions, which was successfully employed for electrochemically detecting luteolin in Gnaphalium affine with acceptable recoveries in comparison with high-performance liquid chromatography. This will provide a new nanozyme sensing platform comprised of electro-synthesized molecularly imprinted conducting polymers and graphene-like two-dimensional layered nanomaterials.

In this study, IrO2-RuO2 composite electrodes were prepared and well characterized. The electrode exhibited a compact structure, with the IrO2-RuO2 binary oxide coatings appearing as finely dispersed crystals. The IrO2-RuO2 composite electrodes were used as the anode to degrade sulfamethazine (SMT) via the indirect oxidation process of hydroxyl radicals. The optimum degradation conditions of SMT were as follows: initial concentration: 50 mg/L; current density: 40 mA/cm2 and initial pH: 6.0 at a supporting electrolyte (Na2SO4)concentration of 0.2 mol/L. The IrO2-RuO2 composite electrodes effectively removes chemical oxygen demand (COD) from actual wastewater: the removal rate was 49.17%. The after-treatment COD value was 107.83 mg/L lower than China's urban sewage COD discharge standard (120 mg/L). These results indicate that the electrocatalytic degradation of SMT with electrodes is feasible. Besides, the effects of the experimental conditions on the sensitivity of the experiment were studied by using an established mathematical model and an artificial neural network (ANN) model representing the first time, which can be used to effectively predict and guide the removal of COD from SMT-containing wastewater using IrO2-RuO2 composite electrodes. The modeling results show that reaction time was the most significant factor affecting SMT removal efficiency, whereas pH value was the most important factor affecting COD removal efficiency.

Hierarchical structural PEDOT@MoS2 nanocomposite is synthesized via a facile electrochemical co-deposition of the intercalation of PEDOT into flower-like MoS2 microspheres. The SEM, TEM, and other characterization results demonstrate the hierarchical PEDOT@MoS2 composite with an enlarged interlayer spacing of MoS2 to 1.02 nm, in which PEDOT nanoparticles act as intercalation, and flower-like MoS2 microspheres are used as a substrate for growth. The electrochemical characterizations indicate that the PEDOT@MoS2 electrode has an ultra-high specific capacitance of 4418 mF cm−2 at 2 mA cm−2 and remarkable cycling stability, retaining 100% of the initial capacitance at a high current density of 100 mA cm−2 after 10,000 cycles. The symmetric PEDOT@MoS2 supercapacitor presents a high energy density of 88.3 mWh cm−2 at 60 mW cm−2, and outstanding cycling stability (93% after 10,000 cycles). These prominent electrochemical performances are attributed to the expanded interlayer spacing, the synergistic effect between PEDOT and MoS2, the low resistance, along with the PEDOT@MoS2 porous structure, indicating great potential applications of the PEDOT@MoS2 electrode in the energy storage field.

In this report, we have prepared 3D porous graphene flexible nanozyme electrode on polyimide by direct laser-writing technology using a home-made computer-controlled laser scribing machine, which is a cost-efficient and one-step mass-production method. This flexible electrode exhibited outstanding mechanical flexibility, distinctive 3D porous structure, expected cycle stability, high conductivity, which was employed as a novel electrochemical nano-sensing platform for intelligent evaluation of fish freshness via simultaneous detection of both xanthine (XT) and hypoxanthine (HX) and smart analysis and digital output using machine learning (ML) model based on artificial neural network (ANN) algorithm. The as-prepared flexible electrode showed an enzyme-like kinetic (nanozyme) characteristic during the detection of XT (0.3–179.9 μM) and HX (0.3–159.9 μM) with a limit of detection (LOD) of 0.26 μM and 0.18 μM, respectively. The fish freshness was evaluated by voltammetric detection of both XT and HX in fish sample with different storage times, and ML model with ANN algorithm was built to realize smart analysis and digital output for evaluating the fish freshness. This will provide an experimental support for biomimetic flexible nano-sensing platform based on nanozyme flexible electrode via facile and rapid one-step mass production and intelligent nano-sensing platform based on ML model for intelligent operation for smart analysis and intelligent transformation for digital output.

An active material electrode with high areal specific capacitance is needed for a high-performance supercapacitor, but it is difficult to achieve this goal for PEDOT-based composites. Here, a novel hierarchical core/shell PEDOT@MoS2 composite was assembled by the electrochemical co-deposition of EDOT and MoS2 submicron spheres. The SEM, TEM images of the as-obtained composite explicitly reveal the core/shell heterostructure of PEDOT@MoS2 with a diameter of about 800 nm. The electrochemical characterizations show that the optimized PEDOT@MoS2 composite possesses a high specific capacitance of 2540 mF cm−2 at 1 mA cm−2 and excellent capacitance retention of 98.5% after 5000 cycles at a high current density of 100 mA cm−2. The assembled P@M-4//PEDOT asymmetric supercapacitor shows a high energy density of 937 Wh m−2 at 6500 W m−2, and outstanding cycling stability with capacitance retention of 100% after 5000 cycles. It is proposed that the enhanced performances are attributed to the robust hierarchical core/shell structures and the synergic effect between PEDOT and MoS2, which is expected to become a promising candidate for applications in high-performance supercapacitors.

The functional aroma materials (fragrance) have been widely applied in food, textile, leather, paper, cosmetic and detergents, which is close to the national economy and people life. At present, the researchs on the long released property and good smell aroma production technology has been focused. The perfuming requirement of 5 trillion RMB food, cosmetic and detergents should be satisfied with the fragrance technology. However, about 10 trillion RMB leather, paper and textile have been not applied in perfuming treatment. Therefore, the key scientific problem of the function mechanism between nano fragrance and fiber materials has been focused. The animal and plant fibers have rich nano-scale pores and structures. The dispersion, interaction function and the bonding property of aromatic molecules on the porous fibers and their sizes and surface properties would effect the quality of aromatic fibers. Based on the above problems, this project would solve the following problems: (1) the aroma synergism, (2) the controllable preparation of fragrance nanocapsules, and (3) the large-scale preparation and industrialization application of nano fragrance and the long-released aroma fibers. We will use many theories such as nanotechnology, perfume chemistry, interface chemistry and collagen chemistry to study the relationship between the natural porous fibers’ nanostructures and their surficial properties, the adsorption and desorption behaviors between nano fragrances and porous fibers. Then the interaction mechanism between nano fragrances and porous fibers and the aroma models with different threshold values have been built up. Different design and modification methods of nano potential aroma materials should be developed. Meanwhile, the self-assembly novel methods of the suited structure, controllable and long-sustained release nano fragrance would be studied on the focus of the different nanostructures of the fibers. The industrialization application technology of nano fragrance and the long sustained-release aroma fibres would also be studied and the corresponding product standards should be formed, aiming at the problem of the multi-scale effect and the unclear amplification rules. Therefore, this project would include four main research contents: (1) the interaction function and synergism mechanism between the nano-interface of the porous fibres and fragrance and nano fragrances, (2) the design of fragrance molecules and their aroma and released property control, (3) the study on the nano fragrance and their sustained-release properties, and (4) preparation and application of novel nano fragrance and nano capsules. Through this project, the large-scale preparation of fragrance nanocapsules can be extended. The aromatic application of nano fragrance in silk, leather and paper should be achieved. Finally, the aroma synergism and long release property of the aromatic productions can be primarily resolved. Therefore, the three guides of technology-production-standards of fragrance nanocapsules and aromatic fiber productions should be realized. The upgrading and updating of leather, textile and paper has been extended. Different productions of nano fragrance, aroma leather, silk and paper could be obtained. The professionalization and high level academic troops containing the different reseach fileds of nano science, perfume chemistry and light chemical engineering would be developed. In conclusion, the interaction mechanism between fragrance naocapsules and porous fibers can be revealed. Meanwhile, the preparation and application technology of fragrance nanocapsules and the long sustained-release aroma fibers should be developed to resolve the bottleneck problems of the fragrance industry. Finally, the core competiveness of the aromatic production in China can be enhanced. Provided that we can get the chance, the research development direction of the aromatic nanomaterials should be guided in the future.

The separation of particles and cells in a uniform mixture has been extensively studied as a necessity in many chemical and biomedical engineering and research fields. This work demonstrates a continuous charge-based separation of fluorescent and plain spherical polystyrene particles with comparable sizes in a ψ-shaped microchannel via the wall-induced electrical lift. The effects of both the direct current electric field in the main-branch and the electric field ratio in between the inlet branches for sheath fluid and particle mixture are investigated on this electrokinetic particle separation. A Lagrangian tracking method based theoretical model is also developed to understand the particle transport in the microchannel and simulate the parametric effects on particle separation. Moreover, the demonstrated charge-based separation is applied to a mixture of yeast cells and polystyrene particles with similar sizes. Good separation efficiency and purity are achieved for both the cells and the particles.

Novel catalysts are of great interest for improved photocatalytic environmental remediation. Using a hydrothermal method, 0D/2D Bi3TaO7/Ti3C2 heterojunctions were designed rationally and characterized systematically as excellent photocatalysts for photocatalytic degradation. The hybrid catalyst exhibits superior performance in visible-light-driven photocatalytic degradation of methylene blue (about 99% degradation efficiency after 2 h) and excellent stability (up to 10 cycles) under visible light irradiation (300 W Xe lamp; λ > 420 nm; light intensity 150 mW cm−2). In addition, Bi3TaO7/Ti3C2 has a larger rate constant (0.032 min−1) than pristine Bi3TaO7 (0.006 min−1). Quantum yield (2.27 × 10−5 molecules/photon) and figure of merit (23.3) of the system were obtained, suggesting that our catalyst has potential for application. Both experimental and computational results indicate that synergistic effects between Bi3TaO7 and Ti3C2 improve photocatalytic performance by enhancing electron-hole pair separation, electronic transmission efficiency, and interfacial charge transfer. These findings contribute to the synthesis of efficient visible-light-driven Bi-based photocatalysts and to the understanding of photocatalytic degradation reactions.

Poly(3,4-ethylenedioxythiophene) (PEDOT) nanoribbons, nanotubes, nanorods were fabricated in a reverse microemulsion system by adjusting the ratio of sodium bis (2-ethylhexyl) sulfosuccinate (AOT) and FeCl3 aqueous solution. The morphologies and structures of nanostructured PEDOT were characterized by SEM, TEM, FTIR, XRD, and XPS. The PEDOT nanoribbons, nanotubes and nanorods can be obtained, when the volume ratio of FeCl3 aqueous solution to AOT hexane (Va/Vh) was between 2.0×10–2 and 3.0×10–2. As-obtained PEDOT nanotubes showed a high specific capacitance of 171.5 F g-1 at 0.4 A g-1, which was greater than the nanoribbons (134 F g-1) and nanorods (145.7 F g-1), respectively. Additionally, the PEDOT nanotubes exhibited excellent stability with a retention rate of 105% after 5000 cycles. This indicates that the as-prepared PEDOT nanotubes have potential applications in high capacity supercapacitors.

The carbon/BiOI composite photocatalysts were synthesis by hydrothermal reaction and characterized by various methods. The as-prepared photocatalysts were used to remove organic pollutants in aqueous solution under visible light irradiation. The C/BiOI samples demonstrated excellent photocatalytic performance for degradation of methyl orange (MO), which is about 4 times higher than that of BiOI. Furthermore, C/BiOI also displayed good stability after 5 cycles testing. Such superior performance was attributed to the enhanced absorption ability and increased separation of photogenerated electrons and holes.

The environmental stability, water-processibility and life-span of black phosphorene (BP) severely limit the application of its electronic devices in aqueous system containing oxygen. We reported the controllable preparation of in-situ reduction and deposition of silver nanoparticles on the BP surface and its amino-functionalized multi-walled carbon nanotubes (NH2-MWCNT) nanocomposite. With the addition of both NH2-MWCNT and Ag+, the BP-based nanocomposite was prepared by ultrasonic-assisted liquid-phase exfoliation and was dispersed in carboxymethyl cellulose sodium (CMC) aqueous solution. The morphology, microstructure, and electrochemical properties of the nanohybrid were characterized. NH2-MWCNT-BP-AgNPs showed high environmental stability, good water-processibility, satisfactory life-spans, superior electrocatalytic capacity with enzyme-like kinetic characteristics. The nanohybrid was applied as electrochemical sensors for single/simultaneous analysis of uric acid (UA), xanthine (XT) and hypoxanthine (HX). Excellent voltammetric responses for simultaneous determination in linear ranges of 0.1–800 μM with a limit of detection (LOD) of 0.052 μM for UA, 0.5–680 μM with a LOD of 0.021 μM for XT, and 0.7–320 μM with a LOD of 0.025 μM for HX under optimal conditions. Besides, the developed nanozyme sensor was employed for simultaneous voltammetric analysis of UA, XT and HX in real samples with acceptable recoveries. This work will provide theoretical guidance and experimental support for the preparation and application of two-dimensional materials, nanozymes and sensing devices.

Ferrofluids have been increasingly used to manipulate particles and cells in microfluidic devices via negative magnetophoresis. They have also been recently exploited to achieve a fast microfluidic mixing through magnetic field-induced flow instabilities at the ferrofluid/water interface. This work presents the first demonstration of electric field-induced instabilities in electroosmotic ferrofluid/water co-flows through a T-shaped microchannel. With the increase in electric field, instability waves and even chaotic flows can be formed when the two fluids merge at the T-junction due to the significant mismatch of their electrical conductivities. The experimentally observed dynamic behaviors of the ferrofluid/water interface are qualitatively captured by the ferrofluid concentration distribution obtained from a 2D numerical model. The measured threshold electric field for observing sustainable flow instabilities is found to decrease with the increase in ferrofluid concentration. While this trend is correctly predicted by the numerical model, the threshold electric field values are substantially under-predicted. The parametric effects that may be responsible for this discrepancy are discussed.

Preconcentrating samples of dilute particles or cells to a detectable level is required in many chemical, environmental and biomedical applications. A variety of force fields have thus far been demonstrated to capture and accumulate particles and cells in microfluidic devices, which, however, all take place within the region of microchannels and may potentially cause channel clogging. This work presents a new method for the electrokinetic preconcentration of 1 μm-diameter polystyrene particles and E. coli cells in a very-low-conductivity medium inside a microfluidic reservoir. The entire microchannel can hence be saved for a post-concentration analysis. This method exploits the strong recirculating flows of induced-charge electroosmosis to concentrate particles and cells near the corners of the reservoir-microchannel interface. Positive dielectrophoresis is found to also play a role when small microchannels are used at high electric fields. Such an in-reservoir electrokinetic preconcentration method can be easily implemented in a parallel mode to increase the flow throughput, which may potentially be used to preconcentrate bacterial pathogens in water.

Insulator-based dielectrophoresis (iDEP) exploits in-channel hurdles and posts etc. to create electric field gradients for various particle manipulations. However, the presence of such insulating structures also amplifies the Joule heating in the fluid around themselves, leading to both temperature gradients and electrothermal flow. These Joule heating effects have been previously demonstrated to weaken the dielectrophoretic focusing and trapping of microscale and nanoscale particles. We find that the electrothermal flow vortices are able to entrain submicron particles for a localized enrichment near the insulating tips of a ratchet microchannel. This increase in particle concentration is reasonably predicted by a full-scale numerical simulation of the mass transport along with the coupled charge, heat and fluid transport. Our model also predicts the electric current and flow pattern in the fluid with a good agreement with the experimental observations.

Microfluidic devices have been widely used since 1990s for diverse manipulations of particles (a general term of beads, cells, vesicles, drops, etc.) in a variety of applications. Compared to the active manipulation via an externally imposed force field, the passive manipulation of particles exploits the flow-induced intrinsic lift and/or drag to control particle motion with several advantages. Along this direction, inertial microfluidics has received tremendous interest in the past decade due to its capability to handle a large volume of samples at a high throughput. This inertial lift-based approach in Newtonian fluids, however, becomes ineffective and even fails for small particles and/or at low flow rates. Recent studies have demonstrated the potential of elastic lift in non-Newtonian fluids for manipulating particles with a much smaller size and over a much wider range of flow rates. The aim of this article is to provide an overview of the various passive manipulations, including focusing, separation, washing and stretching, of particles that have thus far been demonstrated in non-Newtonian microfluidics.

A novel starch stabilized Mg/Al layered Double hydroxides (S-LDHs) was prepared in a facile approach and its fluoride ion removal performance was developed. Characterization of S-LDHs was employed by using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and particle size distribution. The adsorption property was studied through the assessment of the adsorption isotherms, kinetic models, thermal dynamics, and pH influence. The result shows that a low loading of starch of 10 mg onto layered double hydroxides (LDHs) could obviously improve the fluoride removal rate. The S-LDHs had three times higher the adsorption capacity to fluoride than that of Mg/Al LDHs to fluoride. The particle size was smaller and the particle size distribution was narrower for S-LDHs than that for Mg/Al LDHs. The Langmuir adsorption isotherm model and pseudo-second-order kinetic model fitted well with the experimental data. In thermodynamic parameters, the enthalpy (&Delta, H0) value was 35.63 kJ&middot, mol&minus, 1 and the entropy (&Delta, S0) value was 0.0806 kJ&middot, 1K&minus, 1. The values of &Delta, G0 were negative, implying the adsorption process is spontaneous. S-LDHs reveals stable adsorption property in a wide pH range from 3 to 9. The mechanism for fluoride adsorption on S-LDHs included surface adsorption and interaction ion exchange.

TiC whiskers have been synthesized via a carbothermal reduction technique in an α-Al 2 O 3 matrix within a temperature range of 1380–1580 °C in an argon atmosphere. The raw materials consist of TiO 2 , carbon, nickel and NaCl. Various mixing procedures and reaction temperatures were used. The yield of the whiskers is mainly dependent on the mixing procedures and the morphology of the synthesized composite powders is mainly dependent on the synthesis temperatures. The majority of the synthesized whiskers display an ideal aspect ratio of 10–30 with a diameter of 1–3 μm. No significant influence on the growth of the TiC whiskers by the present of the Al 2 O 3 matrix powder can be noted.

This work reports the modified Pechini preparation and properties of an A-site deficient perovskite Sr0.86Y0.08TiO3-δ(SYT). Good chemical homogeneity and electrical conductivity were determined, making SYT a potential conductive component material in a composite anode for solid oxide fuel cells. As an oxide with inherent resistance to oxidation and hydroxylation, SYT could be a substitute for the metallic Ni component in composite anodes for solid oxide fuel cells, particularly for reversible solid oxide fuel cells with attendant high steam concentrations. © 2007 Elsevier B.V. All rights reserved.

La0.8Sr0.2Ga0.8Mg0.115Co0.085O3-d (LSGMC) has been reported as an optimized composition for LSGM-based electrolytes used in intermediate temperature solid oxide fuel cells (SOFCs). Electrocatalytic properties of the interfaces between LSGMC electrolyte and various cathodes: comprised of Sm0.5Sr0.5CoO3-d (SSC), and La0.7Sr0.3Co0.2Fe0.8O3-d (LSCF) in composite forms (70wt.%) with LSGMC (30wt.%) were investigated under both oxygen reduction and evolution conditions. All the oxides were synthesized using the glycine-nitrate process (GNP) followed by unique powder processing to produce the desired phase purity and particle properties. Symmetrical electrochemical cells were fabricated by a screen-printing technique with precisely controlled alignment. Three-electrode linear dc polarization and ac impedance spectroscopy were used to characterize the kinetics of the interfacial reactions in detail. For the composite SSC-LSGMC cathode/LSGMC interface, the cathodic overpotential under 1 A/cm2 current density was as low as 0.085 V at 973 K, 0.062V at 1023K and 0.051V at 1073K in air. Composite LSCF-LSGMC cathode/LSGMC interfaces were found to have about twice the exchange current density of composite SSC- LSGMC/LSGMC interfaces for the same temperature and overpotential conditions.

Separating particles from a heterogeneous mixture is important and necessary in many engineering and biomedical applications. Electrokinetic flow-based continuous particle separation has thus far been realized primarily by the use of particle dielectrophoresis induced in constricted and/or curved microchannels. We develop in this work a new electrokinetic method that exploits the wall-induced non-inertial lift in a straight uniform microchannel to continuously separate particles by intrinsic properties (e.g., size and surface charge). Such an electrically originated lift force arises from the asymmetric electric field distribution around a particle nearby a planar dielectric wall. We demonstrate this method through separating both a binary and ternary mixture of dispersed polystyrene microspheres by size in a T-shaped microchannel. A semi-analytical model is also developed to simulate and understand the particle separation process. The predicted particle trajectories in the entire microchannel agree reasonably well with the experimental measurements.

We have designed and constructed a state-of-the-art system capable of simultaneously performing in-situ FTIR spectroscopy, Raman spectromicroscopy, and impedance spectroscopy on a solid oxide fuel cell (SOFC) under practical operating conditions while the gas composition is monitored in real time by mass spectrometry. Raman spectromicroscopy, in particular, offers capabilities for not only probing surface species on an electrode but also mapping where a specific reaction of interest is taking place on the electrode. Furthermore, both surface reaction kinetics and bulk properties of electrode materials may be deduced from the time dependence of in-situ vibrational spectra collected during transition from one equilibrium state to another. When applied to an SOFC with patterned electrodes perturbed by an electrical, chemical, or optical stimulus, these techniques become even more powerful in investigating active reaction sites and bulk properties of various electrode materials, providing invaluable information that has never before been accessible.

As potential intermediate-temperature SOFC cathodes, perovskite composite cathode materials were evaluated in combination with a La0.8Sr 0.2Ga0.8Mg0.2O3-δ (LSGM) electrolyte. Various cathode materials La0.6Sr0.4Co 0.2Fe0.8O3-δ (LSCF), Ba 0.5Sr0.5Co0.8Fe0.2O 3-δ (BSCF), and Pr0.3Sr0.7Co 0.8Fe0.2O3-δ (PSCF) were compounded with La0.8Sr0.2Ga0.8Mg0.1Co 0.1O3-δ (LSGMC) as a mixed conducting composite element. All powders were synthesized by the glycine-nitrate process (GNP). XRD analysis found resistive phases of LaSrGaO4 and LaSrGa 3O7 present in the calcined layer of composite cathodes on LSGM. A bulk ohmie resistance of 3.81 Ω·cm2 and an interfacial resistance value of 0.16 Ω were measured for LSCF/LSGMC composite cathode on LSGM substrate at 800°C in air. Low-frequency secondary ares in the impedance spectra of LSCF/LSGMC cathode coupled with low current density and low cathode porosity suggested possible mass transfer limitations. The LSCF/LSGMC composite electrode performed best at 800°C (0.11 A/cm 2 at 0.045 V overpotential) while the BSCF/LSGMC performed best at the lowest temperature investigated (0.1 A/cm2 at 700°C and 0.04 V overpotential). ©The Electrochemical Society.

An all-perovskite-based intermediate-temperature fuel cell was fabricated from materials synthesized using glycine-nitrate process (GNP) combustion synthesis and modified Pechini synthesis routes. Yttrium-doped strontium titanate (SYT) was chosen as the conductive ceramic anode component to avoid problems associated with Ni-based anodes. La0.8 Sr0.2 Ga0.8 Mg0.1 Co0.1 O3-δ electrolyte-supported solid oxide fuel cells (SOFCs) with composite ceramic anode and cathode exhibit a relatively high power density of 0.246 Wcm at 800°C at 0.5 V. © 2007 The Electrochemical Society.

Focusing suspended particles in a fluid into a single file is often necessary prior to continuous-flow detection, analysis, and separation. Electrokinetic particle focusing has been demonstrated in constricted microchannels by the use of the constriction-induced dielectrophoresis. However, previous studies on this subject have been limited to Newtonian fluids only. We report in this paper an experimental investigation of the viscoelastic effects on electrokinetic particle focusing in non-Newtonian polyethylene oxide solutions through a constricted microchannel. The width of the focused particle stream is found NOT to decrease with the increase in DC electric field, which is different from that in Newtonian fluids. Moreover, particle aggregations are observed at relatively high electric fields to first form inside the constriction. They can then either move forward and exit the constriction in an explosive mode or roll back to the constriction entrance for further accumulations. These unexpected phenomena are distinct from the findings in our earlier paper [Lu et al., Biomicrofluidics 8, 021802 (2014)], where particles are observed to oscillate inside the constriction and not to pass through until a chain of sufficient length is formed. They are speculated to be a consequence of the fluid viscoelasticity effects.

Membranes of mixed ionic-electronic conductors have been widely studied for gas separation, electrosynthesis, and removal of pollutants. Not only the rates but also the selectivities of these processes are determined critically by the surface catalytic properties of the membranes, which in turn are determined by the morphology, microstructure, and composition of the surfaces. In this study, nanoporous Sr0.25Bi0.5FeO3-δ (SBF) layers, with or without the impregnation of catalysts, were applied to dense SBF membranes using a sol-gel process to investigate the effect of surface modification on the catalytic properties. It is found that both oxygen permeation rates and methane conversion of a dense SBF mixed-conducting membrane coated with a nanoporous SBF layer are much higher than those of an as-sintered SBF membrane without surface modification. Nanoparticles of nickel loaded into the porous SBF surface layer further enhanced methane conversion.