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The design of efficient and robust non-precious metal electrocatalysts towards oxygen evolution reaction (OER) is of great value for developing green energy technologies. The in-situ formed high-valence (oxy)hydroxides species during the reconstruction process of pre-catalysts are recognized as the real contributing sites for OER. However, pre-catalysts generally undergo a slow and inadequate self-reconstruction. Herein, we reported a PO43− optimized CoFe-based OER catalysts with amorphous structure, which enables a fast and deep reconstruction during the OER process. The amorphous structure induced by ligands PO43− is prone to evolution and further form active species for OER. The electron interaction between metal sites can be modulated by electron-rich PO43−, which promotes generation of high active CoOOH. Simultaneously, the etching of PO43− from the pre-catalysts during the catalytic process is in favor of accelerating the self-reconstruction. As a result, as-prepared pre-catalyst can generate high active CoOOH at a low potential of 1.4 V and achieve an in-depth reconstructed nanosheet structure with abundant OER active sites. Our work provides a promising design of pre-catalysts for realizing efficient catalysis of water oxidation.

Organic-inorganic hybrid nanoflowers (NFs) consisting of horseradish peroxidase (HRP) and copper II (Cu2+) are successfully synthesized with the involvement of carbon nanotubes (CNTs) by in situ and post-modification methods. Catalytic activities of in situ synthesized HRP-NF@CNT (HRP-NF@CNT-Is) and post-modification-synthesized HRP-NF@CNTs (HRP-NF@CNT-Pm) are systematically examined. The 30 mg CNTs incorporated HRP-NF@CNT-Is (HRP-NF@ CNT-30Is) exhibits greatly increased catalytic activity and stability toward 3,3 ',5,5 '-tetramethylbenzidine (TMB), thanks to the synergistic effect between HRP-NF and CNTs and the peroxidase-like activity of CNTs in the presence of hydrogen peroxide (H2O2). While HRP-NF@CNT-30Is retains almost 85% of its initial activity even after 10 cycles, HRP-NF (without CNTs) loses half of its initial activity at the same experimental conditions. We study how two experimental parameters, the pH values and temperatures, influence the catalytic activity of HRP-NF@CNT-30Is, in addition to the fact that HRP-NF@CNT-30Is is employed to detect the presence of H2O2 and glutathione (GSH) with colorimetric and spectrophotometric readouts. For instance, HRP-NF@CNT-30Is is used to sensitively detect H2O2 in the range of 20 to 300 mu M with an LOD of 2.26 mu M. The catalytic activity of HRP-NF@CNT-30Is is suppressed in the presence of GSH, and then an obvious color change from blue to nearly colorless is observed. Using this strategy, GSH is also sensitively determined in the range of 20-200 mu M with an LOD of 11.2 mu M. We expect that HRP-NF@CNTs can be used as a promising and novel nanobiocatalyst for various biomedical and industrial applications in the near future. Erciyes University TDK-2021-11004

Nitrophenolates (NPs) are molecular anions that can undergo charge-transfer(CT) transitions determined by the degree of electron delocalization betweenthe phenolate oxygen (donor group) and the nitro group (acceptor). Herewe have studied four different NPs: 4’-nitro-[1,1’-biphenyl]-4-olate (1),7-nitro-9H -carbazol-2-olate (NH linker, 2), 7-nitrodibenzo[b,d]furan-3-olate (oxygen linker, 3), and 7-nitrodibenzo[b,d]thiophen-3-olate (sulphurlinker, 4), and recorded their electronic absorption spectra when isolatedin vacuo to determine the effect of locking the biphenyl spacer group betweenthe donor and acceptor on transition energies. Absorption was identified fromion dissociation (action spectroscopy) using a homebuilt setup (sector massspectrometer combined with pulsed laser). We find that the absorption isbroad in the visible region for all four NPs with significant vibronic features.The lowest energy peak is at 601 ± 4 nm, 606 ± 4 nm, 615 ± 4 nm, and620 ± 4 nm, for 3, 4, 2, and 1, respectively. NP 1 is flexible, and its lowestenergy structure is nonplanar while the other three NPs are planar accordingto density functional theory calculations. Hence in the case of 1 the electronic transition has a higher degree of CT than for the other three, accounting for itsabsorption furthest to the red. Our work demonstrates that oxygen and sulphurare best at conveying the electronic coupling between the donor and acceptorsites as 3 and 4 absorb furthest to the blue (i.e., the degree of CT is lowestfor these two NPs). Based on the average spacing between the peaks in thevibrational progressions, coupling occurs to skeleton vibrational modes withfrequencies of 649 ± 69 cm−1 (3), 655 ± 49 cm−1 (4), and 697 ± 52 cm−1 (2).

Advances in the field of molecular electronics have made possible the directmeasurement of charge transport across single molecules. In particular, workon DNA oligomers has demonstrated that this weakly-conducting biomoleculecan be functionalized through metal-mediated nucleobase pairing in order tosignificantly increase electron mobility across the molecule. The introductionof interacting stacks of single metal ions inside the DNA helix is an attractiveplatform for assay and optimization; for this reason we present a protocolfor the production and processing of nanowires with a metal base pair forsingle-molecule applications. In particular, we describe the construction of DNA duplex wires with a cytosine-Ag+-cytosine base pair (dC:Ag+:dC).A thorough investigation of buffer components suggests the use of divalentmagnesium counterions to stabilize highly mismatched oligonucleotides insolution. We further analyse cleaning and processing of thin gold films forbatch-fabrication of conductive imaging substrates for use in conductivescanning probe assays of single-molecule conductivity. With a clear path toelectrical assays, we suggest that the C:Ag+:C orthogonal nucleotide pair andother similar chemistries may provide a foundation for molecular electroniccomponents in integrated devices

The pulsed current has been proposed to achieve fast charging and extend the lifetime of lithium-ion (Li-ion) batteries. However, the optimal condition of the pulsed current is still inconclusive in previous studies. This article experimentally investigated the effect of the low-frequency positive pulsed current (PPC) charging on the lifetime and charging performance of Li-ion batteries. A two-stage degradation model of Li-ion batteries is developed to determine the inhibitory effect of the PPC on degradation mechanisms at different aging stages. Moreover, the changes in the internal resistance (IR) and the incremental capacity (IC) curve are provided to thoroughly explore the effects of the PPC on the degradation of Li-ion batteries. Compared with the traditional constant current (CC) charging, the lifetime, maximum rising temperature, and energy efficiency of the Li-ion batteries that were cycled by the PPC charging are improved by 81.6%, 60.5%, and 9.1%, respectively, after 1000 cycles. Therefore, low-frequency PPC charging should be considered as a promising charging strategy for Li-ion batteries.

The Ru-catalyzed carbonylation of alkenes with CO2 as a C1 surrogate and imidazole chlorides as the promotor is investigated by a combination of computational and experimental study. The conversion rate of CO2 to CO is positively correlated with the efficiency of both hydroesterification and hydroformylation, which is found facilitated in the presence of chloride additives with a decreasing order of BmimCl ∼ B3MimCl > BmmimCl ∼ LiCl. Taking the hydroesterification with MeOH as a representative example, BmimCl bearing C–H functionality at the C2 site of the cation assists the reduction of CO2 to CO as a hydrogen donor medium, with the anion and cation acting in a synergistic fashion. Subsequent insertion of CO2 into the formed Ru–H bond with the assistance of chloride anion produces the Ru–COOH species, which ultimately accelerates the activation of CO2.

This study includes determination Montelukast sodium by using flow injection chemiluminescence technique, the optimum concentrations were (150) ppm of magnesum ion, (5×10 -4 ) M luminol, (0.001) M hydrogen peroxide, linearity of concetraction (0.1-0.001) M that give the highest luminescence intensity, and correlation cofficient was (0.9054), The relative standard deviation RSD% (2.3) and detection limit (0.0001) M and relative error (0.018) ,the percent recovery (97%). http://dx.doi.org/10.25130/tjps.23.2018.033

Magnetite nanoparticles (MNP)-caused enhancements for H2 yield (HY) are usually justified based on oxidation-reduction potential (ORP), iron ions (Fe+2/+3) concentration, and enzymatic activity, that is pH-dependent. However, the questions “If pH, ORP, and Fe+2/+3 impacts are excluded, will MNP-caused HY enhancement be still present? and how electrical energy input (EEI) affects HY?” are still unanswered. Herein, control, MNP-supplemented, EEI-applied, FeCl3-, and Na2S-supplemented batches, referred as G1, G2, G3, G5, and G6, respectively were conducted, under fixed pH (6.0 ± 0.1). G5 and G6 targeted quantifying sole impact of Fe+2/+3, and ORP, respectively on HY. G1, G2, G3, G5, and G6 achieved HY values of 1.10 ± 0.05, 1.66 ± 0.07, 1.38 ± 0.06, 1.18 ± 0.04, and 1.16 ± 0.05 mol H2/molhexose, respectively. Neither Fe+2/+3 release nor ORP reduction significantly affected HY. Further, Clostridium amylolyticum dominance was almost similar among G2, and G3. Metabolites flux analysis and functional genes’ prediction highlighted that G2 achieved highest hydrogenase expression and lowest homoacetogenic H2 consumption.

In this research study the effects of calcium and magnesium ions on stabilisation of a clay soil were studied by conducting a set of laboratory tests. A special apparatus was employed for carrying out the tests under constant voltage and time. During the tests, solutions of calcium chloride (CaCl2) or magnesium chloride (MgCl2) with different concentrations were injected into the soil samples. The electro-osmotic and electrokinetics methods were used for stabilisation of the soil and the results were compared with each other. In the electro-osmotic technique, distilled water was used as pore fluid, but in the electrokinetic method, calcium chloride or magnesium chloride solutions with various concentrations were injected into the pores of soil samples. The results revealed an increase in strength of the soil in both methods. In the electrokinetic method, the amount of increase in strength was a function of concentration of the solution that was used. The results also indicated that a solution of calcium chloride is more effective in increasing the strength, discharge flow and electro-osmotic permeability than a magnesium chloride solution at various concentrations. In addition, the variations of these properties are a function of the concentration of the given solution.

As a promising cathode material, Na3V2(PO4)2F3 (NVPF) has attracted wide attention for sodium-ion batteries (SIBs) because of its high operating voltage and high structural stability. However, the low intrinsic electronic conductivity and insufficient Na ion mobility of NVPF limit its development. Herein, K-doping NVPF is prepared through a facile ball-milling combined calcination method. The effects of K-doping on the crystal structure, kinetic properties and electrochemical performance are investigated. The results demonstrate that the Na2.90K0.10V2(PO4)3F3 (K0.10-NVPF) exhibits a high capacity (120.8 mAh g−1 at 0.1 C), high rate capability (66 mAh g−1 at 30 C) and excellent cycling performance (a capacity retention of 97.5% at 1 C over 500 cycles). Also, the occupation site of K ions in the lattice, electronic band structure and Na-ion transport kinetic property in K-doped NVPF are investigated by density functional theory (DFT) calculations, which reveals that the K-doped NVPF exhibits improved electronic and ionic conductivities, and located K+ ions in the lattice to contribute to high reversible capacity, rate capability and cycling stability. Therefore, the K-doped NVPF serves as a promising cathode material for high-energy and high-power SIBs.

Here, we report a series of Bi3+-doped Ba2Y1–xScxNbO6 (0 ≤ x ≤ 1.0 mol) phosphors by using the traditional high temperature solid-state reaction. To achieve the structural and photoluminescent (PL) information, several experimental characterizations and theoretical calculations are carried out, including X-ray diffraction (XRD), Rietveld refinement, UV-visible diffuse reflectance and PL spectra, temperature dependent PL spectra, and density functional theoretical (DFT) calculations. The XRD results show that the Bi3+-doped Ba2Y1–xScxNbO6 samples belong to the double-perovskite phase with a cubic space group of Fm3m, and the diffraction positions shift toward high diffraction angle when the larger Y3+ ions are gradually replaced by the smaller Sc3+ ions. In addition, the refined XRD findings show that the Bi3+ ions tend to substitute the Y3+ and Sc3+ sites in the Bi3+-doped Ba2Y1–xScxNbO6 (0

Dust-acoustic waves (DAWs) are analyzed in the small amplitude limit in a collisionless unmagnetized dusty plasma whose constituents are inertial dust grains, massless ions expressed by the generalized ( r , q ) distribution and inertialess Maxwellian electrons using the fluid theory of plasmas. The modified Kadomtsev-Petviashvili (mKP) equation is derived at a critical plasma condition for which the quadratic nonlinearity vanishes. The propagation of single soliton and interaction of two solitons are analyzed for the mKP equation in the context of plasma physics by employing Hirota bilinear formalism. The effects of the flatness parameter r and tail parameter q of the ions on the frequency of the DAWs are studied and the comparison with Maxwellian and kappa distributions is drawn. Using the plasma parameters corresponding to the Saturn’s E-ring, the range of electric field amplitude for dust-acoustic solitary waves (DASWs) for different ion distributions is calculated and is shown to agree very well with the Cassini Wideband Receiver (WBR) observations. The interaction time of two DASWs for non-Maxwellian ion distributions is estimated and shown to be fastest for the ( r , q ) distributed ions. The interesting feature of the interaction between compressive solitons with their rarefactive counterparts is also discussed in detail.

Time/space separation-based modeling methods have been widely researched for estimating lithium-ion battery (LIB) thermal dynamics. However, these methods have been developed in an offline environment and may not perform well in real-time application since the battery systems in electric vehicles (EVs) are usually subject to external disturbances. Furthermore, the onboard measurements of temperature are often corrupted by significant error. To address these problems, we present a reduced model-based observer design for online temperature distribution estimation in LIBs. First, an extreme learning machine (ELM) based offline spatiotemporal model is constructed to approximate the thermal dynamics of LIB. Second, an adaptive reduced order observer is designed based on the offline model developed in the previous step. The offline model is then updated with the estimation results of the observer. As the performance of the estimator is highly related to the placement of sensors, a genetic algorithm (GA) based integrated optimization strategy is also developed to determine the optimal sensor location for online estimation. Finally, the whole temperature distribution is estimated in real time using the observer, the measured voltage, current and the limited available temperature data. Simulation results on a battery thermal system verify the effectiveness of this developed model.

Corrosion behavior of AZ31 magnesium alloy in NH4+-bearing chloride solution with controlled pH was investigated by weight loss experiment, hydrogen collection, and electrochemical test combined with surface morphology and topography observation. The results show that NH4+ and pH of the solution can affect the corrosion of AZ31 magnesium alloy. The existence of NH4+ affects the formation and dissolution of corrosion products, which makes the protective effect of the corrosion product layer weaker. The change of pH value not only affects the corrosion mechanism of AZ31, but also alters the concentration of NH4+ ions in the solution, which further influences the corrosion product layer of AZ31, and finally makes the corrosion of AZ31 change significantly.

White light-emitting diodes (WLEDs) fabricated by single-phase full color emitting phosphor is an emerging solution for health lighting. The crystallographic site occupation of activators in a proper host lattice is crucial for sophisticated design of such phosphor. Here, we reported a high quality white light-emitting phosphor Ba2Ca(BO3)2:Ce3+(K+),Eu2+,Mn2+ with spectral distribution covering whole visible region. Blue light emission originates from Ce3+ ions occupying preferentially Ba2+ site by controlling synthesis conditions. Green and red light are abtained from Eu2+ occupying Ba2+ (and Ca2+) site and Mn2+ occupying Ca2+ site, respectively. In this triple-doped phosphor, strong red emission with a low concentration Mn2+ is realized by the efficient energy transfer from Ce3+ and Eu2+ to Mn2+. Furthermore, high quality white light is accomplished by properly tuning the relative doping amount of Ce3+(K+)/Eu2+/Mn2+ based on efficient simultaneous energy transfer. The results indicate that Ba2Ca(BO3)2:Ce3+(K+),Eu2+,Mn2+ is a promising white light-emitting phosphor in WLEDs application.

Lithium metal batteries are promising devices for the next-generation energy storage due to their ultrahigh theoretical specific capacity and extremely low electrochemical potential. Their inherent problem is the formation of lithium dendrites in cycling, which has induced safety concerns for almost half a century. After understanding the formation mechanism of branching structures, we propose to suppress lithium dendrites by adopting external magnetic fields to induce diffusion enhancement at the interface of the anode, thus attenuating concentration gradient there and reducing the driving force for the formation of dendritic structures. The diffusion coefficient of lithium ions is dependent on the strength of magnetic fields, confirming the effectiveness of magnetic fields in improving Li+ diffusion. After employing the magnetic field of 0.8 T, the concentration gradients at the growth front becomes nearly half of the control case, which leads to a dendrite-free lithium deposition up to the high current density of 10 mA cm−2. Both the CuLiCoO2 batteries and the symmetric LiLi coin cells show a long-term stable cycling at high current densities under the assistance of magnetic field. This diffusion enhanced technique promises a facile and general approach to suppress dendritic structures in secondary batteries, which may help to develop quick charging strategies.

The Licklider Transport Protocol (LTP) is the "convergence layer" of choice in Interplanetary networks based on Delay-/Disruption-Tolerant architecture. It was designed for long-delay scheduled-intermittent links, offering either a reliable or an unreliable service, with "red" and "green" parts, respectively. The aim of this article is to present multicolor LTP, an LTP version consisting in a series of enhancements of which the most significant are the use of monochrome sessions, the introduction of an additional orange color offering a "notified" service, and the definition of default link colors. After a thorough examination of basic LTP mechanisms for all color variants, this article discusses two scenarios where orange seems particularly appealing: video streaming and optical interplanetary links. Numerical results offer further insight into the complex LTP mechanisms and also highlight the difference between LTP retransmissions and bundle protocol retransmissions, the latter benefitting from routing reprocessing. Multicolor LTP has already been implemented as an interplanetary overlay network (ION) plug-in and its enhancements have been proposed to Consultative Committee for Space Data Systems Space Internetworking Services Delay-/Disruption-Tolerant Networking working group for a possible inclusion in the next version of LTP specifications (LTPv2).

To monitor the reaction between Ce4+ ion and Cl– ion at the electron level, an electrochemical experiment was designed in this work. Herein, the intermediate and final products that may be produced during the redox reaction are directly tracked by using cyclic voltammetry, and the influences of Ce4+ ion concentration, temperature and F– ion on the reduction peak potential of Ce4+ ion were investigated. The results show that Ce4+ ion reacts with Cl– ion through an irreversible reaction without any intermediate products, and the rate-determining step of the reaction is diffusion during the electrode reaction. The effects of temperature (20–40 °C) and Ce4+ ion concentration (0.04–0.12 mol/L) on the reduction peak potential of Ce4+ ion can be ignored, but the higher the molar ratio of F– to Ce4+ (0–3 mol/mol), the more easily the reduction of Ce4+ ion to Ce3+ ion occurs. Additionally, the Ce4+ ions are preferentially reduced by thiourea when thiourea is added in the HCl solution, and thiourea inhibits the oxidation of Cl– ions to Cl2 by forming a complex with Cl– ions. This work provides a theoretical basis for the role of thiourea in inhibiting Cl2 production and offers a new way to find new reductants.

The near-infrared (NIR) persistent luminescence materials (PLMs) can remain long-lasting luminescence after removal of the excitation light, which permits bioimaging with high sensitivity owing to the absence of background fluorescence interference from in situ excitation. Recently, the NIR PLMs have aroused intensive research interest in bioimaging. However, the optimal excitation wavelength of current NIR PLMs is located in the ultraviolet region with shallow tissue penetration, making it difficult to activate effectively in vivo, and seriously hindering their further application in bioimaging. Herein, we report a novel kind of Cr3+ ions and Y3+ ions co-doped NIR PLM, Zn1.3Ga1.4Sn0.3O4:Cr3+,Y3+ (ZGSCY), which emits NIR persistent luminescence at 696 nm. Compared with Zn1.3Ga1.4Sn0.3O4:Cr3+ (ZGSC) excited by the light with a wavelength in the biological window (>650 nm), after being co-doped with Y3+ ions, the NIR persistent luminescence performance of ZGSCY is significantly improved because of the increase of trap concentration in the matrix. In addition, we synthesized ZGSCY nanoparticles (NPs) by the combustion method, which exhibit excellent optical properties after being excited by the light with a wavelength in the biological window. After surface modification with PEG, the ZGSCY NPs present low cytotoxicity. Notably, due to the co-doping of Y3+ ions, the signal-to-noise ratio (SNR) of ZGSCY NPs in vivo imaging is about 1.8 times higher than that of the ZGSC NPs. Furthermore, the rechargeable in vivo imaging and passive tumor-targeted imaging are successfully achieved by activating with a light-emitting diode (LED, 659 nm) after intravenous injection of ZGSCY. Thus, this kind of NIR PLM with high excitation efficiency performance in the biological window is expected to promote its biomedical application in deep tissues.

This study aims to investigate the utility of using 15PbF2–(60x)TeO2–25WO3–xNd2O3 (0.1 ≥ x ≥ 1.5) glasses in the nuclear shielding applications for mixed radiation fields at energies ranging from 15 keV to 15 MeV. The effect of Nd3+ ions on gamma attenuation properties of the present glass system was discussed in detail. The radiation attenuation features were investigated for the present glass system by using Monte Carlo radiation transport simulation via Geant4 toolkit. The simulation results were theoretically approved by using Phy-X approach over the entire considered energy range. The obtained results indicate that the values of Zeff and Neff were both highest in the in the τ/ρ dominated energies due to the atomic number dependence of the cross sections of the τ/ρ absorption processes. Moreover, FNRCS values were 0.1152, 0.1152, 0.1153, and 0.1153 cm−1 for PWTN1, PWTN2, PWTN3, and PWTN4 respectively. Finally, an extensive comparative study is also presented between the studied glass system and standard traditional shielding materials. The study suggests PWTN4 is the best photon shield amongst the studied PWTN-glasses.

In this work, calcium niobium gallium garnet (Ca3Nb1.6875Ga3.1875O12 - CNGG) ceramic samples single-doped with Tb3+ and co-doped with Tb3+ and Yb3+ ions were sintered by the solid-state reaction method. The structural characterization of the samples was carried out by X-ray diffraction measurements. The optimal concentration of Tb3+ ions corresponding to the maximum luminescence in the green spectral range in CNGG: x at% Tb (x = 0.1, 0.5, 1, 2, 3, 4, and 5) was determined to be 4 at%. The time-resolved luminescence of the 5D4 level (Tb3+) in the CNGG:x at% Tb samples was analysed to explore the quenching mechanisms involved in the Tb3+ green emission. Co-doped CNGG:4 at% Tb,y at% Yb (y = 0.5, 2, 4, 6, 8, and 10) ceramics were prepared and investigated. It is shown that CNGG:4 at% Tb,y at% Yb phosphors exhibit intense green luminescence under ultra-violet (UV), visible (VIS), and near-infrared (NIR) excitation, thus demonstrating the presence of simultaneous down-conversion (DC) and up-conversion (UC) processes. The dependence of the UC luminescence intensity on the diode laser pumping power was measured and the results indicate a two-photon process based on cooperative energy transfer (CET). Under UV excitation, the lifetime of the 5D4 (Tb3+) level slowly increases with increasing of Yb3+ concentration suggesting the energy transfer from Yb3+ to Tb3+ ions, while under NIR excitation, the lifetime of the 5D4 (Tb3+) level decreases with increasing of Yb3+ ions concentration, indicating the presence of a strong energy transfer from Tb3+ to Yb3+ ions. The highest energy transfer efficiency of ηET ∼ 42 % was determined for the CNGG:4 at% Tb, 10 at% Yb sample. The obtained results indicate that CNGG:(Tb3+, Yb3+) could be efficient new yellowish-green-emitting phosphors.

In very recent years, ultraviolet (UV) persistent luminescent materials (PLMs) have attracted widespread attention due to their potential biological applications. However, owing to the lack of suitable emitters and hosts, the design and development of excellent UV PLMs remain challenging. Here, we report a new Gd-based PLM NaGdGeO4:Bi3+ with super-long UVA persistent luminescence (PersL). By further co-doping Li+ ions to increase the concentration of traps, the UVA PersL intensity of NaGdGeO4:Bi3+ is increased by 5.5 times. The optimal NaGdGeO4:Bi3+,Li+ exhibits excellent UVA PersL and can persist for more than 200 h. Moreover, the phosphor NaGdGeO4:Bi3+,Li+ also exhibits photostimulated property with a red LED or NIR laser excitation after the long-term decay, and can be activated by X-ray. This promising Gd-based UVA PLM is expected to have potential applications in biomedicine through triggering photocatalysts or photosensitizers by its UVA PersL to achieve photodynamic therapy and its potential ability of magnetic resonance (MR) imaging due to Gd3+ ions as MR imaging probe containing in the host NaGdGeO4.

We have demonstrated a highly sensitive novel platform for real-time detection of Mercury (Hg2+) ions after successfully making silver nanowires (AgNWs)-MoS2 nanocomposite and functionalizing it over ungated AlGaN/GaN high electron mobility transistor (HEMT). The AlGaN/GaN HEMT structures were grown over the sapphire substrate using Molecular Beam Epitaxy. AgNWs-MoS2 nanocomposites were optimized for the device functionalization and 1:4 ratio was found highly sensitive for Hg2+ ions. The sensor exhibits high sensitivity towards Hg2+ ions of 1.604 mA/ppb and calculated its Limit of Detection (LoD) up to the range of 20 ppt. The observed sensitivity is highest among previously reported AlGaN/GaN fabricated HEMT based sensors for Mercury (Hg2+) ions detection and is well below the standard permissible limits as set by World Health Organization (WHO) and Environmental Protection Agency (EPA). The enhancement in sensitivity is due to the enhanced surface to volume ratio of AgNW-MoS2 nanocomposite and the highly conductive nature of silver nanowires incorporated in MoS2. Moreover, we also performed sensing on real water samples of tap water and lake water. Further, we showed the smart sensing capability of our developed sensor by illustrating the Internet of Things (IoT) enabled system for next-generation heavy metal ion sensing.

m-Benzoquinones are often regarded as unstable materials in the form of radicals. Herein, an air-stable small molecular m-benzoquinone [4,6-diamino-1,3-benzoquinone (4,6DA1,3BQ)] without bulky grou...

A triangular prism cage 2 with benzene triimide (BTI) as the base and 2,7-naphthalene dimethylene as the supporting pillars was designed and synthesized efficiently. The two parallel BTI planes con...

Background: Propagated sensation along channels occurs because of stimulations during acupuncture therapies and tends to transmit the stimulating signals along the meridians. From the Western medicine aspect, researchers consider the phenomena as neurotransmissions initiated by nerves, and various ions regulate the physiological functions of the nervous systems. Objective: This research investigates the critical characteristics of ions at acupoints and the mechanism of propagated sensation along channels, crossing meridians in traditional Chinese medicine (TCM). Methods: This research first conducts experiments by applying intense pulse light beams, which replace the traditional acupuncture treatments, on designated acupoints of studied human subjects, and employs a thermal infrared imager to monitor the temperature responses, which are induced by post sensation, in adjacent regions of the acupoints. Meanwhile, the research applies a synchrotron radiation technique on adult SD (Sprague Dawley) rats. The study analyzes the output responses with an X-ray Absorption Fine Spectroscopy (XAFS) to investigate the ion distributions in the relevant acupoints, which trigger the propagated sensation crossing meridians. Results: Experimental results demonstrate significant temperature increases simultaneously at the stimulated acupoints and specific other acupoints, whether in the same meridians. Moreover, XAFS experimental results indicate significantly high calcium, potassium, and sulfide ions at the stimulated acupoint regions. On the contrary, the measured chloride ions level at the regions is correspondingly lower. Conclusions: The thermal infrared imager monitoring shows significant temperature variations of crossing-meridian acupoints after implementing the intense pulse light beams on designated acupoints, and it implies the occurring of prolonged sensation along channels using acupuncture therapies. The X-ray absorption spectrum demonstrates significant differences in ion amounts and distributions between the acupoints and non-acupoints, and acupuncture therapies result in ion concentrations in the correlated regions inducing propagated sensation crossing meridians in TCM. Hence, the stimulated acupoints operate as ion reservoirs to provide high-concentration of specific ions to trigger the crossing-meridian post sensation.

The uncontrolled growth of lithium dendrites and accumulation of “dead lithium” upon cycling are among the main obstacles that hinder the widespread application of lithium metal anodes. Herein, an ionic liquid (IL) consisting of 1-methyl-1-propylpiperidinium cation (Pp13+) and bis(fluorosulfonyl)imide anion (FSI−), was chosen as the additive in propylene carbonate (PC)-based liquid electrolytes to circumvent the shortcoming of lithium metal anodes. The optimal 1% Pp13FSI acts as the role of electrostatic shielding, lithiophobic effect and participating in the formation of solid electrolyte interface (SEI) layer with enhanced properties. The in-situ optical microscopy records that the addition of IL can effectively inhibit the growth of lithium dendrites and the corrosion of lithium anode. This study delivers an effective modification to optimize electrolytes for stable lithium metal batteries.

Mixing polyanion cathode materials are promising candidates for the development of next-generation batteries, owing to their structural robustness and low-volume changes, yet low conductivity of polyanion hinders their practical capacity. Herein, the anion-site regulation is proposed to elevate the electrode kinetics and properties of polyanionic cathode. Multivalent anion P2O74− is selected to substitute the PO43− in Na3V2(PO4)3 (NVP) lattice and regulate the ratio of polyanion groups to prepare Na3+xV2(PO4)3−x(P2O7)x (NVPPx, 0 ≤ x ≤ 0.15) materials. The optimal Na3.1V2(PO4)2.9(P2O7)0.1 (NVPP0.1) material can deliver remarkably elevated specific capacity (104 mAh g−1 at 0.1 C, 60 mAh g−1 at 20 C, respectively), which is higher than those of NVP. Moreover, NVPP0.1 exhibits outstanding cyclic stability (91% capacity retention after 300 cycles at 1 C). Experimental analyses reveal that the regulation of anions improves the structure stability, increases the active Na occupancy in the lattice and accelerates the Na+ migration kinetics. The strategy of anion-site regulation provides the researchers a reference for the design of new high-performance polyanionic materials.

In the present study, a Bi$_2$WO$_6$/ZnWO$_4$ photocatalyst was successfully constructed by a modified hydrothermal synthesis method with different molar concentrations of Bi$_2$WO$_6$ with respect to ZnWO$_4$. The variation in molar concentrations of Bi$_2$WO$_6$ changed the photocatalytic properties of the Bi$_2$WO$_6$/ZnWO$_4$ catalyst. The synthesized Bi$_2$WO$_6$/ZnWO$_4$ photocatalyst was characterized by various techniques to decipher its structural and spectral properties. The interaction of Bi$^{2+}$ ionic charge carriers and many-body effects cause the band gap to narrow in Bi$_2$WO$_6$/ZnWO$_4$, as shown by PL analysis. The decrease in band gap energies (E$_g$) from 4.7 eV (ZnWO$_4$) to 3.5 eV (30% Bi$_2$WO$_6$/ZnWO$_4$) is beneficial because less energy is required to excite the valence electrons. The maximum degradation of Plasmocorinth B dye was found with 30% Bi$_2$WO$_6$/ZnWO$_4$ under UV irradiation. This increased activity of 30% Bi$_2$WO$_6$/ZnWO$_4$ can be attributed to the (i) synergistic effect in the bicrystalline framework of Bi$_2$WO$_6$ and ZnWO$_4$, (ii) the high close contact between Bi$_2$WO$_6$ and ZnWO$_4$, and (iii) the small crystallite size. The photocatalytic activity of synthesized Bi$_2$WO$_6$/ZnWO$_4$ photocatalyst shows its significant potential in water/ wastewater treatment application.

Red emitting phosphor plays a significant role in accelerating the improvement of illumination quality for white light emitting diodes (WLEDs). In this work, by using solid-state reaction method, an efficient novel Ba2LuNbO6:Eu3+ phosphor with double-perovskite structure was successfully prepared. Here, a series of Ba2LuNbO6:Eu3+ red phosphors can be efficiently pumped by the near-ultraviolet (UV) light and then present high-brightness at orange emission (598 nm, 5D0→7F1) and red emission (610 nm, 5D0→7F2). The ratio values of 610 to 598 nm in Ba2LuNbO6:Eu3+ phosphors exceed 1 when the content of Eu3+ is larger than 0.4 mol, because the occupation of Eu3+ ions is changed from Lu3+ ions with symmetric sites to Ba2+ ions with asymmetric sites. Besides, the optimized concentration of Eu3+ at the 5D0→7F2 transitions is obtained when x=1, indicating that there is non-concentration quenching in Ba2LuNbO6:Eu3+ phosphors. Moreover, the CIE chromaticity coordinates of Ba2LuNbO6:Eu3+ was calculated to be of (0.587, 0.361), the color purity was calculated to be 72.26% and internal quenching efficiency (IQE) was measured to be 67%. Finally, the thermal stability of Ba2LuNbO6:Eu3+ phosphors was also studied. Our work demonstrates that the novel double-perovskite red-emitting Ba2LuNbO6:Eu3+ phosphors are prospective red emitting elements for WLEDs applications.

Hydroxyl terminated poly(dimethylsiloxane) (PDMS-HT) is used as an electrolyte additive in electrolyte systems containing 1 M LiPF6 in EC:DMC (ratios 1:9; 3:7; 4:6 and 1:1 v/v) to enhance the cycle performance of lithium-ion batteries. Adding a small amount of PDMS-HT to the standard LIB electrolyte leads to improved specific capacity as well as improved capacity retention over prolonged cycles. There is also a slight increase in Li+ ion conductivity when PDMS-HT is added. Also, the PDMS-HT additive allows the formation of a more stable solid electrolyte interface (SEI) layer that enables the LIB cells to be cycled for longer cycles with minimal capacity fading. This combination of improved ionic conductivity and stable SEI layer formation due to the PDMS-HT additive, makes it an excellent candidate for an electrolyte additive for lithium ion batteries.

Remarkable Li-ion battery(LIB) anode materials need to have long cycle life and fast charge/discharge rate, however they are difficult to be realized in the monolayer anode materials. The monolayer β-Bi has the stiffness of only 33.0 N/m, thus the Bi/G heterostructure is proposed to improve the electronic and mechanical properties and to produce better LIB anode performance in this paper. The calculated results show that Bi/G heterostructure has excellent thermodynamic, dynamical and mechanical stability. The band gap is only 0.04 eV, which ensures remarkable electrical conductivity. In addition, the Bi/G heterostructure has higher stiffness (369.2 N/m) than that of monolayer β-Bi and graphene. The diffusion barrier (Ebarrier) of 0.32 eV and volume expansion ratio(VER) of only 4% can ensure the rapid transport of Li+ ions in the charge/discharge cycling process and long life of the LIB. These calculated theoretical results for describing the detail properties of Li storage and diffusion in the Bi/G heterostructure can supply adequate conclusive evidence for the prediction of remarkable properties of Bi/G heterostructure as an anode material for LIBs.

Chloride is the most abundant anion in living systems. Most natural or synthetic chloride anionophores function via hydrogen-bonding interactions. However, dynamic metal-anion coordination can also...

Glycan analysis has evolved considerably during the last decade. The advent of high-resolution ion-mobility spectrometry has enabled the separation of isomers with only the slightest of structural differences. However, the ability to separate such species raises the problem of identifying all the mobility-resolved peaks that are observed, especially when analytical standards are not available. In this work, we report an approach based on the combination of IMSn with cryogenic vibrational spectroscopy to identify N-glycan reducing-end anomers. By identifying the reducing-end alpha and beta anomers of diacetyl-chitobiose, which is a disaccharide that forms part of the common core of all N-glycans, we are able to assign mobility peaks to reducing anomers of a selection of N-glycans of different sizes, starting from trisaccharides such as Man-1 up to glycans containing nine monosaccharide units, such as G2. By building an infrared fingerprint database of the identified N-glycans, our approach allows unambiguous identification of mobility peaks corresponding to reducing-end anomers and distinguishes them from positional isomers that might be present in a complex mixture.

We developed bright yellow-emitting long persistent luminescence (LPL) materials Sr4Al14O25:Mn2+ and Sr4Al14O25:Mn2+,N (N = Zr4+, Ho3+, Er3+) by high temperature solid-state reaction. The addition of Zr4+, Ho3+ and Er3+ can regulate trap distributions and improve energy storage ability of the materials. The LPL performance of SAO:Mn2+,Ho3+ is optimal, considering LPL intensity and duration time. Bright LPL of SAO:Mn2+,Ho3+ can be observed for 3 h by naked eyes in dark after removing the excitation source. Profiles of LPL spectra are different from those of PL, because the two types of Mn2+ centers do not play equal parts in LPL and PL. Trap depths of TL peaks centered at 354 K (peak 1) and 455 K (peak 2) are 0.60 and 0.72 eV, respectively. And peak 1 at 354 K is the effective TL peak responsible for LPL. In SAO:Mn2+,Ho3+, Mn2+ ions doped in Al3+ sites serve as emitting centers, and positively charged Ho Sr · defects are the main effective trap centers. Finally, a feasible LPL mechanism of SAO:Mn2+,Ho3+ was proposed to clarify the generation process of LPL.

Rare earth elements (REE) are strategic resources and the recycling of REE in alternative resources is urgent and gets increasingly attention. However, the separation of REE in these alternative resources is still a challenge due to the low concentration of REE and multi coexisted ions in acidic system. In this study, the species distribution of REE within the pH 0 to 8.0 was calculated. The SBA-15 originated from coal fly ash was modified by two steps with (3-Aminopropyl) triethoxysilane (APTES) and diethylenetriaminepentaacetic dianhydride (DTPADA) to obtain DTPADA-SBA-15 adsorbent, which was applied to the selective adsorption of REE. The results showed that DTPADA-SBA-15 possessed excellent adsorption performance on the selective adsorption of REE, including Eu, Gd, Tb, Nd and Sm, in acidic solution (pH 2) with multi competing ions. The FT-IR and Zeta potential characterization verified that the chemical adsorption through the coordination of O in DTPADA-SBA-15 with REE was dominant at lower pH value. The study of adsorption kinetics indicated that the adsorption of rare earth metal ions followed pseudo-second-order kinetic, of which the adsorption process followed the Langmuir isotherm model.

Hybrid CuO-Co3O4 nanosphere building blocks have been embedded between the layered nanosheets of reduced graphene oxides with a 3D hybrid architecture (CuO-Co3O4-RGO), which are successfully applied as enhanced anodes for lithium-ion batteries (LIBs). The CuO-Co3O4-RGO sandwiched nanostructures exhibit a reversible capacity of ∼847 mA·h·g−1 after 200 cycles’ cycling at 100 mA·g−1 with a capacity retention of 79%. The CuO-Co3O4-RGO compounds show superior electrochemical properties than the comparative CuO-Co3O4, Co3O4 and CuO anodes, which may be ascribed to the following reasons: the hybridizing multicomponent can probably give the complementary advantages; the mutual benefit of uniformly distributing nanospheres across the layered RGO nanosheets can avoid the agglomeration of both the RGO nanosheets and the CuO-Co3O4 nanospheres; the three dimensional (3D) storage structure as well as the graphene wrapped composite could enhance the electrical conductivity and reduce volume expansion effect associated with the discharge-charge process.

The development of uranyl ion detection technology has exhibited its significance in public security and environmental fields for the radioactivity and chemical toxicity of uranyl ion. The WHO standard of uranyl ion makes it necessary to develop highly sensitive uranyl rapid warning system in drinking water monitoring. Herein, a visualized rapid warning system for trace uranyl ion is carried out based on electrochemiluminescence (ECL) imaging technology to give an ultra-low limit of detection (LOD) and high selectivity. Amidoxime, a bi-functional group with both uranyl ion capturing and co-reactive functions, is modified on a conjugated polymer backbone with strong ECL signal to be prepared into three-in-one polymer nanoparticles (PNPs) with self-enhanced ECL property. The captured uranyl ion can enhance the ECL signal of PNPs via resonance energy transfer process to give the LOD as 0.5 ng/L, which is much lower than the known luminescent uranyl sensors. Furthermore, ECL imaging technology is introduced into realizing visualized uranyl rapid warning, and can be successfully applied on natural water samples. This study provides a novel strategy for uranyl rapid warning, and shows its potential meaning in public security and environmental fields.

Gadolinium (III)-based T1 contrast agent have been widely used in clinical MRI. In this study, salicylic acid-gadolinium chelate was prepared via directly coordination reaction of gadolinium ion and salicylic acid. Then, three polyethylene glycols with different molecular weight were modified on the surface of salicylic acid-gadolinium by simple chemical coupling to construct three core-shell structural Gd based composites. The SEM and TEM characterization results show that the composite is a spherical particle with a diameter of about 100–200 nm. The longitudinal relaxation rate r1 of the Gal-PEG-2000 is 11.097 (mmol/L)–1/s, and the ratio of r2/r1 is as low as 2.53. The composite shows good liver and intestines MRI performances after being used in in vivo imaging, showing a good prospect of biological application.

Wadsley-Roth phase titanium niobium oxides have received considerable interest as anodes for lithium ion batteries. However, the volume expansion and sluggish ion/electron transport kinetics retard its application in grid scale. Here, fast and durable lithium storage in entropy-stabilized Fe0.4Ti1.6Nb10O28.8 (FTNO) is enabled by tuning entropy via Fe substitution. By increasing the entropy, a reduction of the calcination temperature to form a phase pure material is achieved, leading to a reduced grain size and, therefore, a shortening of Li+ pathway along the diffusion channels. Furthermore, in situ X-ray diffraction reveals that the increased entropy leads to the decreased expansion along a-axis, which stabilizes the lithium intercalation channel. Density functional theory modeling indicates the origin to be the more stable Fe-O bond as compared to Ti-O bond. As a result, the rate performance is significantly enhanced exhibiting a reversible capacity of 73.7 mAh g(-1) at 50 C for FTNO as compared to 37.9 mAh g(-1) for its TNO counterpart. Besides, durable cycling is achieved by FTNO, which delivers a discharge capacity of 130.0 mAh g(-1) after 6000 cycles at 10 C. Finally, the potential impact for practical application of FTNO anodes has been demonstrated by successfully constructing fast charging and stable LiFePO4||FTNO full cells.

Pressure - and temperature-dependent luminescence properties of 3F3/2 → 4I9/2 transition of Nd3+:GdTaO4 were studied for potential applications in optical sensing. Two isolated emission lines correspond to 3F3/2(R2, 1) → 4I9/2(Z5) transitions, locates at 920 and 927 nm under ambient condition, are very sensitive to pressure with coefficients of −15.6 and −14.5 cm−1/GPa determined in a pressure range up to about 9 GPa. The luminescence intensity ratio between the two emission lines exhibits a large dependence with temperature in a range from 80 to 620 K, the corresponding temperature sensitivity at room temperature is similar to that of Nd3+:YAG. These advantages, together with the other observed features of high stable position relationship under pressure and low thermal shifts for the two emission lines indicate that, Nd3+:GdTaO4 is a promising candidate to be used as pressure and temperature sensors in the near-infrared spectral range.

Three binuclear rare earth based complexes combining RE ions with semirigid tricarboxylic ligand (H3L), namely, [RE2(L)2(DMF)4] [RE = Gd, Tb, and Dy; H3L = 5-((4-Carboxybenzyl)oxy)isophthalic acid; DMF = N,N-dimethylformamide] complexes, were fabricated successfully. The RE2(L)2(DMF)4 complexes consist of two central RE ions with the same coordination environment which were connected by two tridentate bridging carboxylic groups and two syn-syn bidentate bridging carboxylic groups originating from the L3– ligands to form the {RE2} dimeric unit. And thus provides the basis for further constructing a dense three-dimensional (3D) network structure. Moreover, the present RE2(L)2(DMF)4 complexes can be described by a topology diagram with the topology point symbol of {42·6}2{44·62·87·102}. Weak anti-ferromagnetic (AFM) coupling between the adjacent RE ions for all the present complexes is found according to the magnetic calculations. The observed significant cryogenic magnetocaloric effect (MCE) with the maximum magnetic entropy change − Δ S M m a x to be 26.3 J/(kg·K) with Δ H = 7 T in Gd2(L)2(DMF)4 complex makes it competitive for the cryogenic magnetic refrigerant. Moreover, the slow magnetic relaxation behavior at 0.2 T dc field with an obvious large U e f f / k = 45(4) K and τ 0 = 6.5(2)×10−10 s is confirmed in Dy2(L)2(DMF)4 complex. This work not only provides an effective strategy for obtaining molecular materials with high MCE, but also confirms that tricarboxylate ligands are the ideal choice for constructing stable high dimensional geometric structures.

The thermal decomposition of AgNO3 is known to produce metallic Ag, but single-atomic dispersion is hard to achieve instead of the aggregation state of nanoparticles. Herein, we develop an efficient approach to thermally generate and stabilize single Ag atoms via the coordination effect. Two desired Co-Ag phosphonates [AgI2CoIII2(notpH3)2(NO3)]X [X = NO3− (1) or ClO4− (2)] were synthesized by solid-phase grinding method or solution crystallization. Both crystal structures reveal slightly different packing arrangements of various lattice anions and identical one-dimensional (1-D) coordination chains, formed in each case by the coordination of Ag(I) to the metalloligand Co(notpH3) and NO3− anion. The number of Ag ions connected to each NO3− anion reduces from 5 in bulk AgNO3 to 2 in compounds 1 and 2, leading to the AgNO3 component stepwise decomposition at a lower temperature (

Silicon (Si) is regarded as the potential anode for lithium-ion batteries (LIBs), due to the remarkable theoretical specific capacity and low voltage plateau. However, the rapid capacity decay resulting from volume variation and slow electron/ion transportation of Si limit its practical application. Here, matryoshka-type carbon-stabilized hollow silicon spheres (Si/C/Si/C) are synthesized by an aluminothermic reduction and calcination process. The Si/C/Si/C anode materials prepared at 500 °C (Si/C/Si/C-500) exhibit unique structures, in which amorphous region and porous structure are preserved in the Si layers. The anode based on Si/C/Si/C-500 displays an initial specific capacity of 2792 mAh/g at a current density of 100 mA/g. At 1000 mA/g, this anode retains a reversible capacity of 1673 mAh/g, 86.9% of the initial capacity after 200 cycles. Such synthetic strategy can be employed to fabricate other high-capacity anode materials with large volume variation during charge/discharge process

Bastnaesite is an important rare earth mineral and is usually beneficiated by flotation. Sodium silicate is commonly used to depress calcium-bearing gangue minerals, however it can also depress bastnaesite when Ca2+ ions exist in the pulp. In this study, the effect of Ca2+ ions and sodium silicate individually or in combination on bastnaesite flotation was studied through micro-flotation, zeta potential, fluorescence spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements. Micro-flotation results show that the combination of Ca2+ ions and sodium silicate depresses bastnaesite more severely due to their synergistic effect. Zeta potential results show that the combination renders the surface potential of bastnaesite negatively shifted more significantly. Fluorescence spectroscopy shows that the combination decreases the surface hydrophobicity of bastnaesite more severely. XPS shows that the combination increases the adsorption of sodium silicate on bastnaesite by forming hydrophilic Ca-SiO3 precipitate, which causes more serious depression on bastnaesite flotation.