Robust Stability Research Articles

Sensorless fuzzy control algorithm for permanent magnet synchronous motor based on particle swarm optimization parameter identification and harmonic extraction

ABSTRACT In sensorless control of permanent magnet synchronous motor (IPMSM) with sliding mode observer, the problem of parameter robustness and poor stability seriously affects the control effect of sensorless operation. Therefore, a fuzzy sliding mode observer (SMO) phaselocked loop (PLL) combining particle swarm optimization (PSO) parameter identification and recursive least squares adaptive linear (RLS-Adaline) harmonic extractor is proposed. First, the fuzzy controller is used to process the control parameters of the sliding mode observer and the phaselocked loop. Secondly, the RLS-Adaline harmonic extractor is used to effectively filter the higher harmonic component of the back electromotive force (EMF), thus significantly improving the sensorless control effect. Thirdly, the PSO algorithm is used to identify the parameters of the motor, and the effect of parameter identification is judged by the performance index. The experimental results show that the proposed control method can effectively reduce the speed error and rotor position error.

Validation of the AgraStrip® Pro Total Aflatoxin WATEX® Method for Detection of Total Aflatoxins in Corn and Peanut Paste: AOAC Performance Tested MethodSM 032402.

To protect public and animal health against risks provoked by aflatoxins contained therein, maximum limits for aflatoxins are defined. Limit values vary depending on the intended use and regulatory authority, therefore quantitative detection is essential. Validation of a one-step competitive lateral flow immunochromatographic assay for quantitative screening of total aflatoxin (B1, B2, G1 and G2) in corn and peanut paste for the High Sensitivity Range (0-50 µg/kg). Corn or peanut paste test portions are water-based extracted and prepared for testing within 15 minutes. The AgraStrip Pro Total Aflatoxin WATEX test method quantifies the concentration of aflatoxins in the sample. Selectivity, robustness, product consistency and stability were performed in addition to matrix testing. No cross-reactivity was detected against possible interferants. Corn resulted in a LOD and LOQ of 0.9 and 2.8 µg/kg and overall recoveries between 74 and 108%. Peanut paste resulted internally in a LOD and LOQ of 0.8 and 2.3 µg/kg and recoveries between 86 and 98%. Stability testing showed no influence of the age of the respective lot on the result. Robustness testing demonstrated that varying the amount of water used for extraction, extraction time, and delay between extract dilution and analysis did not significantly affect the result. Due to supply chain issues, a change to the outer cartridge required an increase in the test aliquot size, which had no effect on method performance. The test kit was validated for the determination of total aflatoxins in corn and peanut paste. Recovery and precision met the requirements laid down in Codex Alimentarius CXG 71-2009 and acceptable robustness, selectivity, and product consistency and stability were demonstrated. The AgraStrip Pro Total Aflatoxin WATEX test kit in the high sensitivity range (0-50 µg/kg) was approved by the AOAC RI (PTM number 032402).

Revealing Interaction of Fluorinated Propylamine Hydrochloride with Precursor and Defect States of Perovskite Films Toward Efficient Flexible Solar Cells

AbstractThe trap state at the surfaces and grain boundaries of perovskite is one of the major obstacles to the further commercialization of flexible perovskite solar cells (FPSCs). Herein, two innovative multifunctional fluorinated propylamine salt 2,2,3,3,3‐pentafluoropropylamine hydrochloride (PFPACl) and 3,3,3‐triflupropylamine hydrochloride (TFPACl) are in situ introduced onto the photo absorbing layer to improve the performance of the FPSCs. The nuclear magnetic resonance (NMR) spectroscopy indicates strong interactions of both PFPACl and TFPACl with the perovskite precursor components. For the first time, the structures of the supramolecular complexes formed by two additives with FAI are deduced from NOESY NMR data, thus pointing to the importance of the preorganization of the perovskite components in solution before film casting. The experiments and density functional theory（DFT) calculations reveal that PFPACl is likely dissociated more into the form of R‐NH3+‐Cl− due to the higher electronegativity of the fluoroalkyl tail. Therefore, PFPA+ binds more strongly to VFA defects than TFPA+, and anion Cl− has strong enough interaction with VFAI and uncoordinated Pb2+, leading to homogeneous coverage of PFPACl on the entire surface of the perovskite films and better energy alignment with the hole transport layer. Consequently, PFPACl‐treated FPSCs achieved a relatively high PCE of 23.59% with excellent mechanical robustness and operational stability.

Metal-Organic Framework for Aluminum based Energy Storage Devices: Utilizing Redox Additives for Significant Performance Enhancement.

There are various methods being tried to address the sluggish kinetics observed in Al-ion batteries (AIBs). They mostly deal with morphology tuning, but have led to limited improvement. A new approach is proposed to overcome this limitation. It focuses on the use of a redox additive modified electrolyte in combination with framework like materials, which have wider channels. The ordered microporous and interconnected framework of ZIF 67, with large surface area, effectively facilitates the diffusion of aluminum ions. Therefore, AIBs are able to exhibit a superior discharge capacity of 288 mAh g-1 at 0.2 A g-1 current density with robust cycling stability. The addition of potassium ferricyanide as a redox-active species in an aqueous solution of aluminum chloride (supporting electrolyte) leads to significant enhancement in the specific capacity with much higher cycling stability. Al-ion based BatCap devices can be assembled by using ZIF 67 as the cathode, ZIF 67 derived porous carbon as the anode, and a redox additive modified electrolyte. The BatCap device exhibits excellent energy density of 86 Wh kg-1 at a power density of 2 KW kg-1, which is higher than reported aqueous AIBs. The ex situ characterization clearly explains the unexplored mechanism of redox additives in AIBs.

Adsorption of Cadmium and Lead Capacity and Environmental Stability of Magnesium-Modified High-Sulfur Hydrochar: Greenly Utilizing Chicken Feather

Chicken feathers represent a viable material for producing biochar adsorbents. Traditional slow pyrolysis methods often result in sulfur element losses from chicken feathers, whereas hydrothermal reactions generate substantial amounts of nutrient-rich hydrothermal liquor. Magnesium-modified high-sulfur hydrochar MWF was synthesized through magnesium modification, achieving a S content of 3.68%. The maximum equilibrium adsorption amounts of MWF for Cd2+ and Pb2+ were 25.12 mg·g−1 and 70.41 mg·g−1, respectively, representing 4.00 times and 2.75 times of WF. Magnesium modification elevated the sulfur content, pH, ash content, and electronegativity of MWF. The primary mechanisms behind MWF’s adsorption of Cd2+ and Pb2+ involve magnesium ion exchange and complexation with C=O/O=C–O, quaternary N, and S functional groups. MWF maintains robust stability and antioxidative properties, even with low aromaticity levels. Given the lower energy consumption during hydrochar production, MWF offers notable carbon sequestration benefits. The hydrothermal solution derived from MWF is nutrient-rich. Following supplementation with inorganic fertilizer, the hydrothermal solution of MWF significantly enhanced bok choy growth compared to the control group. In general, adopting magnesium-modified hydrothermal reactions to produce hydrochar and converting the resultant hydrothermal solution into water-soluble fertilizer proves a viable strategy for the eco-friendly utilization of chicken feathers. This approach carries substantial value for heavy metal remediation and agricultural practices.

Achieving Near-Unity Red Light Photoluminescence in Antimony Halide Crystals via Polyhedron Regulation.

Exploration of efficient red emitting antimony hybrid halide with large Stokes shift and zero self-absorption is highly desirable due to its enormous potential for applications in solid light emitting, and active optical waveguides. However, it is still challenging and rarely reported. Herein, a series of (TMS)2SbCl5 (TMS=triphenylsulfonium cation) crystals have been prepared with diverse [SbCl5]2- configurations and distinctive emission color. Among them, cubic-phase (TMS)2SbCl5 shows bright red emission with a large Stokes shift of 312 nm. In contrast, monoclinic and orthorhombic (TMS)2SbCl5 crystals deliver efficient yellow and orange emission, respectively. Comprehensive structural investigations reveal that larger Stokes shift and longer-wavelength emission of cubic (TMS)2SbCl5 can be attributed to the larger lattice volume and longer Sb⋅⋅⋅Sb distance, which favor sufficient structural aberration freedom at excited states. Together with robust stability, (TMS)2SbCl5 crystal family has been applied as optical waveguide with ultralow loss coefficient of 3.67 ⋅ 10-4 dB μm-1, and shows superior performance in white-light emission and anti-counterfeiting. In short, our study provides a novel and fundamental perspective to structure-property-application relationship of antimony hybrid halides, which will contribute to future rational design of high-performance emissive metal halides.

Achieving Near‐Unity Red Light Photoluminescence in Antimony Halide Crystals via Polyhedron Regulation

AbstractExploration of efficient red emitting antimony hybrid halide with large Stokes shift and zero self‐absorption is highly desirable due to its enormous potential for applications in solid light emitting, and active optical waveguides. However, it is still challenging and rarely reported. Herein, a series of (TMS)2SbCl5 (TMS=triphenylsulfonium cation) crystals have been prepared with diverse [SbCl5]2− configurations and distinctive emission color. Among them, cubic‐phase (TMS)2SbCl5 shows bright red emission with a large Stokes shift of 312 nm. In contrast, monoclinic and orthorhombic (TMS)2SbCl5 crystals deliver efficient yellow and orange emission, respectively. Comprehensive structural investigations reveal that larger Stokes shift and longer‐wavelength emission of cubic (TMS)2SbCl5 can be attributed to the larger lattice volume and longer Sb⋅⋅⋅Sb distance, which favor sufficient structural aberration freedom at excited states. Together with robust stability, (TMS)2SbCl5 crystal family has been applied as optical waveguide with ultralow loss coefficient of 3.67 ⋅ 10−4 dB μm−1, and shows superior performance in white‐light emission and anti‐counterfeiting. In short, our study provides a novel and fundamental perspective to structure‐property‐application relationship of antimony hybrid halides, which will contribute to future rational design of high‐performance emissive metal halides.

Ligand-Induced Electronic Structure Modulation of Self-Evolved Ni3S2 Nanosheets for the Electrocatalytic Oxygen Evolution Reaction.

Modulating the electronic structure of the electrocatalyst plays a vital role in boosting the electrocatalytic performance of the oxygen evolution reaction (OER). In this work, we introduced a one-step solvothermal method to fabricate 1,1-ferrocene dicarboxylic acid (FcDA)-decorated self-evolved nickel sulfide (Ni3S2) nanosheet arrays on a nickel foam (NF) framework (denoted as FcDA-Ni3S2/NF). Benefiting from the interconnected ultrathin nanosheet architecture, ligand dopants induced and facilitated in situ structural reconstruction, and the FcDA-decorated Ni3S2 (FcDA-Ni3S2/NF) outperformed its singly doped and undoped counterparts in terms of OER activity. The optimized FcDA-Ni3S2/NF self-supported electrode presents a remarkably low overpotential of 268 mV to achieve a current density of 10 mA cm-2 for the OER and demonstrates robust electrochemical stability for 48 h in a 1.0 M KOH electrolyte. More importantly, in situ electrochemical Raman spectroscopy reveals the generation of catalytically active oxyhydroxide species (NiOOH) derived from the surface construction during the OER of pristine FcDA-Ni3S2/NF, contributing significantly to its superior electrocatalytic performance. This study concerns the modulation of electronic structure through ligand engineering and may provide profound insight into the design of cost-efficient OER electrocatalysts.

Manipulating 2D Membrane Interlayer Channels with Accelerated Mass-Transfer Behavior to Boost Solar Desalination.

The scarcity of fresh water necessitates sustainable and efficient water desalination strategies. Solar-driven steam generation (SSG), which employs solar energy for water evaporation, has emerged as a promising approach. Graphene oxide (GO)-based membranes possess advantages like capillary action and Marangoni effect, but their stacking defects and dead zones of flexible flakes hinders efficient water transportation, thus the evaporation rate lag behind unobstructed-porous 3D evaporators. Therefore, fundamental mass-transfer approach for optimizing SSG evaporators offers new horizons. Herein, a universal multi-force-fields-based method is presented to regularize membrane channels, which can mechanically eliminate inherent interlayer stackings and defects. Both characterization and simulation demonstrate the effectiveness of this approach across different scales and explain the intrinsic mechanism of mass-transfer enhancement. When combined with a structurally optimized substrate, the 4Laponite@GO-1 achieves evaporation rate of 2.782kg m-2 h-1 with 94.48% evaporation efficiency, which is comparable with most 3D evaporators. Moreover, the optimized membrane exhibits excellent cycling stability (10 days) and tolerance to extreme conditions (pH 1-14, salinity 1%-15%), verifies the robust structural stability of regularized channels. This optimization strategy provides simple but efficient way to enhance the SSG performance of GO-based membranes, facilitating their extensive application in sustainable water purification technologies.

Stability-Indicating HPLC Method for Determination of Ibuprofen and Famotidine Degradation Products.

A new stability-indicating high-performance liquid chromatographic method for the quantitative determination of ibuprofen and famotidine degradation products in combined pharmaceutical products was developed and validated. The current aim of this study is to develop a rapid, accurate and robust analytical stability indicating impurity method that can separate ibuprofen, famotidine and their related impurities by using a reversed-phase high-performance liquid chromatography. A Zorbax SB-Phenyl column (4.6 × 150mm2, 5-μm particle size) with mobile phase containing phosphate buffer solution with a pH value of 3.0 and acetonitrile was used. The flow rate was 0.8mL/min and the analytes were detected by UV detector at 265nm. The retention times of ibuprofen and famotidine were 18.43 and 5.14min, respectively. This method was validated to confirm specificity, linearity, sensitivity (limit of detection and limit of quantitation), precision, accuracy, robustness and sample stability according to the International Conference on Harmonization guidelines. Studies have been completed and reported with two active substances in the combined dosage form and seven impurities in total. There is no method in the literature that simultaneously distinguishes and quantitatively analyzes both active substances and degradation products.

Scalable decarboxylative trifluoromethylation by ion-shielding heterogeneous photoelectrocatalysis

Electrochemistry offers a sustainable synthesis route to value-added fine chemicals but is often constrained by competing electron transfer between the electrode and redox-sensitive functionalities distinct from the target site. Here, we describe an ion-shielding heterogeneous photoelectrocatalysis strategy to impose mass-transfer limitations that invert the thermodynamically determined order of electron transfer. This strategy is showcased to enable decarboxylative trifluoromethylation of sensitive (hetero)arenes by using trifluoroacetate, an inexpensive yet relatively inert trifluoromethyl group (CF 3 ) source. An ion-shielding layer, formed by trifluoroacetate anions electrostatically adsorbed on a positive molybdenum-doped tungsten trioxide (WO 3 ) photoanode, prevents undesired electron transfer between substrates and photogenerated holes. The practicality of the developed method was demonstrated with robust photoanode stability (approximately 380 hours), a good substrate scope, and scaling capability to achieve 100-gram synthesis by using photoelectrochemical flow cells.

Nitrogen-doped carbon quantum dot as electron acceptor anchored on graphitic carbon nitride nanosheet for improving rhodamine B degradation

Carbon quantum dots (CQDs) hold significant promise for wastewater treatment because of their remarkable attributes, including robust stability, outstanding biocompatibility, minimal toxicity, superior water dispersibility, cost-effective production, and exceptional photo-stability.In this study, CQDs were synthesized using microplasma and tested for the degradation of rhodamine B (RhB) (5 mg/L) under different conditions, with a Solar simulator and UVA illumination. Specifically, graphitic carbon nitride nanosheets (NCN) in conjugation with carbon quantum dots (NCN@CQD) were prepared with different amounts of CQD. The synthesized CQD, NCN, and NCN@CQD underwent characterization using various compositional and structural analytical techniques. The results show that nitrogen species were effectively incorporated into the CQDs framework and CQDs are anchored on NCN forming NCN@CQD successfully. Subsequently, all samples were then investigated in degrading Rhodamin B, RhB, to assess the photocatalytic activity. The results reveal that the presence of CQDs substantially improved the photocatalytic efficiency of NCN. Specifically, the CQDs anchored on NCN exhibited a substantial enhancement in the photoactivity for RhB decomposition under a solar light simulator, surpassing that of pure NCN. The amount of CQD in the NCN@CQD sample exerted a strong influence on the photocatalytic activity. All NCN@CQD samples exhibited remarkable enhancements in both adsorption and photocatalytic performance compared to pure CQD and NCN samples. In an optimization study, a best NCN@CQ photocatalyst was identified, showing a 40 % enhancement of photocatalytic efficiency compared to the use of NCN alone. A visible light photocatalytic activity of 91 % can be attained within 150 min, exhibiting a reaction rate constant of 0.0135 min−1 toward RhB decomposition, which was double as for the individual NCN (0.0067 min−1). The boosted photocatalytic activity resulting from the synergistic effect between NCNs and CQDs can be attributed to the efficient function of CQD as an electron acceptor. The proposed mechanism of photocatalytic degradation of RhB is illustrated in detail.

Aqueous removal of Cr(VI) by Citrus sinensis juice-coated multi-walled carbon nanotubes

AbstractA novel adsorbent was prepared from multi-wall carbon nanotubes (MWCNTs) and Citrus sinensis juice extract-modified MWCNTs (OJMW) and characterized using scanning electron microscopy (SEM), Fourier transform infrared spectra (FTIR), X-ray diffractometer (XRD), BET and thermogravimetric analysis. The results showed that the nanotubes exhibited good surface area, pore size, functional groups, and robust stability at elevated temperatures (308 and 313 K). The adsorbent was applied in water for the sequestration of Cr(VI). The adsorption of Cr(VI) on MWCNTs and OJMW was influenced by factors of adsorption. Optimum removal of Cr(VI) was attained at 180 min contact time, 0.05 g adsorbent dose, and solution pH 2 for MWCNTs and OJMW. The kinetic behaviour of the Cr(VI) adsorption onto MWCNTs and OJMW was governed by the pseudo-first-order and pseudo-second-order kinetic model, respectively. The equilibrium data obtained for the uptake of Cr(VI) onto MWCNTs and OJMW fitted satisfactorily with Freundlich and Langmuir isotherm models, respectively. Meanwhile, MWCNTs and OJMW exhibited monolayer adsorption capacities (qmax) of 44.72 and 12.26 g g−1, respectively, at 298 K. The adsorption process was spontaneous and feasible. The direction of energy flow in the uptake of Cr(VI) onto OJMW and MWCNTs followed endothermic and exothermic adsorption processes, respectively. The adsorption–desorption experiments showed that OJMW had good regenerative abilities.

A novel calibration method based on fixed multi-plane targets for cameras with large field of view

Abstract For camera calibration with large field of view (FOV), the accuracy is impacted by the size of the calibration targets. Considering the challenges associated with producing and carrying large targets, existing methods resort to using small targets to achieve calibration without high accuracy. In order to solve this problem, a photogrammetric calibration method based on the fixed multi-plane targets (FMPT) is proposed in this paper for cameras with large FOV. The FMPT is composed by multiple identical small planar targets, with fixed pose transformation relationships among planar targets. The proposed calibration method involves the following main steps. Firstly, the camera is moved several times to capture a series of images of FMPT. Secondly, the fixed pose transformation matrices of different small planar targets in FMPT are calculated through the initial parameters of camera. Finally, calibration based on photogrammetry is conducted, with a continuous optimization of camera intrinsic and extrinsic parameters based on the multiple 2D and 3D constraint in the FMPT. Simulation and real data experiments show that the calibration accuracy using the proposed method is much higher than that using a small target, and sightly higher than that using a large target. Furthermore, the experiments demonstrate the robust stability of this method, maintaining high calibration accuracy even in the presence of increased noise and error in target production.

Exploring ZnFeSnO4 double spinel: A thorough investigation of mechanical, dynamical, magneto-electronic properties and lattice thermal conductivity

Double spinel materials ABB'O4 emerge as an innovative class of oxides with promising technological applications. First-principles calculations are employed to explore the fundamental properties of the double spinel ZnFeSnO4. Its elasticity and dynamic stability are investigated using the pseudo-potential plane wave (PP-PW) method, while the full-potential linearized augmented plane wave (FP-LAPW) approach is used to study its electronic and magnetic properties. The results reveal favorable thermodynamic stability, mechanical robustness, and dynamical stability for ZnFeSnO4. Analysis using GGA + U (U = 6 eV) in the FP-LAPW framework predicts half-metallic ferromagnetism, a highly desirable characteristic for spintronic applications due to its potential spin-polarized currents. However, the use of the mBJ functional results in semiconducting character with bandgaps of 1.813 eV, and 1.524 eV for spin-up and spin-down, respectively. Hence, the outcomes of the computations pertaining to the electronic characteristics are contingent upon the selection of the exchange-correlation functional. Furthermore, the calculated low lattice thermal conductivity of ZnFeSnO4 indicates its potential suitability for thermoelectric applications.

A novel reinforcement learning based Heap-based optimizer

The Heap-Based Optimization (HBO), a novel meta-heuristic algorithm, constructs a hierarchical heap resembling a company structure to facilitate interaction among search agents. This enables the search agent to learn various levels of information from the population to obtain improved solutions, but it has drawbacks such as limited search capability and slow convergence speed when tackling complex optimization problems. To address these challenges, we propose an enhanced heap optimizer based on reinforcement learning(RLHBO), which demonstrates robust stability, rapid convergence, and high solution accuracy. Firstly, fixed operators are replaced with a reinforcement learning dynamic control search strategy in RLHBO to regulate the search range of agents. This prevents agents from being restricted in their search when encountering local or global optima, thus enhancing their search capability. Additionally, RLHBO introduces a dimensional self-learning strategy and a convergence strategy based on search direction similarity to address issues such as invalid and discrete solutions, accelerating convergence. Furthermore, an initialization strategy based on quasi-oppositional learning is employed to increase the diversity of the algorithm-generated population, surpassing the limitations of random initialization and further boosting convergence speed. Extensive testing on various complex functions from CEC2017 and CEC2022 demonstrates that RLHBO, as presented in this paper, outperforms HBO and numerous other advanced MAs in terms of search capability and convergence speed.

Polymer-Supported Heterogeneous Fenton Catalysts for the Environmental Remediation of Wastewater

Materials based on polymer hydrogels have demonstrated potential as innovative Fenton catalysts for treating water. However, developing these polymer-supported catalysts with robust stability presents a significant challenge. This paper explores the development and application of polymer-supported heterogeneous Fenton catalysts for the environmental remediation of wastewater, emphasizing the enhancement of metal incorporation into catalysts for improved efficiency. The study begins with an introduction to the heterogeneous Fenton process and its relevance to wastewater treatment. It further delves into the specifics of polymer-supported heterogeneous Fenton catalysts, focusing on iron oxide, copper complexes/nanoparticles, and ruthenium as key components. The synthesis methods employed to prepare these catalysts are discussed, highlighting the innovative approaches to achieve substantial metal incorporation. Operational parameters such as catalyst dosage, pollutant concentration, and the effect of pH on the process efficiency are thoroughly examined. The catalytic performance is evaluated, providing insights into the effectiveness of these catalysts in degrading pollutants. Recent developments in the field are reviewed, showcasing advancements in catalyst design and application. The study also addresses the stability and reusability of polymer-supported heterogeneous Fenton catalysts, critical factors for their practical application in environmental remediation. Environmental applications are explored, demonstrating the potential of these catalysts in addressing various pollutants. The Conclusions offers future perspectives, underlining the ongoing challenges and opportunities in the field, and the importance of further research to enhance the efficacy and sustainability of polymer-supported heterogeneous Fenton catalysts for wastewater treatment.

Development and characterization of Artemisia argyi essential oil-loaded nanoemulsion for sustainable weed control: Enhanced stability, amplified activity, protected non-target

Nanotechnology contributes to the development of biopesticides with reduced toxicity, increased stability, improved biosafety, and higher activity against targets. It has demonstrated great potential as a solution for practical applications of essential oils. Herein, the HLB method developed two Artemisia argyi essential oil-loaded nanoemulsions (AEOnano). Further systematically optimizing the ratio led to small droplet size (<200 nm) and low PDI (<0.3). As anticipated, the AEOnano demonstrated robust physical stability when subjected to various stressors. Notably, both indoor and outdoor pot experiments demonstrated that AEOnano outperformed ordinary A. argyi essential oil aqueous emulsions (AEOAE) in weed control. These nanoemulsions allowed a 2–4 times reduction in AEO dosage while maintaining the same weed-killing efficacy. The superior improvement attributed to the nanoemulsions enhanced leaf-wetting capability, improved leaf retention, and resistance to wash-off. In addition, biosafety assessment indicated that AEOnano did not affect the plants (Artemisia argyi, Chrysanthemum morifolium, cotton), which provide orientation for its practical application. Therefore, this study introduces a promising approach to enhance the effectiveness of AEO-based herbicides, which will have a broad application prospect in sustainable agriculture.

La-doped Sr4Fe4Co2O13-δ as a promising in-situ self-assembled composite cathode for protonic ceramic fuel cells

Protonic ceramic fuel cells (PCFCs) exhibit a lower activation energy compared to conventional oxygen-ion conducting solid oxide fuel cells, which makes them better suited for operating at low temperatures. Regrettably, the use of PCFCs at lower temperatures is restricted due to the absence of durable and highly active cathode materials. Herein, we rationally design in-situ self-assembled composite cathodes with the nominal compositions of Sr4-xLaxFe4Co2O13-δ (SLxFC, x = 0.4, 0.8, 1, and 2) for PCFCs. The SL0.4FC, displays a composite of cubic perovskite phase and spinel phase, the other compositions yield a mixture of both orthorhombic perovskite and spinel phases. The self-assembled SL1FC composite cathode has the highest electrocatalytic activity among all samples, particularly at temperatures (<650 °C). For instance, it demonstrates a very low area-specific resistance (ASR) of 0.465 Ω cm2 at 550 °C. The PCFC with the SL1FC composite cathode provides a high peak power density (PPD) of 518 mW cm−2 at the same temperature. More importantly, the SL1FC electrode demonstrates robust long-term stability (400 h for the symmetrical cell mode and 200 h for the single cell mode). This study shows how La doping enhances the electrochemical activity of Sr4Fe4Co2O13-δ and how the synergistic effect of the two phases boosts the electrochemical performance of the composite cathode.

Rational Design of Nitride Phosphor-In-Glass with Robust Stability and Photoluminescence Performance.

Phosphor-in-glass represents a promising avenue for merging the luminous efficiency of high-quality phosphor and the thermal stability of a glass matrix. Undoubtedly, the glass matrix system and its preparation are pivotal factors in achieving high stability and preserving the original performance of embedded phosphor particles. In contrast to the well-established commercial Y3Al5O12:Ce3+ oxide phosphor, red nitride phosphor, which plays a critical role in high-quality lighting, exhibits greater structural instability during the high-temperature synthesis of inorganic glasses. A telluride glass with a refractive index (RI = 2.15@615 nm) akin to that of nitride phosphor (∼2.19) has been devised, demonstrating high efficiency in photon utilization. The lower glass-transition temperature plays a crucial role in safeguarding phosphor particles against erosion resulting from exposure to high-temperature melts. Phosphor-in-glass retains 93% of the quantum efficiency observed for pure phosphor. The assembled white light-emitting diodes module has precise color tuning capabilities, achieving an optimal color rendering index of 93.7, a luminous efficacy of 80.4 lm/W, and a correlated color temperature of 5850 K. These outcomes hold potential for advancing the realm of inorganic package and high-quality white light illumination.