The development of high-performance anode materials is critical for advancing sodium-ion batteries (SIBs) toward practical applications. Herein, we report a novel FeSe2@S-Ti2C heterostructure synthesized via a safe and straightforward Lewis acidic molten salt etching strategy followed by in-situ selenization. This approach enables simultaneous etching of Ti2AlC MAX phase, surface termination with sulfur-containing groups, and uniform anchoring of FeSe2 nanoparticles within the Ti2C MXene matrix, eliminating the need for hazardous HF or post-synthesis metal removal. The resulting heterostructure integrates multiple advantageous features: The highly conductive Ti₂C MXene framework accelerates the transport of Na+, while its structural robustness effectively accommodates the volume expansion caused by Na+ deintercalation. S-containing surface terminations provide additional active sites that enhance Na+ adsorption. Ultimately, the FeSe₂@S-Ti₂C anode demonstrates exceptional sodium-storage performance, characterized by a high reversible capacity of 397.6 mAh g-1 after 350 cycles at 1 A g-1, superior rate capability (227.8 mAh g-1 at 5 A g-1), as well as robust full-cell performance with an initial Coulombic efficiency of 91.2% and a reversible capacity of 493.6 mAh g-1 following 500 cycles at 1 A g-1. Density functional theory calculations further elucidate the underlying mechanism, revealing metallic conductivity, reduced Na+ diffusion barrier (0.30 eV), and enhanced Na adsorption energy (-2.43 eV) in the heterostructure. This work presents a versatile and scalable strategy for constructing advanced MXene-based heterostructures, offering promising avenues for high-performance SIB anodes.

The integration of photonic crystal (PC) architectures with magnetic responsiveness offers a compelling route toward smart micro-materials. However, achieving precise structural control over such composite microspheres via simple fabrication methods remains elusive. Here, we report a facile strategy combining simplified T-junction microfluidics with a concept of controlled HF etching to generate a series of hierarchically porous magnetic photonic crystal microspheres (MPhCMs) with tailored architectures. Crucially, by precisely regulating the etching extent, we achieve two functionally distinct yet structurally related outcomes. Complete etching transforms the spheres into hierarchically porous adsorbents exhibiting an adsorption rate of 92.33

Optical sensor research has drawn great attention for significant market potential and a wide range of applications. Ammonia (NH3) is a gas widely used in industry, but it is also a significant safety hazard for its toxicity, corrosiveness and explosiveness. However, it is challenging to create reliable NH3 optical sensors with high sensitivity, excellent selectivity and fast response simultaneously. In this work, heterostructure membrane Fabry-Pe´rot (F-P) cavities constructed by LiCl@MIL-53-(OH)2 (LiCl was anchored in MIL-53-(OH)2) and TiO2 (LiCl@MIL-53-(OH)2/TiO2) were fabricated for NH3 detection. Compared to the MIL-53-(OH)2/TiO2 heterostructure membrane F-P cavity, the LiCl@MIL-53-(OH)2/TiO2 heterostructure membrane F-P cavity exhibited superior sensing performance toward NH3. Experimental results indicated that the LiCl@MIL-53-(OH)2-2.0/TiO2 heterostructure membrane F-P cavity exhibited excellent selectivity and sensitivity (3.075 nm/ppm), and the lower detection limit achieved to 98 ppb. The results were attributed to the multiple actions of hydrogen bonding of NH3 with Cl- and NH3 coordination to Li+. Additionally, the sensor showed fast optical response time 500 ms, outstanding repeatability and stability. The sensitivity of LiCl@MIL-53-(OH)2-2.0/TiO2 heterostructure membrane F-P cavity toward NH3 at 2.5 ppm and 25 ppm is outstanding, showing the F-P cavity offers a promising solution for real-time NH3 monitoring. Therefore, LiCl was introduced into MIL-53-(OH)2/TiO2 F-P cavity NH3 sensor, which provides a new idea for future optical gas sensors with high performance for gas sensing.

Core-shell photonic microcapsules (PhMCs) have the advantage of rich structural color compared with homogeneous photonic crystal microspheres, and thus have higher application value. How to prepare structurally color controllable PhMCs with responsive functions is increasingly urgent, which is related to the possibility of further expanding their applications. In this report, we integrate microfluidic and controlled etching techniques to conveniently prepare structurally color controllable responsive PhMCs and successfully apply them in the fields of metal ion detection and optical anti-counterfeiting. Microfluidics endows PhMCs with controllable and homogeneous dimensions. Meanwhile, controlled etching gives PhMCs shells a controllable ratio of opal/inverseopal structures. The fully-etched PhMCs were designed as metal ion detectors to identify the existence of metal ions in the solution through the change of structural color. Notably, the partially etched PhMCs have three structural colors of red/green/yellow, which is the first time that triple stop band gaps PhMCs have been prepared based on two materials. The triple information has been switched by adjusting the transmission/reflection modes and the temperature to explore the function of an optical anti-counterfeiting model. Our study provides a new path for the construction of functionalized PhMCs, and further expands its potential application value.

NiTi alloy has excellent advantages in elastocaloric cooling due to its fatigue-resistant high performance and superelasticity. The piezoelectric material Pb(Zr0.52Ti0.48)O3 (PZT) is used in actuators and sensors for its piezoelectric or inverse piezoelectric effect. In this research, the NiTi thin film was coated with PZT to form a Ni49Ti51/PZT heterojunction by magnetron sputtering. The elastocaloric effect of the NiTi film was regulated by the electric field. The inverse piezoelectric effect of PZT was used to trigger the elastocaloric effect of the NiTi film in Ni49Ti51/PZT. This inverse piezoelectric-elastocaloric coupling involved electrical, mechanical, and thermal energy transformations, providing avenues for the development of an elastocaloric effect in refrigeration.

Gas cross sensitivity is a main bottleneck of a single gas sensor. An artificial nose is a sensing device that enable identification of gaseous molecules by analyzing the sensing data through pattern recognition. However, an advanced artificial nose which can identify and detect trace hazardous gases at room temperature and atmospheric humidity is still limited. Optical nose is an artificial nose based on the optical gas sensing array which can convert the signals generated by gases into optical signals at room temperature. Herein, an artificial optical nose which constructed by metal-organic frameworks (MOFs) three-dimensional photonic crystal (3D PC) array has been proposed to identify and detect trace hazardous gases. The operating principle is based on gas molecule-induced refractive index (RI) modulation of the MOFs 3D PC array. Each MOFs 3D PC has different adsorption capability enabled different optical response, which exhibits unique optical fingerprint for 13 hazardous gases with 3 ppm at room temperature 25 degrees C and real-time relative humidity RH 45 %, the response time of MOFs 3D PC array to hazardous gases is within 1 s. Optical fingerprints of 13 hazardous gases is recognized by machine learning classification algorithm used K-Nearest Neighbors (KNN), the average classification accuracy achieves to 97.8 %. Moreover, identification of 13 hazardous gases is also investigated at room temperature 25 degrees C and higher humidity RH 80 %. Furthermore, the application of the optical nose to quantitative detection of unknown hazardous gas concentration is realized, which will allow for addressing challenges in high toxicity and powerful lethality environment.

Ammonia (NH3) is a toxic and corrosive gas widely used in industry that threatens human health and pollutes the environment. Herein, a two-dimensional material graphene oxide (GO) with rich oxygen-containing functional groups and a metal-organic framework material MIL-101(Cr) with ultra-large specific surface area were combined to design a one-dimensional photonic crystal (1D PC) sensor. In the detection of six gases at 3 ppm, the GO and MIL-101(Cr) 1D PC (GO/MIL-101(Cr) 1D PC) demonstrated excellent selectivity for NH3. At concentrations from 0 to 3 ppm, the sensor exhibited good linearity towards NH3 (R2=0.99198), with high sensitivity of 1.35 nm/ppm and a detection limit as low as 222 ppb. The sensor exhibited ultrafast response time of 0.5 s, with outstanding repeatability and stability. The mechanism of excellent sensing performance of the sensor was discussed. This GO/MIL-101(Cr) 1D PC sensor provides an approach for realizing highly sensitive NH3 detection and ultrafast response at low concentrations.

The development of fast and accurate sensors for nerve agents holds immense significance for homeland security and public health. However, the humidity interference from ambient environments and poor sensitivity for trace nerve agents are largely unsolved problems. To overcome the problems, a humidity-independent two-dimensional photonic crystal (2-D PC) sensor is developed by exploiting UiO-66-NH2 2-D PC with excellent sensitivity coupled to a hydrophobic hydrogen-bonded organic framework (HOFs) for detection sarin simulant dimethyl methyl phosphonate (DMMP). Selective sensing results show that the HOFs@UiO-66-NH2 2-D PC sensor presents the outstanding DMMP specificity, and the limit of detection (LOD) for DMMP response of the sensor can reach 508 ± 68 ppb at room temperature. Water-resistant experiments demonstrate that the HOFs@UiO-66-NH2 2-D PC sensor shows excellent stability even under 80% relative humidity (RH). Moreover, the sensor also exhibits a rapid response/recovery time of 1 s/3 s and can maintain excellent sensing performance under heat-treatment of 200 °C and in the long-term storage (30 days). The adsorption kinetics and the hydrogen bond interaction are conducted to elucidate the mechanism of enhanced sensing DMMP properties. These results indicate the potential application of the sensor in the trace nerve agent's detection, especially in humidity environment.

Antiperovskite-type compounds with noncollinear spin arrangements have drawn great interest due to their rich strong-correlation properties associated with unique magnetic structures. Pressure is an effective way to tune the spin ordering and provoke novel phenomena by adjusting their complex exchange integrals. Here, we manipulate the unique magnetic structures in the frustrated antiperovskite Mn3GaN and try to clarify the evolution of strong-correlation physical properties under a high-pressure field up to 12 GPa. High-pressure induces the transition from the magnetic ground state with a typical 120 degrees spin arrangement to a 90 degrees spin configuration, and further to a ferromagnetic state. The observed anomalies in the electronic conduction and thermal expansion curves corresponding to the magnetic phase transitions are also gradually suppressed by pressure. Based on the high-pressure experiments, the T-P magnetic phase diagram is derived and the pressure-induced linear shift of the transition temperatures can be well observed. A spin model based on the classical Heisenberg theory was constructed to clarify the nature of the pressure effects, which is ascribed to the enhancement of the crystal field of N and the Mn-N-Mn superexchange contribution. Our results provide insight into the stabilization of noncollinear spin order.

The rapid and trace detection of sulfur mustard (SM), a classical hazardous chemical warfare agents (CWAs) causing irreversible health damages and fatal, is an urgently serious issue for security safeguard but remains challenges especially in real-time changing atmospheric humidity. Herein, a zeolite imidazolate framework–67 (ZIF–67) three–dimensional (3D) photonic crystal optical sensor has been designed and proposed to detect trace SM simulants 2–chloroethyl ethyl sulfide (CEES). Compared to traditional semiconductors, the optical sensor can work at room temperature and shows significant moisture resistance. At real-time relative humidity (RH) of 35%, the sensor exhibits excellent selectivity among seven interfering gases due to the co-interactions of metal sites Co atoms of ZIF–67 via Co···Cl and Co···S with CEES (C4H9ClS), the ultralow detection limit (16.5 ppb), ultrafast response (0.5s) for CEES can benefit from the ordered structure of ZIF-67 3D photonic crystal and its complete photonic bandgap. Most importantly, at higher RH 50%–95%, the sensor shows excellent moisture resistance and still keeps excellent selectivity, ultralow detection limit (19.1 ppb), ultrafast response (0.5s), long–term stability and reusability for CEES even at RH 95%, warranting its utility as a moisture–resistant trace chemical warfare agent optical sensor.

The relaxor ferroelectric material (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) has attracted great attention due to its excellent electrical properties. High quality Mn-Sm co-doped 0.68PMN-0.32PT thin films were fabricated on the Pt/Ti/SiO2/Si substrates with less oxygen vacancies by using sol-gel based spin coating method. It was found that 2 mol%Sm-1 mol%Mn doped PMN-PT thin films possess high dielectric permittivity (εr ~ 1895.24) and relatively low dielectric loss (tanδ ~ 0.039) at 1 kHz, and superior ferroelectric polarization (Pmax ~ 53.71 μC/cm2, Pr ~ 30.85 μC/cm2) with high dielectric breakdown strength (~ 1586.70 kV/cm), mainly due to its low leakage current density (~ 10-7 A/cm2). This work suggest an effective approach to improve the dielectric, piezoelectric and ferroelectric properties of PMN-PT thin films based on co-doping.

Chlorinated vapors, as one of the poisonous volatile organic compounds (VOCs), seriously pollute the environment and threaten human health. It still remains a major challenge for designing reliable chlorinated vapors sensing materials with high sensitivity. Herein, we propose a simple yet powerful optical sensor based on zeolitic imidazolate frameworks ZIF-8 three-dimensional photonic crystals (3D PCs), which keeps high efficiency in vapor sensing through varying their effective refractive index (RI). ZIF-8 3D PCs sensors with tunable crystal facets and photonic bandgap were prepared by self-assembly of monodisperse polyhedral ZIF-8 particles, which are truncated rhombic dodecahedral (TRD)-, rhombic dodecahedral (RD)-, truncated cubic (TC)-, and spherical (Sphere) ZIF-8 3D PCs sensors. The application of polyhedral ZIF-8 3D PCs sensors for chlorinated vapors detection was investigated. The selectivity was found to be closely related to the exposed crystal facets, and the TRD ZIF-8 3D PCs sensor exhibited excellent selectivity, sensitivity (0.514 nm ppm-1), and sensing performance for chlorobenzene (C6H5Cl) vapor, the ultrafast response time (<= 1 s) and remarkable long-term stability and recyclability, which might ultimately benefit for practical VOCs sensing applications.

Researchers have been working to develop stable and convenient test strips for detecting heavy metals. This paper reports a new portable lead ion test strip based on the exceptional photoluminescence properties of CsPbBr3. The CsBr films deposited on different substrates (rigid, semi-rigid, and flexible substrates) display highly selective luminescent response to Pb2+. For the flexible substrate, CsBr fluorescent probe not only shows lightweight, easy to use in large-scale manufacturing but also exhibits long detection lifetime. In comparison to organometallic perovskite fluorescence sensing of Pb2+, the CsBr fluorescent probe displays better stability and higher detection limit. Moreover, the used test strip can be reused to detect Cl− in solution, the CsBr fluorescent probe also shows a potential for multi-testing in recycling applications.

The effects of rare earth Y content on the microstructure and high-temperature oxidation properties of 47Fe-36Ni-15Cr-1.5Mn alloy at 1000°C were investigated. The results show that 47Fe-36Ni-15Cr-1.5Mn alloy oxidizes at 1000°C under laboratory atmospheric pressure to form an oxide film layer dominated by Cr2O3 and (Fe, Ni, Mn) Cr2O4 spinel, and the oxidation curve of the alloy follows the parabolic law. After the addition of rare earth Y, rare earth phases precipitated along the grain boundaries in the alloy, and the more Y content, the more precipitated phases in the grain boundaries. The alloy with added rare earths was oxidized at a high temperature of 1000 °C for 2160 min, the oxidation law still followed the parabolic law, while the rare earth phase at the grain boundary reacted with the oxygen atoms infiltrated from the outside to generate a rare earth Y-rich oxide residing at the boundary between the grain boundary and the precipitated phase of the alloy. Add 0.5 wt.% rare earth Y 47Fe-36Ni-15Cr-1.5Mn-0.5Y alloy 1000 ° C high temperature oxidation of the formation of spinel oxide crystalline particles, dense and complete oxide film layer, the surface of the addition of a small amount of (0.5 wt.%) rare earth Y after the refinement of the oxide particles, and in the alloy grain boundaries in the form of oxides reside in the alloy to inhibit the cations in the matrix and the oxygen negative ions. and oxygen-negative ions in the alloy matrix, improving the antioxidant performance of the alloy. With the further increase of rare earth Y, during the oxidation of the alloy at high temperature, the precipitation phase at the grain boundary promotes the inward diffusion of oxygen, resulting in the deterioration of the antioxidant property of the alloy.

Chlorinated gases seriously pollute the environment and threaten human health. Limitation of insufficient adsorption sites and interference of atmospheric humidity, designing an advanced sensing device with high adsorption and moisture resistance is still a challenge to detect chlorinated gases for air monitoring. Herein, a moisture-resistant optical sensor based UiO-66 three-dimensional (3D) photonic crystals is achieved. The optical sensor shows customizable structure and tunable optical properties, which are benefit to gas diffusion and signal transduction. The application of the optical sensor for 2.5 ppm carbon tetrachloride (CCl4), dichloromethane (CH2Cl2), chlorobenzene (C6H5Cl) and hydrochloric acid (HCl) detection was investigated in relative humidity (RH) 35%. The sensor exhibits excellent selectivity for HCl, which agree with the density functional theory (DFT) calculations for the adsorption energy. Especially, the sensor exhibits high stability and repeatability under RH 50%- 95%, and the sensing performance of the sensor for 2.5 ppm HCl has improved at RH up to 65%, limit of detection (LOD) can reach 10.9 ppb, ultra-fast response was 0.49 s. The improvements in sensing performance under RH are attributed to moisture-enhanced adsorption mechanism. This work provides a new insight for effective utilization of advanced materials and device to achieve ultra-trace chlorinated gas detection in humid atmosphere.

Mn3GaC exhibits both negative and positive magnetocaloric effects (NMCE and PMCE). Herein, to fabricate high-performance magnetic refrigerants, enhancement of the magnetocaloric effect (MCE) by combining NMCE and PMCE is studied. Compared with composite magnetic refrigerants, an NMCE-PMCE combination in a single magnetic refrigerant considerably enhances the operating temperature range without any loss of magnetic entropy change or relative cooling power (RCP). To realize an NMCE-PMCE combination, the NMCE and PMCE must be clearly identified. The intermediate canted ferromagnetic phase (CFM) between the antiferromagnetic and ferromagnetic phases of Mn3GaC plays a key role in establishing the borderline between the NMCE and PMCE. The effects of substituting Sn, Ge, and Y for Ga on the magnetic phase separation, NMCE, and PMCE of Mn3Ga1−xAxC (A = Sn, Ge, Y) are investigated. Y doping considerably enhances the CFM state, which establishes a buffer region between the NMCE and PMCE in Mn3Ga0.97Y0.03C. Because of this buffer region, the NMCE and PMCE can be controlled in different temperature ranges for practical applications. We achieve an NMCE-PMCE combination and obtain a super-wide working temperature range in Mn3Ga0.97Y0.03C. This work will be helpful in developing a practical magnetocaloric material with a large MCE and a working temperature range.

Excessive hypochlorite (ClO-) is easy to form residues in water, which will seriously endanger human health and environmental pollution. Therefore, it is essential to develop a sensitive fluorescent sensor to detect ClO- in water. Herein, a simple and economical fluorescent probe for the detection of ClO- was designed by highly exfoliated graphite-like carbon nitride (Ex_g-C3N4). The results showed that Ex_g-C3N4 had obvious fluorescence quenching effect on ClO- with high selectivity and anti-interference ability, which was feasible for making probes for detecting ClO- in water. Sensing experiments showed that the Ex_g-C3N4 probe had the detection limit of 5.56 nM while the detection range was 0-62 mM in water. Moreover, the fast response time of Ex_g-C3N4 was less than 30 s, illustrating the superior sensitivity. Besides, the fluorescence sensing experiment was carried out in various liquid conditions, which demonstrated that Ex_g-C3N4 probe had outstanding detecting application in natural environment. A portable fluorescent test strip for rapid detecting ClO- was successfully developed. The response of the probe on test strip towards ClO- was investigated, and the detection limit (0.1 mu M) is low enough to meet the safety requirements in tap water. Furthermore, the quenching mechanism of Ex_g-C3N4 probe was also discussed.

Concerning the part of global warming caused by conventional refrigerant gasses, past decades of research on solid-state cooling technologies based on caloric effects present an attractive alternative with zero -greenhouse gas emission and higher operating efficiency. However, the search for materials with large caloric effects near room temperature has become a challenge in modern material physics. Mn-based antiperovskite compounds are favorable caloric materials which generate a reversible enthalpy change by applying an external field. We report a novel approach of piezo-enhanced elastocaloric-like effect on Mn3SnC for solid-state refrigeration application. In the as-designed Mn3SnC/PZT magnetoelectric hetero-composite, the reversible caloric effect of Mn3SnC was regulated by the electric field-induced strain in the PZT piezoelectricity layer without any external magnetic field. In addition, we proposed an experimental setup for the direct adiabatic temperature change measurement of the caloric effect. The adiabatic temperature change is as high as similar to 0.57 K at 280 K under an electric field of 0.8 kV/cm, which is approximately 2 factors larger than that of the magnetocaloric effect value of Mn3SnC under 3 T. By adopting the first-principles theory, we estimated the entropy change is approximately 2.6 J Kg(-1) K-1 at 280 K which is close to the previous reports. This work demonstrates a novel approach to effectively enhance reversible caloric effects in first-order phase transition materials via electric fields. (C) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

采用固相合成法高温烧结Mn3SnC和Mn3CuN两种化合物制备出相变温区连续变化的Mn3Sn1-xCuxC1-cNx系列化合物,再将不同相变温区的Mn3Sn1-xCuxC1-xNx化合物进行物理混合制备出反钙钛矿复合磁制冷材料.这种磁制冷材料在室温附近具有"平台"状的磁熵变-温度曲线,与Mn3SnC单体材料相比其磁制冷温区由275～285 K扩展为220～300 K,磁熵变-温度曲线的半高宽从5K增大到70 K,但是其磁熵变值大幅降低.推导了这种磁制冷材料的最大磁熵变值与磁熵变曲线半高宽和单体材料相对制冷量之间的定量关系式,解释了扩展制冷温区与提高磁熵变值之间的竞争.此定量公式不仅可用于研究反钙钛矿材料体系,对研究其它复合磁制冷材料体系也有重要的参考价值.本文首次根据单体材料的热流曲线提出了新复合磁制冷材料的计算和预测方法,可极大地简化磁制冷复合材料的设计.