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The notorious tumor microenvironment (TME) usually becomes more deteriorative during phototherapeutic progress that hampers the antitumor efficacy. To overcome this issue, we herein report the ameliorative and adaptive nanoparticles (TPASIC-PFH@PLGA NPs) that simultaneously reverse hypoxia TME and switch photoactivities from photothermal-dominated state to photodynamic-dominated state to maximize phototherapeutic effect. TPASIC-PFH@PLGA NPs are designed by incorporating oxygen-rich liquid perfluorohexane (PFH) into the intraparticle microenvironment to regulate the intramolecular motions of AIE photosensitizer TPASIC. TPASIC exhibits a unique aggregation-enhanced reactive oxygen species (ROS) generation feature. PFH incorporation affords TPASIC the initially dispersed state, thus promoting active intramolecular motions and photothermal conversion efficiency. While PFH volatilization leads to nanoparticle collapse and the formation of tight TPASIC aggregates with largely enhanced ROS generation efficiency. As a consequence, PFH incorporation not only currently promotes both photothermal and photodynamic efficacies of TPASIC and increases the intratumoral oxygen level, but also enables the smart photothermal-to-photodynamic switch to maximize the phototherapeutic performance. The integration of PFH and AIE photosensitizer eventually delivers more excellent antitumor effect over conventional phototherapeutic agents with fixed photothermal and photodynamic efficacies. This study proposes a new nanoengineering strategy to ameliorate TME and adapt the treatment modality to fit the changed TME for advanced antitumor applications.

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BACKGROUND: The use of pesticides to protect crops has long been an important measure to provide healthy and safe agricultural products, but excess pesticides flow into fields and rivers, causing environmental pollution. Earlier methods utilizing organic solvent liquid-liquid microextraction for pesticide residue detection were not environmentally friendly. Therefore, it is significant to find a greener and more convenient detection method to determine pesticide residues. RESULTS: A new method was established to detect three triazole fungicides (TFs), including myclobutanil, epoxiconazole and tebuconazole, in environmental water samples. And the determination was conducted using a high-performance liquid chromatography with the ultraviolet detector (HPLC-UV). The switchable deep eutectic solvent (SDES) can be reversibly switched between hydrophilic and hydrophobic states through temperature modulation. Additionally, the method exhibited excellent linearity for all target analytes within the concentration range of 10-2000 µg L-1, with satisfactory R2 values (≥0.9975). The limits of detection (LODs) ranged from 2.3 to 2.6 µg L-1, and the limits of quantification (LOQs) ranged from 7.8 to 8.7 µg L-1. The accuracy of the method was assessed through intra-day and inter-day precision tests, yielding relative standard deviations (RSDs) in the ranges of 2.8%-6.7% and 2.2%-7.5%, respectively. Density functional theory (DFT) results indicated that hydrogen bonding is a significant factor affecting the binding of DES with triazoles. Three different green assessment tools were used to prove that the SDES-HLLME method had good greenness and broad applicability. SIGNIFICANCE: This is a homogeneous liquid-liquid microextraction (HLLME) method based on the upper critical solution temperature (UCST) type switchable deep eutectic solvent program, which can complete the extraction within a few minutes without dispersant. In terms of pesticide detection, the analytical method is simple and more conducive to environmental protection.

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Aqueous rechargeable zinc-ion batteries (ARZBs) are promising energy storage systems (ESSs) due to lots of advantages, such as high safety, high capacity, abundant resources, and low cost. However, the tunnel-structured Mn-based cathode materials such as α, ß, and γ-MnO2, which is widely used as the cathode of ARZBs, contain a phase transition in which Mn2+ ions are eluted during the discharge reaction of Zn2+ insertion, resulting in decreasing cycle life and rate capability of the ARZBs. Here, in order to enhance the cycle life and rate capability of ARZBs by retaining eluted Mn2+ ions around the ß-MnO2 cathode during the discharge process, tannic acid (TA), a type of polyphenolic biomolecule containing rich -OH groups, is introduced as a coating material. This provides a chelating effect with the eluted Mn2+ ions and hydroxyl groups on the surface of the ß-MnO2 cathode. This study clearly shows that the TA coating improves the performance of the cathode material by using a range of analytical methods. Owing to the chelating effects of TA, TA-coated ß-MnO2 cathode shows a high discharge capacity of 268.2 mAh g-1 at the current of 100 mA g-1 and 86.8% of high capacity retention after 50 cycles. This study provides the coating agents with chelating effects to develop Zn//MnO2 battery chemistry and further improve large ESSs through high electrochemical performance.

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Antiferroelectric materials have shown great potential in electronic devices benefiting from the reversible phase transition between ferroelectric and antiferroelectric phases. Understanding the dipole arrangements and clear phase transition pathways is crucial for design of antiferroelectric materials-based energy storage and conversion devices. However, the specific phase transition details remain largely unclear and even controversial to date. Here, we have grown a series of PbZrO3 on SrTiO3 substrates and elucidated the fine atom structures and phase transition pathways using atomic-resolution transmission electron microscopy. Specifically, a roadmap for ferroelectric to antiferroelectric phase transitions, here with increasing film thickness, is determined as ferroelectric rhombohedral (R3c)-ferroelectric monoclinic (Pc)-ferrielectric orthorhombic (Ima2)-antiferroelectric orthorhombic (Pbam), where Pc and Ima2 phases act as structural bridges. Moreover, the phase transition pathway is strongly related to the synergistic effect of oxygen octahedral tilting and cation displacement. These findings provide an insightful understanding for the theories and related properties of antiferroelectrics.

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The magnetocaloric (MC) and magnetic phase transition (MPT) properties in various types of rare earth (RE)-based magnetic materials have been intensively investigated recently, which are aimed at developing suitable MC materials for low-temperature cooling applications and better elucidating their inherent physical properties. We herein provide a combined experimental and theoretical investigation into two new light RE-based magnetic materials, namely, PrZnSi and NdZnSi compounds, regarding their structural, magnetic, MPT, and low-temperature MC properties. Both of these compounds crystallize in an AlB2-type hexagonal structure with a symmetry of the crystallographic space group P6/mmm and reveal a typical second-order-type MPT with ordering temperatures (TC) at approximately 13.5 and 18.5 K for PrZnSi and NdZnSi compounds, respectively. Moreover, they all exhibit large reversible low-temperature MC effects and remarkable performances, which are identified by the parameters of maximum magnetic entropy changes, relative cooling power, and temperature-averaged entropy change (temperature lift 5 K). The deduced values of these MC parameters under a magnetic field change of 0-7 T reach 16.3 J/kgK, 294.46 J/kg, and 15.79 J/kgK for PrZnSi and 15.4 J/kgK, 284.84 J/kg, and 14.95 J/kgK for NdZnSi, respectively, which are evidently better than those of most updated light RE-based magnetic materials with remarkable low-temperature MC performances, indicating that PrZnSi and NdZnSi compounds hold potentials for practical cooling applications.

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This work studied the phase transition and gel properties of cassava starch in aqueous choline acetate ([Ch][OAc]) solution at different [Ch][OAc]:water weight ratios. The paste viscosity and gel strength followed a similar pattern to the starch phase transition temperature, increasing at a 2:3 [Ch][OAc]:water ratio and then decreasing at 3:2 and 4:1 ratios. However, the mobility of free water in the starch gel decreased as the [Ch][OAc]:water ratio increased. At the same [Ch][OAc]:water ratios, acetylated cassava starch (ACS) underwent phase transition more easily than native cassava starch (NCS), leading to greater granule destruction. Nevertheless, ACS gels displayed more viscous-dominated rheological behavior, lower paste viscosity, viscoelasticity, and weaker water-holding capacity (WHC) than NCS gels. In contrast, cross-linked cassava starch (CCS) gels had higher paste viscosity, gel viscoelasticity, and WHC. However, at a 4:1 [Ch][OAc]:water ratio, the viscoelasticity of CCS gel was lower than NCS gel, and the differences in WHC were minimal, likely due to the incomplete phase transition of especially CCS under this condition. Our findings show that starch chemical modification significantly affects phase transition behavior and gel properties in [Ch][OAc]:water mixtures, with outcomes influenced by the viscosity of the aqueous [Ch][OAc] solution and the interaction between [Ch][OAc] and water.

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Lilium is one of the most widely cultivated ornamental bulbous plants in the world. Although research has shown that variable temperature treatments can accelerate the development process from vegetative to reproductive growth in Lilium, the molecular regulation mechanisms of this development are not clear. In this study, Lbr-miR171b and its target gene, LbrSCL6, were selected and validated using transgenic functional verification, subcellular localization, and transcriptional activation. This study also investigated the differential expression of Lbr-miR171b and LbrSCL6 in two temperature treatment groups (25 °C and 15 °C). Lbr-miR171b expression significantly increased after the temperature change, whereas that of LbrSCL6 exhibited the opposite trend. Through in situ hybridization experiments facilitated by the design of hybridization probes targeting LbrSCL6, a reduction in LbrSCL6 expression was detected following variable temperature treatment at 15 °C. The transgenic overexpression of Lbr-miR171b in plants promoted the phase transition, while LbrSCL6 overexpression induced a delay in the phase transition. In addition, LbrWOX4 interacted with LbrSCL6 in yeast two-hybrid and bimolecular fluorescence complementation assays. In conclusion, these results explain the molecular regulatory mechanisms governing the phase transition in Lilium.

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The ground state of a one-dimensional spin- 1 2 uniform antiferromagnetic Heisenberg chain (AfHc) is a Tomonaga-Luttinger liquid which is quantum-critical with respect to applied magnetic fields up to a saturation field µ 0 H s beyond which it transforms to a fully polarized state. Wilson ratio has been predicted to be a good indicator for demarcating these phases [Phys. Rev. B 96, 220401 (2017)]. From detailed temperature and magnetic field-dependent magnetization, magnetic susceptibility and specific heat measurements in a metalorganic complex and comparisons with field theory and quantum transfer matrix method calculations, the complex was found to be a very good realization of a spin- 1 2 AfHc. Wilson ratio obtained from experimentally obtained magnetic susceptibility and magnetic contribution of specific heat values was used to map the magnetic phase diagram of the uniform spin- 1 2 AfHc over large regions of phase space demarcating Tomonaga-Luttinger liquid, saturation field quantum critical, and fully polarized states. Luttinger parameter and spinon velocity were found to match very well with the values predicted from conformal field theory.

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With the development of technology, multifunctional multiband emitters have been paid much attention due to their wide range of applications, such as LIDAR detection, spectroscopic sensing, and infrared thermal management. However, the development of such emitters is impeded by incompatible structural requirements of different electromagnetic wavebands. Here, we demonstrate coupled modulation between near-infrared (NIR) laser-wavelength and long-wavelength-infrared by constructing a multifunctional emitter (MFE) with a structure of Al/HfO2/VO2, utilizing the phase transition of VO2. The MFE displays excellent thermal modulation capability within the 8-14 µm range, achieving a thermal insulation effect (ε8-14 µm = 0.18) at low temperatures, and heat dissipation effect (ε8-14 µm = 0.64) at high temperatures. The MFE's radiation power regulation capability is 145.06 W m-2 between a temperature of 0 to 60 °C. Moreover, the MFE possesses a large reflectivity modulation value of 0.78 at NIR laser-wavelength (1.06 µm) with a short phase transition time of 1003 ms under 3 W cm-2 laser irradiation. This study provides a guideline for the coordinated control of electromagnetic waves and intelligent collaborative thermal management through simple structural design, thus, having broad implications in energy saving and thermal information processing.

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Metamaterial has been captivated a popular notion, offering photonic functionalities beyond the capabilities of natural materials. Its desirable functionality primarily relies on well-controlled conditions such as structural resonance, dispersion, geometry, filling fraction, external actuation, etc. However, its fundamental building blocks-meta-atoms-still rely on naturally occurring substances. Here, we propose and validate the concept of gradient and reversible atomic-engineered metamaterials (GRAM), which represents a platform for continuously tunable solid metaphotonics by atomic manipulation. GRAM consists of an atomic heterogenous interface of amorphous host and noble metals at the bottom, and the top interface was designed to facilitate the reversible movement of foreign atoms. Continuous and reversible changes in GRAM's refractive index and atomic structures are observed in the presence of a thermal field. We achieve multiple optical states of GRAM at varying temperature and time and demonstrate GRAM-based tunable nanophotonic devices in the visible spectrum. Further, high-efficiency and programmable laser raster-scanning patterns can be locally controlled by adjusting power and speed, without any mask-assisted or complex nanofabrication. Our approach casts a distinct, multilevel, and reversible postfabrication recipe to modify a solid material's properties at the atomic scale, opening avenues for optical materials engineering, information storage, display, and encryption, as well as advanced thermal optics and photonics.

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Topotactic reduction is critical to a wealth of phase transitions of current interest, including synthesis of the superconducting nickelate Nd0.8Sr0.2NiO2, reduced from the initial Nd0.8Sr0.2NiO3/SrTiO3 heterostructure. Due to the highly sensitive and often damaging nature of the topotactic reduction, however, only a handful of research groups have been able to reproduce the superconductivity results. A series of in situ synchrotron-based investigations reveal that this is due to the necessary formation of an initial, ultrathin layer at the Nd0.8Sr0.2NiO3 surface that helps to mediate the introduction of hydrogen into the film such that apical oxygens are first removed from the Nd0.8Sr0.2NiO3 / SrTiO3 (001) interface and delivered into the reducing environment. This allows the square-planar / perovskite interface to stabilize and propagate from the bottom to the top of the film without the formation of interphase defects. Importantly, neither geometric rotations in the square planar structure nor significant incorporation of hydrogen within the films is detected, obviating its need for superconductivity. These findings unveil the structural basis underlying the transformation pathway and provide important guidance on achieving the superconducting phase in reduced nickelate systems.

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2D transition metal oxides have created revolution in the field of supercapacitors due to their fabulous electrochemical performance and stability. Molybdenum trioxides (MoO3) are one of the most prominent solid-state materials employed in energy storage applications. In this present work, we report a non-laborious physical vapor deposition (PVD) and ultrasonic extraction (USE) followed by vacuum assisted solvothermal treatment (VST) route (DEST), to produce 2D MoO3 nanosheets, without any complex equipment requirements. Phase transition in MoO3 is often achieved at very high temperatures by other reported works. But our well-thought-out, robust approach led to a phase transition from one phase to another phase, for e.g., hexagonal (h-MoO3) to orthorhombic (α-MoO3) structure at very low temperature (90 °C), using a green solvent (H2O) and renewable energy. This was achieved by implementing the concept of oxygen vacancy defects and solvolysis. The synthesized 2D nanomaterials were investigated for electrochemical performance as supercapacitor electrode materials. The α-MoO3 electrode material has shown supreme capacitance (256 Fg-1) than its counterpart h-MoO3 and mixed phases (h and α) of MoO3 (< 50 Fg-1). Thus, this work opens up a new possibility to synthesize electrocapacitive 2D MoO3 nanosheets in an eco-friendly and energy efficient way; hence can contribute in renewable circular economy.

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Crystal structural rearrangements unavoidably introduce defects into materials, where even these small changes in local lattice structure could arouse a prominent impact on the overall nature of crystals. Contrary to the traditional notion that defects obstruct carrier transport, herein, we report a promoted transport mechanism of nonluminescent carriers in single-crystalline CH3NH3PbI3 nanowires (1345.2 cm2 V-1 s-1, about a 14-fold improvement), enabled by the phase transition induced defects (PTIDs). Carriers captured by PTIDs evade both the radiative and non-radiative recombinations during the incomplete tetragonal-to-orthorhombic phase transition at low temperatures, forming a specific nonluminescent state that exhibits an efficient long-distance transport and thereby realize a prominent enhancement of photocurrent responsivity for photodetector applications. The findings provide broader insights into the carrier transport mechanism in perovskite semiconductors and have significant implications for their rational design for photoelectronic applications at varied operating temperatures.

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Artificial sensory afferent nerves that emulate receptor nanochannel perception and synaptic ionic information processing in chemical environments are highly desirable for bioelectronics. However, challenges persist in achieving life-like nanoscale conformal contact, agile multimodal sensing response, and synaptic feedback with ions. Here, a precisely tuned phase transition poly(N-isopropylacrylamide) (PNIPAM) hydrogel is introduced through the water molecule reservoir strategy. The resulting hydrogel with strongly cross-linked networks exhibits excellent mechanical performance (∼2000% elongation) and robust adhesive strength. Importantly, the hydrogel's enhanced ionic conductance and heterogeneous structure of the temperature-sensitive component enable highly sensitive strain information perception (GFmax = 7.94, response time ∼ 87 ms), temperature information perception (TCRmax = -1.974%/°C, response time ∼ 270 ms), and low energy consumption synaptic plasticity (42.2 fJ/spike). As a demonstration, a neuromorphic sensing-synaptic system is constructed integrating iontronic strain/temperature sensors with fiber synapses for real-time information sensing, discrimination, and feedback. This work holds enormous potential in bioinspired robotics and bioelectronics.

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The crystal of [C(NH2)3]2Zn(SO4)2 guanidine zinc sulfate was grown and its structure, dilatometric, dielectric, elastic and piezoelectric properties were studied in a broad temperature range, covering the phase transition point. The crystal undergoes a continuous phase transition at 178 K from the room temperature tetragonal phase with a space group I 4 ¯ 2 d to the tetragonal low temperature phase with a space group I 4 ¯ . The structural X-ray studies allowed proposing molecular mechanism associated with the rearrangement in the configuration of N-H⋯O hydrogen bonds and reorientation of guanidine cations in the structure, leading to a change in the symmetry of the low temperature phase. Results of thermal expansion and dielectric studies are typical of a structural nonferroelectric continuous transition. Also measurement of piezoelectric and elastic properties revealed small anomalies at 178 K. Below the transition temperature, a new piezoelectric component, that is a ferroelastoelectric macroscopic order parameter, was found.

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Separation of equally sized particles distinguished solely by material properties remains still a very challenging task. Here a simple separation of differently charged, thermo-responsive polymeric particles (for example microgels) but equal in size, via the combination of pressure-driven microfluidic flow and precise temperature control is proposed. The separation principle relies on forcing thermo-responsive microgels to undergo the volume phase transition during heating and therefore changing its size and correspondingly the change in drift along a pressure driven shear flow. Different thermo-responsive particle types such as different grades of ionizable groups inside the polymer matrix have different temperature regions of volume phase transition temperature (VPTT). This enables selective control of collapsed versus swollen microgels, and accordingly, this physical principle provides a simple method for fractioning a binary mixture with at least one thermo-responsive particle, which is achieved by elution times in the sense of particle chromatography. The concepts are visualized in experimental studies, with an intend to improve the purification strategy of the broad distribution of charged microgels into fractioning to more narrow distribution microgels distinguished solely by slight differences in net charge.

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Traditionally, the study of crystal polymorphism has relied on thermodynamics and measurements averaged over time and the crystal's constituents. This work introduces a kinetic approach to phase identification─millisecond cinematographic electron microscopic imaging of the dynamics of phase transitions of crystals of a few nm in diameter. We demonstrate a remarkable impact of the interface energy on the relative stability of the nanocrystal's polymorphs, enabling in situ manipulation of phase transitions through size increase or decrease. Starting with the B1 NaI polymorph at 298 K, we identified the previously unknown B2 polymorph of a 1 s lifetime upon sublimation of the crystal. From the CsCl liquid phase, we produced the B1 phase, previously described only at 749 K.

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The electronic orders in kagome materials have emerged as a fertile platform for studying exotic quantum states, and their intertwining with the unique kagome lattice geometry remains elusive. While various unconventional charge orders with broken symmetry is observed, the influence of kagome symmetry on magnetic order has so far not been directly observed. Here, using a high-resolution magnetic force microscopy, it is, for the first time, observed a new lattice form of noncollinear spin textures in the kagome ferromagnet in zero magnetic field. Under the influence of the sixfold rotational symmetry of the kagome lattice, the spin textures are hexagonal in shape and can further form a honeycomb lattice structure. Subsequent thermal cycling measurements reveal that these spin textures transform into a non-uniform in-plane ferromagnetic ground state at low temperatures and can fully rebuild at elevated temperatures, showing a strong second-order phase transition feature. Moreover, some out-of-plane magnetic moments persist at low temperatures, supporting the Kane-Mele scenario in explaining the emergence of the Dirac gap. The observations establish that the electronic properties, including both charge and spin orders, are strongly coupled with the kagome lattices.

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Molecular dynamics simulations are utilized to unravel the temperature-driven phase transition in double-layered butylammonium (BA) methylammonium (MA) lead halide perovskite (BA)2(MA)Pb2I7, which holds great promise for a wide range of optoelectronics and sensor applications. The simulations successfully capture the structural transition from low to high symmetry phases with rising temperatures, consistent with experimental observations. The phase transition is initiated at two critical interfaces: the first is between the inorganic and organic layers, where the melting of N-H bonds in BA leads to a significant reduction in hydrogen bonding between BA and iodides, and the second is at the interface between the top and bottom organic layers, where the melting of the tail bonds in BA triggers the phase transition. Following this, BA cations exhibit a patterned and synchronized motion reminiscent of a conical pendulum, displaying a mix of ordered and disordered behaviors prior to evolving into a completely molten and disordered state. While the melting of BA cations is the primary driver of the phase transition, the rotational dynamics of MA cations also plays a critical role in determining the phase transition temperature, influenced by the BA-MA interaction. Such an interaction alters the polarization patterns of MA cations across the phase transition. In particular, an antiparallel polarization pattern is observed in the low-temperature phase. Additionally, displacive elements of the phase transition are identified in the simulations, characterized by the shear and distortion of the inorganic octahedra. Notably, at lower temperatures, the octahedral distortion follows a bimodal distribution, reflecting significant variations in distortion among octahedra. This variation is attributed to an anisotropic hydrogen bonding network between iodides and BA cations. Our study reveals the phenomena and mechanisms extending beyond the order-disorder transition mechanism, suggesting potential phase engineering through strategic tuning of organic and inorganic components.

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Reversible solid oxide cells (RSOCs) are an all-solid-state electrochemical device, which can convert H2 into electricity in the fuel cell (SOFC) mode and electrolyze H2O into fuel gas in the electrolytic cell (SOEC) mode, exhibiting good application prospect in the development of carbon neutrality. However, the degradation of the air electrode caused by Cr-containing steel interconnects is a major obstacle that limits the broader application of RSOCs. Herein, the Cr poisoning effect on La0.6Sr0.4Co0.2Fe0.8O3-σ (LSCF)-based oxygen electrodes under the electrolysis mode was systematically investigated. The phase transition of the sediment during the chromium poisoning process was captured and monitored. When tested under the presence of Fe-Cr interconnects at 800 °C for 40 h, SrCrO4 on the surface of LSCF was clearly identified through XRD and Raman analysis as the main deposition, and with the prolonged operating time, LaCrO3 slowly emerged. Due to the much higher electrical conductivity of LaCrO3 compared to SrCrO4, the negative effect induced by Cr poisoning was offset along with test progressing due to the deposition transition phenomenon. Inspired by the interesting discoveries, transition from SrCrO4 to LaCrO3 can be artificially facilitated by switching the operating mode to the SOEC mode, which can partially recover the dramatic degradation caused by the Cr poisoning effect under the SOFC mode. The feasibility of the in situ electrochemical recovery method was also verified by the experimental results. The peak power density of the cells decreased from 0.829 to 0.505 W/cm2 when operating under the SOFC mode with an Fe-Cr metal connector, and after in situ electrochemical recovery in the SOEC mode, the peak power density recovered to 0.630 W/cm2. This study provides a new strategy for achieving high performance and stability of RSOCs.