ABO3 Perovskite Research Articles

МАГНИТОЭЛЕКТРИЧЕСКИЕ ЭФФЕКТЫ В МУЛЬТИФЕРРОИКАХ

Research of magnetoelectric effects and multiferroic materials, in which these effects are manifested, is among key areas in modern magnetism. This is associated with promising aspects of applying the results to spintronics, orbitronics, and new generation systems for information storage and processing. Despite a great many of already known materials which, in varying degrees, have magnetoelectric properties, the question regarding physical mechanisms and nature of magnetoelectric effects still remains open. Single-phase multiferroics with their magnetic and segnetoelectric properties implemented in a single crystalline phase are of especially great interest for studying. The most known "traditional multiferroics", such as bismuth ferrite, manganites, rare earthearth orthoferrites and orthochromites, fall into the class of perovskite multiferroics, i.e. the crystalline structure of ABO3 perovskites serve as their pre-phase. However, the difference between crystallographic distortions that results in the formation of various crystalline structures, for example, bismuth ferrite and rare-earth orthoferrites/orthochromites, leads to an essential difference in their physical properties, including magnetoelectric ones. Whereas bismuth ferrite characterized by the R3c symmetry space group is a segnetoelectric (i.e. it has spontaneous segnetoelectric polarization), the presence of segnetoelectric polarization in orthoferrites/orthochromites with the Pbnm symmetry space group is impossible from the symmetry standpoint. However, recent experimental and theoretical research works show that under certain conditions magnetoelectric properties are found in both classes of the said multiferroics. This paper is an overview by its nature and discusses magnetoelectric effects in various classes of single-phase multiferroics with the distorted perovskite structure: proper multiferroics exemplified by bismuth ferrite and improper multiferroics exemplified by rare-earth orthoferrites/orthochromites. Consideration is given to basic principles of the symmetry approach used to study magnetoelectric effects in multiferroics; calculations and analysis of magnetoelectric effects in rare-earth orthoferrites/orthochromites are performed through the methods of group-theoretical analysis.

Structural, electrical and dielectric investigations of cerium doped barium zirconate (BaZrO3) nano-ceramics produced via green synthesis: Probable candidate for solid oxide fuel cells and microwave applications

Cerium incorporated barium zirconate nano-ceramics BaZr1-xCexO3-x/2 were fabricated by eco-friendly green combustion using honey as a fuel. FTIR spectra evidenced a prominent band between 400 and 700 cm−1 characteristics of ABO3 perovskites. The bond-length (r) of Zr–O bond is extended through doping of Ce ions. Consequently, the communication among Zr and O bond is weakened. The electrical conductivity rises with temperature, demonstrating that BaZr1-xCexO3-x/2 exhibits ionic and/or electron-hole conduction. The conductivity is observed to enhance with the Ce3+ concentration. At 850 °C, the solid x = 0.10 exhibits enhanced conductivity of 0.0190 S/cm than that of pristine BaZrO3 (0.010 S/cm). The increasing trend of conductivity may be due to decreased grain boundary resistance effect and generation of oxygen vacancies. Dielectric behaviour shows slight frequency dependence performance, the dielectric constant was high (ε = 35–45) in lower frequency region. The dielectric constant declines on enhancing Ce-content which can be explained on the Maxwell-Wagner model.

Performance Evaluation of the SrZrxSn1-xO3 Photocatalytic System for Remazol Yellow Dye Degradation Employing Box-Behnken Design

Contamination of effluents often occurs due to improper disposal of textile dyes or their by-products. These can often be carcinogenic and/or mutagenic to the biome. Given the above, the need for effective methods for treating effluents is clear. This treatment occurs by biological, physical, and/or chemical processes. Regarding chemical processes, heterogeneous photocatalysis stands out, mainly because it guarantees an effective degradation of contaminants. In this sense, mixed metal oxides, act as photocatalysts and constitute structures capable of producing a large family of solids with physical properties suitable for the degradation of many pollutants. Modified ABO3 perovskites, as in the case of the SrZrxSn1-xO3 semiconductor system, are effective in the degradation of textile dyes in effluents. The present work aimed to use the Box-Behnken model to evaluate the performance of the oxides resulting from the structural modifications of the perovskite SrZrxSn1-xO3 system, concerning the discoloration of the golden yellow dye remazol. The synthesized oxides were characterized by instrumental techniques and a Box-Behnken 34 project was developed. From this, the influence of some factors such as structural modification, oxide mass, exposure time, and the number of UVC lamps was evaluated. The discoloration of the dye was monitored from the attenuation of the absorbance at the wavelength 411 nm. According to the results obtained, the highest percentage of discoloration was obtained using the modified oxide SrZr0,25Sn0,75O3 for an approximate time of 6 hours in contact with 1 UVC lamp.

High Energy Efficiency and Thermal Stability of BaTiO3–BiScO3 Thin Films Based on Defects Engineering

ABO3 perovskite ferroelectric thin films have gained wide attention in recent years for high density capacitive energy storage applications. In this regard, BaTiO3–BiMeO3, where Me is a metal catio...

A combinatory ferroelectric compound bridging simple ABO3 and A-site-ordered quadruple perovskite

The simple ABO3 and A-site-ordered AA′3B4O12 perovskites represent two types of classical perovskite functional materials. There are well-known simple perovskites with ferroelectric properties, while there is still no report of ferroelectricity due to symmetry breaking transition in A-site-ordered quadruple perovskites. Here we report the high pressure synthesis of an A-site-ordered perovskite PbHg3Ti4O12, the only known quadruple perovskite that transforms from high-temperature centrosymmetric paraelectric phase to low-temperature non-centrosymmetric ferroelectric phase. The coordination chemistry of Hg2+ is changed from square planar as in typical A-site-ordered quadruple perovskite to a rare stereo type with 8 ligands in PbHg3Ti4O12. Thus PbHg3Ti4O12 appears to be a combinatory link from simple ABO3 perovskites to A-site-ordered AA′3Ti4O12 perovskites, sharing both displacive ferroelectricity with former and structure coordination with latter. This is the only example so far showing ferroelectricity due to symmetry breaking phase transition in AA′3B4O12-type A-site-ordered perovskites, and opens a direction to search for ferroelectric materials.

Predicting lattice parameters for orthorhombic distorted-perovskite oxides via machine learning

Orthorhombic perovskite oxides, ABO3, have been studied extensively for application in advanced functional materials and devices, due to unique and versatile materials properties that arise from stoichiometry engineering. The lattice parameters, a, b, and c, have a critical impact on the structural stability, electronic structure, magnetic ordering, and thus materials performance. In this study, we develop the Gaussian process regression (GPR) model based on the Bayesian optimization to provide statistical relationships among the ionic radii, electronegativities, valence, and lattice constants for orthorhombic perovskite ABO3 compounds with 157 samples. The model shows a high degree of stability and accuracy. After being applied to predict the lattice parameters of doped- and non-synthesized oxides, the GPR model shows promising prediction power as well. The model may be used as an alternative method to obtain lattice parameters as compared to experimental approaches and other modeling methods.

Manipulating Surface Termination of Perovskite Manganate for Oxygen Activation

AbstractFor ABO3 perovskite oxides, one of the key issues limiting their utilization in heterogeneous catalysis is the dominant presence of catalytically inactive A‐site cations at the surface. The engineering of B‐site terminated perovskites is considered as an effective method to address this issue, especially when dealing with Mn/Co‐based perovskite catalysts. However, to date, such a strategy has not been fully successful and remains a major challenge in the field. Herein, a Mn‐terminated La0.45Sr0.45MnO3 (B‐LSM) is successfully synthesized via a one‐pot hydrothermal method, in which low‐valence Mn ions partially occupy the A site to form the active Mn‐excess phase. Experimental results and theoretical calculations reveal that the presence of the surface Mn termination in B‐LSM optimizes the hybrid orbitals of Mn 3d‐O 2p and promotes the activation of surface lattice oxygen, where the pristine inert lattice O2− is evolved into active and stable lattice O2−x. Such structural optimization significantly reduces the activation energy barriers on going from O2− species to important intermediate O− species during O2 activation. Moreover, this results in good stability and Pt‐like activity for the B‐LSM during CO oxidation. This work offers a new chemical route for the design of advanced perovskite‐type oxides possessing novel functions.

Essential role of B metal species in perovskite type catalyst structure and activity on toluene oxidation

The perovskite type materials with transition metals are getting more attention especially as catalysts in total oxidation reaction. This work explores the B metal effect on the catalytic activity of LaBO3 structured perovskites in total oxidation of toluene. The perovskite type oxides were obtained by Pechini method and characterized by X-ray diffraction, nitrogen adsorption/desorption isotherms, thermogravimetric analysis and differential scanning calorimetry, temperature-programmed reduction (H2-TPR), Raman spectroscopy, Fourier transform infrared spectroscopy and particle size analysis. The results showed that LaFeO3 catalyst contained a single orthorhombic LaFeO3 phase, while LaMnO3 contained LaMn2O5 species besides cubic LaMnO3 phase. Both catalysts show very narrow distributions and average values of 55.59 μm and 51.43 μm for LaMnO3 and LaFeO3, respectively. With regard to the H2-TPR profile for the LaMnO3, Mn4+ to Mn3+ reduction and Mn3+ to Mn2+ reduction. Consequently, the redox performance of ABO3 perovskites was found as mainly driven by the B-site transition-metal element character. According to the catalytic tests, the LaMnO3 catalyst was more active for toluene oxidation than LaFeO3 and achieved the lowest light-off temperatures. An excellent agreement between the experimental data and the proposed one-dimensional pseudo-homogeneous model was achieved and corresponding kinetic parameters (estimated rate constants, k, activation energies, EA, and frequency factors, Ar) were estimated. Lower activation energy was estimated for LaMnO3 catalyst (84 kJ mol−1 vs. 99 kJ mol−1 for LaFeO3) confirming that LaMnO3 catalyst was more active for toluene oxidation under reaction conditions presented in this paper.

A Resol-Assisted Cationic Coordinative Co-assembly Approach to Mesoporous ABO3 Perovskite Oxides with Rich Oxygen Vacancy for Enhanced Hydrogenation of Furfural to Furfuryl Alcohol.

It is a challenge to obtain ABO3 perovskite oxides with favorable crystal phase and well-defined porous structure via existing approaches. Here, we design an effective and versatile strategy to construct mesoporous ABO3 perovskite oxides with functionalized nanocrystal frameworks and abundant oxygen vacancy sites via a resol-assisted cationic coordinative co-assembly approach. The as-prepared oxygen vacancy-rich mesoporous LaMnO3 as heterogeneous catalyst exhibits remarkable catalytic activity and stability for hydrogenation of furfural to furfuryl alcohol, including over 99 % conversion and 96 % selectivity. Combined with density functional theory calculation, the catalytic mechanism is elucidated, revealing that porous LaMnO3 nanocrystal framework is conducive to expose oxygen deficiency sites, which can facilitate the interaction between catalyst surface and catalytic substrate, leading to lower barrier in hydrogenation process.

A Resol‐Assisted Cationic Coordinative Co‐assembly Approach to Mesoporous ABO3 Perovskite Oxides with Rich Oxygen Vacancy for Enhanced Hydrogenation of Furfural to Furfuryl Alcohol

AbstractIt is a challenge to obtain ABO3 perovskite oxides with favorable crystal phase and well‐defined porous structure via existing approaches. Here, we design an effective and versatile strategy to construct mesoporous ABO3 perovskite oxides with functionalized nanocrystal frameworks and abundant oxygen vacancy sites via a resol‐assisted cationic coordinative co‐assembly approach. The as‐prepared oxygen vacancy‐rich mesoporous LaMnO3 as heterogeneous catalyst exhibits remarkable catalytic activity and stability for hydrogenation of furfural to furfuryl alcohol, including over 99 % conversion and 96 % selectivity. Combined with density functional theory calculation, the catalytic mechanism is elucidated, revealing that porous LaMnO3 nanocrystal framework is conducive to expose oxygen deficiency sites, which can facilitate the interaction between catalyst surface and catalytic substrate, leading to lower barrier in hydrogenation process.

Preparation and Characterization of LaCr0.99Fe0.01O3 Nanomaterial

Perovskite compounds show great potential in a variety of applications due to their diverse and unique properties and can be modified. Nanomaterial LaCr0.99Fe0.01O3 has been prepared using sol-gel and freeze drying methods. The nanomaterial was then calcined at 700°C for 10 hours and characterized by the analysis techniques of X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Diffuse Reflectance UV-Vis Spectroscopy (DRS UV-Vis), and Transmission Electron Microscopy (TEM). The result of XRD analysis showed that two main crystal phases were formed from the ABO3 perovskite structure, namely LaCrO3 and LaFeO3 which were superimpossed and the crystalline phase size based on the Scherrer method was 23.5 nm. Furthermore, the TEM analysis result shows that there are various forms and hollows. Then, the FTIR spectrum states that there is an interaction between transition metals, and the band gap energy is 2.71 eV.

Performances variations of BiFeO3-based ceramics induced by additives with diverse phase structures

Obviously distortion occurred in the BFBT ceramics after four different space groups of ABO3 perovskite doping. The changed electronic structures resulted in variety polarization, leading to distinction electrical performances of ceramics.

New approach for designing bulk multiferroic composites made of two perovskite oxides with enhanced direct magnetoelectric coupling

The scarcity of single-phase magnetoelectric multiferroics has motivated active research towards the design of composites where polarization and magnetization are coupled through elastic strain at their interfaces. Up to now, most of bulk multiferroic composites are made of immiscible constituents that thus suffer from weak interface connectivity between them. Here, we propose an approach for designing particulate composites with constituents of perovskite ABO3 structure that exhibit solid solubility, by acting on the lowering of the sintering temperature. We show that a BiFe0.95Co0.05O3–PbZr0.52Ti0.48O3 multiferroic composite with improved magnetoelectric coupling can be formed before a solid solution is reached. A Bi-rich interface promotes elastic strain transfer between the two constituents resulting in twice stronger direct magnetoelectric coefficient compared to pure BiFe0.95Co0.05O3. These findings provide an easy and effective strategy for producing upgraded and original multiferroic composites made of constituents with the perovskite structure, known to host a wide variety of functionalities.

Influence of BiFeO3 perovskite on the structure and magnetic properties of lead-free Bi0.5Na0.4K0.1TiO3 films

Lead-free (1-x)Bi0.5Na0.4K0.2TiO3-xBiFeO3 (abbreviated as BNKT-xBFO) ferroelectric films with x in the range from 0.00 to 0.10, were synthesized by the chemical solution deposition technique on Pt/Ti/SiO2/Si substrates. The microstructures and magnetic behaviors of BNKT-xBFO films were analyzed in detail as a function of BFO concentration. X-ray diffraction patterns indicated that BNKT-xBFO films were grown with a single-phase perovskite structure. The pure films showed an antiferromagnetic behavior. The magnetic properties of the films were gradually transferred from antiferromagnetic to ferromagnetic properties when BFO concentration was raised. The saturated magnetization (M S) reached the highest value of 10.3 emu cm−3 at the BFO-doped concentration x = 0.10. Our work will contribute to illuminate the impact of BFO (ABO3 perovskite structure) on the magnetic properties of BNKT materials at room temperature.

Effect of elemental doping on the catalytic activity of ABO3 perovskite oxides during low-pressure gas nitriding

In order to optimize the catalytic activity of the LaFeO3 oxide during low-pressures gas nitriding, the elemental doping by chromium, nickel and cerium was applied in the present work. The effects of doped LaFeO3 oxides on catalytic nitriding efficiency were systematically investigated. A new catalytic feature was proposed to explain the differences in catalytic activity among ABO3 oxides. The microstructure, phase composition and thickness of nitrided layers were characterized by the optical microscope, scanning electron microscope, X-ray diffraction and micro-hardness tester, respectively. The chemical bonds on nitrided surfaces were carefully investigated by X-ray photoelectron spectroscopy. The first-principles calculation was applied to reveal the inner diffusion behavior of nitrogen atoms. The results show that all ABO3 oxides exhibit an excellent catalytic activity in low-pressure gas nitriding. The LaFeO3 and (La0.5Ce0.5)FeO3 oxide show the enhanced catalytic activity as nitriding time prolonging while the LaCrO3 and LaNiO3 oxide present an opposite phenomenon. It depended on the state of active oxygen on nitrided surfaces, which is affected by the valence of doped elements. A critical ratio of adsorbed oxygen to hydroxyl on nitrided surfaces was proved to be 1.33. Beyond this value, ABO3 oxides have a remarkable improvement on catalytic nitriding.

Crystal structure classification in ABO3 perovskites via machine learning

Crystal structure classification of perovskites (ABO3) is done using the Light Gradient Boosting Machine (Light GBM) algorithm. In this work, we have identified features such as electronegativity, ionic radius, valence, and bond lengths of A-O and B-O pairs that enable a priori crystal structure prediction. We have taken 5329 ABO3 perovskites and applied the proposed model to 675 compounds. It successfully categorized the compounds into cubic, tetragonal, orthorhombic, and rhombohedral structures with 80.3% best accuracy using 5-fold cross-validation. Therefore, the model can be used as a preliminary, fast, and inexpensive method to classify perovskites into their respective crystal systems. Feature importance graph and SHapley Additive exPlanations (SHAP) are used in feature ranking and crystal structure prediction. These composition-structure predictions will find applications in ceramic engineering and solid-state chemistry.

First principles hybrid Hartree-Fock-DFT calculations of bulk and (001) surface F centers in oxide perovskites and alkaline-earth fluorides

We report the results of ab initio calculations and analysis of systematic trends for the F centers in the bulk and on the (001) surface in oxide perovskites, such as BaTiO3, SrTiO3, SrZrO3, and PbZrO3, with a corresponding comparison of the F centers in perovskites with those in alkaline earth metal fluorides (CaF2, BaF2, and SrF2). It was found that in perovskites in both bulk F centers and those on their (001) surfaces, two nearest to the vacancy Ti or Zr atoms repel each other, while the next nearest O atoms relax towards the oxygen vacancy. It was also found that the obtained relaxations of atoms in the nearest neighborhood around the F center in ABO3 perovskites are generally larger than in alkaline earth metal fluorides. The bulk and (001)-terminated surface F center ground states in BaTiO3, SrTiO3, and SrZrO3 perovskites are located 0.23, 0.69, 1.12 eV, and 0.07, 0.25, 0.93 eV, respectively, below the conduction band bottom, indicating that the F center is a shallow donor. The vacancies in BaTiO3, SrZrO3, and PbZrO3 are occupied with 1.103e, 1.25e, and 0.68e, respectively, whereas slightly smaller charges, only 1.052e, 1.10e, and 0.3e are localized inside the F center on the perovskite (001) surface. In contrast to the partly covalent ABO3 perovskites, charge is well localized (around 80%) inside the ionic CaF2, BaF2, and SrF2 fluorine vacancy.

First-principles study of structural, electronic and magnetic properties of A-site-ordered quadruple perovskite LaMn3Rh4O12

The introduction of magnetic ions at A-site is a typical modification in traditional ABO3 perovskite materials to achieve the target physical properties. Here, the impact of Mn3+ incorporation on the magnetic coupling and electronic structures of A-site-ordered quadruple perovskite LaMn3Rh4O12 was investigated using spin-polarized first-principles calculations. Our calculations demonstrate that LaMn3Rh4O12 is antiferromagnetic with G-type antiferromagnetic coupling within Mn sublattice and nonmagnetic Rh, which is quite different from the diamagnetic host perovskite LaRhO3. The electronic structure analyses reveal that the formal oxidation state of B-site Rh is +3 with 4d6 electronic configuration and it splits into t2g and eg orbitals (t2g6eg0) in low-spin state, indicating that Rh has no contribution to the magnetic properties and the introduced Mn3+ at the A′-site drives the ordered antiparallel spins coupling. Moreover, LaMn3Rh4O12 exhibits semiconducting behavior and the chemical valence is La3+Mn3+3Rh3+4O2-12. Our study provides an alternative method for beneficial modification of traditional ABO3 perovskites by introducing A-site magnetic ions.

Enhanced Bipolar Strain and Electrocaloric Response in Gadolinium/Tantalum Co-Substituted Sodium Bismuth Titanate Lead-Free Ceramics

High performance piezoelectric materials with an ABO3 perovskite structure have received growing attention in recent research due to their technological applications in sophisticated research, medical and defence devices like piezoelectric sensors, transducers, ultrasonic motors, nano-positioners, actuators and imaging devices, etc. The technical utility of these materials stems from the various possibilities they offer for cation substitution in the A (or) B sites, which provide valuable opportunities for the optimization and tailoring of desired properties. To date, lead based perovskites, such as lead zirconate titanate (PZT), PZN-PT, and PMN-PT materials, have been extensively investigated in the literature. Although lead based materials exhibit highest piezoelectric coefficients, their wide-scale application has often been hampered by considering the toxicity of lead and its effect on environment and health. This triggered the search for alternative materials that could replace the lead-based ceramics and results in less-hazardous production methods, use and recycling. This has led to a continuous search of potentially attractive alternative lead-free ceramic materials to their counterpart lead based materials for specific applications. Among various kinds of lead-free piezoelectric materials, Na0.5Bi0.5TiO3 (NBT)-based materials are considered to be promising candidates for replacing the lead-based materials. They have been extensively investigated by the condensed materials physics community because of their complicate phase transitions and superior piezo-response. Compared to various chemical substitutions, tantalum (Ta) substitution provides superior electro-strain for the NBT- based ferroelectrics, while the effect of tantalum oxide additive was rarely reported. Gd3+ and Ta5+ co-substituted (Na0.5Bi0.497Gd0.003)Ti1-xTaxO3 (NBGT-Tax) lead-free piezoelectric ceramics are synthesized by using hydrothermal technique. The influence of Ta5+ substitution on the sintering, microstructure, phase transition, and various electrical properties of NBGT ceramics was investigated. Tantalum substitution has no remarkable effect on the microstructure and densification within the studied doping composition. The X-ray diffraction studies revealed that both NBGT-Tax (x=0.000) and NBGT-Tax (x=0.003) ceramics exhibited single phases monoclinic crystal structure with Cc phase. However, with substitution of tantalum the antiferroelectric phase zone gets broader. Simultaneously, the temperature for a ferroelectric to antiferroelectric phase transition is reduced along with an increase in temperature for a transition from antiferroelectric phases to paraelectric phases. This results indicate that tantalum occupies B site of the perovskite structure behaving as a donor, producing A-site cation vacancies. The undoped NBGT ceramics shows good ferroelectric and piezoelectric properties (remnant polarization Pr = 34.2 μC/cm2). The value of remnant polarization was found to increase with Ta substitution along with an increase in coercive field as shown in the figure attached. This is because of the ferroelectric properties being influenced by composition and its homogeneity, defects, external field and orientation of domains, which eventually contributed to the materials response. Meanwhile, the addition of Ta leads to an increase in the electro-strain, together with a higher normalized strain. Moreover, the materials with temperature dependent polarization can be used for solid state cooling applications. The NBGT-Tax compositions shows decrement in the remnant polarization with the increasing temperature which causes increment in the change in entropy. Consequently, the material exhibits the conventional electrocaloric effect (ECE). This simultaneous presence of large field-induced bipolar strain and ECE response along with isothermal change in entropy opens window for great potential applications in the field of electronic devices. Figure 1

Progress of two-dimensional ferroelectrics in physical and chemical applications

Ferroelectric materials are intriguing and technologically useful because the spontaneous electric polarization is electrically switchable, leading to fascinating properties and wide range of applications such as field effect transistor, non-volatile memories and sensors. In general, the emergence of ferroelectricity requires an asymmetric structure. Previous studies of ferroelectrics have mainly focused on ABO3 perovskite compounds such as BaTiO3, PbTiO3. For technological demands, the size of the devices is decreasing dramatically that conventional ferroelectric materials will suffer from many constraints at nanoscale. For example, when the thickness of ABO3 film falls below a critical value, the ferroelectricity would probably disappear. Therefore, it is essential to search for the low-dimensional materials with stable ferroelectricity. Atomically thin two-dimensional (2D) materials which exhibit abundant electronic, optical and mechanical properties would be ideal candidates and a variety of 2D ferroelectric materials have been proposed accordingly. The first part of this article reviews the recent theoretical and experimental progress of 2D ferroelectric materials. In contrast to conventional 2D materials, 2D ferroelectrics have reversible spontaneous electric polarization which would give rise to an electrostatic potential from the bottom to the top surface. The electrostatic potential difference on two surfaces would lead to distinct band edge alignments and different electron transfer when they are respectively integrated with other materials, thus changing the properties of adjacent layers. On the other hand, switching the polarization direction could change the surface’s charge density, making it possible to modulate the binding strength of adsorbed species. According to the Sabatier principle, the adsorbate-surface binding strength must be optimal to achieve the maximum efficiency. A ferroelectric surface with tunable activity can provide a platform to enhance specific catalytic performance. What’s more, the intrinsic electric field in 2D ferroelectric materials is also beneficial to separate the photo-generated carriers and inhibit their recombination, which are of great importance in photocatalytic reactions. It is worth noting that, the opposite electric polarizations in ferroelectric materials are bistable, which means the electrical switching of these two states is nonvolatile. The states will remain even the external electric field is retracted. Therefore, it is expected that this intrinsic electric field would be an effective way to achieve nonvolatile control of the properties of adjacent materials and reaction activity. To this end, in the middle part, we focus on four respects, namely the effects of ferroelectric polarization on magnetism, electronic properties, gas adsorption and photocatalytic water splitting to show the applications of 2D ferroelectric materials. Up to now, great efforts have been devoted in ferroelectric materials with out-of-plane spontaneous polarization. Compared to out-of-plane ferroelectricity, in-plane ferroelectrics have unique advantage in terms of preventing vertical perturbations. With the rapid progress of the experimental techniques, 2D ferroelectric materials would hold great potential to be applied in a broader range of applications. At last, a brief overview for 2D ferroelectric materials is presented.