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The commented paper claimed the preparation of a new compound, Bi 1/2 Li 1/2 Fe 1/2 W 1/2 O 3. By this commentary, we show that erroneous experimental evidence was provided for such claims. We demonstrate that the main phase in the commented paper is Bi 2 WO 6. [ABSTRACT FROM AUTHOR]

Counterfeiting has caused great concern all over the world. What's more, the fluorescent materials play an important role in technological research and development for high-security. In this work, lead-metal-organic framework (Pb-MOF) and perovskite (MAPbBr 3) were used in papers to achieving fluorescence counterfeiting. Pb-MOF, as the template or precursor of MAPbBr 3 , were in-situ generated on the surface of cellulose fibers (CFs) to preparing into hand sheets (Pb-MOF@CFs). Through the analysis of experimental results, it was found that ligands, reaction systems, addition sequences of drugs, time, etc. would affect the deposition of Pb-MOF on the surface of CFs. Using CH 3 NH 3 Br (MABr) as the anti-counterfeiting ink to write on Pb-MOF@CFs, the orange writing leaped across the paper, which caused by Pb in Pb-MOF chemically reacting with MABr forming MAPbBr 3. The orange writing displayed green fluorescence under 365 nm ultraviolet lamp excitation. The orange writing with green fluorescence could be extinguished and reconstructed, which had promise for reuse. In addition, fluorescent security papers (MAPbBr 3 @Pb-MOFs@CFs) were prepared by immersing Pb-MOF@CFs in MABr solution. The fluorescence of MAPbBr 3 @Pb-MOFs@CFs opened when the surface of it was scraped under 365 nm ultraviolet lamp. This unique fluorescence property was very important in improving the security of products. Consequently, the ongoing research on perovskite and MOFs materials is of great significance. [ABSTRACT FROM AUTHOR]

• "Ba 3 Bi 2 MoO 9 " compound does not exist. • Mainly a mixture of BaBiO 3 and BaMoO 4 was investigated before. The title paper (Materials Science & Engineering B 296 (2023) 116616) claimed the preparation and detailed characterization by different methods of a novel triple perovskite compound, Ba 3 Bi 2 MoO 9. In this comment, it is shown that the phase Ba 3 Bi 2 MoO 9 does not exist. We show that the absence of the phase analysis resulted in erroneous claims. We demonstrate that the sample in the title paper is mainly a mixture of BaBiO 3 and BaMoO 4. [ABSTRACT FROM AUTHOR]

Organic molecule stabilized manganese stannate (MnSnO 3) perovskite nanoparticles were synthesized using a complexion strategy route. The Rietveld refinement analysis confirmed the formation of orthorhombic structure of manganese stannate with the space group of Pnma. Free standing manganese stannate electrode was fabricated on paper based flexible substrate and investigated the electrochemical performances. The maximum specific capacitance and areal capacitance delivered by electrode were ∼ 183 F/g and ∼ 487 mF/cm2, respectively, at the current density of 0.2 A/g, with an excellent capacitance retention ∼ 93% for 103 cycles at 0.6 A/g. A symmetric supercapacitor was fabricated using the MnSnO 3 as active material on positive and negative electrodes in solid state gel electrolyte configuration. The device achieved the specific capacity value ∼ 156 mAh/g at 0.1 A/g with the energy density and power density of ∼ 10 Wh/kg and ∼ 22 kW/kg, respectively, at 0.5 A/g. These results suggested that manganese stannate nanoparticles are promising candidates for high-performance supercapacitor application. [Display omitted] • Organic molecule stabilized manganese stannate perovskite nanoparticles. • Flexible Au-coated paper based free-standing electrode and symmetric device were fabricated for supercapacitor applications. • Diffusive control mechanism dominated the overall charge storage process. • The fabricated device exhibited excellent stability for energy and power storage performance. [ABSTRACT FROM AUTHOR]

• It is shown that the commented paper has severe errors. • The analysis of the diffraction pattern was made without success. • The chemical composition of the studied crystals is unknown. My comments concern the errors in the crystallographic part of the commented paper. Moreover, the true chemical composition of the studied sample is different than BaNaFeWO 6 as proposed by authors. Therefore, the subsequent data on other measurements may have no scientific value. [ABSTRACT FROM AUTHOR]

By these comments we would like to bring attention of the scientific community to erroneous results reported in the commented paper on the double perovskite "Sr 2 FeVO 6 ". We showed that the claimed compound does not exist (at least, when prepared at ambient pressure and in air) either in the double perovskite modification or any other modifications. We showed that a mixture of Sr 3 (VO 4) 2 , cubic perovskite SrFeO 3− δ , and SrFe 12 O 19 was obtained in the commented paper instead. The observed room-temperature ferromagnetic properties are most probably originated from the presence of ferrimagnetic SrFe 12 O 19. • A "Sr 2 FeVO 6 " perovskite was attempted to synthesize in air. • A mixture of Sr 3 (VO 4) 2 , SrFeO 3− δ , and SrFe 12 O 19 was obtained. • SrFe 12 O 19 ferrimagnet is responsible to room-temperature magnetic properties. [ABSTRACT FROM AUTHOR]

My comments concern the errors in the crystallographic part of the commented paper. The diffraction patterns are erroneously analysed. The crystal structure was not presented in the commented paper. • Correction of erroneous analysis of diffraction patterns. • Comparison of unit cells relation to the content of Ca dopant. • The crystal structure was not given in the commented paper. [ABSTRACT FROM AUTHOR]

My comments concern the errors in the crystallographic part of the commented paper. Moreover, the true chemical composition of the studied sample is different than (BaSr)FeMoO 6 as proposed by authors. Thus, the subsequent data have no scientific value, unless the chemical composition of the sample are clarified. [ABSTRACT FROM AUTHOR]

Perovskite nanocrystals (PNCs) are promising fluorescent nanomaterials that have been employed in a wide range of areas. However, their applications in some specific fields, such as chem-/biosensing remain hampered due to their inherent instability to different external stimuli. Herein, we discover a novel mechanism that ethanol, a chemical that is generally thought to be detrimental to PNCs, could specifically initiate the in-situ crystallization of the precursor salts absorbed by paper fiber to yield standard CsPbBr 3 fluorescent PNCs. Based on systematical experimental verification, it is revealed that ethanol could mediate the interfacial interaction of the PNC precursor salts on the paper fiber to allow for this exceptional in-situ PNC crystallization process. Accordingly, a fluorescence turn-on mode paper sensor for rapid and high-sensitive expiratory alcohol detection is designed, which could fulfill the on-site visualized drink-driving screening requirement. Furthermore, the application of this new mechanism in multidimensional information encryption is also demonstrated. This work not only discovers a new mechanism for PNC crystallization but also expands the sensing application toolbox of PNCs. [Display omitted] • Ethanol can induce the crystallization of perovskite nanocrystals on paper fiber. • This is due to the on-paper interaction of the precursor salts induced by ethanol. • A paper sensor is developed for fluorescence turn-on expiratory alcohol sensing. • The sensor can reach the standard of drinking-driving screening. • This technique can also be used in information encryption. [ABSTRACT FROM AUTHOR]

[Display omitted] • CsPbI 3 QDs were phase engineered (PE) to transfer into aqueous medium. • Low-cost paper based microfluidic device uses PE-PQD probes to detect biomarkers. • Two different colored PE-PQDs were tagged for simultaneous detection. • Endurance of PQDs throughout the detection process is substantiated. This work reports the microfabricated paper based analytical device (mPADs) for fluorometric detection of lung cancer biomarkers Carcinoembryonic antigen (CEA) and Neuron specific enolase (NSE) simultaneously. The device is patterned by wax printing on the paper that features two closed circular assay zone, connected to one sample zone through the grooved microfluidic channels for analyte flow. CsPbI 3 perovskite quantum dots (IPQDs) were phase engineered (PE) for the first time to make it compatible in aqueous and biological medium. As a proof of concept, these PE- IPQDs along with PE CsPbBr 3 perovskite quantum dots (BPQDS) were surface modified with streptavidin and conjugated to specific antibodies for demonstration of multiplexing, via sandwich type immunoassay. In addition to offering benefits of being less expensive, portable, enabling robust and facile operations, these developed mPADs exhibit specific and simultaneous detection of CEA and NSE lung cancer biomarkers. A linear response with a detection limit 0.095 ng/mL and 30.0 ng/mL was achieved for CEA and NSE respectively and while it was 0.12 ng/mL and 32 ng/mL for simultaneous detection. This mPAD device (with negligible toxicity of the probe) thus combines the high-throughput capabilities of a microfluidic network with the high sensitivity and multicolour imaging ability offered by perovskite QDs. This can become a promising diagnostic tool if extended for detection of other proteins or biomarkers involved in environmental and food safety research. [ABSTRACT FROM AUTHOR]

Heteroatom (boron) doped reduced graphene oxide (B-rGO) papers were prepared by the simple self-assembly process of graphene oxide through the deoxygenation in argon atmosphere at 400 °C. The phase purity and crystallinity of the B-rGO paper were studied by X-ray diffraction analysis. The wrinkled paper-like morphology was analyzed by scanning electron microscopy (SEM) and the homogeneity by the elemental mapping. The binding energy states of the B-rGO were confirmed by X-ray photoelectron spectroscopy. The shift in zeta potential values also confirms the heteroatom doping in the rGO paper. From the Raman spectra it was observed that the incorporation of boron into the rGO paper exhibits an improved conductivity and mobility. The current-voltage (J-V) characteristics revealed that the B-rGO paper can be effectively used as a hole transport material (HTM) for perovskite solar cells (PSCs). The largest conversion efficiency of 8.96% was achieved for the FTO/TiO 2 /CH 3 NH 3 PbI 3 /B-rGO/FTO sandwich structure with an active area of 1 cm 2 . [ABSTRACT FROM AUTHOR]

• The commented paper has several errors. • The phase analysis is wrong. • Ba 3 Bi 2 MoO 9 does not exist. My comments concern the severe errors in the crystallographic part of the paper "Development of a novel triple perovskite barium bismuth molybdate material for thermistor-based applications" by D. Panda et al. (Mater. Sci. Engin. B 296 (2023) 116616). Authors have proposed that their sample is a derivative of two different crystals, Ba 2 Bi 2 O 5 and BaMoO 4. Unfortunately, this is not the same as a creation of a new crystal with the supposed chemical formula Ba 3 Bi 2 MoO 9. Moreover, the structure analysis is wrong what is presented by inacceptable high reliability factors. [ABSTRACT FROM AUTHOR]

We bring attention of the scientific community to erroneous claims about the existence of double perovskites "Sr 2 FeVO 6 " and "Ba 2 FeVO 6 " and their solid solutions in the commented paper. In this commentary, we showed that "Sr 2 FeVO 6 " and "Ba 2 FeVO 6 " do not exist. We investigated phase formations in such Sr-Fe-V-O and Ba-Fe-V-O compositions in air from 973 K to 1433 K. With our results, we demonstrated that the phase equilibria are reached after annealing at 1173 K, and a mixture of Sr 3 (VO 4) 2 , cubic perovskite SrFeO 3− δ , and SrFe 12 O 19 is formed in case of "Sr 2 FeVO 6 ", and a mixture of Ba 3 (VO 4) 2 and BaFe 2 O 4 is formed in case of "Ba 2 FeVO 6 ". The mixture of Ba 3 (VO 4) 2 and BaFe 2 O 4 is stable up to 1433 K. However, the cubic perovskite SrFeO 3− δ in the Sr-Fe-V-O system transforms on further heating at 1273 K and above. The reported magnetic transition temperatures of "Sr 2 FeVO 6 " and "Ba 2 FeVO 6 " match well with the transition temperatures of SrFe 12 O 19 and BaFe 12 O 19 , respectively. [ABSTRACT FROM AUTHOR]

The author of this Comment is concerned with severe errors in the crystallographic part of the commented paper. The actual composition of the crystals studied is not known, but the diffraction patterns and Rietveld analysis suggest the chemical formula of Ba 3 (VO 4) 2 :Ca. Moreover, the symmetry should be trigonal. • Several errors in the crystallographic part of the commented paper were found. • New chemical formula and crystal symmetry is proposed. [ABSTRACT FROM AUTHOR]

• Capability of the lead based perovskite halide family towards NH 3 gas sensing both by visual detection as well as electrical detection method. • The compatibility with papers sensor due to low temperature solution processing working at room temperature. • Compatible with extremely low power paper electronics for sensing operation during electrical detection. • The family of lead halide perovskite follows a general sensing mechanism substantiated by molecular dynamics simulation. • Develop them as a common platform for solid state room temperature NH 3 gas sensor with cost effective and disposable, paper based technology. In this paper we show that, high sensitivity and high selectivity room temperature ammonia (NH 3) gas sensors with both visual and electrical response can be made from family of lead halide perovskites with different cations and anions. These sensors, based on papers, act as general platforms for new generation of solid state gas sensors for sensitive detection of NH 3 gas by simple color change (∼10 ppm sensitivity) as well as electrical resistance change with sub ppm sensitivity limited by electrical noise only. The sensors with materials like CH 3 NH 3 PbI 3 (MAPI), CH 3 NH 3 PbBr 3 (MAPB) and CH(NH 2) 2 PbI 3 (FAPI), are grown on paper from solution. MAPB changes color from orange to white and FAPI and MAPI from black to yellow under NH 3 gas exposure respectively. For electrical sensor operation, a fixed concentration (20 ppm) of NH 3 gas, the sensitivity of MAPI is highest at 96 % followed by MAPB at 82 % and FAPI at 65 %. The sensors with electrical read out could trace NH 3 gas well below ppm level with only few nanowatt of power consumption. Based on experiments, a sensing mechanism has been proposed. The proposed mechanism mainly consists of decomposition of the perovskite halides to lead (Pb) halide by preferential adsorption of NH 3 gas molecules. The proposed mechanism has also been substantiated by molecular dynamics simulations. These sensors fabricated by simple solution process on paper substrates and operable at ambient temperature, are compatible with very low power (∼ nW) paper electronics. [ABSTRACT FROM AUTHOR]

My comments concern the severe errors in the crystallographic part of the commented paper. The actual composition of the studied crystals is not known, but the diffraction patterns and Rietveld analysis suggest the chemical formula to be Ba 2 Sr(VO 4)(FeO 4) instead of BaSrFeVO 6. Moreover, the symmetry should be trigonal. [ABSTRACT FROM AUTHOR]

Recently, flexible intelligent wearable devices are in highly demand and it is urgent to increase the flexibility of traditional devices. Organometallic trihalide perovskite materials have become a hot spot in the photoelectric field due to its outstanding optoelectronic properties, which can be crystallized from solutions and vapors. Herein, we demonstrated a simple approach to flexible thin CH 3 NH 3 PbI 3 perovskite films on paper substrates using a dual-source physical vapor deposition method and a brush-coating method. The photodetector devices from the two methods have similar photodetecting and repeatable performances. They well maintained the optoelectronic functionality under bending conditions. Typically, up to 75% of its initial photocurrent was remained after 500 bending cycles, demonstrating good stability against bending deformation. Additionally, a 6 × 6 perovskite photodetector array based on stretchable origami-based techniques were fabricated. It has excellent all-optical acquisition capability and provides potential application in three-dimensional photo sensing. [Display omitted] • Thin perovskite films were deposited on paper substrates using both vapor and solution methods. • The paper-based photodetectors demonstrated good stability against bending deformation, even up to 500 bending cycles. • An origami-based perovskite photodetector array has excellent all-optical acquisition capability. [ABSTRACT FROM AUTHOR]

Traditional test paper cannot be reusable and needs much sample solution. In this study, a reusable perovskite nanocomposite fiber paper consisting of CsPbBr 3 quantum dots in-situ growing in the solid polymer fibers with high concentration is fabricated via microwave and electrospinning methods. RhoB is used as the sample solution because it is a hazardous matter but often occurs in printing and dyeing wastewater or appears in food as additives, and traditional detection system generally requires much sample solution (>1 ml) to concentrate for higher concentrations due to the low detection sensitivity. Just need a droplet of sample solution (<25 μl) can this perovskite fiber paper achieve 0.01 ppm of supersensitive detection, which is superior to a majority of reported detection limit. Different from traditional detection based on luminescence intensity, this detection is a new kind of time-resolved method, so that it gets rid of complex and time-consuming calibration (>1 h) usually in traditional detection, and this time-resolved detection can be achieved within ~3 min. Moreover, this perovskite fiber paper is endowed with recyclable property without losing advantages of supersensitive detection (~0.01 ppm), rapid measuring speed (<3 min), and tiny dosage (<25 μl), which is another advantage than conventional detection systems. • In-situ grow CsPbCl 3 quantum dots in solid polymer fibers with high concentration. • Time-resolved idea for PL sensor that is versatile with rapid measuring speed. • Supersensitive detection limit of 0.01 ppm is achieved by perovskite fiber paper. • Just needs a single-droplet of hazardous solution for detecting on this fiber paper. • Superb self clean ability enables droplet easy to remove thus brought reusability. [ABSTRACT FROM AUTHOR]

We synthesized Tb3+-doped Cs 4 MnBi 2 Cl 12 perovskite crystals by the crystallization. These PCs have extremely strong PL intensity and stability at high temperatures, sunshine and low temperature. The Tb3+-doped Cs 4 MnBi 2 Cl 12 PCs have excellent luminescent properties and stability and can be used in luminous composite fibers and white LED devices field. [Display omitted] • Experiment under normal pressure environment, cost reduction and facile operation. • The Cs 4 Mn(Bi 1- x Tb x) 2 Cl 12 PCs have excellent stability in air. • The PCs have a excellent fluorescence performance with a PLQY of 25.45%. • The PCs were applied to ACFs/PPS composite paper with orange emission. • The composite paper can maintain stability in different real environments. In recent years, all-inorganic perovskites have attracted considerable research attention. However, the advancement of lead-based perovskites has encountered substantial challenges, redirecting current research efforts toward lead-free alternatives. In this study, we synthesized novel Cs 4 MnBi 2 Cl 12 perovskite crystals at 80 °C. Furthermore, Tb3+ ions were introduced to enhance the fluorescence properties and stability of the as-prepared perovskite crystals (PCs). The photoluminescence quantum yield (PLQY) of Tb3+-doped PCs was 25.45 % (∼598 nm), making a two-fold increase compared with the original PCs. In the PCs, [BiCl 6 ]3− octahedrons serve as energy collectors, generating excitons, while [MnCl 6 ]4− octahedrons function as luminescence centers of the receptor. Owing to their entirely inorganic composition, the PCs exhibited exceptional stability under sunlight and across a wide range of temperatures. Finally, we applied the PCs to fiber composite paper and an light-emitting diode (LED) device, which retained their specific stability after the modification. The findings of this study offer nover insight for incorporating perovskites into fiber applications and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Using the WIEN2k code, first-principles simulations of ZrXH 3 (X = Zn, Cd) hydride perovskites are performed to determine their hydrogen storage properties. The purpose of this study is to investigate their structural, optoelectronic, hydrogen storage, mechanical and thermoelectric properties. The structural analysis demonstrates their stability through the heat of formation along with desorption temperature and shows that these compositions belong to the orthorhombic space group Cmcm (no.63). The band structure and density of states are estimated for electronic characteristics, indicating the metallic nature of both compositions. Analysis of elastic properties such as elastic constants, Pugh's ratio, bulk modulus, Poisson's ratio, and anisotropy factor are explored to determine the mechanical stability of these compositions and demonstrate their suitability as a transport medium in hydrogen storage systems even at higher pressure. To study the optical behavior of the perovskites under consideration for hydrogen storage applications, the dielectric parameters, dielectric constants, refractive index, optical conductivity, absorptivity, and energy loss function are studied. The present paper represents the initial theoretical effort toward future exploration of these materials for hydrogen storage applications. [Display omitted] Using the WIEN2k code, first-principles simulations of ZrXH 3 (X = Zn, Cd) hydride perovskites are performed to determine their hydrogen storage properties. The purpose of this study is to investigate their structural, optoelectronic, hydrogen storage, mechanical and thermoelectric properties. The structural analysis demonstrates their stability through the heat of formation along with desorption temperature and shows that these compositions belong to the orthorhombic space group Cmcm (no.63). The band structure and density of states are estimated for electronic characteristics, indicating the metallic nature of both compositions. Analysis of elastic properties such as elastic constants, Pugh's ratio, bulk modulus, Poisson's ratio, and anisotropy factor are explored to determine the mechanical stability of these compositions and demonstrate their suitability as a transport medium in hydrogen storage systems even at higher pressure. To study the optical behavior of the perovskites under consideration for hydrogen storage applications, the dielectric parameters, dielectric constants, refractive index, optical conductivity, absorptivity, and energy loss function are studied. The present paper represents the initial theoretical effort toward future exploration of these materials for hydrogen storage applications. • Stability of ZrXH 3 (X = Zn, Cd) hydride perovskites is confirmed by Enthalpy of formation. • ZrXH 3 (X = Zn, Cd) hydride perovskites have high value of decomposition temperature. • The gravimetric hydrogen storage capacities comes out to be 1.89 % and 1.46 % respectively. • Metallic behavior is reveled by electronic structure of these hydrides. [ABSTRACT FROM AUTHOR]

The merits of adjustable structure and composition and wide source of raw materials have convinced researchers to become more and more obsessed with the discussion of perovskite oxide materials and materials with perovskite structure in recent years. Perovskite type materials with excellent performance and well structural composition are expected to replace Pt/C, IrO 2 and RuO 2 , which are considered to be the most advanced active, valuable and cost-effective catalyst materials in the future. Therefore, finding catalysts with relatively higher economic and catalytic efficiency have always been the ideal goal of research for hydrogen production and O 2 /N 2 reduction. A large number of scholars have made significant efforts in developing various catalysts that remarkably enhance the catalytic activities of hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and nitrogen reduction reaction (NRR). This review aims to summarize some significant achievements in obtaining high-performance perovskite in the main related electro-catalysis field in recent years and provide a reference for the subsequent development of perovskite. This paper introduces the detailed methodology of the preparation of perovskite and discusses the design strategy of perovskite performance enhancement as important entry points to optimize the activity of perovskite. The paper comprehensively reviews the preparation methods of various perovskite with various examples, and also compares their advantages and disadvantages. To improve perovskite performance, most of the existing design strategies are introduced and integrated and novel design schemes are also displayed. The paper finally suggests the improvement potential in perovskite activity, aiming to create better design schemes of new perovskite in the future. • Conventional and new preparation methods of perovskite oxides catalysts are summarized. • Perovskites for hydrogen generation via hydrogen evolution reaction were summarized. • Perovskites for oxygen generation via oxygen evolution reaction were summarized. • Perovskites for nitrogen fixation via nitrogen reduction reaction were summarized. • Further performance improvement strategies of perovskite catalysts for electrochemistry are summarized. [ABSTRACT FROM AUTHOR]

[Display omitted] • Developed a fluorescent sensor based on p-xylylenediamine capped CH 3 NH 3 PbBr 3 perovskite nanocrystals for picric acid sensing. • Steady state and transient spectroscopic studies were conducted to investigate sensing mechanism. • Fabricated a 3D printed device, integrating surface mounting device and paper microfluidics for on-site PA detection. Hand-held, compact and portable sensors for on-site detection of environmental contaminants are in high demand for industry 4.0. Here, we have developed a sensor based on luminescent organic–inorganic metal halide hybrid perovskites nanocrystals (CH 3 NH 3 PbBr 3) with p-xylylenediamine as an additional capping agent for highly sensitive and selective detection of picric acid (PA), with a good linear range of 1.8 μM–14.3 μM achieving detection of limit (LOD) of 0.3 μM. The electrostatic interaction between PA and the capping ligand of perovskite nanocrystals resulted in significant fluorescence quenching, as revealed by the steady-state and time-resolved spectroscopy. The applicability of the developed sensor for PA detection was validated with a 3D printed device integrating surface mounting device (SMD) and paper microfluidics. This prototype device was successfully applied as a fluorescence turn-off sensor to detect PA, showing great potential for on-site detection. This 3D-printed paper-based microfluidic optical sensor proved very efficient for naked-eye detection of PA with an inbuilt excitation source, avoiding the requirement of expensive and complex instrumentation. [ABSTRACT FROM AUTHOR]

In this work we successfully synthesize CsPb(Br x I 1-x) 3 perovskite nanocrystals with different Br/I ratio in a borogermanate glass matrix. The XRD studies show cubic perovskite phase peaks shift as the Br/I ratio changes. The formed nanocrystals have mean size of about 17 nm based on the calculations from the absorption spectra. The smooth change of the Br/I ratio in perovskite nanocrystals allow to obtain luminescence in the range 500–750 nm with quantum yield up to 35 %. The luminescence quantum yield and lifetime of the mixed-halide nanocrystals steadily increase with iodine concentration. Practical application of perovskite glass-ceramics as a radiation converter is shown in the paper. [Display omitted] [ABSTRACT FROM AUTHOR]

High-entropy perovskite oxides (HEPOs) have attracted considerable attention as dielectric ceramics. However, the energy-storage performance of these HEPOs still requires improvement. In this study, a series of (1- x)(Bi 0. 4 Ba 0. 2 K 0. 2 Na 0.2)TiO 3 - x NaNbO 3 high-entropy ceramics were designed and prepared using a high-entropy strategy. The introduction of antiferroelectric NaNbO 3 into the (Bi 0. 4 Ba 0. 2 K 0. 2 Na 0.2)TiO 3 medium-entropy matrix increased the configurational entropy and cationic disorder, resulting in improved energy storage performance. The ceramic with an optimal composition of 0.775(Bi 0. 4 Ba 0. 2 K 0. 2 Na 0.2)TiO 3 -0.225NaNbO 3 achieved a high recoverable energy density (W rec) of 2.523 J/cm3 and a high efficiency (η) of 83.7% at an electric field of 220 kV/cm. Furthermore, the material demonstrated good temperature and frequency stability, as well as good anti-fatigue properties. This paper presents a dielectric ceramic suitable for energy storage under low to moderate electric fields. [ABSTRACT FROM AUTHOR]

In this paper, polycrystalline Lu 1- x Dy x Fe 0.5 Cr 0·5 O 3 (0 ≤ x ≤ 0.15) perovskite ceramics were synthesized via a conventional solid-state-reaction technique. Structural and magnetic properties of the samples were experimentally studied. The cell volume of the lattice expands with the rise in Dy3+ amount. The measuring of magnetic properties shows that the undoped sample exhibits a negative magnetization effect with a compensation temperature of 231.1 K, while the Dy-doped samples display negative magnetization effects between two compensation temperatures. The magnetic switch experiment demonstrates the significant potential for practical applications through stable and repeatable switching of magnetization state by adjusting the external magnetic field between 50 Oe and 300 Oe. Besides, the presence of two compensation temperatures which can be regulated by changing the doping content or external magnetic field provides more possibilities for application. Moreover, based on the comprehensive analysis of the experimental results, it is believed that the negative magnetization effect originates from the competition of magnetic moments in different directions. Meanwhile, the second compensation temperature occurs in low temperature region might be attributed to the additional positive magnetic moment contributed by the paramagnetic Dy3+ ions. [ABSTRACT FROM AUTHOR]

The instability and clumping of lead halide perovskite nanocrystals in polar solutions have limited their practical use. In this paper, a convenient and effective surface modification strategy was applied to substitute the typical oleic acid (OA) with 3-bromopropionic acid (BPA) ligand for the one-step synthesis of CsPbBr 3 NCs in the absence of any inert gas atmosphere with water as the non-solvent. Thanks to the synergistic effect of BPA and OAm on the surface of CsPbBr 3 NCs, it has excellent dispersibility while exhibiting excellent stability in water. Even after being fully submerged in water for 168 h, the material can still emit a vibrant green light, and the emission peak position is stable at 520 nm. In contrast, the CsPbBr 3 NCs of the OA ligand were completely burst in water within minutes. This study opens the door for the direct synthesis and preservation of CsPbBr 3 NCs in the aqueous phase, which will be an important step in advancing their large-scale applications in extreme environments. [ABSTRACT FROM AUTHOR]

In this paper, the enhancement of the perovskite solar cells (PSCs) efficiency through the implementation of a half-tandem structure featuring two absorbent layers of MAPbI 3 and MoTe 2 with a V-shaped nanostructured grating was investigated. MoTe 2 was utilized as the second lower absorbent with a smaller bandgap than the first and upper absorbent, MAPbI 3 , to cover the incident light absorption in the infrared wavelength range. Additionally, the structure was also optimized by introducing a nanostructured V-shaped grating to increase the light propagation path and improve the absorption in the active layers. Also, the critical role of the electron transfer layer (ETL) and hole transfer layer (HTL) in carrier transfer and prevention of charge leakage was examined for materials including TiO 2 , TiO 2 -Gr (5%) nanocomposite, and Al-doped ZnO (AZO) as ETLs, and Cu 2 FeSnS 4 (CFTS) and reduced Graphene Oxide (rGO) as HTLs in four distinct cell configurations. In this study, the optical and electrical models were solved to determine the optimal solar cell structure and materials through a comparative analysis of structures. Our findings revealed substantial improvements in short-circuit current density (J sc), open-circuit voltage (V oc), and power conversion efficiency (PCE), where they increased from 15.27 to 31.55 mA/cm2, 0.91 to 1.30 V, and 11.78 to 27.63%, respectively. This resulted in a 2.35 times efficiency enhancement for the nanostructured V-shaped half-tandem solar cell with MAPbI 3 (250 nm) and MoTe 2 (150 nm) as absorbent layers, AZO (40 nm) as ETL and rGo (40 nm) as HTL compared to the planar non-tandem solar cell with MAPbI 3 (250 nm) as absorbent layer, TiO 2 (40 nm) as ETL and CFTS (40 nm) as HTL. [ABSTRACT FROM AUTHOR]

The perovskite-type hydride compounds are potential candidate materials in the field of hydrogen storage. This paper presents a systematical study of XTiH 3 (X = K, Rb, Cs) using density functional theory. The analysis of formation energy, elastic properties and phonon dispersion curves indicate that all the studied materials are thermodynamically, mechanically and dynamically stable. By analyzing the B/G ratio, it is determined that these compounds are brittle materials. The electronic properties reveal that the XTiH 3 compounds exhibit semi-metallic characteristics. The charge transfer characteristics of these compounds were analyzed using Bader partial charges. Moreover, the thermodynamic characteristics of these compounds were investigated and the dependence of their free energy, entropy and heat capacity on the temperature were analyzed. Finally, the gravimetric hydrogen storage capacities of KTiH 3 , RbTiH 3 and CsTiH 3 were calculated to be 3.36, 2.22 and 1.65 wt%, respectively. The hydrogen desorption temperatures of KTiH 3 , RbTiH 3 and CsTiH 3 were found to be 209 K, 161 K and 107 K, respectively. To our knowledge, this study represents the very first investigation of XTiH 3 compounds and offers valuable references to this hydrogen storage material. [Display omitted] • XTiH 3 (X = K, Rb, Cs) perovskite have been investigated using first-principles. • XTiH 3 perovskite exhibit thermodynamic, mechanical and dynamical stability. • The gravimetric hydrogen storage capacity is found to be 3.36 wt% for KTiH 3. [ABSTRACT FROM AUTHOR]

Lead-free halide double perovskites (DPs) with superior photoelectric performance are of great importance in perovskites materials family. In this paper, a series of rare-earth (RE) based Cs 2 NaRECl 6 (RE = Y, Ce–Nd, Sm–Gd, Dy–Lu) DPs microcrystals (MCs) were prepared by convenient hydrothermal method. Cs 2 NaCeCl 6 and Cs 2 NaEuCl 6 MCs exhibit typical UV emission from the 5d→4f transition of Ce3+ and orange-red emission from characteristic 5D 1 → 7F 0 , 5D 0 → 7F 1 , 5D 0 → 7F 2 , 5D 0 → 7F 3 , 5D 0 → 7F 4 transitions of Eu3+, respectively. The blue light emissions of Cs 2 NaYCl 6 (300–650 nm) and Cs 2 NaLuCl 6 (300–550 nm) are from the respective self-trapped exciton states (STEs). In addition, the bandgap and partial density of state (PDOS) of Cs 2 NaRECl 6 (RE = Ce, Eu, Y, Lu) were calculated based on density functional theory (DFT) to have a further insight into the optical properties of the RE-DPs. The as-prepared RE based DPs have potential applications in advanced lighting, displaying and anti-counterfeiting, etc. [ABSTRACT FROM AUTHOR]

The crystal structure, three-dimensional Young's modulus projection and band structure of Ba 2 AsXO 6 (X = V, Nb, Ta). [Display omitted] • The double perovskite oxides basic properties of Ba 2 AsXO 6 (X = V, Nb, Ta) are predicted via first-principles. • The theoretical calculation shows that these materials satisfy the stuctural, thermodynamic and mechanical stability. • The results show that they are potential photoelectric and thermoelectric materials. • This paper can provide a theoretical reference for the further study of Ba 2 AsXO 6 (X = V, Nb, Ta). In this paper, the structural, mechanical, electronic, optical and thermodynamic properties of Ba 2 AsXO 6 (X = V, Nb, Ta) double perovskite oxides have been studied based on the first principles of density functional theory. By calculating some parameters such as Goldsmith's tolerance factor (t G), octahedral factor (µ), Bartel's tolerance factor (τ), formation energy, binding energy and elastic constants, it is found that these double perovskite oxides have the potential for stable existence. In addition, Ba 2 AsXO 6 (X = V, Nb, Ta) is an anisotropic material, in which Ba 2 AsVO 6 is brittle, Ba 2 AsNbO 6 and Ba 2 AsTaO 6 are ductile. The electronic properties of the materials show that Ba 2 AsVO 6 and Ba 2 AsNbO 6 are indirect bandgap semiconductors with a band gap of 1.676 eV and 2.654 eV respectively, while Ba 2 AsTaO 6 is direct bandgap semiconductor with a band gap of 3.252 eV. The optical properties revealed that these perovskites exhibit favorable far-ultraviolet light absorption characteristics. The thermodynamic properties show that the specific heat capacity of these double perovskite oxides reaches the Dulong-Petit limit at around 800 K. These results indicate that Ba 2 AsXO 6 (X = V, Nb, Ta) double perovskite oxides have broad application prospects in the fields of thermoelectricity and optoelectronics. Furthermore, these results also provide a valuable theoretical basis for their future experimental synthesis. [ABSTRACT FROM AUTHOR]

With the current evolution in artificial intelligence technology, biodegradable biomimetic devices are essential to execute increasingly complicated tasks and respond to challenging work environments. Consequently, the integration of artificial nociceptors holds considerable importance in enhancing the capabilities of humanoid robots. Low-dimensional Hybrid organic–inorganic Perovskites (HOIPs) show promise in emulating biological neurons owing to their inherent ion migration properties. In this work, we present Dion-Jacobson hybrid perovskite (BDAPbI 4 (BDA=NH 3 C 4 H 8 NH 3)) diffusive memristor on a paper substrate to serve as an artificial nociceptor. The symmetric electrode configuration as Paper/Ag/PCBM/BDAPbI 4 /PMMA/Ag demonstrates low operating voltage diffusive memristor with an ON/OFF ratio of ∼103. The surface investigation of device before top electrode deposition via X-ray photoelectron spectroscopy XPS and electrical characteristics of the complete device reveal the interplay between Schottky barrier at BDAPbI 4 /Ag interface and conductive filament formation/rupture within active layer as the origin of the abrupt resistive switching. The characteristics of the diffusive memristor resemble those of biological nociceptors, displaying sensitivity to external stimuli and key attributes such as threshold response, lack of adaptation, and relaxation. These findings underscore the potential application of Dion-Jacobson hybrid perovskites (BDAPbI 4) as diffusive memristors in future neuromorphic intelligence systems. [Display omitted] • Paper based artificial nociceptor devices are idel for green electronics. • Dion Jacobson hybrid perovskite is an excellent choice as resistive switching meadim. • We show the resistance switching ratio ∼103 at low operating voltage. • The complex interplay between Schottky emission and formation/rupture of conducting filament is the origin of resistive switching. • Devices show threshold response, lack of adaptation, and relaxation, analogues to the biological nociceptor. [ABSTRACT FROM AUTHOR]

This paper includes the theoretical investigation performed on the device having structure FTO/TiO 2 /CH 3 NH 3 PbI 3 /PeDAMAPb 4 I 16 /Spiro- OMeTAD. This work is focused on the effects of ETLs and HTLs on the performance of the device structure. Device simulation and various parameters of the perovskite cell are investigated with the help of SCAPS-1D software. In recent years, perovskite solar cells (PSCs) have passed through many advancements but they suffered through instability due to moisture. Due to poor stability of PSCs becomes a major obstacle for its commercialization. This leads to the development of 2D perovskite manufactured from organic cations and inorganic slabs arranged alternately.2D perovskite is of two kinds: Ruddlesden - Popper (RP) phase and Dion-Jacobson (DJ) phase. Both types of 2D perovskite are observed to be much more stable than 3Dperovskite. Due to its stability, it becomes an alternative for 3D perovskite. To improve the stability and efficiency of 2D perovskite both types of 2D phases are merged. To have more stability organic cations are introduced between inorganic slabs which reduces charge transportation. Proposed DJ 2D-3D perovskite solar cells provide an impressive efficiency of 26.03 % even when exposed to much temperature and moisture. Being much more efficient and stable the 2D-DJ/3D perovskite becomes an option to be utilized in photovoltaic applications. • This paper includes theoretical investigation having device structure FTO/TiO 2 /CH 3 NH 3 PbI 3 /PeDAMAPb 4 I 16 /Spiro- OMeTAD. • To improve the stability and efficiency of 2D perovskite both types of 2D phases are merged. • To have more stability organic cations are introduced between inorganic slabs which reduces charge transportation. • Proposed DJ 2D-3D perovskite solar cells provide an impressive efficiency of 26.03 % in more temperature and moisture also. • Being much more efficient and stable the 2D-DJ/3D perovskite becomes an option to be utilized in photovoltaic applications. [ABSTRACT FROM AUTHOR]

The ferroelectric perovskite material Cs 2 AgBiBr 6 has received much attention because of its low poisonous nature and environmental stability. In this paper, we prepared high-quality Cs 2 AgBiBr 6 thin films for self-powered photodetectors using a low-pressure-assisted method, investigated their optical, electrical, and pyroelectric properties, and characterized the film morphology and crystallization. The device modulates the photoelectric process without an external power supply, and has a maximum switching ratio of 1.72 × 106, a response rate of 0.158 A/W, a specific detectivity of 1.39 × 1011 Jones, an external quantum efficiency of 52.8 %, and a fast response time of 15.4/16.8 μs when irradiated with 532 nm light, which is much better than that of previous self-powered devices with the same material on/off ratio and specific detectivity. It is worth mentioning that the pyroelectric effect was observed in the infrared band. In addition, the devices exhibited high stability to water and oxygen in an air environment (25 °C, 60 % humidity), retaining more than 95 % of the initial performance after one month of placement. Our study demonstrates that the lead-free perovskite Cs 2 AgBiBr 6 is a promising and environmentally friendly alternative for the preparation of highly stable self-powered photodetectors and is also of great research value in the field of pyroelectric detection. • The pyroelectric effect of the Cs 2 AgBiBr 6 thin-film device was observed in the infrared band. This paper explains the effect in terms of light-induced changes in the temperature gradient. • The Cs 2 AgBiBr 6 thin films are prepared by a low-pressure-assisted method and the devices have good morphology and properties. • The device modulates the photoelectric process without an external power supply and has a maximum switching ratio of 1.72 × 106 and a response time of 15.4/16.8 μs. The device retains more than 95 % of the initial performance after one month of placement in an air environment (25 °C, 60 % humidity). [ABSTRACT FROM AUTHOR]

Lead halide perovskites are an advanced class of materials with high photoluminescence and optoelectronic properties. However their instability towards moisture and lead toxicity hinders their applications especially in biological sensing. Hence the need for novel lead free perovskite nanocrystals are of utmost important. Herein we synthesized a lead free, highly efficient, stable, cost effective Cs 2 ZnCl 4 perovskite nanocrystals (PNCs) and extends its application in biosensing. The PNCs exhibits bright blue fluorescence upon UV irradiation and was able to selectively detect bilirubin (BR) - a clinically important jaundice biomarker. The intense fluorescence emission of the sensor was completely quenched upon the addition of bilirubin. The sensor could detect bilirubin even in the presence of other interfering biomolecules with a good limit of detection of 26.10 nM. The sensor could successively detect BR in human serum samples. Furthermore, for the visual detection of bilirubin, a paper strip sensor was also designed making the sensor more economical and adaptable. [Display omitted] • Lead free Cs 2 ZnCl 4 Perovskite nanocrystals were synthesized as the fluorescent probe. • The fluorescence intensity of the probe was drastically quenched upon bilirubin addition. • The sensor displayed a good selectivity and sensitivity towards bilirubin over other coexisting biomolecules. • The sensor shows an accurate recovery percent when applied to human serum samples. • For rapid visual detection, a paper strip sensor was also developed. [ABSTRACT FROM AUTHOR]

Perovskite light-emitting diodes (PeLEDs) are widely used in optoelectronics due to their excellent performance. The hole transport layer (HTL) plays a crucial role in the performance of the device. In this paper, we prepared quasi-two-dimensional perovskite light-emitting diodes with doping CsBr into PEDOT:PSS as a composite HTL, and investigated the optoelectronic properties of the devices. The maximum luminance of the CsBr-doped device was 6652 cd/m2 and the maximum current efficiency (CE) was 7.55 cd/A, which were increased by 112 % and 80 % compared with the undoped device, respectively. This is primarily due to the PEDOT:PSS/CsBr composite HTL optimizes the morphology of the perovskite film, passivates the defects of the perovskite film, and suppresses the exciton quenching at the HTL/perovskite emission layer (EML) interface. Meanwhile, CsBr doping helps to enhance the hole transport ability of HTL and thus increase the exciton recombination efficiency, which improves the device performance. The results in this paper can provide experimental support for the development of PeLEDs. • Optimized the hole transport layer (HTL) and prepared quasi-two-dimensional perovskite light-emitting diodes by doping CsBr into PEDOT:PSS. • Enhanced PL strength, suppresses exciton bursting at the HTL/emission layer (EML) interface. • Passivation of defects in perovskite films and enhancement of crystallinity. • Enhanced hole injection ability and exciton recombination efficiency in HTL. • Optimized PeLED's performance is improved in every way. [ABSTRACT FROM AUTHOR]

• CsPbBr 3 perovskite was synthesized as a photoluminescent signal transducer for detecting water content. • A facile water assay device was designed by using the perovskite as the sensing element. • The device is fit for rapid screening of large amounts of samples with high throughput. Excessive water in herbal medicines (HMs) can cause pests infestation, mildew, and decomposition of active ingredients during storage. The classical detection methods for water content are still unsatisfactory due to the requirement of sophisticated manipulation, long time consumption and usage of large amounts of toxic toluene. Herein, hot injection method was adopted to synthesize humidity-sensitive CsPbBr 3 perovskite, which was used to develop a novel photoluminescent (PL) sensor on a paper substrate for rapid detection of water content in HMs with a turn-off mode. Due to the strong ionic nature of CsPbBr 3 and the high aqueous solubility of CsBr, CsPbBr 3 perovskite is very unstable upon the exposure of water. The signal off can be attributed to the phase change from luminescent CsPbBr 3 to non-luminescent CsPb 2 Br 5 according to the results of XRD pattern analysis of CsPbBr 3 perovskite before and after water exposure. The PL intensity of CsPbBr 3 is linearly related to the water content within the range of 1–17 %. For Seutellaria baicalensis and Astragalus flavone , the detection limits are 0.75 % and 0.67 %, respectively. The results of recovery tests for the two HMs are within the range of 96.7–102.5 %. This work realizes the application of CsPbBr 3 perovskite in the field of pharmaceutical analysis, and shows the application potential for the control of water content in other types of samples sensitive to humidity. [ABSTRACT FROM AUTHOR]

A fully stretchable photosynaptic device with low energy consumption is achieved by the intrinsic stretchability of conjugated block copolymers and the accommodation of perovskite quantum dots. The strategy emulates photosynapse functionalities and provides an artificial muscle's neural network with high recognition accuracy, thereby representing potentially major advances in soft optoelectronics. [Display omitted] Emulation of photonic synapses offers a promising avenue for developing low-energy consumption of soft electronics, neurologically inspired robotics, and neuromorphic network computation. In this paper, a fully stretchable photosynaptic device with ultralow energy consumption using intrinsically stretchable poly(δ -decanolactone) (PDL)-based conjugated block copolymers (BCPs) with perovskite quantum dots (PeQDs) is first reported. The findings reveal that selectively choosing solvents for the PDL-based BCPs effectively regulates the assembly of P3HT and the accommodation of PeQDs, leading to improved self-aggregation of PeQDs, increased grain size, and optimized interfaces between P3HT and PeQDs The BCPs/PeQDs composite effectively emulates significant features of photonic synapses, such as paired-pulse facilitation (PPF), spike-dependent and short/long-term neuroplasticity, demonstrating excellent performance, including the fastest response time (1 ms), the highest current contrast (4.9 × 105), PPF (1.93) and ultra-low energy consumption (0.3 aJ) at an operating voltage of –0.1 mV. Furthermore, the BCP/PeQDs exhibit remarkable neuromuscular synapse characteristics, including high strain and bending tolerance and spike-dependent plasticity, enabling the devices to achieve high classification accuracy in artificial neural network simulations during tensile strain. The accommodation solvent selectivity of BCP/PeQDs suggests a promising strategy for advancing neurologically soft electronics, human-like pattern recognition, and neuromorphic computation. [ABSTRACT FROM AUTHOR]

Solar cell encapsulation literature is reviewed broadly in this paper. Commercial solar cells, such as silicon and thin film solar cells, are typically encapsulated with ethylene vinyl acetate polymer (EVA) layer and rigid layers (usually glass) and edge sealants. In our paper, we cover the encapsulation materials and methods of some emerging solar cell types, that is, those of the organic solar cells, the dye-sensitized solar cells and the perovskite solar cells, and we focus on the latter of the three as the newest contender in the solar cell arena. The PSC encapsulation literature is summarized in a comprehensive table we hope the reader may use as a "handbook" when designing encapsulation and long-term stability experiments. Some additional functionalities included in encapsulants are also discussed in our paper, e.g. improving the encapsulants' optical properties and manufacturing them sustainably from biobased materials. [ABSTRACT FROM AUTHOR]

• Three types of IBC structures were conducted for perovskite solar cells by numerical simulations to review their optical response. • Anti-reflection coating with an optimal thickness of 70–80 nm plays an important in determining the optical performance. • The optimal sizes are confirmed by sweeping the structure parameters, suggesting a high photocurrent density of 24.49 mA/cm2. • The light-trapping mechanism is revealed by the position-dependent current density and electric-field distributions. Interdigitated back-contact (IBC) structure design is a promising alternative to further promote the optical absorption and the power conversion efficiency of perovskite solar cells (PSCs). However, their full potential has not been reached owing to the absence of the advanced structure designs and a lack of a deep understanding on the related physics mechanism. In this paper, we proposed three typical IBC configurations featuring flat perovskite layer, textured electron transport layer (ETL) and hole transport layer (HTL), and textured HTL but flat ETL. By the numerical simulations, the optical properties of the three related designs are investigated systematically. The simulation results reveal that anti-reflection coating (ARC) thickness plays an important in determining the device performance and the optimal ARC thickness is suggested to be 70–80 nm. The optimal structure sizes are confirmed by optimizing the structure parameters. In addition, the light-trapping mechanism is clarified by the position-determined photocurrent density and the spatial electric field distributions. Moreover, dependence of optical response under the various perovskite thickness is checked, suggesting that textured IBC structure design is good to achieve high optical absorption. The simulation results demonstrated in this paper provide a valuable guide to design IBC PSCs with high optical performance. [ABSTRACT FROM AUTHOR]

The problem of low stability and high lead content limit the commercial development of halide perovskite. In this paper, the high-energy ball milling is used to rapidly and efficiently synthesize high-entropy Cs(Pb 1/5 Mn 1/5 Ni 1/5 Zn 1/5 Yb 1/5)Cl 3 quantum dots (QDs), the introduction of high-entropy and rare earth ions reduces lead content, increases mixing entropy, and synergistically enhances the photoluminescence (PL) intensity and stability of QDs with other ions. Because the increase of entropy enhances the stability, the QDs still have 70 % PL intensity after 60 days of placement. After the QDs are exposed to the ultraviolet lamp for 8 hours, the PL intensity maintains at 67.1 % due to the loss of ligand. Ionic bonds are easily broken in water, so after soaking in water for 8 hours, the PL intensity of the QDs keeps at 32 %. The thermal stability of QDs is maintained well because of physical and chemical stability of rare earth ions. Since ethanol dissolves the ligands on the surface of the QDs, the non-radiative recombination is enhanced, so the PL intensity of QDs remains at 59 % after soaking for 8 hours. This paper provides a new way that further enhances the stability and solves high lead content of all-inorganic perovskite materials. • All-inorganic perovskite Cs(Pb 1/5 Mn 1/5 Ni 1/5 Zn 1/5 Yb 1/5)Cl 3 QDs were rapidly synthesized by high-energy ball milling. • The introduction of high-entropy and rare earth ions expands the emission range and enhances the luminous intensity. • The high-entropy QDs show good stability of room temperature, water, high temperature, ultraviolet light and ethanol. [ABSTRACT FROM AUTHOR]

Cs 2 CuBr 2 Cl 2 perovskite nanocrystals as a "Switch-Off" fluorescent sensor for nitrobenzene detection. [Display omitted] • An efficient lead free Cs 2 CuBr 2 Cl 2 perovskite nanocrystals for the detection of nitrobenzene were synthesized, • The probe shows a strong fluorescence "turn-off" response in the presence of nitrobenzene. • The limit of detection was obtained in the nanomolar range. • The synthesized probe could detect nitrobenzene in real sample. • A paper strip assay was developed which could effectively detect nitrobenzene. Lead halide nanostructured perovskites are well known for their excellent photoluminescence and optoelectronic properties. However, lead toxicity and instability in moisture impedes its suitability for material use. Here we synthesized a highly efficient, lead free, economical, stable Cs 2 CuBr 2 Cl 2 perovskite nanocrystals (PNCs) via Ligand Assisted Re-Precipitation (LARP) method which is less explored. The sensing application of the synthesized PNCs towards nitro explosives and other small organic compounds were studied. The probe exhibited high selectivity towards nitrobenzene with a lowest detection limit of 57.64 nM. The fluorescent emission intensity was drastically quenched upon the addition of 32 µM nitrobenzene. A Stern-Volmer plot was utilized for the quantification of fluorescence quenching. Further to investigate the quenching mechanism, time correlated single photon counting spectroscopy and other photoluminescence studies were performed pointing out the possibility of fluorescence resonance energy transfer. The work has been further extended to test the capability of the probe to detect nitrobenzene in real water samples and a good recovery percentage ranging from 93-98 % was obtained. Further, a paper strip assay was designed which successfully detected nitrobenzene and can be clearly noticed even with our naked eye making the probe an excellent sensor for nitrobenzene detection. [ABSTRACT FROM AUTHOR]

Recent years, sensors based on perovskite nanomaterials have become one of the most interesting fields while their instability remains as one of the major obstacles for further advancement. In this work, for the first time, a facile and controllable strategy was proposed for in-situ growth of stable CsPbBr 3 nanocrystals in SiO 2 network on poly (vinylidene fluoride) membrane. The formation of SiO 2 network was triggered by the fast hydrolysis of (3-aminopropyl)triethoxysilane as the precursor. Characterization results including UV–vis, FTIR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) indicate successful formation of CsPbBr 3 –SiO 2 nanocomposites. With the protection from SiO 2 network, the fluorescence intensity of CsPbBr 3 nanocrystals maintains 88.11% of initial intensity after 104 days in ambient environment and is stable during the humidity test (RH = 90%, for 30 min). CsPbBr 3 –SiO 2 nanocomposite based membrane can be applied as fluorescent sensors for NH 3 determination in high concentration range based on fluorescence quenching, which shows good linearity, accuracy, precision, and specificity toward NH 3 over common organic vapors. [Display omitted] • With the protection from SiO 2 network, CsPbBr 3 nanocrystals own high stability in ambient environment. • Porous structure of PVDF membrane is beneficial for the nucleation and growth of CsPbBr 3 nanocrystals and gas adsorption. • The whole process of fabrication literally consists of stirring and dropping. • The sensor shows good selectivity, precision and accuracy for NH 3 sensing. • The sensor fills in the shortage of devices capable of high concentration monitoring of NH 3. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) have raised significant attention due to their rapid increase in power conversion efficiency (PCE) in less than 15 years. However, the metal-based counter electrode of the PSC device suffers from stability issues under ambient air conditions. In contrast, the carbon-based electrode perovskite solar cells (CBPSCs) have better stability in ambient air than the metal-based electrode. Based on the bibliometric analysis, this paper presents the research trends and future outlook of CBPSCs spanning from January 1, 2013, to August 31, 2023. The VOSviewer and Biblioshiny (Bibliometrix) software were used to visualize the analyzed dataset retrieved from the Scopus database. The bibliometric analysis includes the CBPSCs annual publication, source network, co-occurrence of all keywords analysis, author analysis, country analysis, research funding analysis, central area in CBPSCs, and progress in CBPSCs. The results show that China was leading in the overall analysis area, including the funding sponsor. The highest PCE-certified record in CBPSC to date was 21.9 %, which is almost comparable to the metal-based electrode (26.1 %). The research trends based on bibliometric analysis reveal that the future research focus will be on the carbon interface and charge transfer, which can be done by engineering the layer or incorporating dopants. This paper is expected to give insight to the researcher or stakeholder in the advancement of CBPSCs. [ABSTRACT FROM AUTHOR]

All-inorganic lead-containing perovskites have shown strong luminescence, but the use of lead has hindered their commercial development due to its stability and toxicity. In this paper, we propose thermal precipitation in ionic liquids (ILs) for synthesizing Bi3+-doped Cs 2 ZrCl 6 double perovskites (Cs 2 ZrCl 6 :Bi3+(ILs)), which have a better crystallinity compared to the Cs 2 ZrCl 6 :Bi3+ (HCl) synthesized by the traditional hydrochloric acid method. Most interestingly, the Cs 2 ZrCl 6 :Bi3+(ILs) exhibits ultra-high photoluminescence quantum yield (PLQY) of up to 78.52%, which is about three times higher than the Cs 2 ZrCl 6 :Bi3+ (HCl) prepared by the traditional method. In addition, the PLQY of this paper is the highest in the reported works for the Cs 2 ZrCl 6 :Bi3+. It has been confirmed that the high PLQY of Cs 2 ZrCl 6 :Bi3+(ILs) is due to the interaction force between N atoms and perovskites in ionic liquid cations, and the cations in ionic liquids can improve the crystallinity of Cs 2 ZrCl 6 :Bi3+(ILs) double perovskite crystallites by passivating shallow defects. The research provides an alternative and efficient method for synthesizing stable lead-free double perovskites with good optical properties. • Bi3+-doped Cs 2 ZrCl 6 double perovskite materials were synthesized in ionic liquids by simple thermal precipitation. • The PLQY of Cs 2 ZrCl 6 :Bi3+ (ILs) was 78.52%, which was about 3 times that of Cs 2 ZrCl 6 :Bi3+ prepared under the HCl system. • The passivation mechanism for the enhanced optical properties of Cs 2 ZrCl 6 :Bi3+ by ionic liquid was proposed and verified. • This work provides an innovative strategy for improving the optical properties of all-inorganic lead-free perovskites. [ABSTRACT FROM AUTHOR]

• The J sc of perovskite solar cells has been improved from 14 mA/cm2 to 22 mA/cm2 using TiO 2 nanowire. • PSC based on TiO 2 nanowire structures have been simulated using FDTD and FE methods. • In compare to the flat structure the performance of 3D perovskite solar cell has been improved by about 61%. • The effects of different phenomena of recombinations on the performance of 3D perovskite solar cells have been studied. • The light harvesting of the absorber layer in 3D perovskite solar cells has been improved. The advantages of perovskite solar cells over other photovoltaic technologies in recent years lead many works to improve the efficiency of these solar cells. The short circuit current density of perovskite solar cells can be improved using 3D structures. The structure that we present is consists of a perovskite layer on a nanowire metal oxide scaffold layer. The morphology of these layers is determined by using a 3D structure algorithm. In this paper, we simulated perovskite solar cells based on the TiO 2 nanowire scaffold layer, which acts as an electron transport layer and a 3D scaffold layer, by using FDTD and FE simulation methods. These methods are respectively used for optical and electrical simulations. According to our simulation results and with our proposed and optimized structure, the maximum power conversion efficiency that we have reached is 18.9%. We ignored some practical limitations to achieve this efficiency. The Period and height of nanowires for this structure are 100 nm and 400 nm respectively. All these dimensions are determined by reviewing the practical papers, so these dimensions can be applied in practical cases. Also in this study, when we apply all recombinations and practical limits, we achieved 14.7% PCE that showed 61% improvement than conventional flat structure perovskite solar cells. Both of these power conversion efficiencies that we achieved can compete against conventional silicon solar cells. Because producing these perovskite solar cells with metal oxide nanowires especially TiO 2 is much more affordable and convenient than conventional silicon solar cells. [ABSTRACT FROM AUTHOR]

Citrate auto-combustion method was employed to create Bi-perovskite (BFO), Zn-ferrite (ZFO) and Sr-hexaferrites (SFO) nanoparticles, which were then mixed up to form matrix composite which used to separate the lead metal ions from wastewater. Based on XRD peaks, the crystallite size was between 30 and 52 nm. The particles' FTIR spectra clearly show that each synthesized compound has unique functional groups. The samples had agglomeration, with each agglomerate including many grains, as shown by the SEM micrographs. The energy band gap of SFO was enhanced and reduced from 3.5 to 1.5 eV by adding BFO and ZFO. For magnetic study, T C as well as μ eff of BFO and ZFO were improved by adding SFO. While the dielectric properties for pure SFO was enhanced after adding BFO and ZFO in the nanocomposite, in this research paper author succeed in preparing nanosample with upgrading magnetic, optical and electric properties more than individual samples' properties. The synthetic BFO/ZFO/SFO nanocomposite produced impressive results in the treatment of wastewater due to their enormous surface area, regulated size, well-defined structure, and high magnetic, optical and electric properties. Kinetic and isotherm analysis are applied to the experimental results. The high correlation coefficient indicates the adsorption of heavy metal ions, which is described by the Langmuir and Freundlich isotherms (R2). For the 97% removal of Pb (II) from wastewater at a contact duration of 40 min at room temperature and pH 7. [ABSTRACT FROM AUTHOR]

The commercialization of the Co-free solid oxide fuel cell (SOFC) cathode was hindered due to its insufficient oxygen reduction reaction (ORR) activity. In this paper, the ORR activity of the cathode material is effectively increased by doping a small amount of low-valence Ln3+ (Nd3+, Sm3+) ions at the B-site of Fe-based perovskite Bi 0.5 Sr 0.5 FeO 3-δ (BSF). Nd3+ increases the free volume (V free) per unit cell of perovskite due to its larger ionic radius, thus increasing the oxygen vacancy concentration of Bi 0.5 Sr 0.5 Fe 0.95 Nd 0.05 O 3-δ (BSFN). Compared with BSF, BSFN has greatly improved the surface oxygen exchange and volume diffusion rate through the electronic conductivity relaxation (ECR) method. At 700 °C, the area-specific resistance (ASR) of BSFN reached 0.062 Ω cm2, which was 65% lower than that of BSF (0.177 Ω cm2), and the peak power density (PDD) of BSFN-based single cell reached 1.10 W cm−2, which was 1.7 times higher than that of BSF-based single cell (0.64 W cm−2). Through DRT analysis, it is concluded that BSFN can accelerate the adsorption/dissociation process of oxygen due to its higher oxygen vacancy concentration compared with BSF, so that ORR is not limited to the three-phase interface but extends to the entire cathode surface. In addition, in the 80 h long-term stability test at 600 °C, the BSFN-based single cell has better long-term stability because the thermal expansion coefficient of BSFN (14.1 × 10−6 K−1) is lower than that of BSF (14.4 × 10−6 K−1). In general, BSFN is expected to become a Co-free base high-performance intermediate temperature SOFC cathode. [ABSTRACT FROM AUTHOR]

Although Pt/C has long been regarded as the most effective HER catalyst, the use of complicated water systems is challenged by high costs and contaminant interference. Therefore, it was shown in this paper that a low-cost perovskite oxide, SrCo 0.7 Fe 0.3 O 3-δ (SCF-X, where X denotes annealing temperature), could be used in oil-field wastewater to promote electrochemical reactions for hydrogen production and that its catalytic activity can be impacted by calcination temperature. And, the outstanding catalytic activity of SCF-800 and 850 is primarily caused by crystal structure distortions and the presence of Co3+/Co4+ coupling pairs as a result of electron transfer between Co and Fe, which increases the concentration of reactive oxygen species. Furthermore, there is now more interest in SCF-850 due to its exceptional stability. In complicated systems, the current work provides a feasible route for perovskite catalysts to produce hydrogen. [Display omitted] • Perovskite oxides successfully catalyze the electrolytic hydrogen production from oilfield wastewater. • The catalytic activity of perovskite electrocatalysts is regulated by controlling the calcination temperature. • More oxygen vacancies in the lattice are beneficial to accelerate the reaction kinetics. [ABSTRACT FROM AUTHOR]

Proton-conducting electrochemical devices such as protonic ceramic fuel cells and protonic ceramic electrolysis cells play a major role in the creation of eco-friendly "green" energy systems. The most studies of proton-conducting materials for these devices are barium cerate zirconates. The layered perovskites are novel class of proton-conducting materials. In this paper, the possibility of cation and oxyanion doping of layered perovskite BaNd 2 In 2 O 7 was carried out for the first time. The most conductive composition BaLa 1.9 Sr 0.1 In 2 O 6.95 demonstrates protonic conductivity value 2·10−5 S/cm at 450 °C. The acceptor-doped two-layer perovskites are the prospective class of proton-conducting materials, and further modification of their composition opens up a new way in the design of solid oxide protonic conductors. [Display omitted] • Acceptor doping leads to increase in the protonic conductivity of BaNd 2 In 2 O 7. • Oxyanion (phosphorous) doping is not suitable method for improving transport properties of BaNd 2 In 2 O 7. • Acceptor doping is the promising method for improving of protonic transport in layered perovskites. [ABSTRACT FROM AUTHOR]