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Constructing heterojunctions of different dimensions formed by perovskite materials and semiconductor photocatalytic materials is an innovative idea for designing efficient photocatalysts. The combination of perovskite materials with photocatalytic materials for photocatalytic hydrogen evolution is less reported. In this paper, 3D LaCoO 3 /CdS heterojunction has been constructed by simple solvothermal method, and the interfacial charge transfer mechanism of S-scheme has been further demonstrated by DFT (density functional theory) calculations and ESR (electron spin resonance) experiments. The transfer mechanism effectively promotes the electron transfer and enhances the hydrogen evolution activity of the catalysts. The highest hydrogen evolution rate up to 18.91 mmol h−1 g−1, which is 9.60 times higher than pure CdS. In addition, it can be observed by SEM that the CdS nanoparticles are dispersed on the surface of the 3D network structure of LaCoO 3 , which effectively inhibits the agglomeration of CdS nanoparticles. Finally, TEM effectively demonstrated the effective interfacial contact between the different dimensions of LaCoO 3 and CdS. This contact facilitates the acceleration of charge transfer. This work provides a reference for the construction of perovskite-based S-scheme heterojunctions. 3D LaCoO 3 /CdS photocatalysts were prepared and a possible mechanism for the photocatalytic hydrogen production activity was proposed. [Display omitted] • Novel 3D LaCoO 3 /CdS S-scheme heterojunction successfully constructed. • LaCoO 3 as a low-cost and highly efficient photocatalyst for hydrogen precipitation. • LaCoO 3 /CdS-10 exhibited optimized H 2 production rate of 18.91 mmol h−1 g−1. [ABSTRACT FROM AUTHOR]

Bacteria are mostly everywhere, some of them affect health safety of human beings, plants and animals all the time. Photocatalytic antibacterial technology has entered people's field of vision due to their high-efficiency and sustainability. In this study, LaCoO 3 precursors were prepared by solvothermal synthesis, and then calcined to obtain self-assembled LaCoO 3 microspheres. Subsequently, LaCoO 3 /Ag 3 PO 4 microspheres were synthesized by in-situ precipitation method. Compared with pure LaCoO 3 microspheres, the introduction of Ag 3 PO 4 nanoparticles can effectively enhance the antibacterial performance of LaCoO 3 /Ag 3 PO 4 nanocomposites. LaCoO 3 /Ag 3 PO 4 nanocomposites' Minimum Inhibitory Concentrations (MICs) against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were tested to be 0.1 mg mL−1 and 0.15 mg mL−1, respectively. Under visible light irradiation for 20 min, the antibacterial rate of nanocomposites against E. coli and S. aureus was 99.9 % and 98.3 %, correspondingly. This can be attributed to the fact that LaCoO 3 /Ag 3 PO 4 heterojunction significantly improves the responsiveness of visible light, carrier separation and migration efficiency of LaCoO 3 , which promotes the nanocomposite to produce a large number of ROS under visible light. In addition, LaCoO 3 /Ag 3 PO 4 nanocomposites had a strong oxidation effect on glutathione (GSH), resulting in the failure of the antioxidant defense system of bacteria. Also, the release of Ag+ and plasma effect of Ag are also important reasons for the high antibacterial performance of LaCoO 3 /Ag 3 PO 4 nanocomposites. The photoresponse of LaCoO 3 -based nanomaterials under visible light is effectively improved by constructing heterojunctions, the separation efficiency of photogenerated electron-hole pairs is increased, and the carrier transport is accelerated, thus achieving high efficiency and broad spectrum antibacterial effect. This research shows that LaCoO 3 nanocomposites can be used as a prospective photocatalytic antibacterial material, enhances the value of practical applications. [ABSTRACT FROM AUTHOR]

New energy sources such as solar energy have been developed and utilized due to the shortage of non-renewable energy, and photoelectric materials have attracted more attention, accordingly. Moreover, flexible optoelectronic devices are crucial in the fields of wearable artificial intelligence, portable energy, and smart medical care. At present, photoelectric devices based on traditional perovskite cobalt oxide rigid films have problems such as inability to bend and deformation, which limits their application environment. Here, natural mica with atomically flat surface, high thermal stability, high transparency and good mechanical flexibility was selected as the substrate for preparing a series of LaCoO 3 flexible photoelectric films. These films exhibit excellent photoelectric properties and flexible properties. More importantly, the flexible film still has fast response speed and reproducible light response after 500 bending cycles. It reveals that all-inorganic perovskite LaCoO 3 is a promising candidate for designing high-performance, flexible and wearable optoelectronic devices. [Display omitted] [ABSTRACT FROM AUTHOR]

Perovskite has attracted a lot of attention in the area of present-day environmental catalysis because of its cheap cost, excellent stability, great catalytic activity, varied structure, and significant transformation flexibility. In order to remove organic contaminants from wastewater, researchers have been experimenting with combining perovskite catalysts with advanced oxidation processes (AOPs). Herein present study, LaCoO3 was synthesized and calcined at 450, 650, and 850 °C (LC450, LC650, and LC850), and the connections between their surface features and crystalline assembly to catalytic performance were thoroughly explored to activate peroxymonosulfate (PMS) in order to degrade aqueous organic contaminants. Further, the catalysts were characterized by XRD, FTIR, FSEM, and TEM, and their catalytic efficiency was investigated. The Co-O bond length is recommended as a biomarker for PMS activation because it strongly influences the Co2+/Co3+ redox capability, regulating the total PMS activation. LC850/PMS has demonstrated the highest degradation efficiency (79%), with kapp value 0.102 min−1. Further modification of these types of perovskite catalysts might be very feasible and promising to degrading organic pollutants. [ABSTRACT FROM AUTHOR]

The study investigates the time-dependent deformation of LaCoO 3 under constant uniaxial compressive stresses at various temperatures ranging from room temperature to 880 °C. Through the acquisition of stress-strain curves at different temperatures, it has been observed that LaCoO 3 exhibits non-linear ferroelastic behavior. The stiffness of LaCoO 3 increases with temperature, up to 600 °C, after which it starts to decrease at higher temperatures. Furthermore, negative creep occurs at lower temperatures, whereas positive creep is observed at temperatures exceeding 600 °C. This can be attributed to transitioning from a ferroelastic creep at low temperatures to a combination of ferroelastic and high-temperature conventional creep at temperatures above 600 °C. The magnitude of both negative and positive creep is proportional to the temperature. The structural stability of LaCoO 3 under creep loading at all temperatures has been assessed by comparing pre-test and post-test X-ray diffraction analyses, which showed the texture formation after testing. [ABSTRACT FROM AUTHOR]

[Display omitted] For the first time, kinetic data on the decomposition of N 2 O over mixed oxide LaCoO 3 with a perovskite structure have been obtained. Bulk LaCoO 3 synthesized using microwave activation exhibited an increased intrinsic reaction rate with a 30 kJ mol–1 lower activation energy. Perovskite samples supported on ZrO 2 -La demonstrated lower intrinsic reaction rates due to the lower content of the LaCoO 3 phase, but the activation energies were also lower by 50–80 kJ mol–1. [ABSTRACT FROM AUTHOR]

In the quest for the development of thermally stable, highly active and low-cost catalysts for use in catalyzed diesel particulate filter, nano-composites are new areas of research. Therefore, we reported the easy synthesis of spinel NiCo 2 O 4 /perovskite LaCoO 3 nano-composite, and its individual oxides NiCo 2 O 4 and LaCoO 3 for comparison. The detailed insights into the physio-chemical characteristics of formed NiCo 2 O 4 / LaCoO 3 nano-composite were done based on various characterization analysis such as X-ray diffraction (XRD), Fourier transform infrared (FT-IR), N 2 physiosorption, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The characterization analysis of NiCo 2 O 4 /LaCoO 3 revealed the successful formation of a chemical interface possessing strong interfacial interaction, resulting in desirable physicochemical characteristics such as small crystallite size, abundant mesoporosity, high specific surface area and activation of surface lattice oxygen. Owing to the desirable characteristics, the activity results over NiCo 2 O 4 /LaCoO 3 nano-composite showed the excellent CO oxidation performance and high soot oxidation activity, recyclability and thermal stability. This work mainly attempts to emphasize the effectiveness of the facile, inexpensive and conventionally used precipitation method for the successful formation of highly efficient nano-composites. [ABSTRACT FROM AUTHOR]

The Z-scheme LaCoO3/ZnO (LCZ) heterojunction photocatalyst was designed and prepared using the hydrothermal method. In the photocatalytic degradation of tetracycline hydrochloride, LCZ exhibited the highest photocatalytic activity with a rate constant of 0.0179 min−1,which is 3.2 and 2.3 times higher than those of pure ZnO and LaCoO3, respectively. This study presents a promising approach with potential applications in the field of photocatalytic degradation. Further theoretical studies reveal that the existence of Z-scheme heterojunction can prevent the recombination of electron-hole pairs, leading to enhanced photocatalytic performance.

The high hydrogen storage capacity (10.5 wt.%) and release of hydrogen at a moderate temperature make LiAlH4 an appealing material for hydrogen storage. However, LiAlH4 suffers from slow kinetics and irreversibility. Hence, LaCoO3 was selected as an additive to defeat the slow kinetics problems of LiAlH4. For the irreversibility part, it still required high pressure to absorb hydrogen. Thus, this study focused on the reduction of the onset desorption temperature and the quickening of the desorption kinetics of LiAlH4. Here, we report the different weight percentages of LaCoO3 mixed with LiAlH4 using the ball-milling method. Interestingly, the addition of 10 wt.% of LaCoO3 resulted in a decrease in the desorption temperature to 70 °C for the first stage and 156 °C for the second stage. In addition, at 90 °C, LiAlH4 + 10 wt.% LaCoO3 can desorb 3.37 wt.% of H2 in 80 min, which is 10 times faster than the unsubstituted samples. The activation energies values for this composite are greatly reduced to 71 kJ/mol for the first stages and 95 kJ/mol for the second stages compared to milled LiAlH4 (107 kJ/mol and 120 kJ/mol for the first two stages, respectively). The enhancement of hydrogen desorption kinetics of LiAlH4 is attributed to the in situ formation of AlCo and La or La-containing species in the presence of LaCoO3, which resulted in a reduction of the onset desorption temperature and activation energies of LiAlH4. [ABSTRACT FROM AUTHOR]

Samples of La1-3xLixM2xCoO3-δ (M = Ca, Sr, Ba; 0≤x≤0,1) were synthesized by co-precipitation method. It is shown that the region of their homogeneity lies in the range of substitutions 0≤ x ≤0.05. The volume of the unit cell increases with the size of the alkaline earth metal that replaces lanthanum. Surface morphology of the obtained mixed oxides was studied by SEM. In all samples (except strontium - containing) paramagnetic Co2+ ions from the impurity Co3O4, which are in different local environments and have different degrees of exchange interaction with each other, are contained in the form of chain fragments -Co2+-O2--Co2+-O2--Co2+-O2— and contain defective centers Со2+, which are formed during the desorption of lattice oxygen from the surface, or in the process of diffusion of oxygen from the volume of material to the surface. In strontium-containing samples La0,85Lix0,05Sr0,01CoO3-δ there are mainly ferromagnetic clusters Co3+-Co4+.

[Display omitted] • Gelatin-based aerogels functionalized with LaCoO 3 and g-C 3 N 5 were successfully fabricated. • The optimized aerogel (GA–LCCN-1.5) exhibited 95.7% removal efficiency for CIP. • CIP degradation was attributed to the generation of 1O 2 , •OH, and SO 4 •− via PMS activation. • GA–LCCN-1.5 showed great reusability with 93.2% CIP removal efficiency after five cycles. • GA–LCCN-1.5 demonstrates a promise for treating water-containing organic contaminants. Three-dimensional porous gelatin-based aerogels functionalized with LaCoO 3 and nitrogen-rich graphitic carbon nitride (g-C 3 N 5) were successfully fabricated via a freeze-drying approach. Herein, the gelatin-based aerogels served as excellent adsorbents and catalysts activating peroxymonosulfate (PMS) to efficiently degrade ciprofloxacin (CIP) from aqueous solutions. In comparison to the pristine gelatin aerogel (GA), the optimized functionalized aerogel (GA–LCCN-1.5) demonstrated a 17.0% superior CIP adsorption performance. Remarkably, GA–LCCN-1.5 exhibited 95.7% removal efficiency for CIP, attributed to the effective generation of •OH, SO 4 •−, and 1O 2 via PMS activation. In addition, high degradation efficiencies over 84.1% were maintained throughout a broad pH range of 3–9. Notably, GA–LCCN-1.5 demonstrated outstanding stability and reusability, with 93.2% CIP removal efficiency even after five reuse cycles indicating significant promise in real applications. Radical quenching and electron spin resonance (ESR) analysis suggest that CIP degradation was dominated by radical and non-radical routes through GA–LCCN-1.5 catalyzed PMS decomposition. Besides, the plausible CIP degradation mechanisms were systemically analyzed and proposed. The toxicities of CIP and the intermediate by-products were evaluated and reported. The findings of this study and insights demonstrate a facile construction of a biopolymer-based aerogel catalyst for synergistic and efficient PMS activation for the removal of antibiotics in water. [ABSTRACT FROM AUTHOR]

Lanthanum (La) nanocomposites LaFeO3, LaNiO3, and LaCoO3 were synthesized using a sol-gel method, and different La to-metal (Fe, Ni, or Co) ratios were attained using various concentrations of salts. The resulting composites were calcined at 540 °C and characterized by XRD, SEM-EDX, FT-IR spectroscopy, XPS, thermogravimetric analysis (TGA), and PL spectroscopy. The activity of the lanthanum composites (LaFeO3, LaNiO3, and LaCoO3) was studied using the photocatalytic degradation of methylene blue (MB) and ortho-toluidine blue (o-TB) under visible light with a wavelength below 420 nm. The change in the concentration of dyes was monitored by using the UV-Vis spectroscopy technique. All composites appeared to have some degree of photocatalytic activity, with composites possessing an orthorhombic crystal structure having higher photocatalytic activity. The LaCoO3 composite is more efficient compared with LaFeO3 and LaNiO3 for both dyes. High degradation percentages were observed for the La composites with a 1:1 metal ratio. [ABSTRACT FROM AUTHOR]

It has become a challenge to further enhance the electrocatalytic performance of perovskite oxides due to their limited active surface area. Herein, we propose a top-down strategy for the amorphization of crystalline LaCoO3 nanopowders with significantly enhanced specific surface area and electrocatalytic oxygen evolution reaction (OER) activity and durability, in which the overpotential at the current density of 10 mA cm–2 reduced from 405 to 293 mV, and the Tafel slope decreased from 96.6 to 63.4 mV dec–1. This work provides an effective method for the property optimization of nanometer perovskite oxides and the design of high-performance electrocatalysts. [ABSTRACT FROM AUTHOR]

Enhancement of thermoelectric properties by virtue of decreased electrical resistance through grain boundary engineering is realised in this study. A robust strategy of optimisation of the transport properties by tuning the energy filtering effects at the interfaces by decreasing the interfacial electrical resistance is achieved in LaCoO 3 (LCO). This is accomplished by the incorporation of multilayer graphene within the parent LCO matrix containing multi-scale nano/micro grains. The present work has attained a substantial increment in electrical conductivity from a value of 96 Scm-1 for bare LCO to ∼5300 Scm-1 at 750 K by incorporating 0.08 wt% multilayer graphene in LCO. No significant change in thermal conductivity is observed due to the presence of multilayer graphene in LCO. A zT of 0.33 at 550 K for 0.08 wt% multi-layer graphene incorporated LCO composite is achieved which is the highest thermoelectric figure of merit value for undoped LCO reported until now. [ABSTRACT FROM AUTHOR]

The basic LaCoO3 perovskite oxides were prepared by the series of methods (reverse co-precipitation, citric acid aided sol–gel, glycine assisted solution combustion), underwent physicochemical characterization (XRD, FTIR, BET, XPS and SEM), followed by their soot oxidation activity tests in both "loose" and "tight" conditions of soot-catalyst contact. The activity tests revealed that the LaCoO3 catalyst formed using glycine assisted combustion synthesis gives the best performance with the T10, T50, and T90 at 361 °C, 404 °C and 445 °C, respectively, in loose contact conditions and T10, T50, and T90 at 306 °C, 330 °C and 355 °C, respectively, in tight contact conditions. Its outstanding performance can be attributed to its unique morphology consisting of scaffolds having an extensively interconnected macroporous network with macropores having nanoporous struts as walls as evidenced by SEM results. Such morphology makes the active sites of inner pores accessible to the gaseous (air) as well solid reactant (soot particles), thereby benefitting soot oxidation reaction. [ABSTRACT FROM AUTHOR]

Elucidation of the relationship among crystal structure, material compositions, and electrocatalytic performance is beneficial to the design of electrocatalysts with high activity. Specially, for bifunctional electrocatalysts, there is a lack of the unified understanding of oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) mechanisms. Based on the first-principles calculations, LaCoO 3 surface reconstructions with different OH coverage under OER/ORR condition are determined. Thereby, the different reaction pathways for OER and ORR with the cooperation of Co and O sites are revealed, under which Co and lattice O sites are activated dynamically, and an overpotential of 0.35 V for the OER and 0.44 V for the ORR are obtained. Furthermore, the octahedra lattice distortion-related bifunctional mechanism (DRBM) is proposed from electron structure analysis, and the bifunctional activity of different B-site doped LaCoO 3 (LaCoMO 3) are studied. Based on this mechanism, we find that OER, ORR, and their bifunctional activity of LaCoMO 3 all exhibit a volcano trend as a function of the O-B-O bond angle formed by Co and lattice oxygen. Consequently, we predict that Mn, Cr, Fe, and Ti doped LaCoO 3 electrocatalysts exhibit remarkable bifunctional activity, which is corroborated by the reported experimental results. This is special type of abstract that is so short and could be inserted after main abstract of article, as a blurb or inserted as annotations into a Table of contents [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • (1) Both the epitaxial strain and the content of surface-adsorbed oxygen affect the heterostructures' photoconductivity. • (2) Mechanical strain generated by bending the fluorphlogopite substrate also has a modulating effect on the photoresponse of the flexible heterostructures. • (3) The heterostructure maintains a good photoresponse after 105 bending cycles without essentially weakening, indicating a superior mechanical durability and stability. The research of high-speed photodetector and high-speed optical receiver garners significant attention due to their indispensable properties in many fields including high-temperature event monitoring, security, and ad hoc network wireless communication. Inorganic perovskite oxides LaCoO 3 films showcase an extensive prospect in this area owing to their remarkable photoconductive effect. Up to present, however, LaCoO 3 films are mostly grown on rigid instead of flexible substrates, greatly limiting their applications to wearable optoelectronic sensors. In this work, we fabricated some flexible LaCoO 3 thin films to study their photoresponse. By inserting SrTiO 3 and BaTiO 3 as buffer layers, we find that LaCoO 3 thin films could epitaxially grow on the fluorphlogopite surface and show a stable photoresponse to visible-light. Nevertheless, we also found that the epitaxial strain and the content of surface-adsorbed oxygen could impact the photoconductivity. The mechanical strain generated by bending the fluorphlogopite substrate has been confirmed to has a tunable effect on the photoresponse. Moreover, with the fatigue tests of 105 bending cycles, the flexible LaCoO 3 thin films maintain a good photoresponse without any essentially weakening, proving a superior mechanical durability and stability. This work not only indicates the feasibility of the LaCoO 3 films applied for flexible photodetectors but also opens a path for other perovskite films applications for flexible substrate. [ABSTRACT FROM AUTHOR]

Constructing of homojunction of sulfides would be an effective method to improve photocatalytic hydrogen evolution activity. However, only pure hexagonal phase Mn0.25Cd0.75S was synthesized so far. Herein, a series of cubic/hexagonal Mn0.25Cd0.75S (CH-MCS) photocatalysts were hydrothermally synthesized by controlling the amount of thioacetamide. When the molar ratio of Mn:Cd:S equals to 1:3:6, the CH-MCS exhibited the maximum H2 production rate of 5.85 mmol g−1 h−1. Moreover, the optimized CH-MCS modified with 10 wt% LaCoO3 reached the maximal rate of H2 evolution to 14.5 mmol g−1 h−1, that is 5.5 folds to pure hexagonal Mn0.25Cd0.75S and 2.5 folds to the optimized CH-MCS, which can be attributed to the cubic/hexagonal crystal phase homojunctions and the enhancement of visible-light absorptions caused by the decoration of LaCoO3. [ABSTRACT FROM AUTHOR]

Acid etching can effectively alter the mineralization properties of perovskite. In this study, LaCoO 3 perovskites were etched via acetic acid (1–3 M) and were used to simultaneously catalyze the oxidation of NO and Hg0 in coal-fired flue gas. The results demonstrated the ability of the modified acetic acid to improve the low-temperature activity of LaCoO 3 perovskite. The acetic acid could erode or dissolve the La–O surface termination and emerge more Co–O surface termination, changing the pore structure, surface morphology, redox capacity, metal oxidation state, and acid-site strength. These changes on the LaCoO 3 perovskite allowed for the low-temperature to simultaneously improve the NO and Hg0 oxidation performances, and the NO reaction temperature was reduced by 25 °C. Moreover, when the concentration of acetic acid exceeded 1 M, part of the active Co ions in the perovskite structure were further dissolved, thereby reducing the NO and Hg0 simultaneous oxidation activity. [Display omitted] • The LaCoO 3 -1/2/3M possessed better oxidation activity than raw LaCoO 3. • The surface modification of acetic acid for LaCoO 3 was favorable for NO and Hg0 to access the surface. • Acetic acid made part of La–O bands be dissolved and more active Co–O bonds be exposed over the surface. [ABSTRACT FROM AUTHOR]

Thin films of crystallized LaCoO3 were grown on Si substrate by Pulsed Laser Deposition at different temperatures (750°C, 850°C and 1000°C). The structural characterization of the LaCoO3 thin films was done by combining several techniques: Scanning Electron Microscopy (SEM), Atomic Force Microscope (AFM), Transmission Electron Microscopy (TEM) and Grazing Incidence X-Ray Diffraction (GIXRD). The thin films crystallized in the expected rhombohedral phase whatever the deposition temperature, with an increase of crystallite size from 70 nm at 750°C to 100 nm at 1000°C, and an average thickness of the thin films of less than 200 nm. At 850°C and 1000°C, the thin films are crack-free, and with a lower number of droplets than the film deposited at 750°C. The grains of LaCoO3 film deposited at 850°C are columnar, with a triangular termination. At 1000°C, an intermediate layer of La2Si2O7 was observed, indicating diffusion of Si into the deposited film.

The utilization of an in-plane lattice misfit in an oxide epitaxially grown on another oxide with a different lattice parameter is a well-known approach to induce strains in oxide materials. However, achieving a sufficiently large misfit strain in this heteroepitaxial configuration is usually challenging, unless the thickness of the grown oxide is kept well below a critical value to prevent the formation of misfit dislocations at the interface for relaxation. Instead of adhering to this conventional approach, here, we employ nanometer-scale large strain fields built around misfit dislocations to examine the effects of two distinct types of strains─tension and compression─on the generation of oxygen vacancies in heteroepitaxial LaCoO 3 films. Our atomic-level observations, coupled with local electron-beam irradiation, clarify that the in-plane compression notably suppresses the creation of oxygen vacancies, whereas the formation of vacancies is facilitated under tensile strain. Demonstrating that the defect generation can considerably vary with the type of strain, our study highlights that the experimental approach adopted in this work is applicable to other oxide systems when investigating the strain effects on vacancy formation.

• Bi@g-C 3 N 4 photoanode decorated with LaCoO 3 cocatalyst for PEC water splitting. • Bi dopant improves the photoelectrocatalytic activity of g-C 3 N 4 toward OER. • Bi@g-C 3 N 4 /LaCoO 3 showed much more anodic photocurrent and more negative onset potential compared with g-C 3 N 4 and Bi@g-C 3 N 4. • Creation of effective charge cascade between Bi@g-C 3 N 4 and LaCoO 3 accelerates separation/transfer of photo-induced charge carriers. The electrophoretic loading of porous perovskite-lanthanum cobaltite (LaCoO 3) on bismuth doped g-C 3 N 4 (Bi@g-C 3 N 4) as a novel photoanode was designed for the efficient photoelectrocatalytic water splitting. Before loading cocatalyst, the photoelectrocatalytic oxygen evolution of g-C 3 N 4 was investigated with various amounts of Bi. The photoconversion efficiency enhanced more than 3.7 times for 3.6% Bi doped compared with that of the pristine g-C 3 N 4. The Mott-Schottky plots showed the amount of band bending for Bi@g-C 3 N 4 is more than that of g-C 3 N 4 resulting in better electron transfer at the photoelectrode/electrolyte interface. By loading LaCoO 3 on Bi@g-C 3 N 4 photoanode, the photoconversion efficiency of 2.3% at 0.28 V (vs. RHE) was obtained under visible light which is more than that of Bi@g-C 3 N 4 (0.92% at 0.48 V vs. RHE) alone. The high photocurrent density of 0.40 mA cm−2 was observed for Bi@g-C 3 N 4 /LaCoO 3 photoanode as compared with Bi@g-C 3 N 4 (0.17 mA cm−2) at the redox potential of O 2 /H 2 O. Also, Bi@g-C 3 N 4 /LaCoO 3 photoanode represents a smaller arc radius in electrochemical impedance spectroscopy Nyquist plot compared with those of g-C 3 N 4 and Bi@g-C 3 N 4. [ABSTRACT FROM AUTHOR]

[Display omitted] • La-Co-O composites with varied La/Co molar ratios were synthesized. • Synergistic effect between Co 3 O 4 and LaCoO 3 of La-Co-O composites were investigated. • The crucial factors determining CO oxidation and CO + NO reduction are different. • Co-existence of Co 3 O 4 and LaCoO 3 is crucial for CO oxidation and CO + NO reduction. • Excess presence of La 2 O 3 is detrimental to both CO oxidation and CO + NO reduction. La-Co-O composites with varied La/Co molar ratios (defined as LCO- r) were synthesized as catalysts for CO oxidation and CO + NO reduction reactions. XRD, N 2 physisorption, H 2 -TPR, O 2 -TPD and XPS measurements were used to characterize the physicochemical properties of the catalysts, which showed that the increase of r value leads to varied phase structures, surface area, oxidizing ability, thermal stability and surface atomic exposures. Catalytic tests showed that LCO-0.3 is the best catalyst for CO oxidation and LCO-0.5 is the best for CO + NO reduction, suggesting the crucial factors controlling the reaction rate was changed, due to the different properties of O 2 and NO. Nevertheless, the co-existence of Co 3 O 4 and LaCoO 3 is important for both reactions, as synergistic effects facilitating the activation of CO and O 2 (or NO) were induced between them. A significant decrease in the activity of both reactions was observed at r > 1.0, due to the formation of chemically stable La 2 O 3 , which covers the catalyst surface and restrains the reaction. [ABSTRACT FROM AUTHOR]

Abstract Nanostructure perovskites such as LaMO3 (where M = transition metal such as Mn, Co, Ni, and Fe) have captured attention in materials science fields due to their promising catalytic properties. In this study, the LaCoO3 perovskite nanoparticles were synthesized by a two‐step route via the sol–gel autocombustion method. In this method, lanthanum nitrate and cobalt nitrate were used as metals sources, after dissolving in distilled water. PVP was used as a surfactant, while urea and glycine were applied as fuel. The sol was formed at the stirring stage at 60°C, and then continued to gelation through water evaporation at 90°C, to end up in the autocombustion state. The product of combustion was washed, centrifuged three times, and heat‐treated at 600°C for 2 h. Synthesized nanoparticles were characterized by scanning electron microscopy, X‐ray powder diffraction (XRD), and particle size analyzer. Characterization results show that nanoparticles were synthesized in a narrow size range, below 100 nm, with perovskite structure using sol–gel autocombustion method; these particles were spherical in shape and without visible porosity on the surface. The purity and crystalline size of nanoparticles were studied through XRD analysis indicating that variation in these parameters depends on the fuel and fuel‐to‐oxidizer ratio, as impurities decreased by increasing the fuel ratio, for both glycine and urea. In addition, using glycine is demonstrated to result in better purity as compared with urea as fuel.

Nanostructure perovskites such as LaMO3 (where M = transition metal such as Mn, Co, Ni, and Fe) have captured attention in materials science fields due to their promising catalytic properties. In this study, the LaCoO3 perovskite nanoparticles were synthesized by a two‐step route via the sol–gel autocombustion method. In this method, lanthanum nitrate and cobalt nitrate were used as metals sources, after dissolving in distilled water. PVP was used as a surfactant, while urea and glycine were applied as fuel. The sol was formed at the stirring stage at 60°C, and then continued to gelation through water evaporation at 90°C, to end up in the autocombustion state. The product of combustion was washed, centrifuged three times, and heat‐treated at 600°C for 2 h. Synthesized nanoparticles were characterized by scanning electron microscopy, X‐ray powder diffraction (XRD), and particle size analyzer. Characterization results show that nanoparticles were synthesized in a narrow size range, below 100 nm, with perovskite structure using sol–gel autocombustion method; these particles were spherical in shape and without visible porosity on the surface. The purity and crystalline size of nanoparticles were studied through XRD analysis indicating that variation in these parameters depends on the fuel and fuel‐to‐oxidizer ratio, as impurities decreased by increasing the fuel ratio, for both glycine and urea. In addition, using glycine is demonstrated to result in better purity as compared with urea as fuel. [ABSTRACT FROM AUTHOR]

Unsatisfactory oxygen mobility is a considerable barrier to the development of perovskites for low‐temperature volatile organic compounds (VOCs) oxidation. This work introduced small amounts of dispersed non‐metal boron into the LaCoO3 crystal through an easy sol‐gel method to create more oxygen defects, which are conducive to the catalytic performance of propane (C3H8) oxidation. It reveals that moderate addition of boron successfully induces a high distortion of the LaCoO3 crystal, decreases the perovskite particle size, and produces a large proportion of bulk Co2+ species corresponding to abundant oxygen vacancies. Additionally, surface Co3+ species, as the acid sites, which are active for cleaving the C−H bonds of C3H8 molecules, are enriched. As a result, the LCB‐7 (molar ratio of Co/B=0.93:0.07) displays the best C3H8 oxidation activity. Simultaneously, the above catalyst exhibits superior thermal stability against CO2 and H2O, lasting 200 h. This work provides a new strategy for modifying the catalytic VOCs oxidation performance of perovskites by the regulation of amorphous boron dispersion. [ABSTRACT FROM AUTHOR]

Perovskite oxides are an important and effective class of mixed oxides which play a significant role in the fields of energy storage and conversion systems. Here we present a series of cobaltite perovskite LaCoO3 particles which have been doped with 0, 5, 10, 20, and 30% of Sr2+ and have been synthesized by a combined sol–gel and molten-salt synthesis procedure, which provides a regular morphology of the particles. These Sr2+-doped LaCoO3 particles have been characterized by powder X-ray diffraction, Raman spectroscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Moreover, these Sr2+ doped LaCoO3 particles have been demonstrated as efficient catalysts for oxygen evolution reaction (OER) based on the measured specific capacitance, total charge, most accessible charge, electrochemically active surface area, and roughness factor using rotating disk and rotating ring-disk electrode techniques. The 30% Sr2+-doped LaCoO3 sample shows enhanced electrocatalytic OER activity in 0.5 M H2SO4 media compared to the LaCoO3 samples doped with 0, 5, 10, and 20% Sr2+. Among all five LaCoO3 samples, the doped LaCoO3 samples demonstrate better OER activity than the undoped sample.

Metal-oxygen bonding of the Ce-doped LaCoO3 system remains largely unexplored despite extensive studies on its magnetic properties. Here, we investigate the structure and local structure of nanoscale La1−xCexCoO3, with x = 0, 0.2, and 0.4, using the Rietveld refinement and synchrotron X-ray absorption techniques, complemented by topological analysis of experimental electron density and electron energy distribution. The Rietveld refinement results show that LaCoO3 subject to Ce addition is best interpretable by a model of cubic symmetry in contrast to the pristine LaCoO3, conventionally described by either a monoclinic model or a rhombohedral model. Ce4+/Co2+ are more evidently compatible dopants than Ce3+ for insertion into the main lattice. X-ray absorption data evidence the partially filled La 5d-band of the pristine LaCoO3 in accordance with the presence of La–O bonds with the shared-type atomic interaction. With increasing x, the increased Ce spectroscopic valence and enhanced La–O ionic bonding are noticeable. Characterization of the local structures around Co species also provides evidence to support the findings of the Rietveld refinement analysis.

Exploring noble‐metal‐free co‐catalysts highly flexible for separating the photogenerated charge carriers is of prime importance for the visible‐light‐driven photocatalysis. Herein, three‐dimensional flower‐like BiOI microspheres were fabricated and applied to support noble‐metal‐free LaCoO3 co‐catalysts to construct a unique LaCoO3/BiOI hybrid photocatalyst with a higher ability in charge separation. As expected, the optimum tetracycline degradation rate of LaCoO3 (4.0 wt%)/BiOI was up to 0.0161 min−1, which was nearly 3.4 fold larger than that of pure BiOI (0.0048 min−1). The enhanced photocatalytic performance was mainly ascribed to the vital role of LaCoO3 co‐catalyst, which acted as an excellent electron collector for capturing the electrons generated by BiOI, effectively promoting the separation of photogenerated charge carriers and prolonging the lifetime of photo‐induced electron‐hole pairs at the same time. Furthermore, the active species trapping experiments revealed that the excellent photocatalytic activity was primarily driven by photogenerated holes and superoxide radicals. This work is expected to provide a new inspiration for rationally designing and fabricating noble‐metal‐free co‐catalyst system with high efficiency applied in environment purification. [ABSTRACT FROM AUTHOR]

Thin films of crystallized LaCoO3 were grown on Si substrate by Pulsed Laser Deposition at different temperatures (750°C, 850°C and 1000°C). The structural characterization of the LaCoO3 thin films was done by combining several techniques: Scanning Electron Microscopy (SEM), Atomic Force Microscope (AFM), Transmission Electron Microscopy (TEM) and Grazing Incidence X-Ray Diffraction (GIXRD). The thin films crystallized in the expected rhombohedral phase whatever the deposition temperature, with an increase of crystallite size from 70 nm at 750°C to 100 nm at 1000°C, and an average thickness of the thin films of less than 200 nm. At 850°C and 1000°C, the thin films are crack-free, and with a lower number of droplets than the film deposited at 750°C. The grains of LaCoO3 film deposited at 850°C are columnar, with a triangular termination. At 1000°C, an intermediate layer of La2Si2O7 was observed, indicating diffusion of Si into the deposited film. [ABSTRACT FROM AUTHOR]

[Display omitted] • Innovative Nanocomposite Synthesis: LaCoO 3 /Co 3 O 4 via ZIF-67 derived. • Visible Light-Antibacterial Efficacy: Exceptional E. coli and S. aureus inhibition. • Mechanistic Insights: ROS production, bacterial defense disruption explained. • Environmental Sustainability: Energy-efficient, reduces traditional antimicrobial agents. The escalating misuse of antibiotics has drastically reduced the availability of effective antimicrobial agents. Thus, necessitating comprehensive research and development efforts to address the challenges posed by drug-resistant bacteria and superbugs. ZIF-67 was synthesized by a simple precipitation reaction, then it was modified by La3+ etching (La3+/ZIF-67) and derived into LaCoO 3 /Co 3 O 4 by one-step calcination. Subsequently, LaCoO 3 /Co 3 O 4 /g-C 3 N 4 P-N junction nanocomposites with visible light-enhanced antimicrobial properties were successfully prepared by compounding LaCoO 3 /Co 3 O 4 nanocomposites and the nonmetallic semiconductor g-C 3 N 4 via wet impregnation method. Compared with LaCoO 3 /Co 3 O 4 , LaCoO 3 /Co 3 O 4 /g-C 3 N 4 nanocomposites exhibited stronger carrier transport, separation efficiency and excellent antibacterial properties. The Minimum Inhibitory Concentrations (MICs) of LaCoO 3 /Co 3 O 4 /g-C 3 N 4 nanocomposites against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were measured to be 0.8 mg·mL−1 and 0.9 mg·mL−1, correspondingly. The nanocomposites exhibited 99.64 % and 95.66 % antibacterial efficiency against the above bacteria under visible light irradiation, respectively. In addition, the positive electrical property of LaCoO 3 /Co 3 O 4 /g-C 3 N 4 nanocomposites (+4.84 mV) facilitates the adequate contact between nanocomposites and bacteria, which greatly shortens the ROS transport pathway. The GSH oxidation simulating the internal metabolism of bacteria revealed that the LaCoO 3 /Co 3 O 4 /g-C 3 N 4 nanocomposites were able to disrupt the antioxidant defense system of bacteria, which eventually led to bacterial apoptosis. [ABSTRACT FROM AUTHOR]

The magnetic properties measurements show that the magnetism of the films weakens with increasing film thickness. Both XAS results of Co L edge and O K edge indicate that the increasing thickness of the film leads to an increase of LS states and a decrease of IS and HS states. [Display omitted] • The magnetic properties characterized by MPMS and XMCD show that the magnetism of the films weakens with increasing film thickness. • Both XAS results of Co L edge and O K edge indicate that the increasing thickness of the film leads to an increase of LS states and a decrease of IS and HS states. • The transport behavior measurements demonstrate that the films have good insulating properties and the electronic transport mechanism follows the 3D-VRH model. • Our results not only demonstrated the feasibility of thickness-induced strain modulating the properties of LCO films, but also strengthen the understanding of the ferromagnetic insulating mechanism in LCO films. Epitaxial tensile-strain is an important factor to determine the superior ferromagnetic insulating property of LaCoO 3 (LCO) epitaxial films. In this paper, the whole development of LCO ferromagnetic insulating properties modulated by thickness-dependent strain effect were studied and we found that the film strain decreased and the ferromagnetic property weakened with increasing film thickness. The measurements of x-ray magnetic circular dichroism confirm that the spin moment of Co3+ ions is significantly larger than its orbital magnetic moment and it also reduces with increasing thickness. The x-ray absorption spectroscopy revealed that the increasing film thickness is unfavorable for the presence of e g electrons, as well as for the intermediate-spin and high-spin states. Overall, the enhancement of film thickness leads to the decrease of the Co-O bond length and the increase of crystal field splitting energy, unfavorable for the electron transfer from t 2g to e g orbitals, and in turn for the stability of intermediate-spin and high-spin states. The electronic transport behavior of LCO film was proved to be a good insulating properties and the temperature dependence of the resistivity is consistent with the 3D-Mott's variable range hopping model. Our results not only demonstrated the feasibility of thickness-induced strain modulating the properties of LCO films, but also strengthen the understanding of the ferromagnetic insulating mechanism in LCO films. [ABSTRACT FROM AUTHOR]

The Z-scheme LaCoO 3 /ZnO (LCZ) heterojunction photocatalyst was designed and prepared using the hydrothermal method. In the photocatalytic degradation of tetracycline hydrochloride, LCZ exhibited the highest photocatalytic activity with a rate constant of 0.0179 min − 1 ,which is 3.2 and 2.3 times higher than those of pure ZnO and LaCoO 3 , respectively. This study presents a promising approach with potential applications in the field of photocatalytic degradation. Further theoretical studies reveal that the existence of Z-scheme heterojunction can prevent the recombination of electron-hole pairs, leading to enhanced photocatalytic performance. [Display omitted] • Z-scheme heterojunction perovskite LaCoO 3 decorated hollow ZnO catalyst (LCZ) was constructed. • The obtained LCZ could completely degrade tetracycline pollutants under simulated solar light. • The possible degradation mechanisms were proposed. [ABSTRACT FROM AUTHOR]

A strontium-doped lanthanum cobaltite perovskite material was prepared, and used as a recyclable and effective heterogeneous catalyst for the direct oxidative coupling of alkenes with aromatic aldehydes to produce α,β-unsaturated ketones. The reaction afforded high yields in the presence of di-tert-butylperoxide as oxidant. Single oxides or salts of strontium, lanthanum and cobalt, and the undoped perovskite offered a lower catalytic activity than the strontium-doped perovskite. Benzaldehyde could be replaced by benzyl alcohol, dibenzyl ether, 2-oxo-2-phenylacetaldehyde, 2-bromoacetophenone or (dimethoxymethyl) benzene in the oxidative coupling reaction with alkenes. To our best knowledge, reactions between these starting materials with alkenes are new and unknown in the literature.

Published magnetic data for LaCoO 3 are successfully analyzed with coexisting 5 D and low-spin (LS) cobalt states. Energy levels of the two states are derived in analytic forms. To this end, fictitious orbital angular momentum l of magnitude one defines the Γ 5 ( 5 D ) state. Our Hamiltonian includes the spin-orbit interaction, and a cubic crystal field embellished by a trigonal distortion9B20(lz2-2/3)-80B40(lz2-9/10). A singlet ground state with an energy gap to the first excited doublet is realized for certain values of the parameters. The temperature-independent paramagnetic susceptibility (TIPS) of the 5 D state has a finite value, which accords with the observation. Whereas, TIPS is symmetry forbidden in the LS state. A rigorous calculation is made of the excitation spectrum in the LS state. The elementary excitation is modeled as a creation of an electron-hole pair that results in an energy level scheme in which the first excited quartet lies above the singlet ground state. The electron spin resonance data are successfully equated with transitions within the excited quartet. Available magnetization data delineate parameters in the 5 D Hamiltonian. The temperature dependence of the susceptibility of our coexisting model is qualitatively reasonable. To improve on a quantitative outcome, we are led to introduce a temperature dependent concentration for the 5 D and LS states. Calculated Bragg diffraction patterns gathered with x-rays tuned to the Co K -edge reveal potential to refine the current crystal structure and to shed light on the origin of the coexisting states., (© 2023 IOP Publishing Ltd.)

Due to increasing interest in the application of perovskites as promising adsorbents, the present study looks at how central composite design (CCD), a subset of response surface methodology (RSM), can statistically play a role in producing optimum lanthanum oxide-cobalt perovskite type nanoparticles (LaCoO3) by using a modified proteic synthesis method. The optimum LaCoO3 produced was tested for its capability in removing methyl orange (MO) and rhodamine B (RhB) dyes from aqueous solution. Calcination temperature and calcination time were optimized with the responses being percentage yield, MO and RhB removal. The best temperature and calcination time obtained were 775 °C and 62 mins, respectively, giving good and appreciable values for the three responses. The resulting optimal LaCoO3 was characterized by Fourier transform infra-red (FTIR), ultraviolet-visible spectrophotometry (UV/vis), scanning electron microscopy (SEM), pH of zero point charge (pHpzc) as well as BET analysis, yielding a mesoporous adsorbent with surface area of 61.130 m2 g−1 as well as 223.55 and 239.45 mg g−1 as the monolayer adsorption capacity values for MO and RhB, respectively. Freundlich model was the best in describing the equilibrium adsorption data with respect to both MO and RhB with the kinetic data for the two dyes both obeying pseudo-second-order kinetics model. [ABSTRACT FROM AUTHOR]

Ammonia synthesis consumes large amounts of energy in traditional industry and causes considerable air pollution to the atmosphere. Therefore, developing green strategies and novel catalysis for NH3 synthesis under ambient conditions using renewable energy is strongly desired. In this work, Er-doped lanthanum cobaltite/attapulgite composites (LaCoO3:Er3+/ATP) were prepared by a sol–gel method. The influence of the Er doping ratio and LaCoO3:Er3+ loading amount on the generation rate of ammonia under visible-light irradiation were investigated. The results show that Er3+-doped LaCoO3 can convert visible light into ultraviolet light and reach the highest conversion rate when the doping amount of the Er element is 6 mol%, which enhances the utilization of solar energy. ATP contributes to the adsorption of N2 and the Co dopant weakens the N≡N bond favoring the activation of N2. Moreover, a direct Z-scheme heterostructure is constructed between LaCoO3:Er3+ and ATP when the loading amount is 10 wt%, which facilitates the separation of charge carriers and preserves the high redox potentials, leading to the enhanced photocatalytic nitrogen fixation performance. Highlights: LaCoO3:Er3+/ATP nanocomposite prepared by sol-gel method. Er3+ doped LaCoO3 convert visible light into ultraviolet light. Co dopant weakens the N≡N bond favoring the activation of N2. Z-scheme LaCoO3:Er3+/ATP enhances the potantial for nitrogen fixation. [ABSTRACT FROM AUTHOR]

Noble metal modification is one of efficient ways to improve the catalytic activity of perovskite-type catalysts towards VOC oxidation. However, precisely how the occurrence of noble metals in perovskite, i.e., substitution and deposition constrain the catalytic activity remains controversial. In this study, Ag substituted LaCoO 3 perovskite (La 1- x Ag x CoO 3) and LaCoO 3 supported Ag (Ag/LCO) catalysts were synthesized by the one-pot method and impregnation, respectively, followed by the characterization of XRD, XPS, HRTEM, O 2 -TPD, H 2 -TPR, and periodic steady-state catalytic oxidation of toluene. In the La 1- x Ag x CoO 3 series, Ag+ was incorporated in structure at the low substitution level, but at high substitution level, partial Ag+ diffused to the surface and was reduced as Ag0. Among Ag/LCO catalysts, different microstructures of Ag, i.e., surface Ag 2 O, surface Ag0, and both surface Ag0 and substituted Ag+ were obtained under calcinations at 250, 450 and 700 °C, respectively. The catalytic activity of above catalysts was compared in terms of the temperatures for toluene conversions of 50% (T 50), 90% (T 90), and specific reaction rate (R s). The catalytic activity of La 1- x Ag x CoO 3 was enhanced with Ag content, but was lower than the Ag/LCO catalysts with identical Ag content. The activity of Ag/LCO increased in the following sequence: LaCoO 3 < Ag/LCO-450 < Ag/LCO-700 < Ag/LCO-250. The distinct effect of Ag substitution and deposition on the catalytic activity of LaCoO 3 was ascribed to the different surface oxygen composition and reducibility, and the interaction between Ag/Ag 2 O and LaCoO 3 support. Unlabelled Image • Substituted Ag+ in LaCoO 3 diffuses to surface as Ag0 with substitution increase. • Surface Ag is Ag 2 O, Ag0, or doped Ag+ after calcinated at 250, 450 and 700 °C. • LaCoO 3 supported Ag catalysts are more active than Ag+ doped LaCoO 3. • Activity is related to surface oxygen, reducibility and interaction of Ag-LaCoO 3. [ABSTRACT FROM AUTHOR]

The cyclic ferroelastic hysteretic behavior of pure LaCoO 3 perovskite ceramic has been studied at different temperatures in four point bending. The stress-strain deformation behavior of LaCoO 3 was analyzed both in the term of the maximum stress in the cycle and in terms of the temperature used when the cyclic testing was performed. The characteristics of the stress-strain hysteresis loops, such as hysteresis loop area and irreversible strain, as well as effective Young's modulus, were analyzed, and it was established that both the loading and the temperature history have a significant influence on the mechanical behavior of LaCoO 3. Young's modulus values are reported to be much higher in the 700–900 °C temperature range as compared to the measurements performed in the RT-400 °C temperature range. [ABSTRACT FROM AUTHOR]

LaCoO 3 suffers spin crossover as a function of temperature, changing from low-spin state to intermediate-state and, at high temperatures, it also changes to a high-spin state. Nano-confinement of this material induces a long-range magnetic ordering, with a critical temperature close to 83 K; and to deepening this debate whether it is a consequence of nanotopology or defects on the surface, we have prepared the compositions of the series La 1 − x □ x Co 1 − x 3 + Co x 4 + O 3 (x = 0.00, 0.04, 0.08 and 0.12). We experimentally found an axial compression of the CoO 6 octahedra, verified by the new elasticity parameter σ ; and, based on the Jahn-Teller theorem, we proposed a spin state and a mean-field model, that successfully fitted the experimental magnetic susceptibility. As an output, we found that the Co(III) sub-lattice has an antiparallel intra-lattice alignment; while the Co(IV) sub-lattice has a parallel intra-lattice alignment. As a part of the ferrimagnetic model considered, the net magnetization of both sub-lattices (Co(III) and Co(IV)), are aligned in opposition. The magnetic behavior of these vacant bulk samples is similar to those nanostructured ones, with the same critical temperature, and therefore we claim that the long-range magnetic ordering found for those nanomaterials has its origin on the Jahn-Teller effect on the surface of the sample. • Samples of the kind L a 1 - x □ x C o 1 - x 3 + C o x 4 + O 3 were produced. • From the apical compression of the C o O 6 octhaedron we developed a mean-field model. • Good theoretical-experimental match for the experimental magnetic susceptibility. • Magnetic arrangement for the material is ferrimagnetic. • The long-range magnetic ordering found on nano-objects of L a C o O 3 is not due to its nanotopology. [ABSTRACT FROM AUTHOR]

• A unique 0D/2D LaCoO 3 /SnS 2 hybrid was prepared by a facile solvothermal method. • LaCoO 3 /SnS 2 showed much boosted visible-light photocatalytic TC degradation rate. • The enhanced activity was ascribed to LaCoO 3 as co-catalyst to capture electrons. • A rational photocatalytic mechanism of TC degradation was proposed. Perovskite-type LaCoO 3 nanoparticles were successfully decorated on the surface of SnS 2 nanosheets served as highly efficient noble-metal-free co-catalysts for the photocatalytic degradation of tetracycline (TC) under visible light irradiation. Noticeably, the optimized TC degradation rate of the resultant LaCoO 3 (10.0 wt%)/SnS 2 hybrid could reach 0.0049 min−1, which was up to 7.0 times greater than that of single SnS 2 (0.0007 min−1). Such a remarkable enhancement could be attributed to LaCoO 3 co-catalysts acted as effective electron collectors for rapid capturing the photogenerated electrons from SnS 2 surface, which effectively accelerated the charge carriers separation and transfer. Moreover, a possible photocatalytic mechanism was proposed. [ABSTRACT FROM AUTHOR]

Perovskite-type oxides, due to their structural stability and special physical and chemical properties, have become important topics in the field of catalytic materials research. This article focuses on the effect of γ-ray irradiation on the catalytic activity of LaCoO 3 and BaPbO 3. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR) were used to analyze the physical and chemical properties of LaCoO 3 and BaPbO 3. Finally, H 2 O 2 catalytic decomposition and toluene catalytic combustion experiments were performed to verify the activity of LaCoO 3 and BaPbO 3 before and after irradiation. The results show that after γ-ray irradiation, the activity of LaCoO 3 and BaPbO 3 on catalytic hydrogen peroxide decomposition was reduced, and the activity of catalytic toluene combustion was enhanced. • The effects of different radiation dose on lattice oxygen in LaCoO 3 and BaPbO 3 were analyzed by XPS. • The effects of different radiation dose on the oxidative capacity of LaCoO 3 and BaPbO 3 were analyzed by TPR. • It was found that γ-ray irradiation enhance the catalytic activity of LaCoO 3 and BaPbO 3 in toluene combustion. [ABSTRACT FROM AUTHOR]

Abstract Ferroelastic mechanical behavior of LaCoO 3 was investigated by the impression test and compared with the conventional compression test using digital image correlation technique for deformation measurement. The results show that the coercive stress for ferroelastic deformation can be detected by impression test, which is less than critical stress for such deformation in the compression test. Room temperature ferroelastic impression creep characterization showed different equilibrium penetration of flat-end punch at different constant stresses, which can be characterized by Prony series equation. [ABSTRACT FROM AUTHOR]