Method For Synthesis Of Complexes Research Articles

Manufacturing Single‐Atom Alloy Catalysts for Selective CO2 Hydrogenation via Refinement of Isolated‐Alloy‐Islands

AbstractSingle‐atom alloy (SAA) catalysts exhibit huge potential in heterogeneous catalysis. Manufacturing SAAs requires complex and expensive synthesis methods to precisely control the atomic scale dispersion to form diluted alloys with less active sites and easy sintering of host metal, which is still in the early stages of development. Here, we address these limitations with a straightforward strategy from a brand‐new perspective involving the ‘islanding effect’ for manufacturing SAAs without dilution: homogeneous RuNi alloys were continuously refined to highly dispersed alloy‐islands (~1 nm) with completely single‐atom sites where the relative metal loading was as high as 40 %. Characterized by advanced atomic‐resolution techniques, single Ru atoms were bonded with Ni as SAAs with extraordinary long‐term stability and no sintering of the host metal. The SAAs exhibited 100 % CO selectivity, over 55 times reverse water‐gas shift (RWGS) rate than the alloys with Ru cluster sites, and over 3–4 times higher than SAAs by the dilution strategy. This study reports a one‐step manufacturing strategy for SAA's using the wetness impregnation method with durable high atomic efficiency and holds promise for large‐scale industrial applications.

Bifunctional electrode materials: Enhancing microbial fuel cell efficiency with 3D hierarchical porous Fe3O4/Fe-N-C structures

The rational development of high-performance anode and cathode electrodes for microbial fuel cells (MFCs) is crucial for enhancing MFC performance. However, complex synthesis methods and single-performance electrode materials hinder their large-scale implementation. Here, three-dimensional hierarchical porous (3DHP) Fe3O4/Fe-N-C composites were prepared via the hard template method. Notably, Fe3O4/Fe-N-C-0.04-600 demonstrated uniformly dispersed Fe3O4 nanoparticles and abundant Fe-Nx and pyridinic nitrogen, showing excellent catalytic performance for oxygen reduction reaction (ORR) with a half-wave potential (E1/2) of 0.74 V (vs. RHE), surpassing Pt/C (0.66 V vs. RHE). Moreover, Fe3O4/Fe-N-C-0.04-600 demonstrated favorable biocompatibility as an anode material, enhancing anode biomass and extracellular electron transfer efficiency. Sequencing results confirmed its promotion of electrophilic microorganisms in the anode biofilm. MFCs employing Fe3O4/Fe-N-C-0.04-600 as both anode and cathode materials achieved a maximum power density of 831.8 ± 27.7 mW m−2, enduring operation for 38 days. This study presents a novel approach for rational MFC design, emphasizing bifunctional materials capable of serving as anode materials for microorganism growth and as cathode catalysts for ORR catalysis.

Manufacturing Single-Atom Alloy Catalysts for Selective CO2 Hydrogenation via Refinement of Isolated-Alloy-Islands.

Single-atom alloy (SAA) catalysts exhibit huge potential in heterogeneous catalysis. Manufacturing SAAs requires complex and expensive synthesis methods to precisely control the atomic scale dispersion to form diluted alloys with less active sites and easy sintering of host metal, which is still in the early stages of development. Here, we address these limitations with a straightforward strategy from a brand-new perspective involving the 'islanding effect' for manufacturing SAAs without dilution: homogeneous RuNi alloys were continuously refined to highly dispersed alloy-islands (~ 1 nm) with completely single-atom sites where the relative metal loading was as high as 40%. Characterized by advanced atomic-resolution techniques, single Ru atoms were bonded with Ni as SAAs with extraordinary long-term stability and no sintering of the host metal. The SAAs exhibited 100% CO selectivity, over 55 times reverse water-gas shift (RWGS) rate than the alloys with Ru cluster sites, and over 3-4 times higher than SAAs by the dilution strategy. This study reports a one-step manufacturing strategy for SAA's using the wetness impregnation method with durable high atomic efficiency and holds promise for large-scale industrial applications.

Metal-Organic Framework-Based Electrodes for Efficient CO2 Electroreduction to Formate at High Current Densities (up to 1 A cm−2)

Achieving efficient CO2 electroreduction for production of valuable chemicals requires affordable, stable, and non-toxic catalysts. One of the most studied and promising products of CO2 reduction is formic acid/formate. The latter species is receiving increased attention as an energy vector [1] or energy storage media (e.g., in CO2 redox flow batteries [2]). At present, the practical application of CO2 reduction to formate still faces challenges due to the lack of electrocatalysts capable of operating at high current densities (> 200 mA cm−2) with low degradation over long-duration operation [3].Traditional metallic catalysts like Bi, Sn, In or Pb when scaled in flow cells typically suffer from low faradaic efficiencies (< 70%) at current densities ≥ 200 mA cm-2, coupled with inadequate durability [4]. Metal-organic frameworks (MOFs) present promising and thus far largely unexplored attributes as electrocatalysts for CO2 reduction, including high atom utilization during catalysis due to their porous crystal structure and tunable pore size distribution [5,6]. However, they also face challenges related to high overpotentials and complex synthesis methods [7].This study elucidates the efficacy of a Bi metal-organic framework (Bi-MOF) synthesized through a rapid and facile method. The Bi-MOF obtained by our proprietary novel method [8], exhibits exceptional catalytic performance. Notably, it demonstrates outstanding faradaic efficiencies towards formate (FEHCOO - = 95–100%) at current densities up to 1 A cm−2 in a gas diffusion electrode, at low catalyst loading (0.5 mg cm−2).Moreover, Bi-MOF displays extended stability, operating continuously for over 20 hours at an industrially relevant current density (200 mA cm−2) and without electrolyte (1.5 M KOH) replenishment. In a flow reactor with 10 cm2 electrode geometric area, a 100% FEHCOO - was obtained during 2-hour electrolysis at 100 mA cm−2 across a broad pH range (8–14). The electrochemical testing of the Bi-MOF was supplemented by surface and structural characterizations to correlate the activity with structural features. This analysis unveiled the role of the organic framework and the reason why Bi-MOF surpasses other Bi-based catalysts, including commercial Bi2O2CO3, Bi2O3, and metallic Bi, in selectivity (FE), cell potential, and durability.These findings hold promise for further scale-up of CO2 reduction to formate using the cost-effective and easily prepared Bi-MOF catalyst.[1] Bienen, F., Kopljar, D., Löwe, A., Aßmann, P., Stoll, M., Rößner, P., Wagner, N., Friedrich, A., & Klemm, E. (2019). Utilizing Formate as an Energy Carrier by Coupling CO2 Electrolysis with Fuel Cell Devices. Chemie Ingenieur Technik, 91(6), 872-882.[2] Hosseini-Benhangi, P., Gyenge, C., & Gyenge, E. (2021). The carbon dioxide redox flow battery: Bifunctional CO2 reduction/formate oxidation electrocatalysis on binary and ternary catalysts. Journal of Power Sources, 495, 229752.[3] Masel, R. I., Liu, Z., Yang, H., Kaczur, J. J., Carrillo, D., Ren, S., Salvatore, D., & Berlinguette, C. P. (2021). An industrial perspective on catalysts for low-temperature CO2 electrolysis. Nature Nanotechnology, 16(2), 118-128.[4] Zou, J., Liang, G., Lee, C., & Wallace, G. G. (2023). Progress and perspectives for electrochemical CO2 reduction to formate. Materials Today Energy, 38, 101433.[5] Mazari, S. A., Hossain, N., Basirun, W. J., Mubarak, N. M., Abro, R., Sabzoi, N., & Shah, A. (2021). An overview of catalytic conversion of CO2 into fuels and chemicals using metal organic frameworks. Process Safety and Environmental Protection, 149, 67-92.[6] Xie, W., Mulina, O. M., O., A., & He, L. (2023). Metal–Organic Frameworks for Electrocatalytic CO2 Reduction into Formic Acid. Catalysts, 13(7), 1109.[7] Köppen, M., Dhakshinamoorthy, A., Inge, A.K., Cheung, O., Ångström, J., Mayer, P. and Stock, N. (2018), Synthesis, Transformation, Catalysis, and Gas Sorption Investigations on the Bismuth Metal–Organic Framework CAU-17. Eur. J. Inorg. Chem., 2018: 3496-3503.[8] Selva-Ochoa, A.G., Habibzadeh F., Gyenge E.L. (2023). Manuscript in preparation. Department of Chemical & Biological Engineering, UBC.

First-in-Human Evaluation of [18F]FDOPA Produced by Organo-Photoredox Reactions.

Photoredox is a powerful synthetic tool in organic chemistry and has been widely used in various fields, including nuclear medicine and molecular imaging. In particular, acridinium-based organophotoredox radiolabeling has significantly impacted the production and discovery of positron emission tomography (PET) agents. Despite their extensive use in preclinical research, no PET agents synthesized by acridinium photoredox labeling have been tested in humans. [18F]FDOPA is clinically used for tumor diagnosis and the evaluation of neuropsychiatric disorders, but its application is limited by complex synthesis methods, the need for expensive modules, and/or the high cost of consumable materials/cassettes. In this report, we integrated a photoredox labeling unit with an automated module and produced [18F]FDOPA for human study. This research not only represents the first human study of a PET agent generated by acridinium-based organophotoredox reactions but also demonstrates the safety of this novel labeling method, serving as a milestone/reference for the clinical translation of other PET agents generated by this technique in the future.

Directional regulation of low-dimensional metal complexes by end-sealed ligands: Butterfly effect of structure

In this work, the relationship between structure and properties of several low-dimensional metal complexes was studied, and an interesting "butterfly effect" was found. Four different low-dimensional metal complexes were precisely constructed using different end-sealing ligands, under the constraint of double end-sealing ligands. Complex-1 [Cd(L1)(L3)], complex-2 [Zn(L1)(L4)] and complex-3 [Cd(L2)(L3)] all formed similar zero-dimensional structures, but complex-4 [Zn(L2)] with single end-sealing ligands formed a one-dimensional structure. Four kinds of metal complexes were tested for fluorescence recognition, and it was found that they all had excellent ion recognition ability. Interestingly, complexes-1−3 with similar structures seek qualitative differences while retaining similarities and complex-4 showed a different property. These differences and similarities in properties vividly reflect the high sensitivity of properties to structures for low-dimensional metal complexes with simple structures. In conclusion, this work not only provided a novel feasible method for the custom synthesis of low-dimensional metal complexes, but also found that the properties of low-dimensional metal complexes are sensitive to structural features.

Fast pyrolysis of biomass with diverse properties to produce liquid hydrogen storage molecules

Liquid organic hydrogen carriers (LOHCs), such as methanol and formic acid, offer a reliable solution for the challenges associated with transporting and storing gaseous hydrogen. However, the current industrial LOHCs are costly and in limited supply due to complex synthesis methods involving gasification and Fischer-Tropsch synthesis. An alternative approach utilizing efficient pyrolysis methods can convert biomass into substances that mimic LOHCs, making them a promising avenue for hydrogen storage. Compounds with a high hydrogen content, including glycolaldehyde, acetic acid, and acetol, hold potential as effective LOHCs. This study seeks to assess how the specific properties of biomass impact the resulting products and target molecules, focusing on identifying the primary sources of LOHC compounds. The experimental results indicate that glycolaldehyde primarily originates from cellulose, while acetic acid is mainly derived from hemicellulose. Acetol is produced from both cellulose and hemicellulose. At a pyrolysis temperature of 500 °C and a particle size of 0.38–0.83 mm, corn cob yields a higher quantity of glycolaldehyde, acetic acid, and acetol (107 mg/g) compared to rice husk (85.6 mg/g) and pine (68.9 mg/g) due to its significant cellulose and hemicellulose content. Notably, the primary sources of these hydrogen storage molecules during pyrolysis are the initial biomass pyrolysis products rather than secondary reactions.

Mesenchymal stem cell‐derived extracellular vesicles: Recent therapeutics and targeted drug delivery advances

AbstractThe targeted drug delivery field is rapidly advancing, focusing on developing biocompatible nanoparticles that meet rigorous criteria of non‐toxicity, biocompatibility, and efficient release of encapsulated molecules. Conventional synthetic nanoparticles (SNPs) face complications such as elevated immune responses, complex synthesis methods, and toxicity, which restrict their utility in therapeutics and drug delivery. Extracellular vesicles (EVs) have emerged as promising substitutes for SNPs, leveraging their ability to cross biological barriers, biocompatibility, reduced toxicity, and natural origin. Notably, mesenchymal stem cell‐derived EVs (MSC‐EVs) have garnered much curiosity due to their potential in therapeutics and drug delivery. Studies suggest that MSC‐EVs, the central paracrine contributors of MSCs, replicate the therapeutic effects of MSCs. This review explores the characteristics of MSC‐EVs, emphasizing their potential in therapeutics and drug delivery for various diseases, including CRISPR/Cas9 delivery for gene editing. It also delves into the obstacles and challenges of MSC‐EVs in clinical applications and provides insights into strategies to overcome the limitations of biodistribution and target delivery.

Low temperature one-step synthesis of Ag nanoparticles on BaTiO3 for synergistic piezo-photocatalytic properties

It is a major constraint that complex synthesis methods limit the application of catalysts. Herein, Ag/BaTiO3 catalyst is synthesized via a facile method, which demonstrates the outstanding catalytic properties. Investigations reveal that Ag-loading BaTiO3 could increase carrier concentration, reduce the electronic impedance and enhance carrier’s separation efficiency under ultrasonic vibration, leading to superior piezocatalytic performance. Therefore, Ag/BaTiO3 catalyst presents the high degradation efficiency of 95.4 % in 50 min for RhB dye solution at light illumination and ultrasonic vibration. Moreover, when Ag content is 0.33 %, the degradation ratio of the sample still remains 81.9 % after 5th cycles, which indicates Ag/BaTiO3 catalyst has good stability. This work provides a novel and easy implement strategy for designing high performance catalysts, and could be extended to other catalytic material.

An innovative stepwise activated coupling reaction for fabricating functional fluorescence probes with potential photosensitive applications

Coupling bright organic emitters with biocomponents such as proteins and amino acids to fabricate biocompatible optical functional materials is receiving increasing attention. Previous reports of an efficient, typical reaction between maleic anhydride (MAH) and amino groups indicated that MAH derivatives have great potential for bioconjugation applications. However, the obstacle of complex synthesis methods and weak fluorescence to this kind of derivative structures based on MAH, have greatly limited their applications. Herein, an innovative strategy was developed based on stepwise activated coupling via a multi-step process. First, a series of donor–acceptor emitting frameworks was constructed by introducing different commercially available electron donors into the electron-withdrawing squaric acid core. Then, these frameworks were further activated to obtain different 3,4-diaryl MAH precursors for bioconjugation, which contributed to a novel light-triggered ring-enlargement effect. Importantly, the MAH precursors triggered catalyst-free coupling reactions at ambient temperature with organic small molecules and biological macromolecules containing primary amine groups. Different fluorescent precursors and abundant biological components were effectively combined, and a water-soluble, biocompatible photosensitizer with efficient photodynamic and photothermal therapy effects was obtained. This strategy is expected to have great potential for biological imaging and theragnostic applications.

Fabrication of BiOBr on carbon fiber cloth as easily recyclable visible-light-driven photocatalyst for purifying wastewater

Visible light-response bismuth bromide oxide (BiOBr) is a widely sought-after semiconductor nanomaterial due to its high photocatalytic activity, but its applications have been limited by complex synthesis methods and low cyclability. Hence, we successfully deposited BiOBr nanosheets on carbon fiber cloth (CFC) by chemical bath precipitation method to obtain efficient and easily recyclable CFC/BiOBr-x photocatalysts (4 × 4 cm2). After in-situ growth of BiOBr nanosheets on CFC, the diameter of a single fiber (CFC/BiOBr-6) was increased from 6.9 to 7.4 μm. Under visible light irradiation, CFC/BiOBr-6 exhibits excellent photocatalytic activity toward RhB (completely degrade) and LVFX (88.9 %) within 120 min, respectively. In addition, CFC/BiOBr-6 still maintained good photocatalytic activity after four cycles (97.9 %). Therefore, CFC/BiOBr-6 possesses great potential for practical photocatalytic applications.

Synthesis and Characterization of Reduced Graphene Oxide Fabricated Over Ruthenium Oxide Through Reflux Method

In this present work, graphene supported ruthenium oxide (rGO/RuO2) was synthesized by reflux method. Spectroscopic techniques were used to characterize the synthesized rGO/RuO2 NPs, including Fourier Transform Infrared (FT-IR), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), and Energy-Dispersive X-ray (EDAX). Synthesized rGO/RuO2 NPs that were prepared via reflux method at 150 °C for 3 hours showed a paper like structure with an average crystalline sizes of reduced graphene and rGO/RuO2 was found to be 14 and 10.3 nm. Therefore, the reflux synthesis method, as compared to more complex and time-consuming synthesis methods, can be used to easily and quickly produce high-quality, uniform-sized rGO/RuO2 NPs. The synthesized material has a successful application in electrochemical sensors, photocatalyst, antioxidant, hydrogen generation, used as catalyst in mines, minerals and fuels.

Lithium Sulfide –Carbon Composite Use as Positive Electrode in Post Lithium Ion Batteries Technology

Li‐ion batteries (LIBs) are the powerhouse for the electronic devices in this modern mobile society, and enabler of the current communication revolution. Consumers demands advanced electronics and sustainable industries in general. To satisfy these demands, the new generation of rechargeable batteries need to provide much higher energy and power density than the actual technology. Commercial LIBs consist of lithium cobalt oxide as positive electrodes and graphite as a negative electrode, this system has energy density values ca. 250 WhL-1.Lithium-sulfur is commonly considered as one of the most promising chemistries for improve traditional lithium-ion batteries in weight sensitive applications due to high theoretical capacity of lithium sulfide (Li2S) and high gravimetric energy density of such cells. Li2S provides a promising route for lithium storage due to high theoretical specific capacity (1166 mAh g−1). This positive electrode material can be coupled with lithium-free negative electrode to develop high-energy-density batteries; this can improve the safety of the devices. Li2S is significantly more thermally stable, and offer greater mechanical stability as no further volumetric expansion occurs upon cycling.Li2S particles must be handled only in inert atmospheres (making production of high-performance cathode materials, on a commercial scale, quite difficult) and suffer from rapid degradation in cells during cycling. There are still challenges with it (e.g., low conductivity, high over potential and irreversible polysulfide diffusion), which have prevented the S utilization and stability. The dissolved polysulfides deposit on the surface of both electrodes resulting in a rapid impedance growth, loss in active material and ultimately battery failure.The complex synthesis method of Li2S–carbon composites restrains the large-scale productivity. We propose an easy and time saving method to synthesize a Li2S based nanocomposite cathode material by wet milling.This work may shed fresh insight into bridging the huge gap between high energy and safety of rechargeable cells for feasible applications. Figure 1

Digital maturity and digital transformation in human resources management: Stability vs development

Digital transformation has impacted all areas of life, including human resources management. Studying digital maturity is relevant because it can help organizations adapt to change and improve human resources strategies for successful transformation. This study explored the relationship between digital maturity, transformation, and human resources management and how organizations can use digital technologies to increase maturity and opportunities and cope with obstacles. Complex analysis, synthesis, induction, deduction, and analogy methods were used as methodical tools to analyse literary sources, information, and communication technologies. The importance of digital maturity for human resources management practices and processes and the digital transformation process in management functions was explored. The drivers, challenges, and outcomes associated with digital transformation initiatives were identified, and the impact of digital maturity and transformation on stability was analysed. The study also examined the possible trade-offs between maintaining stability and promoting development through digital technologies. The importance of continuous learning, training, and skill development in human resources management was assessed to achieve and maintain digital maturity. A conceptual framework focused on the relationship between sustainability and development in the context of digital maturity and transformation in human resources management, providing a comprehensive understanding of these dynamics. The research can help manage digital transformation effectively, provide helpful information for academic and practical human resources management applications, and bring a new perspective to the balance between sustainability and development

Two-Dimensional Silver-Metalated Graphdiyne Nanosheets for Photocatalytic Degradation of Antibiotics

The two-dimensional layered carbon allotrope graphdiyne (GDY) is formed by combining hybridized sp–sp2 carbon atoms. This alkynyl-bonded 2D carbon network with tunable energy levels and high carrier-mobility has excellent potential in solar energy utilization. However, the standard but complex synthesis method of GDYs by epitaxial growth on a metal-crystal surface and the poor activity of metal-free materials limit applications beyond the lab. Here, we produce a silver-metalated GDY (Ag-GDY) through a facile and scalable wet-chemistry strategy, featured by an appropriate band gap at 2.61 eV and good e–/h+ separation ability. These unique characteristics facilitate the reaction between Ag-GDY and oxygen to form a variety of active free radicals. The Ag-GDY photocatalyst displays an excellent ability for the light-driven decomposition of antibiotics. Tetracycline with a concentration as low as 5.0 × 10–5 M is degraded within 30 min by Ag-GDY, showing excellent performance stability of up to five reuse cycles.

Shape-recovering nanocellulose networks: Preparation, characterization and modeling

Development of strong cellulose nanofibril (CNF) networks for advanced applications, such as in the biomedical field, is of high importance owing to the biocompatible nature and plant-based origin of cellulose nanofibrils. Nevertheless, lack of mechanical strength and complex synthesis methods hinder the application of these materials in areas where both toughness and manufacturing simplicity are required. In this work, we introduce a facile method for the synthesis of a low solid content (< 2 wt%), covalently crosslinked CNF hydrogel where Poly (N-isopropylacrylamide) (NIPAM) chains are utilized as crosslinks between the nanofibrils. The resulting networks have the capability to fully recover the shape in which they were formed after various drying and rewetting cycles. Characterization of the hydrogel and its constitutive components was performed using X-ray scattering, rheological investigations and uniaxial testing in compression. Influence of covalent crosslinks was compared with networks crosslinked by the addition of CaCl2. Among other things the results show that the mechanical properties of the hydrogels can be tuned by controlling the ionic strength of the surrounding medium. Finally, a mathematical model was developed based on the experimental results, which describes and predicts to a decent degree the large-deformation, elastoplastic behavior, and fracture of these networks.

Reformulation of Theories of Kinematic Synthesis for Planar Dyads and Triads

Methods for solving planar dyads and triads in kinematic synthesis are scattered throughout the literature. A review of and a new compilation of the complex number synthesis method for planar dyads and triads is presented. The motivation of this paper is to formulate uniform solution procedures, pointing out the commonalities of various approaches and emphasizing a consistent method for synthesizing mechanisms defined by specified precision positions. Particular emphasis is given to the solution method using compatibility linkages. The textbook Advanced Mechanism Design Vol II by Erdman and Sandor (1984) only includes a small portion of the available information on this method, and several researchers have added to the basic knowledge in the years since. In some cases, the approach and nomenclature were not consistent, yielding a need to describe and chart a generic formulation and solution procedure for dyads/triads using compatibility linkages and solution structures. The present method offers benefits for solving for exact dyad/triad solutions for complex multiloop mechanisms and could be a promising tool for reducing the computational load of finding complex mechanisms, and for visualizing properties of the solution space.

Spider silk-derived nanoporous activated carbon fiber for CO2 capture and CH4 and H2 storage

High surface area porous carbon with fibrous microstructure offers a broader application potential than powder form. However, controlling the microstructure with high porosity is difficult, and if possible then through a complex and time-consuming synthesis method. Herein, the development of high surface area nanoporous activated carbon fiber by activating spider silk (natural biomaterials) using potassium hydroxide is being reported. The specific surface area (SSA) and total pore volume for the developed material were 2730 m2/g and 1.56 cc/g, respectively, and its surface contain high oxygen content. Its high SSA and oxygen-rich surface provide an enhanced CO2 capture and energy carrier gases (H2 and CH4) storage capacity. The CO2 capture capacity at 0 °C and 25 °C, 25 bar, were estimated to be 23.6 and 15.4 mmol/g, respectively, among the highest reported values for porous carbon fiber. Moreover, the developed sample has shown the CH4 storage capacity of 8.6 mmol/g at 0 °C, 25 bar, and for H2, it was 4.1 wt% at − 196 °C, 25 bar. In addition, the developed carbon material demonstrated an easy regeneration and almost negligible loss in uptake capacity, confirmed by adsorption-desorption cycles. The observation of high porosity and promising gas storage and recyclability in spider silk-derived activated carbon fiber indicates that the employed method can effectively convert biomaterials into high surface area activated carbon fibers for advanced energy and environmental applications.

Scale-up synthesis of high-quality solid-state-processed CsCuX (X = Cl, Br, I) perovskite nanocrystal materials toward near-ultraviolet flexible electronic properties.

High-quality CsCu2X3 and Cs3Cu2X5 (X = Cl, Br, I) nanocrystals (NCs) exhibit excellent optoelectronic, physical, and chemical properties for detection of UV radiation due to large carrier mobility and lifetime, and heavy atoms. The nanocrystal materials can be prepared via a low-cost and simple solid-state synthesis. However, poor reproducibility and complex synthesis methods of obtaining perovskite NC thin films represent a drawback for the fabrication of the commercial photoelectric device. To address these issues, we develop highly stable CsCu2X3 and Cs3Cu2X5 NC materials using a facile solid-state reaction method for the scale-up production of halogen lead-free perovskites. We suggest a distinctive way to design a series of nanocrystalline perovskites using short-term synthesis and study the mechanism of perovskite formation using thermal solid-state synthesis. These all-inorganic and lead-free CsCu2X3 and Cs3Cu2X5 exhibit large photoluminescence quantum yields (PLQYs) up to 95.2%. Moreover, flexible paper photodetectors based on this series of lead-free perovskites show strong photoselectivity and bending stability at 254 nm, 365 nm, and 405 nm wavelengths. High-quality responses with a responsivity of 1.1 × 10-3 A W-1 and detectivity of 2.71 × 109 jones under UV illumination (10 μW cm-2) at a bias voltage of 5 mV are demonstrated. These results open prospects for designing photodetectors, LEDs, and other photosensitive devices.

A facile mixed complex synthesis method for perovskite oxides toward electrocatalytic oxygen reduction.

The perovskite-type La(0.5+x)Sr(0.5-x)FeO3-δ (x = 0.00, 0.10, 0.20) oxides for the electrocatalytic oxygen reduction reaction (ORR) were synthesized by a facile reaction-EDTA/citric acid mixed complex sol-gel method. The cubic single-phase perovskite structure of the as-prepared oxides is demonstrated using powder X-ray diffraction (XRD). Scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy/selected area electron diffraction (TEM-SAED), and X-ray photoelectron spectroscopy (XPS) characterizations were also conducted for the perovskite-type La(0.5+x)Sr(0.5-x)FeO3-δ (x = 0.00, 0.10, 0.20) oxides. Furthermore, the electrochemical ORR properties of the as-prepared oxides in alkaline media were studied, with the oxides exhibiting good electrocatalytic ORR performance.