Solution Precipitation Method Research Articles

A novel CoCuNi-sulfide nanocatalyst derived from trimetallic zeolitic imidazolate framework for boosting oxygen evolution reaction performance: comparison study of sulfides and oxides

The investigation of multi-component transition metals has been undertaken as a means to enhance the oxygen evolution reaction (OER) performance contrasted with single-component transition metals. In this study, we prepare a series of monometallic (ZIF-67), bimetallic (ZIF-CoCu), and novel trimetallic zeolitic imidazolate frameworks (ZIF-CoCuNi) via a facile one-step room-temperature solution precipitation method. The optimized CoCuNi-sulfide nanoparticles with amorphous structure and rough surface exhibit superior catalytic activity for OER in 1 mol L-1 KOH with a low overpotential of 210 mV at a current density of 10 mA.cm−2 and negligible reduction in operational capabilities following a stability test lasting 24 hours. This study showcases that both the sulfidation process and the synergy of multiple components yield favorable outcomes in terms of enhancing the activity and stability of OER. These findings present a new approach to fabricating and developing high-efficiency and low-cost electrocatalysts, which have an essential part in the conversion of energy.

Surface in situ Co-Mn modification over LaMnO3 perovskite with enhanced activity for ethane combustion

Catalytic combustion is one of effective ways to remove short-chain alkanes. In this study, we elaborately designed a novel catalyst of in situ Co-Mn decorated LaMnO3 perovskite for ethane catalytic combustion, in which extra Mn and Co species were introduced via acidic KMnO4 and Co(NO3)2 solution precipitation method. The addition of Mn and Co could not only slightly etch LaMnO3, thereby increasing specific surface area and redox property, but also generate new active phase CoMn2O4, thus accelerating reaction. Among all the as-prepared catalysts, CMO/LMO-0.5 exhibited admirable ethane removal efficiency with a T90 of 365 °C, a reaction rate of 0.46 mmol·g−1·h−1, a TOF value of 0.64 mmol·g−1·h−1, and excellent hydrothermal stability and reusability. Moreover, according to in situ DRIFTS, a possible pathway was proposed. This work can rationalize an alternative approach to develop an active catalyst for short-chain alkanes catalytic combustion or other catalytic systems.

Preparation and Judd-Ofelt Analysis of Warm Red Luminescent Eu3+ Complexes for Semiconductor Lasing Devices.

Six novel red photoluminescent Eu3+ complexes with 3-formyl chromone as the primary sensitizer (L) were synthesized using the solution precipitation method. These complexes are [Eu(L3).X] where X is 2H2O (C1), phen (C2), neo (C3), bipy (C4), dmph (C5), and biquno (C6). These complexes were characterized by elemental analysis, EDAX analysis, SEM, FT-IR, thermo-gravimetric analysis (TGA/DTA) and photoluminescence spectra. The transition rates, quantum efficiency, and J-O intensity parameters were calculated using emission data and luminescence decay time (τ). Complexes exhibit a strong emission peak (5D0 → 7F2) of the Eu3+ ion in their luminescence emission spectra in solid and solution states, making them an effective emitter of the red color in OLEDs. The branching ratio of these complexes ranges from 80.67-82.92 in solid and 50.53-62.65 in solution state; CIE color coordinate of complexes falls in the red region. The color purity ranges [CP(%)] values for solid 95.26-97.27% and for solution ranges 85.11-93.43%. Correlated color temperature (CCT) of the complexes (C1-C6) ranged from 2710 to 3049K in the solid state and 1775 to 2450K in the solution state. These complexes are promising red emitters in OLEDs, semiconductors, and leasing devices.

Influence of surface interaction between Ag/Mn3O4 on zinc-ion storage performance

Manganese-based compounds, as the most widely used among aqueous zinc-ion batteries cathode materials, have the advantages of high theoretical specific capacity and high voltage. However, their low electrical conductivity and poor cycling stability make them unsuitable for practical applications. Surface modification with metal ions is the most effective and convenient method for improving the situation. Composites deposited with Ag on the surface of Mn3O4 (referred to as AMO) are prepared by the aqueous solution precipitation method. The specific capacity of the AMO-0.5 composite is 423.1 mAh/g at a current density of 0.1 A g−1, and the capacity retention is 87.7% after 1000 cycles at 1.5 A g−1. The surface interaction of AMO improves the intrinsic defects of the material, enhances the electrical conductivity, stabilizes the crystalline structure of the material, and hinders the Jahn-Teller effect. Ag nanoparticles can also inhibit the gas bubbles generated by water decomposition during the cycling process and prevent the dissolution of Mn2+, thus improving the cycling stability. The study on the synergistic mechanism of surface-modified metal nanoparticles can provide inspirations for the development of other similar new materials.

Alleviated mechanical structure decay and accelerated transport kinetics via KNCHCF@NiHCF core–shell structure for aqueous potassium-ion batteries

The sluggish ion transport and mechanical decay caused by K+ intercalation can hinder the K+ storage ability of Prussian blue analogs (PBAs), potential cathode materials for potassium-ion batteries (PIBs). The construction of composite materials using adjustable chemical components of PB is an effective method to improve cycling stability. In this study, a core–shell structure of KNiCoFe(CN)6@NiFe(CN)6 (KNCHCF@NiHCF) was prepared to utilize the inertness of Ni2+ and the stability of Fe–CN–Ni bonds and enhance the performance of PBAs. Different concentrations of NiHCF coating (Ni-0, Ni-2, Ni-5, and Ni-60) were introduced into the outer layer of KNCHCF using a simple solution precipitation method. The aforementioned core–shell structure and the corresponding built-in electric field enhanced the structural stability and K+/e− transport kinetics of the fabricated materials. And Ni-5 exhibited the best electrochemical performance with excellent durable cycling stability and rate performance. Furthermore, the reversible single-phase insertion and extraction reaction of K+ storage mechanism within the Ni-5 cathode was revealed using ex-/in-situ characterization techniques. This strategy may facilitate the development of other cathode materials for rechargeable metal ion batteries.

Highly efficient inverted organic light-emitting devices by tuning particle size of ZnO nanoparticles

Inverted organic light-emitting devices (OLEDs) have been extensively researched because they can provide many advantages such as low driving voltage and high environmental stability in display applications. However, the electron injection is a critical issue in the inverted OLEDs because the work function of the ITO cathode is too high to inject electrons from the cathode into the adjacent organic layer. In this paper, we enhanced the electron injection by tuning the particle size of ZnO nanoparticles (NPs). Hexagonal wurtzite ZnO NPs with different size were synthesized by the solution precipitation method. As the particle size increases, the photoluminescence spectrum in the visible region shifts to the long wavelength due to the narrowing of band gap. The electrical resistivity decreases with increasing the particle size. The inverted phosphorescent OLEDs with a tris(2-phenylpyridine)iridium(III) emitter have been fabricated using ZnO NPs with different size. As the particle size increases from 3.0 to 6.2 nm, the enhanced injection of electrons from the ZnO NPs to the organic electron transport layer results in the decrease of the driving voltage and the increase of the maximum external quantum efficiency (EQE). The maximum EQE of 26.02 % was achieved in the inverted OLEDs with 6.2 nm ZnO NPs.

Enhancing the potential of rapeseed cake as protein-source food by γ-irradiation.

Rapeseed cake serves as a by-product in the oil extraction industry, characterized by its elevated protein content. However, the presence of antinutritional factors limits the utilization of rapeseed cake as a viable protein source. In this study, different doses of γ-irradiation were used to irradiate rapeseed cake and rapeseed protein isolate was extracted through a modified alkaline solution and acid precipitation method from rapeseed cake. The chemical composition and in vivo acute toxicity of rapeseed protein isolate were determined. The protein recovery rate of rapeseed protein isolate was 39.08 ± 3.01% after irradiation, while the content of antinutritional factors was significantly reduced. Moreover, γ-irradiation did not have any experimentally related effects on clinical observations or clinicopathology in mice. Overall, the reduced antinutrients and increased functional properties suggest that the irradiation of rapeseed cake (<9 kGy) could be utilized as a pre-treatment in the development of rapeseed cake-based value-added protein products.

Synthesis, luminescentand computational analysis of red light emitting Eu (III) organic complexes for OLEDs

Six novel red photoluminscent eight co–ordinate Eu3+ complexes were synthesized by using 6–Chloro–chromone–3–aldehyde as main ligand (L) which are represented as [Eu(L3).X] where X is 2H2O (C1), 1,10-Phenanthroline (C2), Neocuproine (C3), 2,2′-Bipyridyls (C4), 5,6-Dimethyl-1,10-Phenanthroline (C5), Bathophenanthroline (C6). The above complexes synthesized by solution precipitation method were characterized by elemental analysis, EDAX analyzer to describes the presence of C, H, O, Cl and Eu. Scanning electron microscope (SEM) to indicates semicrystalline nature of complexes, transmission electron microscopy (TEM) to describes size of complexes lies in 55 to 60 nm, nuclear magnetic resonance (1H NMR) and infrared radiation (FT-IR) to describe the coordination between Eu3+ ion and ligand and ancillary ligands. Thermo-gravimetric analysis (TGA/DTA) tells that complexes are stable upto 290 °C, and photoluminescence (PL) analysis. By using PL data and luminescence decay time (τ), the transition rates, quantum efficiency and the Judd-Ofelt intensity parameters were determined. The luminescence emission spectra for complexes in both states show an intense emission peak (5D0→7F2) at 614 nm (solid) and at 613 nm (solution) of Eu3+ which is responsible to make them an efficient red color emitter in luminescent devices. These complexes are applicable in light emitting devices, traffic signals and home appliances. Percentage branching ratio (βr) and CIE color coordinates value of all synthesized complexes in both states were analyzed. The value of Percentage branching ratio (βr) is 79.92–84.65 % in solid state whereas in solution state the value lies in range 49.37–75.37 % and values of percentage branching ratio (βr) suggests that these complexes are used in lasers and radars systems. The color purity [CP(%)] values are found to be 92.96–94.31 % in solid and 81.24–93.70 % in solution. The band gap is calculated and found to be in the range of 3.7–3.9 eV and used in semiconductor and electroluminescent devices. The complexes (C1–C6) are considered as warm light source because the complexes heaving values of correlated color temperature (CCT) in between 2785 and 3024 K in solid state and 1734 to 2912 K in solution state, which can be efficiently used in LEDs present in hotels, lounges and in many home appliances. The above investigation suggests that synthesized complexes are significant emitters with broad area of utility in laser, electroluminescent materials and display devices.

K x Mn[Mn(CN)6] as a High Capacity Positive Electrode Material for Potassium Batteries

Recently, Na-ion and K-ion batteries have attracted attention as next-generation secondary batteries.1 Prussian blue analogues (PBAs) are promising cathode materials for these batteries. In 2014, it was reported that Na x Mn[Mn(CN)6] exhibited higher capacity in Na cells than the theoretical capacity based on Mn2+/3+ redox, which could be attributed to the reduction of Mn in [Mn(CN)6] to monovalence.2 Thus, PBA with Mn at the C-coordination site exhibits unique properties, but there is no report of high capacity in K cells. In this study, K x Mn[Mn(CN)6] (KMnHCM) was synthesized, and K+ ion extraction/insertion properties were evaluated. KMnHCM was synthesized by the solution precipitation method.3 The solution was sufficiently deoxygenated by bubbling nitrogen gas, and synthesis was performed under N2 atmosphere. The obtained samples were washed three times with deionized water under N2 atmosphere, and then dried at 150 °C under vacuum. The active material was mixed with conductive carbon (KB) and binder (PVdF) at a weight ratio of 7:2:1 in a glove box under an Ar atmosphere. Galvanostatic charge-discharge tests were conducted in a two-compartment three-electrode cell using a composite electrode coated on an Al foil as the working electrode, an activated carbon counter electrode, and an Ag+/Ag reference electrode. Figure 1(a) shows the X-ray diffraction (SXRD) patterns and Rietveld refinement results of the synthesized sample. The diffraction patterns of KMnHCM can be attributed to the monoclinic structure with space group P21/n and are almost identical to that previously reported. SXRD patterns were successfully fitted with the satisfied R values, and the composition of KMnHCM was estimated to be K1.87Mn[Mn(CN)6]0.96·0.29H2O. Figure 1(b) shows the charge-discharge curves of KMnHCM. The electrode showed an initial charge capacity of 163 mAh g-1 and an initial discharge capacity of 220 mAh g-1, corresponding to respective ~2.0 and 2.76 potassium extraction and insertion, respectively, from/into K x Mn[Mn(CN)6]. The discharge capacity exceeds the theoretical capacity of 160 mAh g-1 based on the Mn2+/3+ redox of K1.87Mn[Mn(CN)6]0.96·0.29H2O. Furthermore, the additional plateau was observed at the low voltage of around 1.5 and 1.7 V in the discharge and charge curves, respectively. The extremely high capacity and the third plateau at low voltage are similar to Na x Mn[Mn(CN)6] in Na cells.2 Thus, the third plateau would be attributed to the reversible redox of [MnII(CN)6]4-⇄[MnI(CN)6]5-. In the talk, we will further discuss the charge-discharge mechanisms, including redox behavior and structural changes of KMnHCM during charge/discharge.

Medicinal Plant-Derived Copper Nanoparticles Effectively Manage Early Blight Disease in Tomato: An In vitro Study

Aims: Early blight of tomato (Solanum lycopersicum L.) incited by Alternaria solani is an economically important disease. This paper analyses the efficacy of copper nanoparticles (Cu-NPs) as an alternative to its existing management practices that predominantly rely on toxic fungicides which are potentially harmful to humans and the environment.&#x0D; Study Design: The experiment was conducted in a completely randomized block design with 7 treatments viz. T1:Cu-NPs from tulsi leaves, T2:Cu-NPs from neem leaves, T3:Cu-NPs from bael leaves, T4: Cu-NPs from chemical A (prepared from 0.2 M of Cu(NO3)2.3H2O + 0.2 M Ascorbic acid), T5: Cu-NPs from chemical B (0.2 M Cu(NO3)2.3H2O + 0.2 M CuCl2 + 0.4 N NH4OH), T6: Carbendazim 50 WP as check and T7: Control. Each treatment was tested at two levels of in vitro concentrations (i.e. 300 and 500 ppm) and the treatments were replicated thrice.&#x0D; Place and Duration of Study: Considering the importance of the disease and for developing an effective management strategy, the present study was carried out in the Department of Plant Pathology, College of Agriculture, Odisha University of Agriculture and Technology, Bhubaneswar during 2020-21.&#x0D; Methodology: Stable Cu-NPs were synthesized through three green synthesis methods by using bael (Agel marmelos L.), tulsi (Ocimum sanctum L.), and neem (Azadirachta indica L.) leaves and two chemical synthesis methods (i.e. chemical A and B).&#x0D; Results: The size (diameter) of the Cu-NPs from Agel marmelos, Ocimum sanctum, and Azadirachta indica were 427.4, 1,019, and 246.5 nm, and that from the aqueous solution reduction method and precipitation method were 1,537 and 867.8 nm, respectively. The synthesized Cu-NPs were evaluated against Alternaria solani at 300 and 500 ppm while Carbendazim 50 WP served as the standard check. The Azadirachta indica leaf-derived Cu-NPs at 300 and 500 ppm in the in vitro potato dextrose ager (PDA) medium exhibited the maximum mycelial growth inhibition of 60.24% and 75.9%, respectively. The size of Cu-NPs showed an inverse relation with the antifungal efficacy that indicated greater cellular penetration of smaller nanoparticles whereas much lower inhibition of mycelial growth in Carbendazim 50 WP as a check showed the lowest growth inhibition of 39.75% (300 ppm) and 59.03% (500 ppm).&#x0D; Conclusion: The results thus indicated higher efficacy of nanoformulations at lower concentrations that can be effectively used for the development of new nano-based plant protection agents against the early blight of tomatoes.

Bentonite-Chitosan composites or beads for lead (Pb) adsorption: Design, preparation, and characterisation

This study investigated the efficiency of mixing bentonite with chitosan via different preparation methods, subsequently the different forms were investigated for their ability to remove Pb(II) ions from solution. The different forms of bentonite-chitosan (Bt-Ch), composites and beads, were prepared via solution blending and precipitation methods, respectively and in the weight ratios of 90%/10%, 70%/30% and 50%/50%. The beads were further subdivided, identified as “beads-A" and “beads-B", and were formed by adding either bentonite suspension or bentonite powder, respectively, to solubilised chitosan solution. The composites and beads were characterised by X-ray fluorescence (XRF), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and pH at zero point charge. XRF analysis showed a cation exchange mechanism occurred when chitosan was initially mixed with the bentonite. TGA results confirmed that beads contained more chitosan compared to their corresponding weight ratio equivalent composites. XRD results showed that chitosan was intercalated within the interlayer space of the bentonite for Bt-Ch composites and Bt-Ch beads-A and that the interlayer spacings increased with increasing chitosan loading. Though similar amounts of chitosan were present in both Bt-Ch beads-A and beads-B, there were fewer reflection shifts for beads B suggesting less intercalation of chitosan when the bentonite was added as a powder. FTIR spectra from the Bt-Ch composites and beads confirmed the presence of both chitosan and bentonite, and the NH bands of chitosan shifted to lower frequencies demonstrating their involvement in the bonding mechanism of chitosan with bentonite. The experimental adsorption data correlated well with both non-linear Langmuir and Freundlich isotherm models, and in which both chemisorption and physisorption processes played crucial roles. The Langmuir-maximum adsorption capacities of Pb(II) ions for all the analysed Bt-Ch composites and beads was found to range from 42.48 ± 4.22 to 94.60 ± 5.63 mg/g. The amount of chitosan present in the adsorbent and its distribution within or outside the interlayer space of the bentonite was shown to have pronounced effects on the Pb(II) uptake by the different Bt-Ch composites/beads, and although the chitosan greatly enhanced the adsorption of Pb(II) a cation exchange mechanism with the clay was still a dominant process. The adsorption of Pb(II) was also significantly affected by the presence of other multi-competing ions. Moreover, the developed Bt-Ch composites/beads exhibited good potential for re-use after five cycles of regeneration, thus, indicating their potential as cost-effective adsorbents for removal of Pb(II) ions from both drinking and wastewater.

Silver phosphate–bacterial cellulose nanocomposites as visible light photocatalyst for wastewater purification

Silver phosphate (Ag3PO4) nanoparticles were deposited on bacterial cellulose (BC) nanofibrils as an eco-friendly, efficient, and reusable visible light active photocatalyst. BC–Ag3PO4 nanocomposites (BCAgP) with different BC/Ag3PO4 weight ratios were prepared by solution-precipitation method. The nanocomposites were characterized by UV-Visible diffuse reflection spectroscopy, XRD, FTIR, BET, and FESEM. Highly crystalline Ag3PO4 nanoparticles were well entrapped inside nano fibrillated BC matrix and eventually deposited along the fibers. Photocatalytic activity of the BCAgP nanocomposites were investigated by dye degradation experiments under solar light. The composite with BC: Ag3PO4 weight ratio of 1:4 (BCAgP14) showed the highest photocatalytic efficiency compared to other weight ratios and pure Ag3PO4. The sample also shows good photocatalytic activity even after 4 runs indicating its photostability. Higher photocatalytic efficiency of BCAgP14 nanocomposite was explained due to optimum Ag3PO4 loading and higher visible light absorption capacity. Bacterial cellulose is supposed to improve the photocatalytic activity of silver phosphate by promoting the adsorption of dyes and extending the charge recombination time under visible light of Ag3PO4 photocatalyst.

Laboratory synthesis, spectroscopic characteristics, and conversion relationships of five calcium sulfate double salts relevant to Mars

Calcium sulfate veins have been found in Gale crater and Endeavour crater as indicators of Martian fluid events. The presence of mixed-cation sulfates has been suggested because a wide variety of sulfates containing different cation elements have been detected in in-situ exploration targets (e.g., soils, drilled materials, calcium sulfate veins, and sandstones). In order to establish a spectroscopic library of mixed-cation sulfates, five calcium sulfate double salts (CSDS) were successfully synthesized using high-temperature solid phase reaction and aqueous solution precipitation methods. The phase and homogeneity of these samples were confirmed by X-ray diffraction (XRD). Raman, mid-infrared (MIR), visible and near-infrared (VNIR), and Laser-induced breakdown spectrometry (LIBS) spectra were also collected to study vibrational features and elemental emission properties. All these spectral data are valuable for the mixed-cation sulfate detections by those payloads with similar spectroscopic technologies empolyed on Mars. We also studied the conversion relationships among five CSDS, providing constraints for their origins in sedimentary (e.g., calcium sulfate veins) and volcanic environments on Mars.

Structural Insights and Photophysical Screening of Sm (III) Complexes with Heterocyclic Ligand for Optical Applications.

Five novel bright orange color emitting Sm(III) complexes (C1-C5) have been synthesized via energy efficient and cost effective solution precipitation method with 5-phenyl 2-furoic acid as primary organic sensitizer and nitrogen donor neocuproine, 2, 2- bipyridyl, bathophenanthroline, and 1,10-phenanthroline as secondary ligands. All the newly synthesized metal complexes are thoroughly characterize to examine the appropriateness of the organic ligand for the sensitization process. All the outcomes of the various advanced and fundamental spectroscopic techniques validate the bonding of carboxylate group with the Sm(III) ion. The luminescence spectra reflects the dominance of magnetic dipole transition which designate the occurrence of harmonized chemical environment in the coordination sphere which is further validated by enhanced values of intensity ratio. These complexes possess suitable thermal stability with excellent photoluminescent features as confirmed by thermogravimetric analysis and photoluminescence studies. The luminescence lifetime of samarium complexes [C2-C5] is relatively long due to the synergistic effect presented by ancillary ligands. The emission color of the synthesized complexes show shift from orange to bright orange red color which is displayed through CIE color coordinates.

Reaction of stoichiometric hydroxyapatite with different crystallinity in Mg&lt;sup&gt;2+&lt;/sup&gt; aqueous solution

The reaction of stoichiometric hydroxyapatite (HAp) with different crystallinity in Mg2+ aqueous solution was investigated using X-ray absorption near edge structure (XANES). Crystallinity is one of important factors for the properties of HAp. Therefore, this study aimed to clarify the effect of crystallinity on the behavior of HAp in aqueous solutions. Stoichiometric HAp samples with different crystallinities were prepared using an aqueous solution precipitation method and subsequent calcination. The Mg-K XANES spectra of the HAp pellets after immersing in Mg(NO3)2 aqueous solution were classified into two groups: those of Mg-doped HAp and Mg(OH)2. This difference is caused by the solubility of the HAp pellets in water, owing to their crystallinity. This result provides insights into the reaction mechanism of HAp in the human body and facilitates selection of suitable biomaterials.

Synthesis, Characterization and Gas Adsorption of Unfunctionalized and TEPA-Functionalized MSU-2

Michigan State University-2 (MSU-2) is notable potential adsorbent for carbon dioxide (CO2) due to its intrinsic properties, which include its highly interconnected three-dimensional (3D) wormhole-like framework structure, high specific surface area, and its large total pore volume, as well as its large amount of surface silanol hydroxyl groups, which facilitate the amine functionalization process. In this study, unfunctionalized MSU-2 was synthesized via a fluoride-assisted two-step process via the solution precipitation method, using Triton X-100 as the surfactant and tetraethylorthosilicate (TEOS) as the silica precursor. Then, the synthesized MSU-2 was functionalized using varying tetraethylenepentamine (TEPA) loadings of 20–60 wt%. The effect of different TEPA loadings on the properties and CO2 adsorption capacity of the MSU samples was investigated. Studies of the CO2 adsorption of the unfunctionalized and TEPA-functionalized MSU-2 samples was conducted at 40 °C and 1 bar of pressure. Furthermore, scanning electron microscopy (SEM); surface area and porosity (SAP) analysis; carbon, hydrogen, nitrogen, and sulfur (CHNS) analysis, X-ray diffractometry (XRD); Fourier transform infrared (FTIR) spectrometry; and thermogravimetric analysis (TGA) were utilized to characterize the resultant unfunctionalized and TEPA-functionalized MSU-2 with different TEPA loadings in order to study their morphologies, pore characteristics, elemental compositions, crystallographic structures, functional groups, chemical bonding, and thermal stability, respectively. The comprehensive results obtained from the analytical instruments and the CO2 adsorption studies indicated that the TEPA-functionalized MSU-2 with 40 wt% of TEPA loading achieved the highest average CO2 adsorption capacity of 3.38 mmol-CO2/g-adsorbent.

Hierarchical nickel oxalate superstructure assembled from 1D nanorods for aqueous Nickel-Zinc battery

Hierarchical superstructures in nano/microsize can provide improved transport of ions, large surface area, and highly robust structure for electrochemical applications. Herein, a facile solution precipitation method is presented for synthesizing a hierarchical nickel oxalate (Ni-OA) superstructure composed of 1D nanorods under the control of mixed solvent and surfactant of sodium dodecyl sulfate (SDS). The growth process of the hierarchical Ni-OA superstructure was studied and indicated that the product had good stability in mixed solvent. Owing to smaller size, shorter pathway of ion diffusion, and abundant interfacial contact with electrolytes, hierarchical Ni-OA superstructure (Ni-OA-3) showed higher specific capacity than aggregated micro-cuboids (Ni-OA-1) and self-assembled micro/nanorods (Ni-OA-2). Moreover, the assembled Ni-OA-3//Zn battery showed good cyclic stability in aqueous electrolytes, and achieved a maximum energy density of 0.42 mWh cm−2 (138.75 Wh kg−1), and a peak power density of 5.36 mW cm−2 (1.79 kW kg−1). This work may provide a new idea for the investigation of hierarchical nickel oxalate-based materials for electrochemical energy storage.

Tuning the Photometric Properties of Ternary Sm3+ Complexes Involving Mixed-Ligands.

This research article deals with the synthesis of ternary Sm3+ complexes with 6,8-dichlorochromone-3-carboxaldehyde through solution-precipitation method. The photometric properties of resultant complexes were tuned by coordinating N-donor heterocyclic ligands with Sm3+ ion. The emission spectra, obtained in the visible region have been studied. Under optical excitation of 370nm, the complexes displayed characteristic Sm3+-centered emission peaks at ~ 563, 600 and 647nm in solution as well as in powder state. The complexes showed thermal stability up to 175°C. The complexes delivered quantum yield as high as 7.91% and longest emission lifetime of 0.564ms. The color coordinates of the complexes, located in deep orange (in solution) and red (in powder) spectral region, matched well with the Society of Motion Picture and Television Engineers and European Broadcasting Union. The properties of complexes have been investigated to a significant extent due to their easy synthesis and potential applications as orange-red light emitter in a wide range of photonic applications such as display devices, OLEDs, dashboards, optical systems.

A low-toxic luminescent terbium(III)-loxoprofen complex for bio-optical imaging

A novel green-emitting terbium(III)-loxoprofen complex (Tb-LPF) was synthesized via a simple solution precipitation method, and the corresponding chemical composition and structure were determined by elemental analysis and infrared absorption spectra. The thermal stability of Tb-LPF was investigated through thermogravimetric analysis. The photophysical properties of Tb-LPF were measured by UV absorption and photoluminescence spectra. Furthermore, the biological toxicity of Tb-LPF was determined using MTT assay and flow cytometry based on MCF-7 cells. The experimental results demonstrated that Tb-LPF exhibited strong green emission and low toxicity, endowing Tb-LPF with a potential capability to act as an imaging probe in optical detection and bio-tissue imaging.

Highly efficient inverted phosphorescent organic light-emitting devices with ZnO nanoparticles electron injection layer

We have developed highly efficient inverted phosphorescent organic light-emitting devices (OLEDs) using ZnO nanoparticles (NPs). The wurtzite structured ZnO NPs having an average particle size of about 5 nm were synthesized by solution-precipitation method. The inverted phosphorescent OLEDs with a tris(2-phenylpyridine) iridium(III) emitter have fabricated using ZnO NPs and 2,2’,2”-(1,3,5-benzinetriyl)-tris-(1-phenyl)− 1-H-benzimidazole (TPBi) electron transport layer. ZnO NPs effectively inject electrons from cathode to the electron transport layer. The maximum external quantum efficiency and current efficiency of the phosphorescent inverted OLEDs with ZnO NPs were 15.8% and 55.1 cd/A, respectively.