Spherical Flowers Research Articles

Simultaneous CO2 mineral sequestration and nickel separation from laterite leachate: Thermodynamic and experimental study

Global warming resulting from escalating CO2 emissions and rising nickel demand present dual challenges to the sustainable development. In this study, a process for simultaneous nickel separation and CO2 mineral sequestration was proposed by using the leachate derived from the process of roasting laterite with copperas followed by water leaching. From the thermodynamic study, it was found that nickel can dissolve in the leachate in the form of nickel-ammonium complexes, while magnesium precipitated as carbonates. Furthermore, Eh-pH (potential vs. pH) results demonstrated that the conditions for the formation of nickel-ammonium complexes closely resemble those for magnesium carbonates. Under optimized conditions with the initial solution pH of 10.8, CO32–/Mg molar ratio of 2, reaction temperature of 30 °C, and reaction time of 1 h; over 95 % of Mg and 100 % of Fe can be converted into carbonates or hydroxides, with no more than 1 % Ni loss. Higher pH and CO32–/Mg molar ratios, along with lower temperatures, facilitated the separation of nickel from the magnesium and iron. The phase and microstructure of the precipitates were significantly influenced by the reaction temperature. At 30 °C, the precipitation product was MgCO3·3H2O, exhibiting a microstructure resembling porous spherical flowers; whereas at 80 °C, the precipitated phase was Mg5(OH)2(CO3)4·4H2O, also displaying a microstructure akin to porous spherical flowers. Efficient separation of nickel and magnesium in NH3–(NH4)2CO3-H2O was achieved by leveraging their distinct reaction properties, simultaneously sequestering CO2. This process achieved the maximum selective Ni recovery and CO2emission reduction in one step.

Preparation and oxygen-evolution-reaction performance of sulphur-doped flower-like NiFe-based composites supported on biomass porous carbon

Hydrogen gas generated through water electrolysis can replace fossil fuels. Thus, developing cost-effective and efficient water-splitting electrocatalysts for oxygen evolution reaction is highly important. Herein, biomass-porous-carbon-supported sulphur-doped flower-like NiFe-based alloy composites are prepared using an in situ impregnation–heat treatment technology. The spherical flower (diameter ≈ 1 μm, petal thickness ≈ 20 nm) main components are Ni0.5Fe0.5 and Fe9Ni9S16. The 800 °C heat-treated catalyst demonstrates outstanding catalytic performance in oxygen evolution reactions. At a current density of 10 mA cm−2 , it exhibits a minimal overpotential of 298.62 mV

Scalable slot-die coated flexible supercapacitors from upcycled PET face shields.

Upcycling Covid19 plastic waste into valuable carbonaceous materials for energy storage applications is a sustainable and green approach to minimize the burden of waste plastic on the environment. Herein, we developed a facile single step activation technique for producing activated carbon consisting of spherical flower like carbon nanosheets and amorphous porous flakes from used PET [poly(ethylene terephthalate)] face shields for supercapacitor applications. The as-obtained activated carbon exhibited a high specific surface area of 1571 m2 g-1 and pore volume of 1.64 cm3 g-1. The specific capacitance of these carbon nanostructure-coated stainless steel electrodes reached 228.2 F g-1 at 1 A g-1 current density with excellent charge transport features and good rate capability in 1 M Na2SO4 aqueous electrolyte. We explored the slot-die coating technique for large-area coatings of flexible high-performance activated carbon electrodes with special emphasis on optimizing binder concentration. Significant improvement in electrochemical performance was achieved for the electrodes with 15 wt% Nafion concentration. The flexible supercapacitors fabricated using these electrodes showed high energy and power density of 21.8 W h kg-1 and 20 600 W kg-1 respectively, and retained 96.2% of the initial capacitance after 10 000 cycles at 2 A g-1 current density. The present study provides a promising sustainable approach for upcycling PET plastic waste for large area printable supercapacitors.

Synthesis of CuO/rGO nanocomposites for carcinogenic Congo red photodegradation

Removal of carcinogenic Congo red from polluted water is challenging because of its chemical stability and inertness. Here, CuO microsphere assembled rGO nanosheets were successfully fabricated by a simple hydrothermal method for photocatalytic degradation of Congo red. The morphology and microstructure of the CuO/rGO nanocomposites were studied by scanning electron microscopy and X-ray diffraction. The results showed that the produced CuO has a spherical flower like structure that crystallised in the monoclinic crystal phase with a diameter of about 5 μm, combined with thin rGO nanoplates. Fourier transform infrared spectroscopy and Raman spectroscopy confirmed the existence of chemical bonds and vibrational modes of both CuO and rGO. The effect of H2O2 content on the photocatalytic characteristics of as-prepared samples was investigated. The results showed that H2O2 played a key factor in the photocatalytic efficiency. The content of 1 ml H2O2 (30%) exhibited the highest photocatalytic efficiency toward Congo red dye degradation in CuO/rGO (50 mg) under UV light radiation, where it completely removed over 95% Congo red in 100 ml of solution (20 mg L−1) after 120 min of illumination.

Hierarchical ZnO nanostructure flowers loaded with AgI nanoparticles for photodegradation of methylene blue under UV visible radiation

Hierarchical ZnO spherical flowers loaded with different weight contents of AgI nanoparticles were synthesized by deposition-precipitation method at room temperature and tested for photodegradation of methylene blue (MB) under UV visible light irradiation. The as-prepared photocatalysts were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) connected with energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). XRD patterns and SEM images of ZnO and AgI/ZnO hierarchical spherical flowers present pure phase of hexagonal wurtzite ZnO structure flowers and hexagonal wurtzite ZnO flowers supported with cubic AgI nanoparticles with size range of 80–90 nm on top. The photodegradation of MB was increased with increasing in the weight content of the loaded AgI nanoparticles on the surface of ZnO flowers. The 10% AgI/ZnO nanocomposites have the highest photocatalytic efficiency in degrading MB by h+ and ●OH as the main active species under visible light irradiation within 60 min.

Efficient photocatalytic degradation of dyes using photo-deposited Ag nanoparticles on ZnO structures: simple morphological control of ZnO.

In this work, morphology-controlled ZnO structures were prepared via a hydrothermal method by simple adjustments in the NaOH concentration. The NaOH concentration variation from 0.2 to 1.2 M resulted in the formation of ZnO structures in shapes such as walnut, spherical flower, flower, rod, and urchin-like. The extent of OH− ions is the main factor influencing the growth of ZnO structures. Well-defined morphologies, good crystallinity, and optical properties were obtained for all ZnO structures. Among these ZnO structures, ZnOsf (spherical flower-like) structure showed a greater percentage of photodegradation of methyl orange and rhodamine B dyes. Surface plasmon resonance was achieved by modifying the surface of ZnO with Ag nanoparticles. ZnOsf was loaded with Ag nanoparticles by a facile photo-deposition method. Ag–ZnOsf showed superior photoactivity and recyclability for the degradation of methyl orange and rhodamine B. Therefore, modification of different ZnO structures can help realize potential catalysts for future environmental applications.

Hierarchical Sr-ZnO/g-C3N4 heterojunction with enhanced photocatalytic activities

It is urgent to develop new photocatalytic materials that could optimize H2 generation and efficiently degrade environmentally persistent pollutants. Herein, Sr-ZnO/g-C3N4 spherical flowers composed of hierarchical nano-rods composites have been successfully synthesized via facile single step method and utilized in photocatalysis for efficient degradation of Methylene green (MG) and H2 production under UV–vis irradiation. The resultant Sr-ZnO/g-C3N4 showed enhanced activities for MG degradation (i.e. 96 % in 20 min), and H2 evolution (31.2 μmolh−1 g-1) which is much obvious compared to the bare g-C3N4, ZnO and Sr-ZnO. It is investigated that Sr ion doping has extended the light absorption toward visible light region. The g-C3N4 grafted Sr-ZnO provided an extra boost up absorption spectra in the visible light region compared to bare ZnO. The photoluminescence spectroscopy and photo-electrochemical measurement confirmed excellent photo-generated charge carrier’s separation in the hierarchical structure of spherical flowers. The improved activities are attributed to the combined impact of in-situ doping, hierarchical morphology, and heterojunction formation.

Photocatalytic HA deposition on TiO2 of Ti-0.2Pd surface immersed in simulated body fluid

Effect of photocatalysis on apatite formation on Ti-0.2Pd alloy when the metal is immersed in a physiological solution is investigated. The surface of Ti-0.2Pd was treated by a method of thermal oxidation at 400 and 600 °C in air. Immersion tests of Ti-0.2Pd pieces in a simulated body fluid (SBF containing 27 mM HCO3−) at 37 °C for 14 days under ultraviolet (UV) irradiation and in dark environment were carried out. Glancing angle X-ray diffraction and Fourier transform infrared spectroscopy were used to examine the crystallinity and composition of the deposition. Two different morphologies of carbonated hydroxyapatite (HA) deposition: spherical flower shape and dot shape are found formed on the samples. Spherical flower-shaped HA has higher crystallinity and higher Ca/P ratios (1.2–1.4) which are related to the effect of photocatalysis. Dot shaped HA with lower crystallinity and lower Ca/P ratio (0.8–1.0) is found formed on most dark immersed pieces. This work suggests the UV irradiation causes the change of the morphology and crystallinity of HA but has no effect on the quantity of HA formed on Ti-0.2Pd. The chemical composition of the deposition produced on Ti-0.2Pd under UV lighting is closer to that of a crystallized HA compared to that formed in dark.

Magnetic MoS2: a promising microwave absorption material with both dielectric loss and magnetic loss properties

In order to obtain magnetic MoS2 and investigate the influence of magnetic moment on the microwave absorption properties of MoS2, transition metal element Ni-doped MoS2 (0–30 at%) was obtained by a hydrothermal synthesis. The results revealed that the low doping concentration (<10 at%) did not significantly change the crystal structure of MoS2, and the Ni element formed a NixMo1−xS2 compound within the MoS2 bulk phase. While the high doping concentration (10–30 at%) led to the formation of impurities. The hydrothermal products which were formed by the accumulation of pleated nanosheets looked like spherical flowers. As the doping concentration further increased, the spherical particles became more compact. The magnetization of MoS2 could be increased by proper amount of Ni doping. When doping with 3 at% Ni (Ni-3), the Ms value increased from 0.53 emu g−1 for non-doped MoS2 to 0.93 emu g−1. When the doping ratio was further increased, the Ms value of the material decreased. The zigzag edges and variations in the number of vacancies in the materials may be the root of changes in magnetic properties. The overall performance of Ni-3 was also the best in the examined doping range. Compared with non-doped MoS2, the matching thickness decreased from 3.50 to 2.05 mm, while the minimum reflection loss value decreased from −55.18 to −58.08 dB, and the effective absorption bandwidth (<−10 dB) increased from 3.05 to 5.19 GHz. The excellent absorption performance of the doped materials can be attributed to the change of complex dielectric constant and complex permeability of MoS2 and resulting in the improvement of loss capability. This study may introduce new opportunities for fully exploiting these nanocrystals for microwave absorption, even for diluted magnetic semiconductors.

Hybrid porous flower-like NiO@CeO2microspheres with improved pseudocapacitiveproperties

Spherical flowerlike NiOand NiO@CeO2(2.5, 5.0 and 7.5 wt%) composites are successfully prepared by a simple hydrothermal method. NiOmaterials show spherical flower morphology with a radius of 4–5 μm, and the CeO2nano-particles deposit on the surface of NiOpetals (nanosheets), and then form porous NiO@CeO2flower-like microspheres. NiOpetals are covered with electrochemical active CeO2nanoparticles, leading to an advantageous synergistic storage effect due to the charge redistribution in the NiO|CeO2interface, which can decrease the polarization and accelerate the ion diffusion. NiO@CeO2(5.0 wt%) electrode shows an excellent specific capacitance of 960.4 F g−1at 20 A g−1and keeps about 95.84% capacitance retention after 10000 cycles. Whereas the NiO, NiO@CeO2(2.5 wt%) and NiO@CeO2(7.5 wt%) electrodes have capacitances of 543.6, 1428 and 1143.6 F g−1corresponding to capacitance retentions of 74.39%, 62.55% and 58.41% after 10000 cycles, respectively. The first-principles calculation exhibits that a strong chemical bond between O and Ce(Ni) can be formed at the interface, and such a chemical bonding between the two components is very helpful for the stabilization of the composite during repeated cycles, responsible for the good cycling performance of the materials. Therefore, the super capacitance and excellent cycling stability of NiO@CeO2(5.0 wt%) electrode at high current density can be ascribed to the unique composition design and architectures.

Conspecific Pollen on Insects Visiting Female Flowers ofPhoradendron juniperinum(Viscaceae) in Western Arizona

Phoradendron juniperinum (Viscaceae) is a dioecious, parasitic plant of juniper trees ( Juniperus [Cupressaceae]) that occurs from eastern California to New Mexico and into northern Mexico. The species produces minute, spherical flowers during early summer. Dioecious flowering requires pollinating insects to carry pollen from male to female plants. I investigated the pollination of P. juniperinum parasitizing Juniperus osteosperma trees in the Cerbat Mountains in western Arizona during June–July 2016. I examined pollen from male flowers, aspirated insects from female flowers, counted conspecific pollen grains on insects, and estimated floral constancy from proportions of conspecific pollen in pollen loads. The tricolpate pollen from P. juniperinum was subangular in shape with open furrows in polar view and oval-spherical in shape in equatorial view. Most insects on flowers were small ( 1 grain, and numbers of grains on insects did not differ among the species collected. Phoradendron juniperinum was most likely pollinated by 2 species of flies in Hippelates (Chloropidae) and Desmometopa (Milichiidae) and 1 species of parasitic wasp in Apanteles (Braconidae). Insects in these genera were widespread and frequently collected, with half of specimens carrying conspecific pollen that comprised most of the pollen load. Other Diptera carrying conspecific pollen included 1 species in Olcella (Chloropidae), 2 species in Mythicomyia (Mythicomyiidae), and 1 species in Scatopsidae. Other Hymenoptera with conspecific pollen included 1 species of bee in Lasioglossum (Halictidae), 1 species of wasp in Parancistrocerus (Vespidae), and 3 species of parasitic wasps in Chalcidoidea. Minute flies, such as Tephritidae or Chloropidae, are the most common pollinators among P. juniperinum and the 2 other examined species of Phoradendron (P. californicum and P. coryae). Pollination of Phoradendron likely differs among species due to different host plants, plant communities, and flowering seasons.

Conspecific Pollen on Insects Visiting Female Flowers on the Oak Parasite Phoradendron coryae (Viscaceae)

Phoradendron coryae (Viscaceae) is a dioecious, parasitic plant on oak trees and shrubs in Quercus (Fagaceae), and it occurs from Arizona to Texas and into northern Mexico. The species produces minute spherical flowers during summer. Dioecious flowering requires pollinating insects to carry pollen from male to female plants. I investigated the pollination of P. coryae parasitizing Quercus turbinella shrubs at 3 sites at different elevations in the Cerbat Mountains of northwestern Arizona during August–September 2015. I examined pollen from male flowers, aspirated insects landing on female flowers, and counted conspecific pollen grains carried by insects. The tricolpate pollen of P. coryae was semiangular to subangular in polar view and circular to depressed oval in equatorial view. Female flowers were visited by 2 species of Coleoptera in 2 families, 6 species of Diptera in 6 genera and 3 families, and 1 species of Hymenoptera. Insects on flowers were extremely small (most <3 mm in length), and nearly all (99%) of the pollen carried by insects was from P. coryae. Conspecific pollen was found on 67% of the insects identified. Pollen loads were low, with only 25% of the insects carrying ≥5 grains. The beetle Attalus futilis (Melyridae) was the most frequently aspirated species, comprising 71% of the insects collected and occurring at all 3 sites. Most A. futilis (64%) carried P. coryae pollen. The second most frequently collected insects were 2 species of Hippelates and Liohippelates flies (Chloropidae). The Liohippelates carried the most P. coryae pollen. Other insects with pollen included 2 additional species of Chloropidae, 2 species of flies in Tachinidae and Tephritidae, a species of beetle in Chrysomelidae, and a species of parasitic wasp in Figitidae. Phoradendron coryae appeared to be pollinated mostly by A. futilis beetles due to their apparent abundance and by Liohippelates flies due to their relatively high pollen loads.

The royal irises (Iris subg. Iris sect. Oncocyclus): Plastid and low‐copy nuclea data contribute to an understanding of their phylogenetic relationships

AbstractIris sect. Oncocyclus species generally occur in small populations or locally scattered over rocky hillsides, steppes, and deserts from the north Caucasus to the eastern Mediterranean. Species of this section are easily recognized by their inflorescences of a single, large, spherical flower and sepals with a dark signal spot and adjacent beard of multicellular hairs. We present here results of the first phylogenetic study of sect. Oncocyclus based on one low‐copy nuclear and six plastid markers from 33 of approximately 42 species and infraspecific taxa. Gene trees are congruent and nuclear markers are more potentially parsimony informative than plastid markers. We identify clades that do not correspond to previously described species groups based on size, color, and shape of perianth parts and show that hypotheses of species monophyly are not supported. In general, diversification is greatest along terminal branches suggesting that species diversified in isolation. The Caucasus is suggested as the ancestral area for sect. Oncocyclus and the eastern Mediterranean as an important area of diversification.

Hierarchical chrysanthemum-flower-like carbon nanomaterials grown by chemical vapor deposition

Novel hierarchical chrysanthemum-flower-like carbon nanomaterials (CFL-CNMs) were synthesized by thermal chemical vapor deposition based on acetylene decomposition. A scanning electron microscope and a transmission electron microscope were employed to observe the morphology and structure of the unconventional nanostructures. It is found that the CFL-CNMs look like a blooming chrysanthemum with a stem rather than a spherical flower. The carbon flower has an average diameter of 5 μm, an average stem diameter of 150 nm, branch diameters ranging from 20 to 70 nm, and branch lengths ranging from 0.5 to 3 μm. The morphologies of the CFL-CNMs are unlike any of those previously reported. Fishbone-like carbon nanofibers with a spindle-shaped catalyst locating at the tip can also be found. Furthermore, the catalyst split was proposed to elucidate the formation mechanism of CFL-CNMs. A large and glomerate catalyst particle at the tip of the carbon nanofiber splits into smaller catalyst particles which are catalytic-active points for branch formation, resulting in the formation of CFL-CNMs.

Flower-like mesoporous silica: a bifunctionalized catalyst for rhodium-catalyzed asymmetric transfer hydrogenation of aromatic ketones in aqueous medium

Functionalized flower-like mesoporous silica with a chiral organorhodium functionality incorporated within its silica framework is prepared through an assembly of chiral 4-((trimethoxysilyl)ethyl)phenylsulfonyl-1,2-diphenylethylenediamine and tetraethoxysilane under a cooperative dual-template approach followed by complexation with organorhodium complexes. Structural characterization discloses its mesostructure and well-defined single-site chiral organorhodium functionality, while electron microscopy analyses reveal the uniformly distributed three-dimensional spherical flowers constructed by the stacking of leaf-shaped nanoflakes. In particular, as a bifunctionalized heterogeneous catalyst, it shows excellent catalytic activity and high enantioselectivity in the asymmetric transfer hydrogenation of aromatic ketones in aqueous medium (more than 99% conversion and up to 97% ee). The superior catalytic performance is attributed to the synergistic effect of the salient cetyltrimethylammonium bromide phase-transfer function and confined chiral organorhodium catalytic nature. Furthermore, this heterogeneous catalyst could be recovered easily and reused repeatedly (ten times) without affecting its ee value, showing a practical application in asymmetric synthesis.

Simple Room-Temperature Mineralization Method to SrWO4 Micro/Nanostructures and Their Photocatalytic Properties

A simple room-temperature mineralization method has been developed to synthesize SrWO4 micro/nanostructures with diverse morphologies, including nanoparticle, dumbbell, shuttle, sphere, spherical flower, bundle of straw, and dendrite. The products were characterized by X-ray diffraction, scanning electron microscope, UV–vis absorption, and Raman spectroscopy. The influence of pH on the size and morphology of the as-obtained products was investigated in detail. Taking the synthesized SrWO4 spheres as an example, we also investigated the photocatalytic properties of as-synthesized products for photocatalytically splitting water into H2 and O2 under UV light irradiation.

Designed synthesis and magnetic properties of Co hierarchical nanostructures

Size and shape controlled fabrication of magnetic Co microsphere, nanoribbon, nanochain and rose-like microarchitecture has been successfully realized via a simple hydrothermal route. X-ray diffraction analysis suggests that Co hierarchical nanostructures are identified as hexagonal phase. Magnetic hysteresis measurements demonstrate that the obtained different Co hierarchical structures show structure-dependent magnetic properties. Saturation magnetization ( M S) found for Co spherical flowers and spherical powders are larger than Co nanoribbons, smaller than sphere-rebuilt micro particles or chain-like structures. Chain-like and nanorribon structures have abnormally large coercivity ( H C). H C values of Co nanoribbons and one dimensional chains become as large as 256 Oe and 316 Oe.

&lt;i&gt;Hibiscus&lt;/i&gt; 属植物に関する研究 (第9報)

1. The flower type of syriacus was classified into 3 groups and 9 types based on the investigation of 54 different clones.Group I. Single flowered type (25 clones)I-a Narrow petal type (7 clones)I-b Medium petal type (13 clones)I-c Broad petal type (5 clones)Group II. Semi-double flowered type (20 clones)II-a Gion-mamori type (4 clones)II-b Hanagasa type (7 clones)II-c Rose type (9 clones)Group III. Double flowered type (9 clones)III-a Irregular type (2 clones)III-b Chrysanthemum type (3 clones)III-c Pompon type (4 clones)2. The Group I (Single flowered type) could also be divided into three sub-groups according to the number of petals per flower, viz. i) number of petals 5 (basic number) (9 clones), ii) number of petals 5-6 (12 clones) and iii) number of petals 8-11 (4 clones). Even in flowers with petals twice as many as the basic number, petals were of the same size as basic one and were arranged in a single row, so that the flowers remained single in appearance. The size of flower was the most variable in this group, ranging continuously from 7.6 to 13.3cm in diameter (Table 1, Fig. 1, 2, 3 and 6).3. The Group II (Semi-double flowered type) consisted of flower type in which inner petals were much smaller than outer single-row petals. Those with a small number of inner petals were classified as Type II-a (Gion-mamori), while those with large number of inner petals as Type II-b (Hanagasa). In Type II-c (Rose), inner petals were somewhat larger in size than II-a and b and some of them were originated from the style. Type II-a was as fertile as the flowers of Group I, while II-b rarely produced seeds and II-c never produced seeds (Table 2, Fig. 4 and 5).4. In Group III (Double flowered type) inner and outer petals were of the same size. In Type III-a (Irregular), styles of about 1/3 of the flowers were transformed into petals. In Type III-b (Chrysanthemum), petals were rather smaller and were more or less regularly arranged, and styles of 1/2-2/3 of the flowers turned into petals. In Type III-c (PomPon), the small spherical flowers possessed the smallest but numerous petals, and the whole style was transformed into petals. Some examples of prolification were found in the last type; such flowers consists of more than 70 petals (Table 3, Fig. 7 and 8).