Hierarchical Flower-like Structure Research Articles

An insight on the growth mechanism of Cu2ZnSnS4 via hydrothermal route

In the current study, we successfully prepared Cu2ZnSnS4 (CZTS) microparticles using the hydrothermal method at 180 °C, where thiourea was used as a sulphur precursor. To investigate the growth mechanism of CZTS, time-dependent X-ray diffraction (XRD)pattern was studied. The morphology and shape of the synthesized microparticles were examined by field emission scanning electron microscopy (FE-SEM). UV-DRS(UV- Diffusion Reflectance Spectrometer) studies were used to study the optical properties. The morphology played a vital role in the formation of CZTS. This is clearly observed in SEM images where there is a transformation from agglomeration to a hierarchical flower-like structure. The synthesized powder using hydrothermal processes demonstrated the Cu2ZnSnS4 is formed in kesterite phase. The band gap of as-produced CZTS microparticles determined by UV-DRS spectra measurements was 1.57 eV, which is close to the ideal value for photo absorption applications. We analyze the changes in surface properties of particles using X-ray photoelectron spectroscopy (XPS). Understanding the mechanism in preparation of such hierarchical flower like CZTS enables the application of such structure in a wide sector, including photocatalysis and photovoltaics.

Gas-sensing properties and first-principles comparative study of metal (Pd, Pt)-decorated MoSe2 hierarchical nanoflowers for efficient SO2 detection at room temperature

The online detection and control of concentration for agricultural greenhouse gas SO2 is an important technology to ensure normal agricultural production. This paper reports on a facile hydrothermal method to synthesis Pd-decorated and Pt-decorated MoSe2 nanomaterials, i.e. multistage flower-like structures with attached nanometallic particles and nanosheets hierarchical structures. The Pd/MoSe2 and Pt/MoSe2 hierarchical materials were characterized for the nanostructure, microscopic morphology and elemental compositions. The gas-sensing properties results show that the Pd/MoSe2 and Pt/MoSe2 nanofilm sensors have good sensitivity, stability and response rate to SO2 gas. The response values for the metal Pd and Pt decorated samples to 20 ppm SO2 were 2.04 and 3.42 times higher than those for the intrinsic MoSe2 samples at room temperature. The hierarchical flower-like structure proved to be beneficial in providing more adsorption drop points. In addition, based on the first-principles, the geometrical parameters and electronic properties of the metal-decorated modified structures were calculated to comparatively investigate the enhanced sensing mechanism of SO2 by nanoflower materials. The Pt-MoSe2 nanofilm sensor achieves a high sensitivity detection with a response value of 2.89 for low concentration (1 ppm) of SO2, which is confirming the promotion of charge transfer by metal decorating. This study suggests that Pd-MoSe2 and Pt-MoSe2 hierarchical structures may be recommended for the detection of the agricultural greenhouse gas SO2.

BiOCl/SrHA nanoparticle for photocatalytic degradation of a malachite green dye

In this research, we discuss the removal of malachite green dye by strontium hydroxyapatite supported BiOCl. A modified hydrolysis model, one can synthesise BiOCl/SrHA. BiOCl/SrHA was characterized using Fourier transform-infrared spectroscopy (FTIR), UV-visible (UV-vis) analysis, X-ray diffraction (XRD), energy diffraction X-ray (EDX), and scanning electron microscopy (SEM). SEM outcome confirmed the dispersion of BiOCl onto strontium hydroxyapatite. The shape of the BiOCl catalytic samples overlapped with each other to form 3D hierarchical flower-like structures. The UV-visible was used as a radiation source during photocatalysis. BiOCl/SrHA had an effect on malachite green dye degradation. The oxidative removal occurred through hydroxyl radical formation. UV-visible (UV-vis) /BiOCl/SrHA showed perfect photocatalytic property for the decay of malachite green (MG) from an aqueous solution. According to kinetics analysis, the dye degradation rates could be in a pseudo-first-order model.

Bismuth oxyiodide nanocomposites supported on strontium hydroxyapatite enhance UV-Vis light-driven photocatalytic activity

In this research, we discuss the removal of basic fusion (BF), and crystal violet (CV) dyes by strontium hydroxyapatite supported BiOI. In a modified hydrothermal model, one can synthesize BiOI/SrHA. BiOI/SrHA was characterized using Fourier transform-infrared spectroscopy (FTIR), UV-visible (UV-vis) analysis, X-ray diffraction (XRD), energy diffraction X-ray (EDX), and scanning electron microscopy (SEM). SEM outcome confirmed the dispersion of BiOI onto strontium hydroxyapatite. The shape of the BiOI catalytic samples overlapped with each other to form 3D hierarchical flower-like structures. The UV-visible was used as a radiation source during photocatalysis. BiOI/SrHA had an effect on malachite green dye degradation. The oxidative removal occurred through hydroxyl radical formation. UV-visible (UV-vis) BiOI/SrHA showed perfect photocatalytic property for the decay of Basic Fuchsin (BF) and Crystal Violet (CV) from an aqueous solution. According to kinetics analysis, the dye degradation rates could be in a pseudo-first-order model

Facile fabrication of three-dimensional MnO2 for trichloroethylene degradation by plasma catalysis

Non-thermal plasma (NTP) coupled with catalyst is a cutting-edge technique for the abatement of chlorinated volatile organic compounds (Cl-VOCs), which are typically chemically stable, highly toxic and non-biodegradable. In this study, different morphologies of 3D MnO2 catalysts were fabricated facilely through a hydrothermal method and coupled with NTP for trichloroethylene (TCE) degradation. Among the various catalysts tested, MnO2 IV exhibited the highest TCE degradation performance, with removal efficiency, mineralization and energy yield ranging from 44.3% to 94.8%, 28.9% to 90.1% and 5.76 to 2.31 g/kWh, respectively, at voltage levels between 7 and 11 kV. The relationship between the physicochemical properties of the catalysts and their degradation performance was established through various characterization methods. The exceptional catalytic efficiency of MnO2 IV can be ascribed to its hierarchical flower-like structure, the greatest specific surface area (120 m2/g), the weakest Mn-O bonds, increased lattice defects and oxygen vacancies, and lower H2 reduction temperature. These characteristics facilitate enhanced transfer, adsorption, and utilization of reactive oxygen species in NTP on the surface of MnO2 IV, promoting the deep oxidation of TCE. The optimization of operational parameters was achieved using response surface methodology, with results indicating that the applied voltage exerted the greatest influence on both the mineralization rate and energy yield. The optimal operating conditions were determined, with initial TCE concentration, applied voltage, and gas flow rate values identified as 393 ppm, 7.3 kV, and 0.83 L/min, respectively. Lastly, the TCE degradation mechanism in the NTP-MnO2 catalyst system was hypothesized based on the identification of various plasma reactive species and organic intermediates. This study provides new insights for the improvement of the VOCs oxidation performance in plasma catalytic system.

Energy band-adjusted BiPO4/BiOClxBr1-x photoelectrochemical sensor for enhancing 4-CP detection

BiPO4 nanoparticles were loaded into BiOClxBr1-x with hierarchical flower-like structures by hydrothermal method, and an energy band-adjusted BiPO4/BiOClxBr1-x heterojunction with high photoelectrochemical properties was synthesized. Comparing BiPO4 and BiOClxBr1-x to BiPO4/BiOClxBr1-x, improved photoelectrochemical properties are obtained on BiPO4/BiOClxBr1-x. The high performance of BiPO4/BiOClxBr1-x may be attributed to the formation of junction between BiOClxBr1-x and BiPO4, efficiently enhancing charge separation and lowering the recombination rate of photogenerated carriers. The PEC sensor was optimized by adjusting the Cl/Br molar ratio of BiPO4/BiOClxBr1-x. The optimal coupling of the oxidation efficiency and light absorption capacity in various band structures is what causes the 5% BiPO4/BiOCl0.75Br0.25 heterojunction to exhibit the maximum photoelectrochemical activity. The PEC sensor of 5% BiPO4/BiOCl0.75Br0.25 heterojunction presents the low detection limit of 0.11 nM (S/N = 3), and it also exhibits high linear ranges (R2 = 0.9927) of 2–20 μM with good selectivity and stability for the 4-CP detection.

The electromagnetic wave absorption composite of flower-like structure NiCo2O4 and Fe3O4 derived from low-temperature preparation method

The NiCo2O4@Fe3O4 composites with excellent electromagnetic wave absorption performance was prepared by the low-temperature (50 °C) co-precipitation method, avoiding the traditional high-temperature hydrothermal synthesis method. The specific surface area of the composite material was increased due to the combination of NiCo2O4 with 3D hierarchical flower-like structure and Fe3O4 with spherical structure, which is conducive to the full reflection and scattering of electromagnetic waves. The combination of typical magnetic material and excellent dielectric material could adjust the impedance matching value of the material and thus the absorption loss performance of electromagnetic wave was improved. The ε value of the dielectric material was larger than those of magnetic materials and the maximum reflection loss value appeared at the high frequency (the thickness is small), while the μ value of magnetic materials was larger than those of dielectric materials and the maximum reflection loss value generally appeared at low frequency (the thickness is large).The results showed that the maximum RL value reached −53.35 dB at about 13 GHz with the thickness of 2.0 mm and the effective absorption bandwidth was 4.4 GHz when the weight ratio (NiCo2O4:Fe3O4) of composite samples was 6:1. The excellent EMW absorption property was mainly due to the combination of NiCo2O4 and Fe3O4, which could achieve impedance matching to loss EMW by dielectric loss and magnetic loss.

Dual co-catalysts Ag/Ti3C2/TiO2 hierarchical flower-like microspheres with enhanced photocatalytic H2-production activity

Solar-powered semiconductor photocatalysis is considered a powerful strategy for addressing environmental pollution and energy crisis. Nevertheless, the separation and transfer abilities of photogenerated photocatalysts remain unsatisfactory. Herein, dual Ti3C2 nanosheets/Ag co-catalysts synergistically decorated hierarchical flower-like TiO2 microspheres for boosting photocatalytic H2 production were fabricated by electrostatic self-assembly and subsequent photoreduction procedures. The optimal Ag/Ti3C2/TiO2 composite demonstrated an excellent photocatalytic H2-production rate of 1024.72 μmol g−1 h−1 under simulated solar irradiation, achieving nearly 40, 2.3, and 1.8 folds with respect to that obtained on pristine TiO2, optimized Ti3C2/TiO2 composite, and Ag/TiO2 composite, respectively. The considerably improved photocatalytic H2-production activity is associated with the synergistic effect of the hierarchical flower-like structure of TiO2, excellent electrical conductivity of Ti3C2, and surface plasmon resonance effect of Ag, which enhances the light absorption capacity and promotes the separation and transfer of photogenerated carriers. This study provides insight into the design of high-efficiency photocatalysts with dual co-catalysts for solar H2 production.

Fabrication of ultrahigh supercapacitor device based on ZnCo2O4@MnO2 with porous nanospheres decorated on flower-shaped structure

Being a fundamental component of energy storage devices, high-performance supercapacitors are always of utmost significance. In addition to long-term cycle durability, these supercapacitors should have higher power and energy densities. So, here we report an innovative approach for designing the hierarchical flower-like structures of binary metal oxides decorated with porous nanospheres of manganese oxide. The synergistic coupling of ZnCo2O4 and MnO2 offers a twofold charging capacity, while the porous framework provides good accessibility to the ions of electrolytes for storage inside the material. Furthermore, the Asymmetric device (ASD) is fabricated to achieve high energy density by employing ZnCo2O4@MnO2 as an anode material and activated carbon as a cathode material. The fabricated device exhibits an ultrahigh energy density of 247 Wh/kg at 1250 W/kg power density and good cycle stability after 5000 charge-discharge cycles with 97.2 % retention. Moreover, an array of 51 LEDs is lightened for nearly 16 min by connecting six asymmetrical devices in series to each other. As an astonishing result of the fabricated electrochemical asymmetric supercapacitive device, it holds great promise for industrial energy storage solutions.

Sulfur-doped Sn3O4 nanosheets for improved photocatalytic performance

Sn3O4 has shown great potential in photocatalytic water purification and energy conversion. However, it is still suffering from limited visible light-harvesting ability and sluggish charge-carrier separation. Nonmetal heteroatom doping is considered as an effective strategy to regulate the electronic structure and improve the photocatalytic performance. Herein, S-doped Sn3O4 was synthesized by a simple hydrothermal method using L-cysteine as sulfur source. It was found that the hierarchical flower-like structure of Sn3O4 would be destructed gradually by sulfur (S) doping. Nevertheless, the as-obtained S(1%)-doped Sn3O4 exhibits remarkable improved photocatalytic degradation performance of azo-dye methyl orange (MO) and antibiotic metronidazole (MTZ). S doped on the lattice of Sn3O4 can narrow the band bap to enhance sufficient photoadsorption, facilitate separating the charge carriers and producing the predominant active species (O2·-) compared with pristine Sn3O4 photocatalyst, resulting in the enhancement of MO/MTZ photogradation activity. This work demonstrates a simple route for S doping in Sn3O4 and provide guidance for the controllable design and synthesis of high-efficient photocatalysts by nonmetal heteroatom doping.

A robust superhydrophobic coating with multi-dimensional micro-nano structure on 5052 aluminum alloy

This paper presents a new method to constructing a robust superhydrophobic surface with multi-dimensional roughness on 5052 aluminum alloy (SHC-Al). The microstructure and surface properties of the SHC-Al were investigated using various techniques including Field emission scanning electron microscope (FESEM), Energy dispersive X-ray spectroscopy (EDS), Laser confocal scanning microscope (CLSM), Fourier transform infrared spectrometer (FTIR), X-ray diffractometer (XRD), Contact angle measuring instrument and electrochemical techniques. The findings indicated that the surface had a hierarchical flower-like micro-nano rough structure, with a water contact angle (WCA) of 162.4° and a rolling angle (SA) of 3.2°, making it easy to clean. Furthermore, the superhydrophobic property can be restored after 90 wear cycles or 33 tape stripping. Electrochemical results demonstrated that the coating had a low corrosion current of 2.742 × 10−9 A·cm−2. The coating remained effective in preventing corrosive mediums from reaching 5052 aluminum surface after soaking in 3.5 wt% NaCl solutions for 72 h, with a coating protection efficiency of 97.9 %, demonstrating excellent anticorrosion properties. Additionally, the coating showed exceptional stability. The results demonstrate that the as-prepared superhydrophobic surface is robust and corrosion-resistant, which hold great promise for practical applications.

Hierarchical Flower-Like VS2 Nanosheets Cathode for High-Performance Aqueous Zn-ion Batteries

Aqueous rechargeable zinc-ion batteries (ZIBs) are an attractive alternative to lithium-ion batteries because of their superior safety and inexpensive price. However, the main challenge faced by ZIBs is the search for high-capacity materials that can hold large-diameter Zn ions. Herein, hierarchical flower-like VS2 nanosheets are synthesized as high-performance anode materials for ZIBs. The special hierarchical flower-like structure and morphology afford a large contact area and short Zn2+ ion diffusion distance. Therefore, VS2 nanosheets displays a reversible specific capacity (218.3 mAh g−1 at 100 mA g−1) and stable cyclic stability (87.7% capacity retention). VS2 nanosheets have a superior electrochemical performance, enabling a novel design approach for other ZIBs cathode materials.

Controllable Architecture of ZnO/FeNi Composites Derived from Trimetallic ZnFeNi Layered Double Hydroxides for High-Performance Electromagnetic Wave Absorbers.

The optimization design of micro-structure and composition is an important strategy to obtain high-performance metal-based electromagnetic (EM) wave absorption materials. In this work, ZnO/FeNi composites derived from ZnFeNi layered double hydroxides are prepared by a one-step hydrothermal method and subsequent pyrolysis process, and can be employed as an effective alternative for high-performance EM wave absorber. A series of ZnO/FeNi composites with different structures are obtained by varying the molar ratios of Zn2+ /Fe3+ /Ni2+ , and the ZnO/FeNi composites with a Zn2+ /Fe3+ /Ni2+ molar ratio of 6:1:3 show a hierarchical flower-like structure. Owing to the strong synergistic loss mechanism of dielectric-magnetic components and favorable structural features, this hierarchical flower-like ZnO/FeNi sample supplies the optimal EM wave absorption performance with the highest reflection loss of -52.08dB and the widest effective absorption bandwidth of 6.56GHz. The EM simulation further demonstrates that impedance matching plays a determining role in EM wave absorption performance. This work provides a new way for the fabrication of a high-performance metal-based EM wave absorber.

Hierarchical Structure Carbon-Coated CoNi Nanocatalysts Derived from Flower-Like Bimetal MOFs: Enhancing the Hydrogen Storage Performance of MgH2 under Mild Conditions

The construction of transition metal nanocatalysts has become an attractive way to improve the hydrogen storage performance of MgH2. However, it is still a great challenge to obtain multielement transition metal nanocatalysts, improve the hydrogen storage capacity of MgH2 under mild conditions (<573 K), and reduce the apparent activation energy of hydrogen absorption and desorption. In this work, a flower-like CoNi-MOF was successfully synthesized by sacrificing templates. After further pyrolysis, we obtained hierarchical structure flower-like MOF derivatives assembled by CoNi@C nanoparticles with an average particle size of 15.1 nm. Then, MgH2-x wt % CoNi@C nanocomposites are fabricated through the ball milling process. Due to the unique hierarchical flower-like structure of MOF derivatives, the inhibition of an amorphous carbon shell on CoNi alloy growth and agglomeration, and the synergistic catalysis of Mg2Co and Mg2Ni, the MgH2-10 wt % CoNi@C nanocomposite exhibits excellent hydrogen storage capacity under mild conditions and low apparent activation energy: At 473 K, the nanocomposite can quickly absorb 5.0 wt % H2 in 5 min, and even at 373 K, it can still absorb 4.2 wt % H2 in 60 min. At 573 and 548 K, it can release 4.8 and 3.1 wt % H2, respectively. The apparent activation energies for hydrogen absorption and desorption decrease remarkably to 24.9 and 67.3 kJ/mol, respectively, which are significantly better than those for MgH2-10 wt % Co@C (44.7 and 79.8 kJ/mol) and MgH2-10 wt % Ni@C (39.0 and 78.9 kJ/mol) nanocomposites. The first-principles calculation indicated that the hydrogen adsorption energy of the Mg–CoNi model is as low as −5.87 eV. This work provides a new strategy for the design of highly efficient multielement transition metal hydrogen storage material catalysts with a hierarchical structure.

A polydiacetylene-based smart cellulose aerogel functionalized by ZnO/MoS2 heterojunction for simultaneous visual detection and photocatalytic degradation of gaseous VOCs

The integration of visual detection and degradation of volatile organic compounds (VOCs) is greatly desired for addressing ever-growing environmental problems. Herein, a chemically cross-linked cellulose aerogel is explored as substrate material, combing with ZIF-8/MoS2 derived 2D ZnO/MoS2 heterojunction. Then polydiacetylene (PDA) was self-assembled on the aerogel via topochemical polymerization to obtain a smart gas sensing and eliminating hybrid aerogel (PZMCA) with high porosity (>96%). The intrinsic stimulate responsiveness and the flower-like hierarchical structure of PDA contributed to a sensitive and fast color response to gaseous toluene with 10 s. Moreover, by regulating the mass ratio of ZnO and MoS2, the PZMCA presented enhanced photocatalytic ability for toluene (97% of degradation efficiency with 180 min) under solar light irradiation. GC-MS reveals the possible mechanism and pathway of the photocatalytic degradation of toluene. The robust, uniform, versatile and functional aerogels could hopefully provide practical applications in VOCs detection and photocatalytic degradation.

Oxygen vacancy-rich BiOBr microflowers for enhancing photocatalytic reduction of nitrobenzene under visible light

BiOBr has successfully been used as a photocatalyst in the selective oxidations of alcohols and amines into carbonyl compounds, however its utilization in the photocatalytic reduction reactions, especially the transfer hydrogenation of nitrobenzene (NB) to valuable organic products such as aniline, azoxybenzene, and azobenzene has rarely been reported. For the first time, we reveal the feasibility of using oxygen vacancy-rich BiOBr flower-like microsphere (BBr_OV) as a photocatalyst and hydrazine monohydrate as a green hydrogen source for such reaction. The existence of OV is probed by high-resolution transmission electron, electron paramagnetic resonance and X-ray photoelectron studies. The NB reduction activity is boosted from ~29% for pristine BiOBr microplate to ~90% for the BiOBr enriched with oxygen vacancies. Detailed characterizations disclose that the enhanced photocatalytic performance is attributed to synergistic roles of oxygen defective and hierarchical flower-like structure, endowing the BBr_OV with efficient NB adsorption/activation, enlarge surface area, improved optical absorption, and increased charge carrier generation/separation efficiency. This work not only reveals a new application of OV-rich BiOBr in the photocatalytic transfer hydrogenation of nitroarene, but also highlights the promoting catalytic effect derived from rich OV surfaces.

Synthesis of flower-like S-doped SnO2 hierarchical structure for gas sensing application at room temperature

Ammonia is one of the most common gases in life, which is produced in industrial emissions and agricultural activities. Therefore, effective detection of ammonia at low concentrations is vital for human health. Tin disulfide (SnS2) by virtue of its physical affinity and high surface area has become a promising material for gas sensing applications. The flower-like S-doped SnO2 3D hierarchical structure was succeeded in preparation via a two-step method. A variety of methods such as XRD, SEM, and TEM were utilized to characterize the prepared materials for the investigation of their surface morphological characteristics and elemental content. The morphological characterization analysis indicated that the prepared material was a self-assembled hierarchical flower-like SnS2 modified by SnO2 nanoparticles. In addition, the results from the elemental composition analysis showed the existence of Sn, O, and S elements in the material. Through experiments, we further tested the sensitivity, selectivity, and long-term stability of the S-doped SnO2 gas-sensitive material against NH3 at room temperature, and analyzed its sensing mechanism. As a result, the S-doped SnO2 was tested with a response value of 3.6 for 50 ppm ammonia’s outstanding performance in terms of selectivity and long-term stability. This work highlights the advantages of flower-like S-doped SnO2 3D hierarchical structures for NH3 sensors.

Hierarchical flower-like nanostructures of manganese–cobalt–copper nanoneedles for high performance symmetric supercapacitor

Hierarchical flower-like structures of nanoneedles of ternary metal oxides comprising of Manganese–Cobalt–Copper (MCC) are synthesized on nickel foam by a simple hydrothermal technique. The synthesis of MCC is done with varying concentrations of manganese and copper, and the products are studied using X-ray photoelectron spectroscopy, X-ray diffraction, and scanning electron microscopy. Electrochemical studies of MCC electrodes are performed using cyclic voltammetry, galvanostatic charge discharge and electrochemical impedance spectroscopy. Ternary metal oxide electrode demonstrates better electrochemical performance in comparison to mono and bimetallic oxide electrodes, which can be attributed to synergistic effects between the metals. Specific capacitance of 1607 F/g at scan rate 5 mV/s is shown by the best performing MCC electrode. The capacitance retention is 98.33% after 2800 charge-discharge cycles. Symmetric device fabricated by the MCC electrode delivers energy density of 37 W h/kg at a power density of 228 W/kg.

Fabrication of multifunctional WO3.H2O flower-like micro/nanostructures for the oily wastewater treatment

A multifunctional flower-like WO3.H2O coated mesh with superhydrophilic/underwater superoleophobic properties was fabricated for oily wastewater treatment. The XRD and the FESEM analysis demonstrated the orthorhombic phase and flower-like structure of WO3.H2O. The AFM study confirmed the rough surface structure of the mesh. The mesh displayed outstanding superhydrophilic-underwater superoleophobic behavior. The special wettability of flower-like WO3.H2O mesh may be attributed to its intrinsic high surface energy and hierarchical flower-like rough structure. The mesh with the flower-like structure maintained its excellent underwater oil repellency even after many cycles of different mechanical tests. The consistency in underwater superoleophobicity of the flower-like WO3.H2O coated mesh in different pH and saline environments as well as in long-term storage tests demonstrates its excellent chemical and long-term durability. In addition to the separation of oil-water mixtures with lighter and heavier oils, the mesh can also be employed as a primary unit for emulsion separation. Moreover, the flower-like WO3.H2O coated mesh could also remove efficiently the organic contaminant by the synergistic effect of adsorption and photocatalytic activity. These excellent performances enable the mesh to be employed for sustainable oil-water separation in the practical field.

Inside–outside OH– incursion involved in the fabrication of hierarchical nanoflake assembled three-dimensional flower-like α-Co(OH)2 for use in high-performance aqueous symmetric supercapacitor applications

IntroductionThe energy industry has been challenged by the current high population and high energy consumption, forcing the development of effective and efficient supercapacitor devices. The crucial issues until now have been high production cost, deprived cyclic stability, and squat energy density. To resolve these problems, various approaches have been taken, such as the development of long-life electrode materials with high capacity, rapid charging, and slow discharging to overcome poor life cycle stability. ObjectivesIn the present work we focus on fabricating cost-effective unique-morphology, high-surface-area alpha-Co(OH)2 for application in an aqueous-electrolyte symmetric supercapacitor. MethodsIn this study, hierarchical nanoflakes assembled in three-dimensional (3D) flower-shaped cobalt hydroxide (HN-3DF-α-Co(OH)2) electrode were synthesized using the solvothermal method with sodium dodecylbenzene sulfonate (SDBS) and methanol as solvents. Spectroscopic and microscopic techniques were used to characterize fabricated HN-3DF-Co(OH)2, which revealed that the materials electrode exhibited the alpha phase with a hierarchical flower-like structure. A half-cell electrochemical assembly (three-electrode assemble cell) and symmetric full cell (two-electrode assemble cell) were examined in an aqueous electrolyte. ResultsIn three-electrode assembly cells, HN-3DF-α-Co(OH)2 exhibited 719.5 Fg−1 specific capacitance (Csp) at 1 Ag−1 with excellent cyclic retention stability of approximately 88% after 3000 cycles. In two-electrode symmetric supercapacitive systems, HN-3DF-α-Co(OH)2 achieved a maximum Csp of 70.3 Fg−1 at 0.4 Ag−1 with the highest energy density of approximately 6.25 Wh/kg at a power density of 328.94 W/kg. The fabricated two-electrode assembly cell with the HN-3DF-α-Co(OH)2 electrode retained cyclic stability of approximately 85% after 5000 repeated charge and discharge cycles. ConclusionSolvothermally-synthesized, optimized HN-3DF-α-Co(OH)2 showed outstanding electrochemical performance results in three- and two-electrode systems. This unique aqueous symmetric supercapacitor can be used to design cost-effective symmetric capacitors based on metal hydroxide.