Morphology Of Microspheres Research Articles

Lanthanum Cerate Microspheres for Efficient Fluoride Removal from Wastewater.

The performance of lanthanum cerate microspheres (LCM) at removing fluoride was analyzed in batch experiments after they were synthesized via the hydrothermal strategy. The ball-shaped microsphere morphology of LCM is confirmed by SEM and TEM. The synthesized LCM adsorbent showed excellent adsorption capacity in the pH range 3.0-7.0, with the optimal pH range being 3.5-4.5. The Langmuir adsorption model was more appropriate than the Freundlich model for describing the adsorption isotherm. The LCM adsorbent exhibited a significantly higher Langmuir adsorption capacity of 104.83 mg/g at pH 4.0, surpassing that of any other reported adsorbent. We investigated the adsorption of fluoride under a variety of conditions, including the presence of distinct anions. Furthermore, testing the adsorbent in actual groundwater demonstrated its high effectiveness in removing fluoride. Different useful analytical techniques were used for measurements and to learn and deduce the adsorption mechanism.

Rapid fabrication of biomimetic PLGA microsphere incorporated with natural porcine dermal aECM for bone regeneration.

Bioactive microspheres coated with acellular extracellular matrix (aECM) have received extensive attention in bone tissue engineering. In this work, biomimetic microspheres with different aECM ratios, uniform size and controllable size were prepared easily by blending natural porcine dermal aECM and poly (lactic-co-glycolic acid) (PLGA) using electrohydrodynamic spraying and solidification actuated by solvent extraction method. In this work, the appropriate polymer concentration and preparation voltage were investigated, and the surface morphology of the microspheres was observed by scanning electron microscope. Sirius red was used to visualize aECM exposure on the surface of the microspheres. The in vitro and in vivo experiments were carried out to evaluate the bioactivity and osteogenic properties of the microspheres. The results showed that the morphology and size of PLGA microspheres had little influence on the aECM blending. In vitro experiments showed that the higher the content of aECM, the better the cell adhesion performance. In vivo, rat calvarial defect models were observed and characterized at 4 and 8 weeks postoperatively, and the values of BV/TV of 50aECM/PLGA were 47.57 ± 1.14% and 72.92 ± 2.19%, respectively. The results showed that the skull healing effect was better in aECM-containing microspheres. In conclusion, aECM/PLGA composite microspheres can increase cell adhesion performance through the addition of aECM. Moreover, in vivo experiments have proved that aECM/PLGA microspheres are beneficial to bone repair, which means the aECM/PLGA microspheres are a promising bone tissue engineering material.

Size-Dependent Response of Hydrothermally Grown SnO2 for a High-Performance NO2 Sensor and the Impact of Oxygen.

A NO2 sensor with a detection limit down to the ppb level based on pristine SnO2 has been developed through a facile poly(acrylic acid)-mediated hydrothermal method. SnO2 particles of solid microsphere, hollow microsphere, and nanosphere morphologies were synthesized, with respective constitutional crystallite of size ∼2 μm in length and 10-20 nm and ∼7 nm in diameter. All sensors show great selectivity to NO2. The hollow microsphere sensor exhibits the best performance, with medium specific surface area (SSA), followed by the nanosphere sensor with the largest SSA. This is attributed to the superposition of two opposite effects on sensor response with increased SSA: more adsorption sites and fewer electrons to be taken out with overly small crystallite that may reach complete depletion. O2 is found to speed up the response and recovery times but reduce the response because O adsorbates facilitate the adsorption/desorption of NO2 thermodynamically, and the two oxidizing gases compete in harvesting electrons from SnO2. The adverse effect of humidity can be minimized by operating the sensor at 110 °C. The response of the hollow microsphere sensor to 50 ppb of NO2 is 8.8 (Rg/Ra) at room temperature, and it increases to 15.1 at 110 °C. These findings are useful for developing other oxidizing gas semiconductor sensors.

Preparation of rGO/MoSe2 nanocomposites for enhanced microwave absorption of whole X and Ku bands.

rGO-MoSe2 nanocomposites were prepared via a one-pot hydrothermal method in which MoSe2 microspheres (MS) were decorated on rGO sheets. Three nanocomposites named F1, F2, and F3 were prepared using different weight ratios of MoSe2 MS to rGO: (3 : 1), (4 : 1), and (5 : 1), respectively. FESEM images showed a flower-like porous morphology of the MoSe2 microspheres. All the rGO-MoSe2 nanocomposites exhibited remarkable microwave absorption properties as demonstrated by strong reflection loss (-58 dB to -99 dB) and an ultrabroad effective absorption bandwidth (equivalent to 90% attenuation), which covers whole X and Ku frequency bands at matching thicknesses of 2.8-3.2 mm. The minimum reflection loss reached -98, -99, and -75 dB for F1, F2 and F3, respectively. The excellent absorption properties of the rGO-MoSe2 nanocomposites is related to the unique morphology and micro size of MoSe2 in which incident waves are attenuated by multiple reflections and scattering.

Abalone shell-derived Mg-doped mesoporous hydroxyapatite microsphere drug delivery system loaded with icariin for inducing apoptosis of osteosarcoma cells.

Hydroxyapatite (HAP) porous microspheres with very high specific surface area and drug loading capacity, as well as excellent biocompatibility, have been widely used in tumour therapy. Mg2+ is considered to be a key factor in bone regeneration, acting as an active agent to stimulate bone and cartilage formation, and is effective in accelerating cell migration and promoting angiogenesis, which is essential for bone tissue repair, anti-cancer, and anti-infection. In this study, abalone shells from a variety of sources were used as raw materials, and Mg2+-doped abalone shell-derived mesoporous HAP microspheres (Mg-HAP) were prepared by hydrothermal synthesis as Mg2+/ icariin smart dual delivery system (ICA-Mg-HAP, IMHA). With increasing of Mg2+ doping, the surface morphology of HAP microspheres varied from collapsed macroporous to mesoporous to smooth and non-porous, which may be due to Mg2+ substitution or coordination in the HAP lattice. At 30% Mg2+ doping, the Mg-HAP microspheres showed a more homogeneous mesoporous morphology with a high specific surface area (186.06 m2/g). The IMHA microspheres showed high drug loading (7.69%) and encapsulation rate (83.29%), sustained Mg2+ release for more than 27 days, sustained and stable release of icariin for 60 hours, and good responsiveness to pH (pH 6.4 > pH 5.6). In addition, the IMHA delivery system stimulated the rapid proliferation of bone marrow mesenchymal stem cells and induced apoptosis in MG63 cells by blocking the G2 phase cycle of osteosarcoma cells and stimulating the high expression of apoptotic genes (Bcl-2, caspase-3, -8, -9). This suggests that the abalone shell-based IMHA may have potential applications in drug delivery and tumour therapy.

Optical tracking of the heterogeneous solvent diffusion dynamics and swelling kinetics of single polymer microspheres.

The diffusion dynamics of small molecules into polymer entities is crucial for driving their morphology and function, which can be applied to research fields such as optical identification, medical implantation and intelligent sensing platforms. Herein, we demonstrate a nondestructive bright-field imaging strategy to monitor and control the morphology of polymer microspheres by varying the interfacial interaction and diffusion in a penetrant bath. The nanoscale interface movement of single polymer microspheres was tracked and converted into the diameter variation during the swelling event with sub-pixel accuracy, which is consistent with the calculation using Li-Tanaka's kinetic equations. More interestingly, the solvent diffusion dynamics along different directions of one particle are heterogeneous, indicating the non-uniform internal structure of a soft confined assembly. The swelling characteristics of single polymer microspheres can be quantified by this simple imaging strategy, and the transient intermediate swelling states are captured. To model the lifetime and stabilization times of microplastic entities, solvent selectivity and thermodynamic regulation were introduced to obtain the activation energy down to the single micro-entity level. This optical methodology shows capability for decoding the complex diffusion mechanism in polymer entities and provides guidance for the design of drug delivery systems, sensor platforms, and optical responsive materials.

Electron transfer at the heterojunction interface of CoP/MoS2 for efficient electrocatalytic hydrogen evolution reaction.

Modulating the electronic states of electrocatalysts is critical for achieving efficient hydrogen evolution reaction (HER). However, how to develop electrocatalysts with superior electronic states is an urgent challenge that must be addressed. Herein, we prepared the CoP/MoS2 heterojunction with a microsphere morphology consisting of thin nanosheets using a facile two-step method. The catalyst's ultrathin nanosheet structure not only provides an extensive surface area for exposing active sites, but it also enables ion transport and bubble release. Electron transfer occurs between CoP and MoS2, optimizing the heterojunction's charge distribution and enhancing the intermediates' adsorption capabilities. As a result, the CoP/MoS2 heterojunction exhibits outstanding electrocatalytic hydrogen evolution activity with an overpotential of only 88 mV at a current density of 10 mA cm-2, which exceeds both the sulfide heterojunction Co9S8/MoS2 and the phosphide heterojunction CoP/CoMoP2. The experimental results and DFT calculation results show that the former has stronger synergistic effects and higher HER activity. This work sheds light on the exploration of efficient heterojunction electrocatalysts with excellent electronic structures.

Regulating hollow structure of CL-20 microspheres using microjet droplet technology to enhance safety and combustion performance

Hollow energetic microspheres have attracted great attention in the field of materials due to their wide application potential. However, scalable, simple, and low-cost production methods have not been achieved yet. In this study, using nitrocellulose (NC) as a binder, hollow and porous hollow CL-20 microspheres were prepared by the assist of microjet droplet technology. The effects of receiving liquid temperature, solution concentration, and solvent type on the morphology, particle size, shell thickness, and pore size of the CL-20 microspheres were systematically investigated. Furthermore, the influences of shell thickness and pore size on the dispersibility, crystal structure, thermal decomposition, mechanical sensitivity, and combustion behavior of CL-20 microspheres were further studied. The results showed that precise control over the shell thickness and pore size of CL-20 microspheres could be achieved by adjusting the process parameters. Compared to raw CL-20, the CL-20 microspheres exhibited excellent dispersibility and improved thermal and safety performance (raw CL-20 vs CL-20 microspheres, 40.3° vs 27.1° ∼ 29.1°; 240.4℃ vs 241.1 ∼ 246.2℃; 2 J vs 25 ∼ 32.5 J). Ignition experiments demonstrated that the hollow and porous hollow structures significantly enhanced the combustion flame of CL-20, shortened the burning time, and thereby improved energy release efficiency. This preparation method is simple and efficient, providing a new approach for the fabrication of multi-structured hollow energetic microspheres.

A novel synthesis of β-CD@SA@Ag composite hydrogel microspheres with high catalytic activity and environmental adaptability

The composite of hydrogels and noble metal nanoparticles has wide applications in the field of functional materials. In this paper, we developed a novel and green strategy to synthesize a kind of composite hydrogel microspheres containing silver nanoparticles and β-cyclodextrin (β-CD) modified sodium alginate (β-CD@SA@Ag) without use of strong reducing reagent. First, β-CD was chemical linked to SA by epichlorohydrin (ECH) to form the β-CD modified polymer (β-CD@SA). then AgNO3 was added to the as-prepared polymer solution, in which silver nanoparticles were formed by the reducing power of β-CD units. Subsequently, by reversed-phase emulsion method and ionic cross-linking, a kind of β-CD@SA@Ag hydrogel microspheres were obtained. The structure and morphology of the composite material were characterized in detail by Fourier infrared spectroscopy (FT-IR), thermogravimetric analysis (TG), scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). Test data indicated that silver nanoparticles evenly dispersed in the composite material. On the basis, the adsorption and catalytic performances of the β-CD@SA@Ag hydrogel microspheres were studied towards to the reduction of aromatic nitro compounds. Research results showed that the β-CD@SA@Ag hydrogel microspheres had excellent catalytic activity along with high environmental adaptability. whether in pure water, tap water or river water, aromatic nitro compounds can be completely reduced within 2–13 min. Moreover, the morphology of microspheres of the composite material endows the composite material with high stability and reusability. We believe that our work would provide a new idea for the green synthesis of organic-inorganic composite functional materials.

Effect of the Nature and Concentration of the Fuel on the Structure and Morphology of ZnO Microspheres Produced via Spray Solution Combustion Synthesis

Synthesis of ultradisperse spherical ZnO powders was accomplished by spray solution combustion, employing four distinct fuels, namely methenamine, glycine, urea, and citric acid. Using X-ray diffraction analysis, scanning electron microscopy, and low-temperature nitrogen adsorption, the impact of the main process parameters (composition and concentration of fuel, temperature and rate of the carrier gas flow) on the structure and morphology of ZnO particles was demonstrated. A synthesis temperature of 700°C was found to be sufficient to generate crystalline ZnO with a homogeneous phase composition, regardless of the type and amount of fuel. It was shown that the initial pH of the precursor solution does not affect the formation of the ZnO phase. At rates of carrier gas flow above 4 L min–1, the presence of by-products is detected. It has been determined that the excess and type of fuel significantly affect the morphology of the synthesized ZnO microspheres and can be used to control the technological characteristics of the powder and the kinetics of sintering.

Biomass-based controllable morphology of carbon microspheres with multi-layer hollow structure for superior performance in supercapacitors

The electrochemical properties of corn starch (CS)-based hydrothermal carbon microsphere (CMS) electrode materials for supercapacitor are closely related to their structures. Herein, cetyltrimethyl ammonium bromide (CTAB) was used as a soft template to form the corn starch (CS)-based carbon microspheres with radial hollow structure in the inner and middle layers by hydrothermal and sol-gel method. Due to the introduction of multi-layer hollow structure of carbon microsphere, more micropores were produced during CO2 activation, which increased the specific surface area and improved the capacitance performance. Compared to commercial activated carbon, the four different morphologies of corn starch CMS had better electrochemical performances. Consequently, the proposed CO2–(CTAB)-CS-CS exhibits a high discharge specific capacitance of 242.5F/g at 1 A/g in three-electrode system with 6 M KOH electrolyte, better than commercial activated carbon with 208.5F/g. Moreover, excellent stability is achieved for CO2–(CTAB)-CS-CS with approximately 97.14 % retention of the initial specific capacitance value after 10,000 cycles at a current density of 2 A/g, while the commercial activated carbon has 86.96 % retention. This implies that the corn starch-based multilayer hollow CMS could be a promising electrode material for high-performance supercapacitors.

Effect of hydrothermal pH values on the morphology of special microspheres of lignin-based porous carbon and the mechanism of carbon dioxide adsorption

The study reports the economic and sustainable syntheses of a lignin-based porous carbon (LPC) for CO2 capture application. The pH values of hydrothermal solution affected the polymerization and aromatization of spheroidization, with morphological changes from blocky to microsphere. In addition, the reliable mechanisms of CO2 adsorption were proposed by combining experiments with Gaussian16 simulations based on DFT. The electrostatic attraction of oxygen-containing functional groups and the diffusivity resistance of CO2 in the pores are the key factors for the CO2 adsorption. ​The carboxyl groups have the strongest electrostatic attraction to CO2. LPC-pH 1 has the highest carboxyl group content, possessing a CO2 adsorption capacity of up to 5.10 mmol/g at 0℃, 1 bar. Furthermore, CO2 diffusion resistance became a main factor as the adsorption temperature increases. The innovative combination of quantum chemical calculations and microscopic properties provides a viable pathway for an insight into the future control of lignin-based carbon formation.

CO2‐Etching Creates Abundant Closed Pores in Hard Carbon for High‐Plateau‐Capacity Sodium Storage

AbstractHard carbon (HC) has become the most promising anode material for sodium‐ion batteries (SIBs), but its plateau capacity at ≈0.1 V (Na+/Na) is still much lower than that of graphite (372 mAh g−1) in lithium‐ion batteries (LIBs). Herein, a CO2‐etching strategy is applied to generate abundant closed pores in starch‐derived hard carbon that effectively enhances Na+ plateau storage. During CO2 etching, open pores are first formed on the carbon matrix, which are in situ reorganized to closed pores through high‐temperature carbonization. This CO2‐assisted pore‐regulation strategy increases the diameter and the capacity of closed pores in HC, and simultaneously maintains the microsphere morphology (10–30 µm in diameter). The optimal HC anode exhibits a Na‐storage capacity of 487.6 mAh g−1 with a high initial Coulomb efficiency of 90.56%. A record‐high plateau capacity of 351 mAh g−1 is achieved, owing to the abundant closed micropores generated by CO2‐etching. Comprehensive in situ and ex situ tests unravel that the high Na+ storage performance originates from the pore‐filling mechanism in the closed micropores.

Statistical 3D morphology characterization of vaterite microspheres produced by engineered Escherichia coli

Hollow vaterite microspheres are important materials for biomedical applications such as drug delivery and regenerative medicine owing to their biocompatibility, high specific surface area, and ability to encapsulate a large number of bioactive molecules and compounds. We demonstrated that hollow vaterite microspheres are produced by an Escherichia coli strain engineered with a urease gene cluster from the ureolytic bacteria Sporosarcina pasteurii in the presence of bovine serum albumin. We characterized the 3D nanoscale morphology of five biogenic hollow vaterite microspheres using 3D high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) tomography. Using automated high-throughput HAADF-STEM imaging across several sample tilt orientations, we show that the microspheres evolved from a smaller more ellipsoidal shape to a larger more spherical shape while the internal hollow core increased in size and remained relatively spherical, indicating that the microspheres produced by this engineered strain likely do not contain the bacteria. The statistical 3D morphology information demonstrates the potential for using biogenic calcium carbonate mineralization to produce hollow vaterite microspheres with controlled morphologies. Statement of significanceThe nanoscale 3D structures of biomaterials determine their physical, chemical, and biological properties, however significant efforts are required to obtain a statistical understanding of the internal 3D morphology of materials without damaging the structures. In this study, we developed a non-destructive, automated technique that allows us to understand the nanoscale 3D morphology of many unique hollow vaterite microspheres beyond the spectroscopy methods that lack local information and microscopy methods that cannot interrogate the full 3D structure. The method allowed us to quantitatively correlate the external diameters and aspect ratios of vaterite microspheres with their hollow internal structures at the nanoscale. This work demonstrates the opportunity to use automated transmission electron microscopy to characterize nanoscale 3D morphologies of many biomaterials and validate the chemical and biological functionality of these materials.

Preparation of drug-loaded microspheres with a core-shell structure using silk fibroin and poly lactic-co-glycolic acid and theirapplication.

Advances in bone tissue engineering offer novel options for the regeneration of bone tissue. In the current clinical treatment, the method of accelerating bone tissue regeneration rate by promoting early angiogenesis has been widely accepted. This study aimed to develop a long-acting slow-release system using the pro-angiogenic drug tetramethylpyrazine (TMPZ) and pro-osteogenic drug icariin (ICA), which can be administered locally to achieve the sequential release of TMPZ and ICA for better clinically efficiency in the treatment of bone defects. This study aimed to prepare microspheres with a core-shell structure using two polymers, poly lactic-co-glycolic acid and silk fibroin, by coaxial electrostatic spraying. Based on the therapeutic model for bone defects, the pro-angiogenic drug TMPZ and pro-osteogenic drug ICA were encapsulated in the shell and core layers of the microspheres, respectively. Subsequently, TMPZ and ICA were released sequentially to promote early angiogenesis and late osteogenesis, respectively, at the site of the bone defect. The optimal preparation parameters for preparing the drug-loaded microspheres were identified using the univariate controlled variable method. Additionally, microsphere morphology and core-shell structure, such as physical properties, drug-loading properties, invitro degradation and drug release patterns, were characterised using scanning electron microscope and laser scanning confocal microscopy. The microspheres prepared in this study were well-defined and had a core-shell structure. The hydrophilicity of the drug-loaded microspheres changed compared to the no-load microspheres. Furthermore, invitro results indicated that the drug-loaded microspheres with high encapsulation and loading efficiencies exhibited good biodegradability and cytocompatibility, slowly releasing the drug for up to three months. The development of the drug delivery system with a dual-step release mechanism has potential clinical applications and implications in the treatment of bone defects.

Stable multi-electron reaction stimulated by W doping VS4 for enhancing magnesium storage performance

Rechargeable magnesium batteries (RMBs) hold promise for offering higher volumetric energy density and safety features, attracting increasing research interest as the next post lithium-ion batteries. Developing high performance cathode material by inducing multi-electron reaction process as well as maintaining structural stability is the key to the development and application of RMBs. Herein, multi-electron reaction occurred in VS4 by simple W doping strategy. W doping induces valence of partial V as V2+ and V3+ in VS4 structure, and then stimulates electrochemical reaction involving multi-electrons in 0.5% W-V-S. The flower-like microsphere morphology as well as rich S vacancies is also modulated by W doping to neutralize structure change in such multi-electron reaction process. The fabricated 0.5% W-V-S delivers higher specific capacity (149.3 mA h g−1 at 50 mA g−1, which is 1.6 times higher than that of VS4), superior rate capability (76 mA h g−1 at 1000 mA g−1), and stable cycling performance (1500 cycles with capacity retention ratio of 93.8%). Besides that, pesudocapaticance-like contribution analysis as well as galvanostatic intermittent titration technique (GITT) further confirms the enhanced Mg2+ storage kinetics during such multi-electron involved electrochemical reaction process. Such discovery provides new insights into the designing of multi-electron reaction process in cathode as well as neutralizing structural change during such reaction for realizing superior electrochemical performance in energy storage devices.

Crystallization-driven formation poly (l-lactic acid)/poly (d-lactic acid)-polyethylene glycol-poly (l-lactic acid) small-sized microsphere structures by solvent-induced self-assembly

Improving hydrophobicity through the regulation of surface microstructures has attracted significant interest in various applications. This research successfully prepared a surface with microsphere structures using the Non-solvent induced phase separation method (NIPS). Poly(D-Lactic acid)-block-poly(ethylene glycol)-block-poly(D-Lactic acid) (PDLA-PEG-PDLA) block polymers were synthesized by ring-opening polymerization of D-Lactic acid (D-LA) using polyethylene glycol (PEG) as initiator. PLLA/PDLA-PEG-PDLA membrane with microscale microsphere morphology was fabricated using a nonsolvent-induced self-assembly method by blending the triblock copolymer with a poly(L-lactic acid) (PLLA) solution. In phase separation processes, the amphiphilic block copolymers self-assemble into micellar structures to minimize the Gibbs free energy, and the hydrophilic segments (PEG) aggregate to form the core of the micelles, while the hydrophobic segments (PDLA) are exposed on the outer corona resulting in a core-shell structure. The Stereocomplex Crystalline (SC), formed by the hydrogen bonding between PLLA and PDLA, can facilitate the transition from liquid-liquid phase separation to solid-liquid phase separation, and the PEG chain segments can enhance the formation of SC. The membrane, prepared by adjusting the copolymer content and PEG chain length, exhibited adjustable microsphere quantity, diameter, and surface roughness, enabling excellent hydrophobicity and controlled release of oil-soluble substances.

Measurement of micropore by resonant probe with microsphere

A micro–nano coordinate measuring machine (CMM) is an instrument for high-precision measurement of micro-precision parts. The top of its probe is a microsphere with a diameter of tens to hundreds of micrometres. When the probe microsphere touches the part for measurement, its accuracy is affected by the surface morphology of the microsphere. A tuning fork resonant probe used for micro–nano CMMs is used to measure the contour of the micropore in automotive fuel injection nozzles in this study. Combined with the self-made optical fiber microsphere cross-sectional circle parameters at the top of the tuning fork probe, precise measurement of micropore diameter and roundness is achieved. During the experiment, the microsphere and micropore were measured by two independent systems, and thus, the error caused by the initial measurement angle of the microsphere and micropore is evaluated. The experimental results indicate that the measured micropore diameter is 194.542 µm and the roundness is 2.551 µm. The error caused by the initial measurement angle evaluated by the cubic Hermitian interpolation method can be ignored relative to the measurement results. The micropore structure parameters are precisely measured by the resonant probe combined with the morphology information of its top microsphere in this study, providing a research method for improving the measurement accuracy of micro–nano CMMs by combining microsphere morphology features.

Cornstalk hydrochar produced by phosphoric acid-assisted hydrothermal carbonization for effective adsorption and photodegradation of norfloxacin

Hydrochars have been widely applied in removing pollutants from aqueous solutions. In this study, hydrochars synthesized by H3PO4-assisted hydrothermal carbonization (HC-xPs) were used to remove norfloxacin (NOR) from water through synergistic adsorption and photodegradation. HC-xPs showed the morphology of carbon microspheres with an average diameter of 0.3 μm. The specific surface area of the hydrochar carbonized with 5 mol/L H3PO4 (HC-5P) was 11.2 times higher than that of the pristine hydrochar (HC). Furthermore, phosphorus-containing functional groups were introduced to HC-5P, beneficial to its adsorption of NOR. The highest NOR adsorption was achieved on HC-5P with the maximum Langmuir capacity of 69.1 mg g−1, owing to multiple mechanisms including electrostatic effects, π-π interactions, hydrophobic interactions, and hydrogen bonding. Compared with HC, HC-5P also demonstrated increased visible light absorption capacity. The first-order rate constant of HC-5P on combined adsorption and photodegradation of NOR was 12.0 times of HC. The photodegradation intermediates were identified by HPLC-MS to understand NOR degradation pathways. This work can be extended to the preparation of low-cost and highly efficient hydrochars for adsorption and photodegradation of pollutants in water.

CoSe2@ZnS microsphere arrays with remarkable electrochemical performance for hybrid asymmetric supercapacitor

This study presents a simple hydrothermal synthesis method for preparing CoSe2, ZnS, and their nanohybrid combinations (ZnS-70 % CoSe2 and ZnS-50 % CoSe2, referred to as ZC-1 and ZC-2) for the first time. These materials are intended for application in a supercapacitor (SC) and are synthesized through an ex-situ wet-chemical approach. The research thoroughly examines the electrochemical properties of as-prepared electrodes and how they relate to their structure and morphology to understand their charge storage mechanism better. The detailed characterization reveals that a one-step hydrothermal reaction obtains the cubic crystal structure of the ZnS with microsphere morphology, and the CoSe2 presents a snow crystals-like morphology with a highly smooth and transparent surface appearance. The systematic electrochemical examination declares the typical pseudocapacitive charge storage response owing to fast Faradaic redox reactions with good reversibility and rate capability. Notably, a high capacitance of CoSe2-ZnS nanohybrid (denoted as ZC-2) is realized by the synergistic effect between ZnS and CoSe2 supported by the impedance, cyclic voltammetry, and charge/discharge studies. High specific energy with a power of 46.71 Wh/kg (899.21 W/kg) and 9 Wh/kg (5400 W/kg) is realized by adding an optimal voltage and capacitance simultaneously by fabricating a hybrid asymmetric HASCs (ZC-2||AC HASC) in aqueous solution. This study believes that metal sulfide and selenide-based nanohybrids can be effective candidates for competing in the growing electrochemical energy storage demand.