Oxide Hydroxide Research Articles

A simple one-step method to synthesise CuO films having different morphologies for flexible supercapacitor electrodes

ABSTRACT Copper oxide (CuO) films with a thickness of about 1.5 μm having three different morphologies (nanoplate, nanoflake and nanowire) were synthesised by a simple and fast chemical method. Scanning electron microscopy, X-ray diffraction and electrochemical methods were used to analyse the morphology, determine the crystal structure and characterise the electrochemical performance. CuO with a nanowire structure exhibited the best performance. The specific capacitance was as high as 147 F g−1 at a specific current of 0.6 A g−1, while the capacitance remained at 74.4% after 5000 charge/discharge cycles, showing good stability. The simple synthesis described has a low energy consumption and could be used in the fabrication of other metal oxide and flexible hydroxide electrodes.

Fagus orientalis Yüzeyinin ZnO/TiO2/FAS-17 Bazlı Nanopartiküllerle İşlenmesi

Aim of study: In this research, the surface of Fagus orientalis (beechwood) was chosen as a substrate due to its widely used strong biostructure in the wood industry. It was functionalized with ZnO, TiO2, and FAS-17 nanoparticles to enhance its service life.
 Material and methods: FAS-17 (Trimethoxysilane) and ammonium hexafluorotitanate were purchased from Sigma-Aldrich, and zinc borate from Etimine S.A. Methanol, ethyl alcohol, hydrochloric acid, sodium hydroxide, and zinc oxide were provided by TEKKIM. Characterization methods included FTIR, TG/DTA, XRD, SEM, and EDX. Hydrophobicity was determined by water contact angle using KSV Cam101. UV-Vis analysis used a Shimadzu UV-160 spectrophotometer, surface roughness was measured with a Marsurf M 300 device (ISO 4287), and color analysis was performed with a Datacolor Elrepho 450 X spectrometer (ASTM 2021).
 Main results: The thermal stability of wood was significantly improved through the hydrothermal deposition of ZnO/TiO2 nanoparticles. Additionally, hydrophobization was achieved using Triethoxy-1H,1H,1H,2H,2H,2H-perfluorodecylsilane (C14H19F13O3Si), referred to as FAS-17.
 Research highlights: The study demonstrated that the introduction of ZnO/TiO2 nanoparticles improved the thermal stability of wood. Furthermore, the use of FAS-17 resulted in effective hydrophobization. The thermal stability of wood was improved with ZnO/TiO2 nanoparticles. In addition, hydrophobization was supplied by FAS-17.

Iron-doped carbon nanotubes with magnetic enhanced Fe(VI) degradation of arsanilic acid and inorganic arsenic: Role of intermediate iron species and electron transfer

Arsanilic acid (p-AsA), a prevalently used feed additive, is frequently detected in environment posing a great threat to humans. Potassium ferrate (Fe(VI)) was an efficient way to tackle arsenic contamination under acid and neutral conditions. However, Fe(VI) showed a noneffective removal of p-AsA under alkaline conditions due to its oxidation capacity attenuation. Herein, a magnetic iron-doped carbon nanotubes (F-CNT) was successfully prepared and further catalyzed Fe(VI) to remove p-AsA and total As species. The Fe(VI)/F-CNT system showed an excellent capability to oxidize p-AsA and adsorb total As species over an environment-related pH range of 6–9. The high-valent iron intermediates Fe(V)/Fe(IV) and the mediated electron-transfer played a significant part in the degradation of p-AsA according to the probes/scavengers experiments and galvanic oxidation process. Moreover, the situ formed iron hydroxide oxide and F-CNT significantly improved the adsorption capacity for total As species. The electron-donating groups (semiquinone and hydroquinone) and high graphitization of F-CNT were responsible for activating Fe(VI) based on the analysis of X-ray photoelectron spectroscopy (XPS). Density functional theory calculations and the detected degradation products both indicated that the amino group and the C–As bond of p-AsA were main reactive sites. Notably, Fe(VI)/F-CNT system was resistant to the interference from Cl−, SO42−, and HCO3−, and could effectively remove p-AsA and total As species even in the presence of complex water matrix. In summary, this work proposed an efficient method to use Fe(VI) for degrading pollutants under alkaline conditions and explore a new technology for livestock wastewater advanced treatment.

Ensemble meta machine learning for predicting the adsorption of anionic and cationic dyes from aqueous solutions using Polymer/graphene/clay/MgFeAl-LTH nanocomposite

Adsorption is one of the most promising wastewater treatment methods due to its simplicity and efficacy at ambient temperature and pressure. However, the technical and economic feasibility of this process largely depends on the performance of the utilized adsorbents. In this study, a promising adsorbent made of polyethyleneimine, graphene oxide (GO), bentonite, and MgFeAl-layered triple hydroxide (MgFeAl-LTH) has been synthesized and characterized. The results revealed that the synthesized nanocomposite (abbreviated as PGB-LTH) possesses good porosity and crystallinity. The adsorption performance of the PGB-LTH nanocomposite towards two harmful water pollutants (i.e., methyl orange (MO) and crystal violet (CV)) was investigated, and the results revealed that the nanocomposite outperforms its parental materials (i.e., GO, bentonite, and MgFeAl-LTH). The maximum adsorption capacity (qmax) of MO and CV onto the nanocomposite could reach 1666.7 and 1250.0 mg/g, respectively, as predicted using the Langmuir adsorption isotherm. Additionally, the PGB-LTH nanocomposite is highly reusable with an insignificant decline in performance upon repetitive use. In terms of thermodynamics, MO adsorption onto the nanocomposite is exothermic while CV adsorption is endothermic despite that both dyes adsorb spontaneously as revealed by the negative values of the Gibbs free energy change at all the examined temperatures. The generated adsorption data were utilized for constructing and assessing ensemble meta-machine learning techniques aimed at cost-effective simulation and prediction of the proposed adsorption method. Bagging and boosting methods were developed and evaluated intensively using the obtained adsorption data. The Extra Trees model achieved promising results as evidenced by the high correlation coefficient of 99% as well as low computed RMSE and MAE errors of 11.42 and 5.11, respectively, during the testing phase. These results demonstrate the model strong capability to effectively simulate and predict the adsorption process in question.

Injectable Microparticle-containing hydrogel with controlled release of bioactive molecules for facial rejuvenation

The skin is the largest organ and a crucial barrier for protection against various intrinsic and extrinsic factors. As we age, the skin's components become more vulnerable to damage, forming wrinkles. Among different procedures, hyaluronic acid-based hydrogel has been extensively utilized for skin regeneration and reducing wrinkles. However, it has limitations like low retention and weak mechanical properties. In this study, we suggested the poly(l-lactic acid) (PLLA) microparticles containing alkaline magnesium hydroxide and nitric oxide-generating zinc oxide and rejuvenative hyaluronic acid (HA) hydrogels including these functional microparticles and asiaticoside, creating a novel delivery system for skin rejuvenation and regeneration. The fabricated rejuvenative hydrogels have exhibited enhanced biocompatibility, pH neutralization, reactive oxygen species scavenging, collagen biosynthesis, and angiogenesis capabilities in vitro and in vivo. Additionally, an excellent volume retention ability was demonstrated due to the numerous hydrogen bonds that formed between hyaluronic acid and asiaticoside. Overall, our advanced injectable hydrogel containing functional microparticles, with controlled release of bioactive molecules, has a significant potential for enhancing the regeneration and rejuvenation of the skin.

Features of obtaining a vacuum-dense weakly conductive ceramics based on barium aluminate

Ceramics based on barium aluminate with additives of iron (III) oxide and lithium hydroxide were obtained by solid-phase synthesis. It has been established that high-temperature treatment in an oxidizing medium contributes to the production of vacuum-dense samples that meet the «absolutely impermeable» tightness criterion, with a density of 3,75 g/cm3 , with a compressive strength limit of 597,1 MPa and a specific electrical conductivity in the range of 1,50·10‒7‒1,05·10‒4 Cm/ cm (at 90‒300 °C).

Immunogenicity of different nanoparticle adjuvants containing recombinant RBD coronavirus antigen in animal model.

Ongoing mutations of SARS-CoV-2 present challenges for vaccine development, promising renewed global efforts to create more effective vaccines against coronavirus disease (COVID-19). One approach is to target highly immunogenic viral proteins, such as the spike receptor binding domain (RBD), which can stimulate the production of potent neutralizing antibodies. This study aimed to design and test a subunit vaccine candidate based on the RBD. Bioinformatics analysis identified antigenic regions of the RBD for recombinant protein design. In silico analysis identified the RBD region as a feasible target for designing a recombinant vaccine. Bioinformatics tools predicted the stability and antigenicity of epitopes, and a 3D model of the RBD-angiotensin-converting enzyme 2 complex was constructed using molecular docking and codon optimization. The resulting construct was cloned into the pET-28a (+) vector and successfully expressed in Escherichia coli BL21DE3. As evidenced by sodium dodecyl-polyacrylamide gel electrophoresis and Western blotting analyses, the affinity purification of RBD antigens produced high-quality products. Mice were immunized with the RBD antigen alone or combined with aluminum hydroxide (AlOH), calcium phosphate (CaP), or zinc oxide (ZnO) nanoparticles (NPs) as adjuvants. Enzyme-linked immunosorbent assay assays were used to evaluate immune responses in mice. In-silico analysis confirmed the stability and antigenicity of the designed protein structure. RBD with CaP NPs generated the highest immunoglobulin G titer compared to AlOH and ZnO after three doses, indicating its effectiveness as a vaccine platform. In conclusion, the recombinant RBD antigen administered with CaP adjuvant NPs induces potent humoral immunity in mice, supporting further vaccine development. These results contribute to ongoing efforts to develop more effective COVID-19 vaccines.

Chitosan-coated magnetic nanorods and nanospheres: physicochemical characterizations and potential as methotrexate carriers for targeted drug delivery

Abstract Spherical magnetite nanoparticles were employed in the almost all magnetic based drug delivery studies. But as we all know the shape of employed particles is one of the major deterministic properties that can significantly affect the physicochemical and biological features of nanostructures and so can fluctuate efficiency of drug delivery. However, it is worthy of consideration that so far no study has investigated the effect of the shape of nanoparticles in drug delivery. To some extent this deficiency in publications may be due to the fact that the synthesis of other forms of magnetite nanoparticles is not as developed as spherical nanoparticles. But recent experiments paved the way for the synthesis of magnetite nanoparticles specially magnetite nanorods (MNRs). So, for the first time, in the current experiment magnetite nanospheres (MNSs) and MNRs were compared in the potential for drug delivery. Chitosan is a natural and biocompatible compound that widely employed as coating material for the fabrication of anticancer drug nano-carriers. So in the present study this carbohydrate was chosen as coating material for the magnetic nanostructures. MNSs were synthesized via a co-precipitation reaction, and MNRs were obtained from the chemical reduction of iron oxide hydroxide (FeOOH) nanorods. Both nanostructures were loaded with methotrexate (MTX), and the release of the drug was measured. The chitosan-coated MNSs (C@MNSs) were 7–18 nm in diameter, and the chitosan-coated MNRs (C@MNRs) were 5–21 nm in width and 29–108 nm in length and had a porous structure. The C@MNSs had a magnetic saturation of ∼80 emu/g, whereas that for the C@MNRs was ∼45 emu/g. The synthesized nanostructures exhibited low toxicity and were able to release the drug inside the cells. The findings of this study demonstrate the suitability of C@MNRs as an alternative to spherical nano-carriers for the efficient and contained delivery of anticancer drugs to designated target cells.

Application of FeOOH nanorods as a heterogeneous Fenton catalyst: The Matter of aspect ratio

Due to the growing global population and shift towards industrialized societies, water pollution and the management of wastewater are becoming significant issues. Hence, there is a need for innovative approaches to remove contaminants from effluent streams to protect the environment and human health. The Fenton's reaction is an established method for wastewater treatment, and iron oxide hydroxide (FeOOH) nanorods have immense potential as heterogeneous Fenton catalysts. The catalytic potency of nanorods is determined by their morphology, especially their length. Therefore, this study aimed to synthesize FeOOH nanorods of different mean lengths (49–101 nm) and evaluate their catalytic activity in a Fenton's reaction. Nanorods with an average length of 78 nm had the highest catalytic activity, and 87% of methyl orange was degraded over the reaction. The greater catalytic activity of these nanorods can be attributed to their larger surface area compared to the other investigated sizes. FeOOH nanorods have a porous structure; thus, their surface area is not directly related to their particle size. These outcomes indicate that the porosity and surface area play a significant role in determining the performance of heterogeneous catalysts and, as a result, must be considered to develop efficient catalysts for environmental remediation.

Recycling of NdFeB magnets: Model supported iron minimization via in-situ hydrolysis during leaching and hematite precipitation in an autoclave

The NdFeB magnets are a significant component of technological applications, which contain a remarkable quantity of rare earth elements (REEs). For this reason, the recycling of NdFeB magnets is essential for the reuse of these elements. This research represents the recycling strategy of NdFeB magnets, which consists of iron minimization through in-situ hydrolysis during oxidative leaching and hematite precipitation in an autoclave. The influence of the experimental parameters in the hydrolysis of Fe3+ in a nitric acid medium on the formation of a mixture of iron oxide hydroxide was examined in detail. Afterward, the effect of the temperature, time and, water addition on the iron and REEs precipitation in the autoclave was investigated by the ANOVA analysis based on the Box-Behnken design. According to the particle swarm optimization algorithm, maximum REEs extraction and minimum iron extraction were achieved in a solution of 1.82 mol/L nitric acid, at a solid/liquid ratio of 11/100, a temperature of 60 °C, and a stirring speed of 415 rpm. The mean leaching efficiencies of REEs and iron are calculated to be 76% and 7%, respectively. The optimal parameters for hematite precipitation in the autoclave were determined to be a process temperature of approximately 137 °C, a processing time of approximately 3 h and 55 min, and a water addition of approximately 20%. The optimum parameters are in harmony with the validation experiments.

Preparation of chromium oxide by hydrothermal reduction of sodium chromate aqueous solution with hydrogen and application to chromite ore processing

Chromium oxide (Cr2O3) has wide application in various industries. Its traditional production process, uses sodium carbonate (Na2CO3), which is converted into cheaper byproducts, including sodium sulfate (Na2SO4) and sodium bisulfate (NaHSO4). These byproducts contain hexavalent chromium (Cr(VI)), which can lead to serious environmental pollution. In this work, a cleaner production process for Cr2O3 through the hydrothermal reduction of a sodium chromate (Na2CrO4) aqueous solution with hydrogen (H2) was studied. Nearly single-phase chromium oxide hydroxide (CrOOH) formed as a solid product after the hydrothermal reduction. Then, Cr2O3 was obtained by the thermal decomposition of CrOOH. The advantages of the new process are remarkable. First, the raw material, the Na2CrO4 aqueous solution, was the direct intermediate product in the pressure oxidative leaching of chromite ore with sodium hydroxide (NaOH). Second, the reduction efficiency of Cr(VI) increased up to 97.6%, and the total yield of chromium from Na2CrO4 to Cr2O3 was as high as 94.2%. Finally, 96.6% of sodium could be converted into NaOH, so the aqueous solution in the hydrothermal hydrogen reduction process could be recycled as the leaching agent for the pressure oxidative leaching process of chromite ore. Consequently, a complete cleaner and shorter preparation route from chromite ore to Cr2O3 was achieved by integrating three processes: the pressure oxidative leaching of chromite ore, the hydrothermal reduction of the Na2CrO4 aqueous solution, and the thermal decomposition of CrOOH. The new method achieves the high-efficiency use of chromium resources, cyclic utilization of material, and extremely low environmental pollution of Cr(VI), and well exemplifies the principle of the 3Rs (Reduce, Recycle, Reuse).

Description and evolutionary biogeography of the first Miocene jumping spider (Aranaea: Salticidae) from a southern continent

Abstract Examination of a fossil from a Miocene Konservat-Lagerstätte (c. 11–16 Mya) from Australia shows it to be an astioid jumping spider that is here described as Simaetha sp. indet. Fossilization in the iron oxide–hydroxide mineral goethite led to a high-fidelity preservation of not only the exterior, but of the pharyngeal plate and a neuropile in the cephalothorax. The discovery of the fossil supports the molecular-based hypothesis that the Late Oligocene/Early Miocene radiation of astioid genera occurred in Australasia. Modern Asian genera then would be the result of northward migrations from Australia rather than a movement in the other direction. Biogeographically, the Miocene Simaetha fits within the predicted bioclimatic distribution of the genus today, though the bioclimatic requirements of the fossil species are now found in eastern Queensland rather than in central New South Wales. Simaetha, it seems has retained its original bioclimatic profile for 15 Myr, even though climatic and ecological conditions in Australia have changed significantly. The fossil record now shows the independent evolution of modern genera during the Early Miocene in at least five different salticid lineages on two continents. These salticid radiations occurred at a time of planet-wide, rapid climatic and ecological change.

The effect of Zr(IV) addition on the phosphate removal properties of MgAl-LDH

Recovery of phosphate from wastewater represents a sustainable alternative to phosphate rock, a limited resource. Magnesium aluminum layered double hydroxides (MgAl-LDH), are promising sorbents due to their high phosphate removal capacity by anion-exchange (26–124 mgP/g). Furthermore, an increased sorption capacity has been reported by the addition of zirconium (Zr(IV)) into the LDH lattice. However, ambiguity exists especially in relation to the incorporation of Zr and the stability of the MgAl-LDH. To understand how Zr(IV)-addition affects the phosphate sorption properties (both capacity and mechanism) on the atomic level, solid state multi-nuclear NMR spectroscopy was combined with complimentary characterization techniques to study a series of MgAl-LDH with Zr to Al ratios of 1:9 and 1:1, which had the Mg to (Al + Zr) ratio fixed at 2:1. The LDH were synthesized by coprecipitation and subsequently aged or hydrothermally treated to improve the crystallinity (particle size). No evidence of Zr(IV) incorporation in the LDH was observed, instead Zr was present as Zr(IV)-hydroxide (X-ray amorphous) and crystalline Zr(IV) oxide after aging and hydrothermal treatment, respectively. The segregation of Zr(IV) and resulting lower Al content in the MgAl-LDH decreased the phosphate sorption capacity from 45 to 54 to 16–20 mgP/g. Zr (hydr)oxide impurities removed <3 mgP/g. Moreover, 31P MAS NMR spectroscopy quantified that the MgAl-LDH contributed to <62% of the total P removal capacity.

BGzEro – backfilling measures with low CO2 footprint

Abstract. In Germany, the Federal Company for Radioactive Waste Disposal (BGE) is responsible for the construction and operation of deep, geological repositories. BGE operates the Asse II mine and the Konrad and Morsleben repositories. Initially, these mines were excavated to extract raw materials. As a result, they have large void volumes on multiple levels. The stability of the unfilled cavities is limited in time so that backfilling measures are required for stabilisation. However, there are many requirements to consider when selecting backfill materials. BGE aims at making its locations climate neutral. Backfilling measures are particularly affected by this effort because of the large material volumes required and the greenhouse gas emissions that are released during material transport and during the entire material production chain. Bulk materials that are produced from the rock debris from the excavation of the respective mine have the smallest carbon dioxide (CO2) footprint. In order to use this rock debris, this material will be stored in underground excavations and large voids. In order to backfill the underground cavities in accordance with the requirements, the debris will be crushed in an underground crushing plant prior to backfilling. However, numerous cavities in the three mines mentioned above can only be backfilled with flowable, self-levelling and self-hardening materials. Generally, cement-based backfill materials and magnesia binders can be distinguished. The CO2 footprint of mixtures with cement increases primarily with the proportion of Portland cement clinker. For this purpose, recipes containing high proportions of supplementary cementitious materials such as pozzolan and latent hydraulic additives have been developed. Magnesia binders contain the binders magnesium oxide and/or magnesium hydroxide. Depending on the raw materials and the manufacturing process, different amounts of greenhouse gases are generated during their production. The classic approach is to use magnesium oxide, which is obtained by calcining magnesite (MgCO3). However, a lot of energy is required for this process, and the carbon dioxide content of the magnesite is released. Due to the extensive experience in the development of backfill materials and emplacement technologies, BGE has entrusted BGE TECHNOLOGY GmbH with the optimisation of the procedures for backfilling and the development of new backfill materials with the lowest possible CO2 footprint. Thus, raw materials and supply chains have been evaluated and are improved with regard to their environmental performance, taking into account all aspects of transport and logistics. The current focus of work is on the development of magnesia binders with natural brucite (magnesium hydroxide). Another positive aspect is the reduction of heat development of the backfill material during hardening. Furthermore, the reliability of supply for the implementation of the backfilling measures can be increased by a market analysis. The examples show that BGE and BGE TECHNOLOGY GmbH are on the right track to protect humans and the environment through the safe disposal of radionuclides and the realisation of sustainable, future-oriented technologies.

Fe-doping and oxygen vacancy achieved by electrochemical activation and precipitation/dissolution equilibrium in NiOOH for oxygen evolution reaction

The poor conductivities and instabilities of accessible nickel oxyhydroxides hinder their use as oxygen evolution reaction (OER) electrocatalysts. Herein, we constructed Fe-NiOOH-OV-600, an Fe-doped nickel oxide hydroxide with abundant oxygen vacancies supported on nickel foam (NF), using a hydrothermal method and an electrochemical activation strategy involving 600 cycles of cyclic voltammetry, assisted by the precipitation/dissolution equilibrium of ferrous sulfide (FeS) in the electrolyte. This two-step method endows the catalyst with abundant Fe-containing active sites while maintaining the ordered structure of nickel oxide hydroxide (NiOOH). Characterization and density functional theory (DFT) calculations revealed that synergy between trace amounts of the Fe dopant and the oxygen vacancies not only promotes the generation of reconstructed active layers but also optimizes the electronic structure and adsorption capacity of the active sites. Consequently, the as-prepared Fe-NiOOH-OV-600 delivered large current densities of 100 and 1000 mA cm−2 for the OER at overpotentials of only 253 and 333 mV in 1 mol/L KOH. Moreover, the catalyst is stable for at least 100 h at 500 mA cm−2. This work provides insight into the design of efficient transition-metal-based electrocatalysts for the OER.

Adsorption Removal of Phosphate from Rural Domestic Sewage by Ca-Modified Biochar Derived from Waste Eggshell and Sawdust

In recent years, in order to improve the rural living environment, rural domestic sewage treatment has received more and more attention in China. However, the standard compliance rate of total phosphorus (TP) in rural domestic sewage after treatment is very low, and TP has become the main pollutant that prevents rural domestic sewage treatment facilities from meeting water pollutants discharge standards. In this study, to prepare calcium-modified biochar composites (E-BC) by one-step pyrolysis, waste eggshell (E) was employed as a calcium source and waste pine sawdust (BC) was employed as a carbon source. The E-BC composites produced were effective in adsorbing phosphate (P) from aqueous solutions in a broad pH range of 3–11, with good adsorption selectivity. E-BC’s adsorption capacity for P increased as the pyrolysis temperature increased from 700 °C to 900 °C, which was attributed to the higher specific surface area and calcium oxide content at higher pyrolysis temperatures. The E-BC sample, which was made from eggshell (filtered through 100 mesh sieves) and pine sawdust (filtered through 100 mesh sieves) with a mass ratio of 2:1 and a pyrolysis temperature of 900 °C, had a maximum adsorption capacity of 301 mg/g. The Langmuir model and pseudo second-order model were the best at describing the adsorption process, and the predominant sorption mechanism for P is the chemisorption reaction of calcium oxide or calcium hydroxide with phosphate to create hydroxyapatite. E-BC can effectively remove P from rural domestic sewage. The total phosphorus (TP) removal rate in rural domestic sewage ranges from 95.3 to 99.5%. After adsorption treatment, the discharge of TP in rural sewage meets the second-grade (TP &lt; 3 mg/L) or even the first-grade (TP &lt; 2 mg/L). This study provides an experimental basis for efficient P removal using E-BC adsorbent materials and suggests possible applications in rural domestic sewage.

Removal of Phosphorus from Domestic Sewage in Rural Areas Using Oyster Shell-Modified Agricultural Waste–Rice Husk Biochar

In order to promote the improvement of rural living environments, the treatment of rural domestic sewage has attracted much attention in China. Meanwhile, the rural regions’ sewage discharge standards are becoming increasingly stringent. However, the standard compliance rate of the total phosphorus (TP) is very low, and the TP has become the main limiting pollutant for the water pollutant discharge standards of rural domestic sewage treatment facilities. In this study, oyster shell waste was employed as a calcium source, and agricultural waste–rice husk was used as a carbon source to synthesize calcium-modified biochar adsorbent materials (Ca-BC) by a simple one-step pyrolysis method. The resultant Ca-BC adsorbent materials demonstrated efficient phosphate (P) adsorption from aqueous solutions over a wide pH range (3–11) and adsorption selectivity. Ca-BC’s adsorption capacity for P increased with the pyrolysis temperature, increasing from 700 °C to 900 °C, which was attributed to the higher specific surface area and calcium oxide content at higher pyrolysis temperatures. The Ca-BC sample, which was made from oyster shells and rice husks with a mass ratio of 2:1 and a pyrolysis temperature of 900 °C, had a maximum adsorption capacity of 196.2 mg/g. The Langmuir model and pseudo-second-order model were the best at describing the adsorption process, and the predominant sorption mechanism for P is the precipitation of calcium oxide or calcium hydroxide with phosphate to create hydroxyapatite. Ca-BC can effectively remove P from rural domestic sewage. The removal rate of the total phosphorus (TP) in rural domestic sewage is 93.9–99.4%. After the adsorption treatment, the discharge of the TP in the rural sewage met the second-grade (TP &lt; 3 mg/L) or even the first-grade (TP &lt; 2 mg/L) Discharge Standard of Water Pollutants for Centralized Rural Sewage Treatment Facilities (DB33/973-2021). This study provides an experimental basis for efficient P removal by Ca-BC adsorbent materials and suggests possible applications in rural domestic sewage.

Multifunctional PDO Thread Coated with Mg(OH)2/ZnO Nanoparticles and Asiaticoside for Improved Facial Lifting.

As interest in skin aesthetics increases, treatments to suppress aging are increasing. Among them, a facelift is the most effective procedure for improving wrinkles. However, side effects including inflammatory reactions occur due to the limitations of the PDO thread itself used during the procedure. In this paper, to improve the function of PDO thread, inorganic particles such as magnesium hydroxide (MH) and zinc oxide (ZO) and a biologically active agent, asiaticoside, were coated on the surface of PDO thread using ultrasonic coating technology. The coated thread exhibited excellent biocompatibility, promoted collagen synthesis, reduced inflammation, and stimulated angiogenesis in vitro and in vivo. The multifunctional PDO thread has shown promising potential for skin regeneration without inducing fibrosis. Such a practical coating system and the developed multifunctional PDO thread suggest new possibilities for developing safer and more effective materials in cosmetic and regenerative medicine to prevent aging and improve skin aesthetics.

Boron and nitrogen co-doped carbon-based nanomaterials/nickel oxide/hydroxide hybrids for sunlight induced photocatalytic water cleaning

B doped as well as B and N co-doped highly reduced graphene oxide and multiwall carbon nanotubes/Ni oxide and Ni hydroxide nanohybrid layers were synthesized using a one-step laser technique. NiO nanoparticles, graphene oxide platelets, and multiwall carbon nanotubes were used as starting materials for the preparation of the composite layers. H3BO3 was used as B precursor and urea as well as NH3 as N precursors for B and N co-doping of the composite layers. The influence of the nature and concentration of the B and N precursors on the physico-chemical properties of the nanohybrid layers, chemical composition and chemical bonding states, crystalline structure, as well as charge transfer properties was systematically investigated. The relation between the physico-chemical properties and functional characteristics of the nanohybrid layers, photocatalytic removal of water contaminants under simulated sun irradiation conditions was studied, identifying the optimum concentrations of the dopant precursor materials. The mechanism of the photodegradation process was explored, based of the band structure of the composites. The main intermediates, reactive oxygen species implied in the photocatalytic degradation processes of organic molecules, was investigated through the addition of scavengers to the organic dye test solutions. The highest photocatalytic activities were achieved for B and N co-doped samples synthesised using H3BO3 as B and urea as N precursors.

Localized Phase Transformation Triggering Lattice Matching of Metal Oxide and Carbonate Hydroxide for Efficient CO2 Photoreduction.

Orderly heterostructured catalysts, which integrate nanomaterials of complementary structures and dimensions into single-entity structures, have hold great promise for sustainability applications. In this work, it is showcased that air as green reagent can trigger in situ localized phase transformation and transform the metal carbonate hydroxide nanowires into ordered heterostructured catalyst. In single-crystal nanowire heterostructure, the in situ generated and nanosized Co3 O4 will be anchored in single-crystal Co6 (CO3 )2 (OH)8 nanowires spontaneously, triggered by the lattice matching between the (220) plane of Co3 O4 and the (001) plane of Co6 (CO3 )2 (OH)8 . The lattice matching allows intimate contact at heterointerface with well-defined orientation and strong interfacial coupling, and thus significantly expedites the transfer of photogenerated electrons from tiny Co3 O4 to catalytically active Co6 (CO3 )2 (OH)8 in single-crystal nanowire, which elevates the catalytic efficiency of metal carbonate catalyst in the CO2 reduction reaction (VCO = 19.46mmol g-1 h-1 and VH2 = 11.53mmol g-1 h-1 ). The present findings add to the growing body of knowledge on exploiting Earth-abundant metal-carbonate catalysts, and demonstrate the utility of localized phase transformation in constructing advanced catalysts for energy and environmental sustainability applications.