One-step Approach Research Articles

One-step microwave pyrolysis-H3PO4 activation of woody biomass: Insight into the product characteristics and life cycle assessment

Microwave-assisted pyrolysis coupled with chemical activation was developed to prepare the woody biomass-derived activated carbon (AC) with desirable structural characteristics. In this study, sawdust powder was impregnated with phosphoric acid before being microwave-pyrolyzed to achieve AC. The utilization of microwave greatly enhanced the transformation of volatiles into gaseous components, and the yield of char increased when phosphoric acid accelerated the secondary polymerization of volatile matters. Microwave-induced activation may alter the interaction between activator and sawdust-derived organic species, enriching the categories of oily components. The char originating from microwave-activation treatment has a high graphitization degree, exhibiting superior thermal stability and hydrophilic property. Moreover, one-step microwave-activation approach increased specific surface area (978.2 m2g−1 versus 13.0 m2g−1 in conventional pyrolysis) and improved the formation of porous structure. The life cycle assessment analysis revealed that microwave-activation technique had a low environmental impact due to enhanced heating efficiency and reduced energy consumption.

Mo-doped carbon-dots nanozyme with peroxide-like activity for sensitive and selective smartphone-assisted colorimetric S2− ion detection and antibacterial application

Sulfur ion (S2−) plays a significant and considerable role in many living organisms and ecosystems, while its abnormal content can pose a serious hazard to human health and ecological environment. Hence, it is extremely meaningful to construct a highly sensitive and selective analytical platform for S2− detection in complex microenvironment, particularly in biological systems. In this study, phosphomolybdic acid and L-Arg were utilized to prepare a new molybdenum doped carbon-dots nanozyme (Mo-CDs) with great peroxidase-like activity by one-step hydrothermal approach. In the presence of H2O2, Mo-CDs converted 3, 3′, 5, 5′-tetramethyl benzidine (TMB) into blue oxTMB, but S2− strongly reduced the blue solution to colorless and then brown, which established significant selectivity toward S2−. Mo-CDs illustrated a wide linear range (2.5 μM-900 μM) and low detection limit (LOD = 76 nM) by ultraviolet and smartphone-assisted visualized colorimetric analysis. Especially, the smartphone-assisted analysis platform successfully realized quick, portable, sensitive and visible identification of S2− with high recovery (95.7–106.7 %) and excellent specificity in water samples. More importantly, Mo-CDs was developed to antibacterial applications based on good peroxidase-like activity. This research not only constructed a new and efficient carbon-dots nanozyme and a low-cost, portable, visual analysis platform for real-time detection of S2−, but also proposed a novel design strategy and methodology for exploiting multifunctional nanozyme detection tool with great practical application.

Ni-based compounds in multiwalled graphitic shell for electrocatalytic oxygen evolution reactions

Here, we report a general strategy for designing a metal/carbon system, via a facile and environmentally friendly one-step approach, from metal acetate as an active electrocatalyst in oxygen evolution reaction (OER) during water decomposition. As a demonstration, a nanostructured Ni/C composite induced from nickel acetate is revealed in great detail. The resulting material is composed of: metallic nickel (Ni), nickel(II) oxide (NiO), and nickel carbide (Ni3C) coated with a graphitic shell and deposited on a carbon platform. Our findings underscore the prominent role of nickel species, including Ni0, Ni2+, and Ni3+, in driving the catalytic activity. Notably, the catalyst exhibits an overpotential of 170 mV, a Tafel slope of 49 mV·dec−1, an electrocatalytic surface area (ECSA) of 964.7 cm2, and a turnover frequency (TOF) value of 52.8 s−1, surpassing RuO2. The Raman spectra also suggest a graphitic "self-healing" phenomenon post-OER, attributed to the reduction of oxygen-containing groups. Carbon in the system (i) facilitates electron transfer, (ii) allows homogeneous distribution of Ni nanoparticles avoiding their agglomeration, and (iii) promotes durability of the electrocatalyst by serving as a protective barrier, shielding the core metal compounds. What is more, density functional theory (DFT) calculations allowed to optimized geometry of the model cluster Ni8O8(OH)8 describing two different sites on the β-NiOOH surface (001) and two different intermediates, (i)L-OOH and (ii)L-OOH. This facilitated to propose the reaction mechanisms involving both hydroxide ions and water molecules as reducers. Therefore, the chemisorption of OH− and H2O molecules at the NiOOH active center accompanied by bond breakage and the formation of a lattice hydroperoxide as an important intermediate is presumed. What is more, the proposed fabrication method for electroactive metal/carbon composites was validated with an iron and iron/nickel mixture.

One-step preparation of orange-red Emitting carbon dots for visual detection of copper ions in the water environment

In this study, p-aminophenol and o-phenylenediamine were used as materials in a straightforward one-step hot solvent approach for generating a nitrogen-doped carbon dot. Fourier Transform Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and UV–Vis analysis were used to analyze the resultant CDs composites. Furthermore, fluorescence and absorption spectroscopy were used to assess the optical characteristics. Following the addition of Cu2+, CDs’ fluorescence was quenched statically, resulting in the formation of a non-fluorescent complex. Based on this, a highly selective fluorescent technique was developed with a detection limit of 2.71 μM and a relevant linear range of 10–100 μM for Cu2+. More convenient to carry and detect sodium alginate gel beads doped with carbon dots were prepared for visual detection of Cu2+. Using this method, Cu2+ ions from various environmental sources can be detected rapidly, cheaply, environmentally friendly, and selectively.

Construction of a novel Mott-Schottky heterostructure gas sensor g-C3N4/SnO2 with layered nanorods array for high-sensitivity acetone detection

Developing exhaled acetone sensors with high performance can be effectively applied to the medical diagnosis and the health monitoring. Herein, a two-dimensional (2D) layered graphitic carbon nitride (g-C3N4) with tunable electronic structure, abundant edge sites, and high stability is proposed, and it is further coupled with stannic oxide (SnO2) by one-step hydrothermal approach to construct a Mott-Schottky heterostructure with layered nanorods array. The exceptional response of the as-fabricated g-C3N4/SnO2 gas sensor to 50 ppm acetone at 100 °C is four times higher than that of the pristine SnO2 sensor. Additionally, the g-C3N4/SnO2 sensor’s remarkable selectivity, long-term stability against acetone gas, and detection limit of 250 ppb are exhibited. The unique hierarchical design and the Mott-Schottky heterostructure creation which validated by electrochemical study, may be in charge of the enhanced acetone sensing capabilities of g-C3N4/SnO2 gas sensor. This work will provide a concise and effective avenue to construct hierarchical composite with Mott-Schottky heterostructure for high-performance acetone gas sensor.

Single-step template-free synthesis of fluoro-functionalized covalent organic frameworks with a tunable hollow structure for extraction of phthalate acid esters from human urine

Phthalate acid esters (PAEs) are recognized as endocrine disruptors, exhibit carcinogenic characteristics, and have the potential to impair fertility, thereby posing significant risks to both the environment and human health. Consequently, biomonitoring and exposure assessment of PAEs are of paramount importance. Presently, the majority of detection methods for PAEs are centered on aqueous matrices, and the development of techniques for the identification of PAEs in complex matrices remains an area of active research. This paper designed and synthesized a novel fluoro-functionalized hollow covalent organic framework (F-HCOF), characterized by a tunable hollow spherical structure and enriched with fluorine functional groups, through a one-step self-template approach, which effectively regulated the formation of the hollow structure. The synthesized F-HCOF with tunable hollow structures and abundant F functional groups provided efficient diffusion pathways and adsorption sites, facilitating robust and selective adsorption of the target PAEs. Using F-HCOF as a coating, a solid-phase microextraction method was developed to extract PAEs from complex matrices. The method exhibited limits of detection ranging from 0.0108 to 0.0581 ng L−1, with enrichment factors spanning from 2535.3 to 8985.3. The self-made F-HCOF fibers demonstrated the capability to effectively enrich PAEs under various interference conditions, further verifying their feasibility for practical sample analysis. This work provided a strategic approach for the synthesis of F-functionalized hollow COF adsorbents and explored the formation process of hollow spheres. It enables matrix interference-resistant analysis of PAEs, and offers a practical method for studying PAEs exposure and metabolism within the human body.

Bioactive potential of unpurified hydrothermal xylooligosaccharides: Implications for prebiotic formulations from sugarcane bagasse

This study explored the bioactive potential of xylooligosaccharides (XOS) obtained from sugarcane bagasse through one-step hydrothermal process approach, applied here without the typical purification or further processing steps commonly required to produce XOS for use as prebiotic. We investigated various processing conditions to optimize the yield and biofunctional properties of these unpurified, hydrothermally produced XOS-rich hemicellulose hydrolysates from sugarcane bagasse. The prebiotic efficacy of these unpurified XOS-rich hydrolysates was evaluated by their ability to support the metabolism of bifidobacteria in anaerobic fermentation. The results revealed that the chain length of XOS significantly influenced their effectiveness as a carbon source, with longer chains (beyond hexoses) being less efficient. Despite the presence of lignin and sugar degradation by-products, generally considered detrimental in such processes, they did not negatively affect bifidobacteria growth. In addition, variations in the degree of acetyl substitutions on the XOS mildly influenced the production of short-chain fatty acids. Importantly, unpurified XOS-rich hydrolysates produced under selected hydrothermal conditions demonstrated bioactive performance that was comparable to, or even superior to, commercial prebiotics. These findings confirm the practical viability of using unpurified, hydrothermally derived XOS-rich hydrolysates from sugarcane bagasse as prebiotics, emphasizing the innovative approach of eliminating purification and additional processing, thereby simplifying the production process while still maintaining high prebiotic efficacy.

Exceptional light harvesting in copper doped CaTiO3 nanocuboids with surface nanosteps for the photo remediation of toxic Cr(VI) ions and dyes

Addressing the rising concerns of water pollution caused by harmful inorganic and organic contaminants is very crucial and photocatalysts with exceptional light harvesting capability are a promising way to tackle these issues. This study investigates the transformation of CaTiO3 into a visible light-active photocatalyst via copper doping. Copper-doped CaTiO3 nanocuboids were synthesized via a one-step solvothermal approach, resulting in the formation of distinctive nanostep substructures on the surface. Morphological analysis revealed the successful incorporation of copper ions into the perovskite matrix, as evidenced by the transition from smooth to rough, uneven surface features. X-ray diffraction confirmed the incorporation of Cu2+ ions into the Ti4+ site, while visible range absorption indicated a reduction in the bandgap. Furthermore, doping decreased the rate of charge carrier recombination and increased their average lifetime, prolonging the duration of active species. This modification facilitating efficient absorption of visible light and increase in the charge separation, leads to enhanced photocatalytic activity. The doped catalyst exhibited exceptional performance in the remediation of hexavalent chromium ions (98.5 % Cr6+ ions reduction to Cr3+ ions in 20 min), methylene blue (99.4 % degradation within 120 min), and eosin yellow (99.8 % degradation within 80 min) pollutants. This research underscores the potential of doping as a viable strategy for tailoring photocatalytic properties and addressing water pollution challenges.

An unprecedented sensitive material for detecting trimethylamine derived from polyoxometalates @ bimetallic metal organic frameworks

Polyoxometalates (POMs) and metal organic frameworks (MOFs) have attracted increasing attention in the gas sensor field for the detection of volatile organic compounds. Herein, we present novel sensitive materials (PW12-NiO-ZnO hollow polyhedron) derived from POMs@bimetallic MOFs by using a one-step solvothermal approach. The micro-nano structure, compositions, and other chemical and physical properties of the samples were clarified through characterization such as XRD, SEM, TEM and XPS. Significantly, sensor based on PW12-NiO-ZnO hollow polyhedron presents a notable response value as high as 62.6 toward 100 ppm trimethylamine at 350℃, which is nearly 4.3 times that of pure ZnO. Moreover, we conducted other performance tests on the sensor to verify the high selectivity, good response/recovery properties and perfect long-term stability toward trimethylamine. Importantly, possible products on the surface of sensitive materials were analyzed by in situ diffuse reflectance infrared Fourier transform spectra (DRIFTS). In addition, these improved sensing performances is most benefiting from the incorporation of polyoxometalates and the p-n heterojunction between NiO and ZnO. As a pioneering study, this work provides an effective approach for designing diverse sensitive materials in the sensor applications.

One-step fabrication of AlPO4 nanosheet reinforced ceramic coatings with improved fracture toughness and hydrogen resistance

Ceramic coatings have great potential in protecting vital metal structural components in hydrogen energy and nuclear fusion reactors. Fracture toughness and hydrogen permeation resistance are two key characteristics that determine life span and performance of these coatings. However, there is still no strategy to simultaneously enhance both of these two characteristics. Herein, we developed a one-step approach to fabricate AlPO4 nanosheet reinforced α-Al2O3 ceramic coating with simultaneously enhanced fracture toughness and hydrogen permeation resistance. Different from the external nanosheet addition method of the conventional techniques for fabricating nanosheet reinforced coatings, AlPO4 nanosheets were in-situ formed within α-Al2O3 ceramic coating though a one-step heat treatment process. Owing to the positive reinforcing effect of AlPO4 nanosheets, the fracture toughness of the coating increases by 3 times, achieving an ultrahigh KIC value of 7.1 MPa/m2. Meanwhile, the hydrogen permeation resistance of the coating increases by 78 %, reaching as high as 3440 times that of the steel substrate. Additionally, the Cr–P bonds formed between the coating and substrate ensure their good bonding, with their bonding strength increasing up to 36 MPa. The combination of high hydrogen permeation resistance, high fracture toughness, and high bonding strength makes the AlPO4 nanosheet reinforced ceramic coating a promising alternative for reducing hydrogen permeation in various hydrogen-related fields. This study also provides critical insights and practical guidelines for constructing high-performance functional coatings via nanosheet reinforcement.

Constructing highly dispersed Pd on Ca-Al layered double hydroxide for efficiently selective oxidation of cumene

The selective oxidation of cumene to produce cumene hydroperoxide (CHP) with high yield continues to be a challenge when using traditional catalysts, despite the importance of CHP as a key intermediate in phenol industry. Herein, Ca-Al layered double hydroxide (CaAl-LDH) supported Pd was prepared by one-step co-precipitation approach, wherein the Pd species on the CaAl-LDH support were highly dispersed and evidenced by TEM and CO-DRIFTS characterization. The synthetic Pd/CaAl-LDH exhibited the remarkably high catalytic performance, and the selectivity of CHP could reach a very high level (92.1 %) on the high cumene conversion of 52.0 %. The high loading of Pd (4 wt.%) leads to the obvious aggregation of Pd on the edge and surface of CaAl-LDH, Pd nanoparticles could accelerate the decomposition of target product CHP, and thus resulting the decrease of CHP in selectivity. The reaction mechanism was studied by simple radical scavenging experiments, and it was suggested that the activation of oxygen molecules was the main pathway for Pd/CaAl-LDH to promote the oxidation reaction of cumene.

A Case of Nasoseptal Flap Reconstruction for Refractory Medial Canthal Fistula.

Sino-orbital cutaneous fistulas (SOCFs) are a rare and challenging complication from conditions including granulomatosis with polyangiitis. SOCFs are difficult to manage due to poor vascular supply, compromised tissue, and systemic immunocompromise, which lead to a high rate of recurrence. Given the overall rarity of SOCFs, optimal surgical repair remains controversial, with options ranging from conservative management, onlay grafts, and vascularized flaps. This case report describes a novel one-step approach to SOCF closure using a composite chondral mucosal nasoseptal flap in a patient with a large left medial canthal SOCF that had recurred despite 2 prior attempts at closure including a vascularized paramedian forehead flap. Nasoseptal flaps may provide vascularized mucosal tissue to allow for greater success in closure over traditional, external flaps, and skin grafts.

Revolutionizing ELISA: A one-step blocking approach using lipid bilayer coatings

Enzyme-linked immunosorbent assay (ELISA) is an essential technique for biomolecule detection in diagnostics and research, but traditional protocols are time-consuming and variable. Conventional blocking agents like bovine serum albumin (BSA) pose ethical issues and potential assay interference. This study presents a one-step lipid-blocking approach to simplify the ELISA procedure. Compared to conventional blockers, the Lipid Universal Coating Assembly (LUCA) antifouling blocker showed comparable sensitivity while significantly reducing processing time and steps. Furthermore, it showed improved co-blocking efficacy and signal intensity in conventional protocols when combined with minimal BSA concentrations. Stability tests under accelerated aging confirmed the robustness of the LUCA antifouling blocker. Additionally, it effectively facilitated antibody detection for COVID-19 antigens in direct ELISA and human IL-6 antigen in Sandwich ELISA, suggesting its versatile applicability. Taken together, our findings reveal that one-step lipid blocking not only streamlines the ELISA process but also maintains high sensitivity and specificity, providing an efficient, user-friendly, and environmentally friendly alternative to traditional ELISA blockers and a robust platform for rapid diagnostics.

Engineering p-d orbital hybridization in PdSb bimetallene for energy-saving H2 production parallel upgrade plastic waste

The electrochemical conversion of PET-derived ethylene glycol into high-quality chemicals parallel energy-saving H2 production is an optimal solution to the serious environmental pollution of plastics. In this paper, p-d orbital hybrid PdSb bimetallene with defect-rich crimped surface is synthesized by a one-step solvent approach. PdSb bimetallene exhibits excellent electrocatalytic performance in ethylene glycol and PET hydrolysate oxidation attributed to the unconventional p-d orbital hybridization feature and metallene structure. PdSb bimetallene shows better properties than Pd metallene and commercial Pd black catalysts under ethylene glycol conditions and PET hydrolysate. Besides PdSb bimetallene can oxidize ethylene glycol to produce the valuable product glycolic acid with high Faradaic efficiency and selectivity. Besides, PdSb bimetallene can oxidize PET-derived ethylene glycol into glycolic acid with high selectivity in EGOR||HER system. This study provides insights into the synthesis of metallene with p-d orbital hybridization properties, coupled with energy-saving H2 production parallel upgrade plastic waste.

Double EUS-guided bypass for gastric outlet and biliary tract malignant obstruction: A standardized one-step approach (with videos).

Double EUS-guided bypass for gastric outlet and biliary tract malignant obstruction: A standardized one-step approach (with videos).

An eco-friendly convenient approach for the synthesis of guar gum integrated copper nanoparticles: Investigation of its catalytic activity in the C[sbnd]N Ullmann coupling reactions and study of its anti-human kidney cancer effects

We carried out this research was in order to evaluate the potency of guar gum (GG) hydrogel to conduct CuO NPs synthesis by adopting an eco-friendly approach as well as to study its role as catalyst and in relieving cancerous cell lines. In this context, we accomplished the CuO NPs/GG synthesis by employing a simple one-step approach and identified its characters through UV–Visible (UV–Vis) spectroscopy, X-ray diffraction (XRD), transmission electronic microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-rays spectroscopy (EDS), elemental mapping and ICP-OES analysis. XRD and TEM results of CuO NPs/GG showed the face centered cubic (fcc) structures and predominantly spherical shaped with a size of 20–30 nm. After the characterization, the prepared CuO NPs/GG nanocatalyst was used as catalyst in the N-arylation of amines (indole and imidazoles) through C(aryl)-N chemical bond arrangement from the related aryl halides (I, Br, Cl) by Ullmann-type coupling reactions. It is worth mentioning that the novel catalyst has the potential of being recycled seven times without much change in activity. Furthermore, the anti-kidney cancer properties of CuO NPs/GG nanocomposite were assessed by MTT assay about the cytotoxicity and anti-human on normal (HUVEC) and human kidney cell lines i.e. ACHN, CaKi-2 and HEC293. The corresponding IC50 values were 18.5, 17.2, and 15.6 µg/mL, respectively. The viability of malignant human kidney cell line reduced dose-dependently in the presence of the nano bio-composite. After clinical study, CuO NPs/GG nano bio-composite can be utilized as an efficient drug in the treatment of human kidney cancer in human.

Fluorescent Mn3O4 quantum dot as catechol oxidase nanozyme: A robust nano-platform for sensitive dopamine detection

The development of multifunctional semi-conductor nano-enzymes has attained significant interest recently, due to their ease in fabrication, cost-effectiveness, and wide range of applications. In this work, we report the synthesis of ammine-functionalized Mn3O4 quantum dots (Mn3O4 QDs) with excellent luminescence properties. These QDs have been developed via the reduction of permanganate using L-cysteine through a simple, facile one-step bottom-up approach. The steady-state enzyme kinetic studies revealed the superior Catechol-Oxidase mimic activity of the Mn3O4 QDs with a Michaelis-Menten constant (Km) of 133.19 µM, and maximum reaction velocity (Vmax) of 69.40 µMs−1. Due to this superior enzymatic activity, dopamine (DA) gets easily oxidized into DA-quinone and eventually polymerized to form polydopamine. Schiff base/Michael addition reaction between nucleophilic ammine on the surface of QDs and the aromatic chain makes the probe and analyte come closer and leads to the formation of a charge transfer complex, resulting in fluorescence quenching of QDs. This fluorescence quenching has been quantified to develop a turn-off sensor for DA. The sensing characteristics are highly selective and sensitive towards DA with a detection limit of 18 nM. The synthesised Mn3O4 QDs with superior enzyme-mimicking properties have tremendous potential as fluorescent probes in imaging and health care applications.

Biomimetic Calcium Phosphate Nanoparticles: Biomineralization Models and Precursors for Composite Materials.

The formation of calcium phosphate under the control of water-soluble polymers is important for understanding bone growth in living organisms. These experiments also have spin-offs in the creation of composite materials, including for regenerative medicine applications. The formation of calcium phosphate (hydroxyapatite) from calcium chloride and diammonium phosphate was studied in the presence of polymers containing carboxyl, amine, and imidazole groups. Depending on the polymer composition, solid products and stable dispersions of positively or negatively charged nanoparticles were obtained. Oppositely charged nanoparticles can interact with each other to form a macroporous composite material, which holds promise as a filler for bone defects. The formation of a calcium phosphate layer around a living cell (dinoflagellate Gymnodinium corollarium A. M. Sundström, Kremp et Daugbjerg) using positive composite nanoparticles is a one-step approach to cell mineralization.

4D-STEM and Eels Analysis of Complex C-Based Sensor Architectures

Transforming high-carbon precursors into open-porous carbon foams and coatings via thermal processes is gaining attention as a sustainable method for various applications, including catalysis, energy utilization, and sensing [1]. In this research, we adopt a one-step laser patterning approach to selectively pyrolyze doctor-bladed ink coatings on flexible PET substrates, thereby producing highly porous, intricately designed CO2 sensor structures with a thickness of about 50 µm. Our ink formulation includes glucose as a pore-forming agent and adenine as a nitrogen source to enhance sensing capabilities. Laser processing in an oxygen-rich setting results in flexible, highly porous sensor heterostructures characterized by distinct areas enriched with nitrogen and oxygen functionalities. The laser intensity’s attenuation with depth leads to the development of a distinctly porous graphitic surface layer (serving as the electrical transducer layer) and a denser nitrogen-enriched lower sensor layer, linked by a narrow transitional region [2]. To understand the formation and functionality of these sensors, we conducted an in-depth TEM analysis of cross-sections of the complete device, prepared through ultramicrotomy cross-sectioning. STEM-EELS elemental distribution maps distinctly show the chemical composition differences between the upper and lower layers of the sensor. Principal component analysis was utilized to separate the complex sensor structures into their constituent crystalline and amorphous carbon and nitrogen-containing phases. 4D-STEM analysis exposed the arrangement of the crystalline graphitic phase and the orientation of graphite basal planes adjacent to the pores of the open-porous sensor. Analyzing these structural parameters is essential for understanding the electrical performance of the sensor, as depicted in Figure 1 [3]. Figure 1: A (top)) SEM micrograph of sensor embedded in epoxy, (bottom) depth-dependent thermal laser intensity attenuation; B (left)) HA ADF-STEM micrograph showing different sensor layers, (middle) STEM-EELS nitrogen distribution map, (right) PCA bond analysis, C) HRTEM images of sensor from transducer (top) and sensor (bottom) layers with SAED image of respective ROIs (inset); D) 4D-STEM analysis depicting misalignment angle between graphitic carbon basal plane normal relative to the pore surface normalReferences[1] M. Hepp, et al. npj Flexible Electronics 6, 1-9 (2022)[2] H. Wang, et al. Advanced Functional Materials 32, 2207406 (2022)[3] C. Ophus, et al. Microscopy and Microanalysis 28, 390-403 (2022) Acknowledgements: We acknowledge use of the DFG-funded Micro-and Nanoanalytics Facility (MNaF) at the University of Siegen (INST 221/131-1). Figure 1

Corrosion-resistant superhydrophobic composite coating with mechanochemical durability

It is important to improve the corrosion resistance of magnesium alloy for expanding its application field. Poor durability seriously restricts the practical application of superhydrophobic anti-corrosion coatings. Here, a durable superhydrophobic anti-corrosion coating was prepared on AZ31 Mg substrate via a facile one-step spraying approach. The microscale glass fibers (GF) and nanoscale hydrophobic SiO2 particles were integrated into the epoxy resin (ER) to construct superhydrophobic composite coating (ER/GF-SiO2). Benefitting from the air cushion and physical barrier effect of superhydrophobic coating, the ER/GF-SiO2 coating exhibits good reinforced protectives properties. Compared with the AZ31, the corrosion current density of superhydrophobic coating decreased by three orders of magnitude and the low-frequency impedance modulus decreased by one order of magnitude. The ER/GF-SiO2 coating still maintained a high protective efficiency (89.44 %) after immersion in 3.5 wt% NaCl solutions for 13 d. The ER/GF-SiO2 coating shown good mechanochemical durability. The superhydrophobicity can be maintained after 40 m of sandpaper abrasion, 30 min of water impact, 20 min of sand impact, and 80 cycles tape-peeling. Furthermore, the high bond strength of the coating-substrate was verified by energetic analysis of molecular dynamics simulation at a microscopic level. The facile and effective preparation process provides an effective strategy for large-scale industrial production of durable superhydrophobic coating.