Cr2O3 Nanoparticles Research Articles

Quasi-in-situ monitoring of passive film growth of Inconel 718 alloy

The effect of different passivation times on the structure and properties of the passivated film of Inconel 718 alloy fabricated by laser powder bed fused (LPBF) was investigated by electrochemical techniques and surface analysis. The results delineated that the structure of the passive film changed from a p-type semiconductor to a p-n bilayer semiconductor structure with increasing film formation time; the thickness of the film increased from the initial 1.65 nm to 4 nm, which promoted a significant increase in polarization resistance. In the initial stage, the Cr2O3 nanoparticles of the passive film grow in interconnected aggregates. In contrast, in the termination stage, porous NiO nanoparticles are formed due to the dehydration precipitation of hydroxide.

A comparative study on the structural, optical, and magnetic behavior of transition metal (Co and Mn) ions substituted Cr2O3 nanoparticles

A comparative study on structural, optical, and magnetic properties of TMxCr2−xO3 (TM = Co and Mn) nanoparticles was synthesized using a simple co-precipitation method with subsequent heat treatment. The structural characterizations of as-prepared nanoparticles were performed using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. XRD pattern revealed the formation of rhombohedral Cr2O3 phase with space group R3¯c. The FTIR spectra illustrated the shifting of absorption bands of Cr2O3 nanoparticles with Co and Mn substitution due to strain induced within the crystal lattice. X-ray photoelectron spectroscopy (XPS) confirmed the presence of a mixed oxidation state of Cr and oxygen defects in the prepared nanoparticles. Furthermore, XPS spectra also demonstrated the presence of Co and Mn having +2 oxidation state. The reduction in optical band gap of host material was observed with Co and Mn substitution. The magnetic properties of as-synthesized nanoparticles were recorded using a SQUID magnetometer and temperature-dependent magnetic measurements illustrated the decrease of Neel temperature with Co and Mn substitution. It was also demonstrated that magnetization increases below about ∼ 120 K due to spin canting and spin frustration for both TM ions substituted Cr2O3 nanoparticles and is fitted using the 3D spin-wave model with Curie-Weiss law. The magnetic studies revealed the mixed paramagnetic (PM) and antiferromagnetic (AFM) order at room temperature and AFM mix with ferromagnetic (FM) order at low temperature explained using the bound magnetic polarons (BMP) model.

Microwave-assisted preparation of polysubstituted imidazoles using Zingiber extract synthesized green Cr2O3 nanoparticles

Cr2O3 nanoparticles were prepared using Zingiber officinal extract which were used as an efficient and reusable catalyst in the practical synthesis of polysubstituted imidazoles by means of a convenient reaction of aromatic aldehydes with ammonium acetate and benzil under microwave irradiation and H2O as solvent. The structure of the compounds was studied by IR and 1H-NMR spectrum. The most important benefits of this process are operational simplicity, reasonable reaction times, and excellent yield of products. The results show that the optimal conditions for the formation of imidazole derivatives are as follow: power of 400 W, reaction time of 4–9 min, H2O as a solvent, and 15 mmol of catalyst amount.

Human biomonitoring and personal air monitoring. An integrated approach to assess exposure of stainless-steel welders to metal-oxide nanoparticles

In welding, there is a potential risk due to metal-oxide nanoparticles (MONPs) exposure of workers. To investigate this possibility, the diameter and number particles concentration of MONPs were evaluated in different biological matrices and in personal air samples collected from 18 stainless-steel welders and 15 unexposed administrative employees engaged in two Italian mechanical engineering Companies. Exhaled breath condensate (EBC) and urine were sampled at pre-shift on 1st day and post-shift on 5th day of the workweek, while plasma and inhalable particulate matter (IPM) at post-shift on 5th day and analysed using the Single Particle Mass Spectrometry (SP-ICP-MS) technique to assess possible exposure to Cr2O3, Mn3O4 and NiO nanoparticles (NPs) in welders. The NPs in IPM at both Companies presented a multi-oxide composition consisting of Cr2O3 (median, 871,574 particles/m3; 70 nm), Mn3O4 (median, 713,481 particles/m3; 92 nm) and NiO (median, 369,324 particles/m3; 55 nm). The EBC of welders at both Companies showed Cr2O3 NPs median concentration significantly higher at post-shift (64,645 particles/mL; 55 nm) than at pre-shift (15,836 particles/mL; 58 nm). Significantly lower Cr2O3 NPs median concentration and size (7762 particles/mL; 44 nm) were observed in plasma compared to EBC of welders. At one Company, NiO NPs median concentration in EBC (22,000 particles/mL; 65 nm) and plasma (8248 particles/mL; 37 nm) were detected only at post-shift. No particles of Cr2O3, Mn3O4 and NiO were detected in urine of welders at both Companies. The combined analyses of biological matrices and air samples were a valid approach to investigate both internal and external exposure of welding workers to MONPs. Overall, results may inform suitable risk assessment and management procedures in welding operations.

GREEN SYNTHESIS OF CHROMIUM OXIDE NANOPARTICLES - STUDY OF ITS ANTIBACTERIAL, PHOTOCATALYTIC AND THERMODYNAMIC PROPERTIES

An endeavor has been made to report the herbal synthesis of chromium oxide (Cr2O3) nanoparticles using aqueous extract of nigella sativa seed extract as a capping agent and chromic sulphateas a precursor material. The structural, morphological and optical properties of the Cr2O3 nanoparticles were analyzed by X - ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and UV- Visible spectroscopy. The antibacterial efficacy of chromium oxide nanoparticles was tested against Staphylococcus aureus, Klebsiella pneumonia and Pseudomonas aeruginosa. The photocatalytic activity of biosynthesized Cr2O3 nanoparticles was evaluated by degrading methylene blue dye and Congo red dye under the irradiation of visible light. Apart from this, ultrasonic velocity, density and viscosity were measured for different concentrations of Cr2O3 nanofluid using ultrasonic techniques. Thermoacoustical such as adiabatic compressibility, free length, acoustic impedance, relaxation time and absorption coefficient values are computed from the measured data and the results are interpreted in terms of particle - fluid interactions.

A Single Layer of Chromium Oxide Nanoparticles Films Coated with Carbon by Applying Exploding Wire Technique for Efficient Solar Selective Absorber

The efficiency of solar energy absorption in solar heaters is increased by the use of selective absorption coating that possesses high absorption of solar radiation in the UV-visible spectrum as well as low emission at the operating temperature in the infrared region. In this work, novel selective coatings were synthesized by improving the selectivity of chromium oxide (Cr2O3) nanoparticles by doping with carbon nanoparticles using the exploding wire technique for carbon rods by high current in suspended Cr2O3 particles. The structural properties and surface topography were studied by XRD and FE-SEM, which illustrate the carbon-coated Cr2O3 nanoparticles. The prepared nanoparticles were mixed with a support material, Polyvinyl pyrrolidone (PVP) as a matrix, for use as a selective coating for three metals, namely copper, aluminium and stainless steel (SST). Reflectivity measurements were performed within the UV-Visible spectrum to calculate the absorption of solar radiation using numerical integration. The reflectivity was also measured in the range from 2.5 to 25 μm to calculate the thermal emission of the solar heater within the proposed operating temperature of 373 K. The measurements showed good efficiency of using the produced material as a selective coating which was prepared in a simple way compared to conventional methods. The best sample with efficient absorptance (α) for solar spectrum and of lowest emittance (ε) in IR region was for Al substrate coated by Cr2O3:C:PVP of α =0.886 and ε= 0.260.

Effects of air annealing treatments on the microstructure, components, and mechanical properties of magnetron sputtered Al2O3–Cr2O3–ZrO2 composite coatings

To investigate the effects of air annealing on the microstructure, components, and mechanical properties of ceramic composite coatings, Al2O3–Cr2O3–ZrO2 composite coatings were prepared on silicon substrate using radio frequency magnetron sputtering at room temperature, and then air-annealed in a temperature range of 450–850 °C for 30 min. The results indicated that the phase-structure and superficial characteristics, including morphology and surface roughness, were not visibly altered in the annealed coatings up to 600 °C; the elemental component distributions remained uniform. The improvement in the mechanical properties was attributed to the growth of oxide grains. There were no significant changes in the components of Al, Cr, Zr, and O in the annealed coatings. However, an increase in the Cr component and a decrease in the Zr component occurred on the coating surface; the overall structure of the composite coatings possessed a favorable heat resistance. Upon annealing at 750 °C, the thermally-driven formation of uniform and refined nanoparticles on the coating surface was responsible for the effective enhancement of the mechanical properties. Furthermore, annealing at 850 °C induced the enlargement of the precipitated Cr2O3 nanoparticles and the generation of micro-defects, resulting in a drastic morphological evolution, an evident increase in the surface roughness, and a significant decrease in the mechanical properties. This study provides new perspectives on designing novel thermal barrier coatings and understanding the role of high temperature air annealing on the microstructural transformation.

Producing Hydrogen Energy Using Cr2O3-TiO2 Nanocomposite with Animal (Chitosan) Extract via Photocatalaysis

In this study, an efficient photocatalyst for water splitting was developed. The Cr2O3 and TiO2 nanoparticles (Cr2O3-TNPs) nanocomposite with (Chitosan extract) was created using ecologically friendly methods, such as the impregnation technique as TiO2 exhibits nano spherical (TNPs) shape structure. According to the researchers, this nanocomposite material enhanced its ability to absorb ultraviolet light while also speeding up the recombination of photogenerated electrons and holes. The TNPs and prepared Cr2O3-TNPs were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive x-ray spectroscopy (EDX), and UV-visible absorbance. The XRD of TNPs showed a Tetragonal phase with 8.9 nm of average crystallite size and 14.2 nm for nanocomposite. FE-SEM images showed that the average particle size in the range of (12.5-57.5) nm and UV-VIS absorbance has energy gap of 3.8 eV, while the energy gap of Cr2O3-TNPs is 2.8 eV. It was found that the performance of photocatalysts of the nanocomposite for hydrogen generation was superior. It gave the highest rate of hydrogen production (3.6) ml at 80 min when exposed to ultraviolet light. Moreover, the nanocomposite revealed high H2 production rate under ultraviolt light irradiation (λ < 400 nm). The Cr2O3-TNps have high photocatalytic effectiveness due to their wide ultraviolt light photoresponse range and excellent separation of photogenerated electrons and holes.

A study on green synthesis, characterization of chromium oxide nanoparticles and their enzyme inhibitory potential.

The conventional chemical methods of nanoparticles synthesis have been effectively replaced by nanoparticle synthesis mediated by plants. The current study describes the environmental friendly synthesis of chromium oxide nanoparticles (Cr2O3 NPs) using Erythrophleum guineense plant extract. The synthesis of Cr2O3 NPs was validated by UV/VIS spectroscopy, Energy Dispersive X-Ray (EDX), Scanning Electron Microscopy (SEM), and X-ray diffraction (XRD) studies. The appearance of the Sharpe peak at 460 nm in the UV/Vis spectrum and the colour change caused by surface plasma resonance confirmed the formation of Cr2O3 NPs. The EDX spectrum of Cr2O3 nanoparticles revealed the presence of carbon, oxygen, and chromium, while SEM analysis revealed an irregular round morphology (with a size below 400 nm). In addition, XRD studies suggested their crystalline nature by the characteristic peaks at 34° and 36° and 42° (2Ɵ), respectively. The green synthesized Cr2O3 NPs showed promise as in-vitro cholinesterase inhibitor at tested concentrations (62.5–1,000 μg/ml), with IC50 values of 120 and 100 μg/ml against Acetylcholinesterase (AChE) and Butyrylcholinesterase (BChE), respectively. The results suggested that the green synthesized Cr2O3 NPs could be used in the future to stop enzyme from working and for other biological activities.

Optical and morphological properties of poly(vinyl chloride)-nano-chitosan composites doped with TiO2 and Cr2O3 nanoparticles and their potential for solar energy applications

Optical and morphological properties of poly(vinyl chloride)-nano-chitosan composites doped with TiO2 and Cr2O3 nanoparticles and their potential for solar energy applications

The effect of a surfactant and dispersant mixed Cr2O3 nanoparticles on the analysis of stability and physicochemical properties of a Mesua ferrea biodiesel blend

This research work focuses on the stability and physicochemical characteristics of chromium oxide (Cr2O3) nanoparticles in Mesua ferrea biodiesel (BD20). The Cr2O3 nanoparticles were combined at 60, 80, and 100 mg/L. The dispersant (QPAN80) and surfactant (CTAB) were introduced (at 1:1 ratio) for the Cr2O3 nanoparticles. A mechanical agitator and probe sonicator were used to introduce Cr2O3 nanoparticles into BD20. The stability and physicochemical properties of various nanofuel samples were tested. A spectrophotometer was used to measure stability (absorbance and transmittance) on two separate days, Day 1 and Day 20. Compared to CTAB mixed and base nano fuels, dispersant-based nano fuels were shown to be more stable. Furthermore, the inclusion of Cr2O3 nanoparticles together with dispersion and surfactants improved important fuel properties. In terms of stability and physicochemical properties, BD20 + Cr2O3 80 mg/L + DSP 80 mg/L has shown better outcomes than remaining fuels. The heating value and cetane number were improved for surfactant and dispersant added Cr2O3 nano fuel while the viscosity, relative density, and flashpoint were shown slightly opposed results. The higher absorbance and lower transmittance were perceived as 4.58 and 87.7% while the heating value and cetane number were 41.33 MJ/kg and 60, respectively, for BD20 + Cr2O3 80 mg/L + DSP 80 mg/L.

Retraction Note: Computer-aided design of the effects of Cr2O3 nanoparticles on split tensile strength and water permeability of high strength concrete

Retraction Note: Computer-aided design of the effects of Cr2O3 nanoparticles on split tensile strength and water permeability of high strength concrete

Energy harvesting feasibility from photovoltaic/thermal (PV/T) hybrid system with [formula omitted]-glycerol nanofluid optical filter

In this interdisciplinary experimental study a new nanofluid-based optical filter (NFOF) was designed and tested for a photovoltaic/thermal (PV/T) hybrid system. To this end, Ag/ Cr2O3 nanoparticles (NPs) were synthesized with 5% concentration of Ag, then the obtained Ag/Cr2O3 NPs were suspended in glycerol (C3H8O3). The prepared nanofluid optical filter is outstanding and novel from some aspects: (i) the simple synthesis method of Ag/Cr2O3 NPs, (ii) bears desirable transmittance, (iii) high stability of nanoparticles in base fluid, (iv) low-cost production process, (v) acceptable overall energetic and exergetic efficiency. The intense solar irradiance occurs in the visible spectrum range where most solar systems are designed based on this range. Moreover, the highest spectral response of the silicon type solar cells can be achieved in wavelengths between 650 nm and 1075 nm (ideal window). Therefore, the prepared NFOF filters was designed to have maximum transmittance in wavelengths between 650 nm and 1075 nm for efficient photo-electrical conversion. Accordingly, they should have high absorbance in the wavelengths out of the said region (especially visible spectrum) for optimum photo-thermal conversion. The incident of spectra out of ideal window not only doesn't have any contribution to PV cell electricity generation, but also increases cell temperature which subsequently reduces its efficiency and longevity. For this purpose, NFOF was used as a selective thermal absorber that protects PV cell against unrequired spectra. Three different concentrations of Ag/Cr2O3 NPs were suspended in glycerol (10 ppm, 40 ppm, and 80 ppm). The performance of the hybrid PV/T system was checked by photothermal/electrical conversion efficiency, merit function, and overall exergy efficiency. The maximum photothermal energy conversion efficiency is 31.55% which is obtained by Ag/Cr2O3-glycerol (80 ppm) NFOF. Also, the highest value of photoelectric energy conversion is 13.25% which is obtained when there is no filter. Moreover, the Ag/Cr2O3-glycerol (40 ppm) NFOF caused the highest amount of overall energy efficiency (41%) and merit function (1.558). When E(λ)≠0, the highest and lowest overall exergy efficiency during 30 min testing was obtained by glycerol and Ag/Cr2O3-glycerol (80 ppm), while this is completely inverse when E(λ) = 0.

Green Nanotechnology: Recent Research on Bioresource-Based Nanoparticle Synthesis and Applications

In the last decades, the idea of green nanotechnology has been expanding, and researchers are developing greener and more sustainable techniques for synthesizing nanoparticles (NPs). The major objectives are to fabricate NPs using simple, sustainable, and cost-effective procedures while avoiding the use of hazardous materials that are usually utilized as reducing or capping agents. Many biosources, including plants, bacteria, fungus, yeasts, and algae, have been used to fabricate NPs of various shapes and sizes. The authors of this study emphasized the most current studies for fabricating NPs from biosources and their applications in a wide range of fields. This review addressed studies that cover green techniques for synthesizing nanoparticles of Ag, Au, ZnO, CuO, Co3O4, Fe3O4, TiO2, NiO, Al2O3, Cr2O3, Sm2O3, CeO2, La2O3, and Y2O3. Also, their applications were taken under consideration and discussed.

Bio‐fabricated chromium (III) oxide nanorods for catalytic and bactericidal applications in water treatment

AbstractThe treatment of chemical and biological contaminants in water through bio‐fabricated metal nanoparticles is one of the promising sustainable methods. Herein, an efficient synthesis of novel chromium oxide nanorods is introduced by Illicium verum fruit extract as a bio‐reducing, capping, and stabilizing agent. The morphological, optical, catalytic, and bactericidal properties of nanorods are investigated by various techniques. The UV–visible spectra displayed strong absorption peak in the region of 309.8 nm, whereas Fourier transform infrared presented the characteristic vibrations at 605.65 and 651.94 cm−1 attributed to CrO binding mode. Scanning electron microscopy results showed that chromium oxide nanoparticles are well‐dispersed with small rod‐shaped morphology. The average size of nanorods was found to be ~15 to 20 nm in length. Due to their ultra‐large surface area and strong π–π interaction, the plant‐coated nanorods were tested for the catalytic removal of methyl orange (MO), a common water‐soluble textile dye. Adsorption potential of Cr2O3 nanoparticles was monitored by UV–visible spectrophotometer, which showed 90–95% successive decrease in the absorption maxima of aqueous MO (1 μM). The elimination rate of MO was drastically improved from 45 to 30 min, while a combination of Cr2O3 nanorods and sodium borohydride NaBH4 was used. Bactericidal activities of these nanorods were tested against vast number of Gram‐positive and Gram‐negative bacteria. The significant results were obtained with 27 mm zone of inhibition against Klebsiella. oxytoca and Serratia. marcescens. This quick and simple procedure can be scaled up for commercial applications of new, eco‐friendly, and cost‐effective water treatment process.

Nd2O3, Cr2O3, and V2O3 Nanoparticles via Calcination: Synthesis, Characterization, Antimicrobial and Antioxidant Activities

Nd2O3, Cr2O3, and V2O3 nanoparticles were prepared by calcining the precursor materials that are novel mixed ligand complexes: [Nd(BDC)(ADMPY)(OAc)].H2O, [Cr(BDC)(ADM PY)Cl].H2O, and [V(BDC)(ADMPY)Cl].H2O, where BDC = 1,4-benzenedicarboxylic acid and ADMPY = 2-amino-4,6-dimethyl pyrimidine. The generated compounds were examined through several techniques such as elemental analysis (C.H.N), UV-Vis spectroscopy, thermal analysis (thermogravimetric, differential thermogravimetry, and differential thermal analysis), FT-IR spectra, X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). The TEM micrographs showed that neodymium oxide nanoparticles assumed agglomerated platelet-like particles, with particle sizes around 30.16 nm, while chromium oxide NPs showed solid block material with compact density and fewer pores with nearly spherical shape and 56.12 nm size. The vanadium oxide NPs were an agglomeration of small spherical nanoparticles of 28.4 nm size. The antimicrobial properties of the samples were assessed using two strains of Gram-positive bacteria, two strains of Gram-negative bacteria, and one strain of yeast. The antimicrobial results demonstrated that a large spectrum of activity characterizes the tested compounds because they are active on Gram-positive and Gram-negative bacteria, especially on Gram-positive strains. The antioxidant activity of prepared compounds was assessed by scavenging free radicals of DPPH. Metal oxide NPs also showed promising results as antioxidants.

Modelling the hardness of weld metal in the submerged arc welding of low carbon steel plates: addition of CR2O3 nanoparticles

ABSTRACT One of the mechanical properties of weldments influenced by the heat input generated by the Submerged Arc Welding (SAW) process is the Hardness of Weld Metal (HWM). This research was carried out to develop a non-linear regression model using the Response Surface Methodology (RSM) to predict the HWM in the SAW of low-carbon steel plates (St37) in the presence of Cr2O3 nanoparticles. For developing the regression model, current, voltage, stick-out, welding speed, and Cr2O3 nanoparticles were considered as the input variables and the HWM as the response. Analysis of variance was carried out to check the validity of the regression model and decide on the significant variables affecting the HWM. SEM and EDX analysis were performed on the weld to study the microstructure and elemental variables. The main and interactive effects of the input variables on the HWM were presented in graphical forms and analysed. The results showed that increasing the thickness of Cr2O3 nanoparticles increased the HWM due to grain refinement in the weld metal. Furthermore, optimisation of the model was developed for finding the optimum values of the HWM. Finally, confirmation tests were carried out and they indicated that the error of the empirical model was 4.36%.

MOF-derived In2O3 nanotubes/Cr2O3 nanoparticles composites for superior ethanol gas-sensing performance at room temperature

Semiconductor metal oxide gas sensors have been frequently used for real-time monitoring of various gases in different applications. However, the working temperature is usually high (>150 °C), which limits their application. In this work, the composites of In2O3 nanotubes derived from metal-organic framework (MOF) and Cr2O3 nanoparticles were successfully prepared via solvothermal and impregnation method. The structure, surface morphology and elementary of In2O3/Cr2O3 composites were characterized. Due to the synergistic effects of unique hollow tube structure, large specific surface area and p-n heterojunctions, the In2O3/Cr2O3 composites sensor exhibits excellent ethanol sensing performance at room temperature, including high response under low concentration (less than 5 ppm), excellent selectivity, good repeatability, fast response/recovery time, and long-term stability. The sensing mechanism was discussed in detail. This work provides a feasible synthesis strategy to prepare metal oxide-based hybrid composites, which could be used for fabrication of gas sensor with low energy consumption and high response.

Towards room-temperature and above magnetoelectricity in CoFe2O4/Cr2O3 core/shell nanoparticles

This work provides an effective approach to increase the magnetoelectric (ME) operating temperature of primordial sesqui oxide Cr2O3. The CoFe2O4 (core)/Cr2O3 (shell) nanoparticles with varying molar fractions are prepared via the sol-gel auto-combustion method. The phase-purity and coating induced micro-strains in core as well as shell have been validated from the Rietveld refinement of x-ray diffraction data, and are complementary to the Fourier transform infrared spectroscopy and Raman spectroscopy studies. Transmission electron microscopy measurement confirms the core/shell configuration of the nanoparticles. The magnetization measurements suggest screening of ferromagnetic interaction of CoFe2O4 (core) due to Cr2O3 shell over it, such that core/shell nanoparticles respond like single domain particles. A careful inspection of the impedance and modulus data suggest single relaxation in the studied frequency/temperature range for all the compositions. Both, the relaxation and the conduction processes are found to be polaronic obeying Mott variable range hopping mechanism. Direct ME measurements on these samples manifests the presence of linear magnetoelectricity for temperature as high as 400 K―a hallmark of enhancement in ME operating temperature of parental Cr2O3 phase and therefore widen its scope to meet the necessity of ME based potential applications.

Ultralow secondary electron emission and improved vacuum surface insulation of polyimide with scalable nanocomposite coating

Polymers with high surface electric insulation capability are greatly demanded in various electrical devices operating in vacuum ambient. Low secondary electron emission (SEE) is favorable to mitigate vacuum flashover by inhibiting the SEE avalanche across the surface. Although numerous approaches, esp. the surface modifications, promote the flashover strength of the insulator, a facile yet cost-effective modification strategy of a high-quality and scalable flexible insulator remains a formidable challenge. Herein, a facile ion-exchange technique is implemented to fabricate a nanoscale polyimide/chromic oxide (PI/Cr2O3) nanocomposite coating comprising hundreds of organic/inorganic interfaces securely adhered to a flexible PI substrate, which features ultralow secondary electron emission yields (SEEY). The low emissivity is achieved by introducing weakly emissive Cr2O3 nanoparticles as well as interfacial traps within the nanocomposite layer, which outperforms the existing and modified polymers. The PI/Cr2O3 shows a remarkable increase in flashover strength while keeping sufficient mechanical durability. The proposed surface engineering strategy is convenient and scalable, bringing up new insight into industrial applications.