To solve the problem of ammonia wastewater pollution generated from preparing rare earth carbonate using the ammonium bicarbonate precipitation method,an eco-friendly precipitant,magnesium bicarbonate,was used to prep...To solve the problem of ammonia wastewater pollution generated from preparing rare earth carbonate using the ammonium bicarbonate precipitation method,an eco-friendly precipitant,magnesium bicarbonate,was used to prepare lanthanum cerium carbonate.The lanthanum cerium sulfate solution obtained from the smelting and separation of Baotou mixed rare earth ore was used as the raw material.The influence of pH on the content of impurities,including SO^(2-)_(4)and magnesium,and the existing states of SO^(2-)_(4)n lanthanum cerium carbonate products,as well as the thermal decomposition behavior of the products,were deeply explored.SO^(2-)_(4)mainly exists in the form of rare earth sulfate complex salts in lanthanum cerium carbonate products.The fo rmation of the salts can be effectively avoided by adjusting the pH of the precipitation process.Then the content of SO^(2-)_(4)in the product is controlled.When the pH ranges from 6.00 to 7.12,the content of SO^(2-)_(4)in the product ranges from 0.42 wt%to 0.99 wt%.The content of MgO is lower than 0.04 wt%.Both contents meet the requirements of the national standard GB/T 16479-2020.In this study,lanthanum cerium carbonate products with low-content SO^(2-)_(4)were prepared.In addition,the existing states of SO^(2-)_(4)in the products are revealed.The research provides a new method for controlling the impurity content in preparing lanthanum cerium carbonate.展开更多
BACKGROUND Inflammatory bowel disease(IBD)is a common chronic intestinal inflammatory disease.High oxidative stress is a treatment target for IBD.Cerium oxide(CeO2)nanomaterials as nanozymes with antioxidant activity ...BACKGROUND Inflammatory bowel disease(IBD)is a common chronic intestinal inflammatory disease.High oxidative stress is a treatment target for IBD.Cerium oxide(CeO2)nanomaterials as nanozymes with antioxidant activity are potential drugs for the treatment of colitis.AIM To synthesize hollow cerium(H-CeO2)nanoparticles by one-step method and to validate the therapeutic efficacy of H-CeO2 in IBD.METHODS H-CeO2 was synthesized by one-step method and examined its characterization and nanoenzymatic activity.Subsequently,we constructed dextran sulfate so-dium(DSS)-induced colitis in mice to observe the effects of H-CeO2 on colonic inflammation.The effects of H-CeO2 on colon inflammation and reactive oxygen species(ROS)levels in IBD mice were detected by hematoxylin and eosin staining and dichlorofluorescein diacetate staining,respectively.Finally,the biological sa-fety of H-CeO2 on mice was evaluated by hematoxylin and eosin staining,blood routine,and blood biochemistry.RESULTS H-CeO2 nanoparticles prepared by the one-step method were uniform,monodi-sperse and hollow.H-CeO2 had a good ability to scavenge ROS,∙OH and∙OOH.H-CeO2 reduced DSS-induced decreases in body weight and colon length,colonic epithelial damage,inflammatory infiltration,and ROS accumulation.H-CeO2 administration reduced the disease activity index of DSS-induced animals from about 8 to 5.H-CeO2 had no significant effect on body weight,total platelet count,hemoglobin,white blood cell,and red blood cell counts in healthy mice.No significant damage to major organs was observed in healthy mice following H-CeO2 administration.CONCLUSION The one-step synthesis of H-CeO2 nanomaterials had good antioxidant activity,biosafety,and inhibited deve-lopment of DSS-induced IBD in mice by scavenging ROS.展开更多
Recycling rare earth elements(REEs)from waste is necessary for an environmentally sustainable reuse and wastewater management approach.Na-A zeolite was synthesized from coal fly ash(CFA)and applied for Ce^(3+)adsorpti...Recycling rare earth elements(REEs)from waste is necessary for an environmentally sustainable reuse and wastewater management approach.Na-A zeolite was synthesized from coal fly ash(CFA)and applied for Ce^(3+)adsorption.Fourier transform infrared(FTIR)spectra show peaks at 790,500 and 467 cm^(-1),which are bond vibrations of Si-O-Si,Si with Al-O and Si-O-.The surface area is 15.88 m^(2)/g,with a pore size of 2.14 nm.SEM images show a cubic shape,which indicates the formation of zeolite.Field emission and energy disperse spectroscopy(EDS)shows the formation of Si,Al,Na,and O.Na-A zeolite was applied for Ce^(3+)adsorption.The optimum conditions for Ce^(3+)adsorption are 50 ppm concentration,360 min,and pH 6.The maximum adsorption capacity is 176.49 mg/g.Based on the results,it is found that the adsorption of Ce^(3+)by Na-A zeolite is pseudo-second-order.The desorption test using HNO_(3) is more effective than using HCl and H_(2)SO_(4).A desorption efficiency of 97.22%is obtained at 4 cycles.Adsorption test using real sample wastewater demonstrates an adsorption efficiency of 83.35%.展开更多
Enhanced UV-B radiation represents a major environmental factor impacting global cereal production.Researchers have explored various approaches to reduce the detrimental impact of UV-B radiation on crops.Recently,engi...Enhanced UV-B radiation represents a major environmental factor impacting global cereal production.Researchers have explored various approaches to reduce the detrimental impact of UV-B radiation on crops.Recently,engineered nanoparticles,particularly cerium oxide nanoparticles(CeO_(2)-NPs),have attracted widespread interest for their ability to boost plant tolerance to a range of abiotic stresses.This study investigates how CeO_(2)-NPs application affects the morphology,physiology,biochemistry,and transcriptomics profiles of wheat seedling roots subjected to enhanced UV-B stress.The findings demonstrate that CeO_(2)-NPs notably promoted root length,fresh and dry weights,and root activity(p<0.05)under enhanced UV-B stress.CeO_(2)-NP treatment reduced the content of hydrogen peroxide<(H_(2)O_(2))and malondialdehyde(MDA)in wheat,alleviating oxidative damage in seedling roots and partially restoring the root phenotype.Under non-UV-B stress conditions,CeO_(2)-NP treatment triggered the difference of 237 transcripts in plants relative to the control group.Under enhanced UV-B stress,CeO_(2)-NP treatment exhibited differentially expressed genes(DEGs)linked to the antioxidant defense mechanism responsible for reactive oxygen species(ROS)scavenging,compared to the non-nanoparticle control.This suggests that ROS scavenging may be a key mechanism by which CeO_(2)-NPs enhance wheat resistance to enhanced UV-B radiation.This study elucidates a potential molecular mechanism through which CeO_(2)nanoparticles may enhance wheat tolerance to UV-B stress.展开更多
Cerium(Ce) compounds have attracted considerable attention as key components in functional coatings due to their many outstanding properties.This work provides a comprehensive review of recent advances in the applicat...Cerium(Ce) compounds have attracted considerable attention as key components in functional coatings due to their many outstanding properties.This work provides a comprehensive review of recent advances in the application of Ce in functional coatings.The role of Ce in the improvement of functional properties such as corrosion-resistance,self-healing,superhydrophobicity,wear-resistance,and UV shielding is reviewed from the perspective of functional mechanism and applied research.Furthermore,the strategies,processes,practical problems,and current challenges in the research of functional coatings containing Ce are summarized and discussed.The objective is to highlight the great potential of Ce in functional coatings,and to explore new applications of Ce in the development of novel coatings.Thus,this work aims to enhance the application value of Ce,solving the problem of unbalanced application of rare-earth elements.展开更多
Enlarging the steric hindrance to the molecular structures of extractants is a common way to improve their selectivity.To improve the separation factor of thorium(Ⅳ)and cerium(Ⅳ),cyclic groups having large steric hi...Enlarging the steric hindrance to the molecular structures of extractants is a common way to improve their selectivity.To improve the separation factor of thorium(Ⅳ)and cerium(Ⅳ),cyclic groups having large steric hindrance such as phenyl,cyclohexyl,and benzyl were introduced into theα-aminophosphonate extractant molecules.Bis(2-ethylhexyl)((phenylamino)methyl)phosphonate(PAMP),bis(2-ethylhexyl)((cyclohexylamino)methyl)phosphonate(CAMP),and bis(2-ethylhexyl)((benzylamine)methyl)phosphate(BAMP)were synthesized and applied in the separation and recovery of thorium(Ⅳ)and cerium(Ⅳ)from sulfuric acid solution.The separation ability between cerium(Ⅳ)and thorium(Ⅳ)descends in the order of CAMP>BAMP≈Cextrant230>DEHAMP>>PAMP,which is consistent with the decreasing order of steric hindrance.Nearly non-extraction of both cerium(Ⅳ)and thorium(Ⅳ)and the lowest separation ability for PAMP will be due to the conjugation of the lone pair of the amino N atom and benzene ring in PAMP.Furthermore,the extraction of REs(Ⅲ)by CAMP is lower than that of thorium(Ⅳ).Thermodynamic parameters(ΔG^(0),ΔH^(0),ΔS^(0))and extraction equilibrium constants were determined.An extraction process was developed to separate and retrieve thorium(Ⅳ)and cerium(Ⅳ)from a bastnaesite leaching solution.The final product purity of CeO2and ThO2is 99%and 98.4%,respectively,and the yields are 90.2%and 97.6%,respectively.展开更多
The purity of electronic-grade chemicals significantly impacts electronic components.Although crystallization has been used to purify cerium ammonium nitrate(CAN),the impurity removal mechanism underlying different cr...The purity of electronic-grade chemicals significantly impacts electronic components.Although crystallization has been used to purify cerium ammonium nitrate(CAN),the impurity removal mechanism underlying different crystallization parameters remains unclear.Traditional analytical methods of inductively coupled plasma mass spectrometry(ICP-MS)have problems in detecting trace Fe accurately,because of the high concentration of Ce and interference of polyatomic ions.Therefore,this study developed a new method integrating the standard addition and internal standard methods and explored the role of the kinetic energy discrimination mode.This new approach effectively overcomes Ce-related matrix interference and fills the gap in ultra-trace impurity detection.Furthermore,the study investigated the effects of cooling rate,seed mass loading and seed size on the removal of Fe impurity.The seed mass loading affects the average crystal size through regulating secondary nucleation and crystal growth.The removal of Fe in CAN is determined by surface adsorption and agglomeration.Under the condition of the cooling rate of 0.2 K·min^(-1),and addition of 0.5%(mass)600-680 μm seeds,the Fe content is the lowest,at only 0.24 mg·L^(-1),and the Fe removal rate reaches 92.28%.展开更多
Roasting bastnaesite concentrates is a crucial process in extracting rare earths.This study explored an efficient suspension roasting technology and investigated the bastnaesite pyrolysis and cerium(Ce)oxidation.Relev...Roasting bastnaesite concentrates is a crucial process in extracting rare earths.This study explored an efficient suspension roasting technology and investigated the bastnaesite pyrolysis and cerium(Ce)oxidation.Relevant analytical tests were applied to evaluate the phase and surface property variations of bastnaesite,and isothermal kinetic analysis of bastnaesite pyrolysis and Ce oxidation was performed.The results revealed that bastnaesite decomposed rapidly and accompanied by Ce oxidation,and the gas-solid products were identified as CO_(2),Ce_(7)O_(12),La_(2)O_(3),CeF_(3) and LaF_(3),with Ce oxidation restricted by bastnaesite pyrolysis.As roasting time prolonged,cracks and pores appeared on bastnaesite surface;the BET specific surface and pore diameter increased.In later roasting period,the pore diameter continued to increase but the specific surface decreased,assigned to particle fusion agglomeration and pore consolidation.Additionally,the surface C content reduced and Ce(Ⅳ)content increased gradually as roasting progressed.The reaction kinetics all followed Avrami-Erofeev equations,the reaction orders of bastnaesite pyrolysis and Ce oxidation decreased with decreasing reaction temperature.The calculated activation energies at lower temperatures were higher than those calculated at higher temperatures.This study analyzed the bastnaesite reaction mechanism to supply a reference for the application of suspension roasting technology in bastnaesite smelting.展开更多
Construction of elaborate configuration to enhance the intrinsic activity of NiMo-based catalyst candidates holds promise for accelerating the hydrogen evolution reaction(HER)kinetics.Herein,a novel cerium-doped NiMo ...Construction of elaborate configuration to enhance the intrinsic activity of NiMo-based catalyst candidates holds promise for accelerating the hydrogen evolution reaction(HER)kinetics.Herein,a novel cerium-doped NiMo phosphate(labeled as Ce-NiMo(PO_(4))_(0.66))is designed and fabricated via a facile hydrothermal and phosphatization method.A comprehensive characterization reveals that the introduction of the rare metal element cerium with an enriched 4f electronic distribution near the Fermi level modulates the hybridization of the 3d-2p orbitals and optimizes the electronic structure of the NiMo-based phosphate catalysts,which leads to the synergy between the nickel-molybdenum dual sites and the phosphate active unit to synchronously enhance the water dissociation and proton dehydrogenation transfer of the HER process.Consequently,Ce-NiMo(PO_(4))0.66 exhibits excellent alkaline HER performance with overpotentials at 10 and 500 mA·cm^(-2)current densities being only 40 and 295 mV,respectively,and desirable long-term durability at industrial current densities of 500 mA·cm^(-2).An overall hydrazine splitting(OHzS)constructed with Ce-NiMo(PO_(4))_(0.66)as a hydrazine oxidation reaction(HzOR)and HER bifunctional electrocatalyst has been constructed to achieve industrial current densities at the low voltage of 0.92 V,verifying its practical feasibility for sustainable hydrogen production and degradation of hydrazine pollutants.This work highlights that regulating the 3d-2p hybridization state through the inducing 4f orbital electronic state is a feasible means for enhancing the HER activity of transition metal compound catalysts.展开更多
Rare earth carbonates are essential precursors for the synthesis of oxide materials.In this study,we utilized in situ monitoring equipment to explore the alterations in the crystallization during the coprecipitation s...Rare earth carbonates are essential precursors for the synthesis of oxide materials.In this study,we utilized in situ monitoring equipment to explore the alterations in the crystallization during the coprecipitation synthesis of cerium carbonate.By controlling the crystallization pathway and in the absence of any te mplating agents,we successfully synthesized a unique sphe rical self-assembled cerium oxide particle(Ceria-S).The Ceria-S exhibits excellent polishing performance.The crystallization process of cerium carbonate at 50℃persists for roughly 50 min.During the initial stages of crystallization from 0 to t_(3),the precipitated particles are amorphous.This is followed by a plateau phase of crystal growth from t_(3)to t_(5).Subsequently,during the burst crystallization phase from t_(5)to t_(6),Ce_(2)(CO_(3))_(3)·6H_(2)O and Ce_(2)O(CO_(3))_(2)·nH2O are formed,exhibiting a rod-like crystal morphology.By rapidly drying the precipitated particles at 60℃for 10 min and calcining,Ceria-S is obtained.The Ceria-S,with an average diameter of 180 nm,is assembled from primary cerium oxide nanoparticles of approximately 15 nm.Owing to the self-assembly structure of cerium oxide spherical nanoparticles,they exhibit a significantly larger specific surface area,resulting in an elevated concentration of Ce^(3+)as high as 35.5%.The Ceria-S exhibits a polishing removal rate of 420 nm/min,effectively decreasing the surface roughness(S_(a))of K9 glass from 1.605 to 0.404 nm.展开更多
Correction to:J.Iron Steel Res.Int.https://doi.org/10.1007/s42243-025-01460-1 The publication of this article unfortunately contained mistakes.The revised and accepted dates were not correct.The corrected dates are gi...Correction to:J.Iron Steel Res.Int.https://doi.org/10.1007/s42243-025-01460-1 The publication of this article unfortunately contained mistakes.The revised and accepted dates were not correct.The corrected dates are given below.展开更多
Zinc calcium phosphate （Zn-Ca-P） coating and cerium-doped zinc calcium phosphate （Zn-Ca-Ce-P） coating were prepared on AZ31 magnesium alloy. The chemical compositions, morphologies and corrosion resistance of coat...Zinc calcium phosphate （Zn-Ca-P） coating and cerium-doped zinc calcium phosphate （Zn-Ca-Ce-P） coating were prepared on AZ31 magnesium alloy. The chemical compositions, morphologies and corrosion resistance of coatings were investigated through energy-dispersive X-ray spectroscopy （EDS）, X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, electron probe micro-analysis （EPMA） and scanning electron microscopy （SEM） together with hydrogen volumetric and electrochemical tests. The results indicate that both coatings predominately contain crystalline hopeite （Zn3（PO4）2·4H2O）, Mg3（PO4）2 and Ca3（PO4）2, and traces of non-crystalline MgF2 and CaF2. The Zn-Ca-Ce-P coating is more compact than the Zn-Ca-P coating due to the formation of CePO4, and displays better corrosion resistance than the Zn-Ca-P coating. Both coatings protect the AZ31 Mg substrate only during an initial immersion period. The micro-galvanic corrosion between the coatings and their substrates leads to an increase of hydrogen evolution rate （HER） with extending the immersion time. The addition of Ce promotes the homogenous distribution of Ca and formation of hopeite. The Zn-Ca-Ce-P coating has the potential for the primer coating on magnesium alloys.展开更多
The co-doping of iron and cerium into TiO2 was studied by means of X-ray diffraction, Raman spectroscopy, UV Vis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy, when separately doping via the so...The co-doping of iron and cerium into TiO2 was studied by means of X-ray diffraction, Raman spectroscopy, UV Vis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy, when separately doping via the sol-gel method, iron was introduced in the fralnework of anatase TiO2 whereas cerium was not; interestingly, both iron and cerium were introduced in tile framework when co-doping by the sol-gel method. The co-doped TiO2 behaves much more intense surface hydroxyl concentration than the separately-doped and pure TiO2. This observation demonstrates for the first time a cooperative effect in the co-doping of transitional metals in the framework of TiO2.展开更多
This work presents an investigation of solvent extraction parameters in order to obtain high purity cerium from a mixture containing other rare earths elements, as an alternative to oxidation and selective precipitati...This work presents an investigation of solvent extraction parameters in order to obtain high purity cerium from a mixture containing other rare earths elements, as an alternative to oxidation and selective precipitation or dissolution. The study was carried out using a sample of sulfuric liquor obtained from the leaching of monazite rich in light rare earth elements (La, Ce, Pr, Nd) provided by INB (Indústrias Nucleares do Brasil S.A.). Experiments were carried out in chloridric, nitric and sulfuric media. The nitric and hydrochloric solutions were prepared by precipitation of the REE from the sulfuric liquor as rare earths oxalate, calcining the precipitate and dissolving it with nitric or hydrochloric acid. The separation of cerium was investigated in its trivalent and tetravalent forms. The parameters investigated were: type and concentration of extractant, type and amount of the oxidizing agent, liquor acidity, and volumetric ratio between organic and aqueous phases. The preference of the organic phase to extract cerium in its oxidized form (IV) over the other rare earths elements was confirmed, allowing the obtainment of a high purity cerium solution. The best results were achieved in nitric medium, with cerium in its tetravalent form, using cationic extractants (P507 or D2EHPA) and a mixture of potassium persulfate and silver chloride as oxidizing agents, yielding over 99% of cerium extraction with over 99% of purity.展开更多
Electrospinning technique was used to fabricate PVP/Ce（NO3）3 composite microfibers. Different morphological CeO2 nanofibers were obtained by calcination of the PVP/Ce（NO3）3 composite microfibers and were character...Electrospinning technique was used to fabricate PVP/Ce（NO3）3 composite microfibers. Different morphological CeO2 nanofibers were obtained by calcination of the PVP/Ce（NO3）3 composite microfibers and were characterized by scanning electron microscopy （SEM）, Transmission electron microscopy （TEM）, X-ray diffraction （XRD）, thermal gravimetric and differential thermal analysis （TG-DTA）, and （FTIR）. SEM micrographs indicated that the surface of the composite fibers was smooth and became coarse with the increase of calcination temperatures. The diameters of CeO2 hollow nanofibers （300 nm at 600 ℃ and 600 nm at 800 ℃ ） were smaller than those of PVP/Ce（NO3）3 composite fibers （1-2 um ）. CeO2 hollow nanofibers were obtained at 600 ℃ and CeO2 hollow and porous nanofibers formed by nanoparti- cles were obtained at 800 ℃. The length of the CeO2 hollow nanofibers was greater than 50 um. XRD analysis revealed that the composite microfibers were amorphous in structure and CeO2 nanofibers were cubic in structure with space group O^5H - FM3m when calcination tem- peratures were 600-800 ℃. TG-DTA and FTIR revealed that the formation of CeO2 nanofibers was largely influenced by the calcination temperatures. Possible formation mechanism of CeO2 hollow nanofibers was proposed.展开更多
s: The influences of cerium and cerium carbide on the strength, plasticity, impact toughness and other mechanical properties of steels were investigated by means of metallography, scanning electron microscopy, impact ...s: The influences of cerium and cerium carbide on the strength, plasticity, impact toughness and other mechanical properties of steels were investigated by means of metallography, scanning electron microscopy, impact test, tensile test and other experimental methods. The results show that cerium in solid solution of the steel matrix can inhibit the grain growth of austenite and enhance the temperature of grain coarsening by fifty degrees at least. An excess of cerium addition will segregate to grain boundaries, and considerably reduce the impact toughness of the steel. The cerium carbide can obviously improve the plasticity and toughness of steels, but does not noticeably affect the yield strength of steels.展开更多
it was found by XPS and XRD that cerium existed as CeO_2 in iron based catalyst for dehydrogenation of ethylbenzene to styrene. and CeO_2 can be partly reduced under the reaction conditions to create Ce(3+)/Ce(4+) red...it was found by XPS and XRD that cerium existed as CeO_2 in iron based catalyst for dehydrogenation of ethylbenzene to styrene. and CeO_2 can be partly reduced under the reaction conditions to create Ce(3+)/Ce(4+) redox couples in the catalyst. The experiment of XPS and TPR-GC showed that there is an interaction between Ce oxide and Fe oxide, resulting in the shift of negative charge from iron to cerium and in the difficulty of Fe_2O_3 reduction to Fe_3O_4 in Fe_2O_3-CeO_2 system.The role of cerium promoter in the catalytic process was supposed to enhance the electron transfer among neighboring Fe active-sites of the catalyst and to improve the redox process of ethylbenzene dehydrogenation in the presence of steam by transferring oxygen from water to the active phase of the catalyst.展开更多
Cerium tartrate(CeTar),produced in this study by precipitating cerium nitrate with potassium sodium tartrate(KNaTar),was examined as a corrosion inhibitor.Weight loss tests show inhibition efficiency of 71.7% with Ce(...Cerium tartrate(CeTar),produced in this study by precipitating cerium nitrate with potassium sodium tartrate(KNaTar),was examined as a corrosion inhibitor.Weight loss tests show inhibition efficiency of 71.7% with Ce(NO_(3))_(3) and 88.7% with CeTar inhibitor for one-month exposure to mild steel in 7 g/L NaCl solution.The inhibition efficiency drops to 28.6% with the fo rmer and remains around 8 7% with the latter inhibitor after six months of exposure.Similar results from electrochemical testing indicate that the inhibition efficiency decreases by adding cerium nitrate.Still,the cerium tartrate inhibitor demonstrates a nearly constant inhibition efficiency for up to 30 d,i.e.,≈90%.Electrochemical impedance spectroscopy(EIS) performed in these cases shows the following results:(ⅰ) with cerium nitrate,a film of iron and cerium oxide,which on prolonged exposure diminishes,and(ⅱ) with cerium tartrate,the formation of a bimetallic film(Fe-tartrate-Ce) and a mixture of cerium hydroxide and iro n oxide that protects steel for a longer duration.These inferences are based on the analyses of scanning electron microscopy/energydispersive X-ray analysis(SEM/EDAX),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron(XPS),and Raman spectroscopy results.展开更多
Organic?inorganic hybrid coating on the surface of aluminum-tube used in refrigeration equipment using cerium ion (III) as the additive was fabricated by sol?gel method, and the structure of the coating was confirmed ...Organic?inorganic hybrid coating on the surface of aluminum-tube used in refrigeration equipment using cerium ion (III) as the additive was fabricated by sol?gel method, and the structure of the coating was confirmed by FT-IR. The results of the characterization show that the corrosion resistance of the coating with 1.5 mmol/L cerium ion (III) gains significant improvement, in which the colour retention time of CuSO4 extends to 500 s, the anti-acid and alkali corrosion rates reduce by 67% and 70% compared with the blank one, respectively, and the salt spray tests also show good corrosion resistance. The electrochemical tests demonstrate that the self-corrosion current density and potential of the sample with hybrid coating are about 2.877×10?7 A/cm2 and?0.550 V, respectively. The metallographic and SEM images show that the hybrid coating is uniform and dense, and the EDS analysis confirms that the coating is mainly composed of Al, Si and Ce elements.展开更多
Cerium oxide/silicon rubber was prepared via mechanical blending.Mechanical and frictional properties,as well as thermal stability after thermo-oxidative ageing were investigated in this rubber composite.3D surface pr...Cerium oxide/silicon rubber was prepared via mechanical blending.Mechanical and frictional properties,as well as thermal stability after thermo-oxidative ageing were investigated in this rubber composite.3D surface profilometry,scanning electron microscopy(SEM)and thermogravimetry analysis(TGA)were used to study the friction surface characteristics,friction mechanism and thermal stability,respectively.Additionally,swelling experiments were carried out to investigate the variation of crosslinking density.After thermo-oxidative ageing,the tear strength of cerium oxide/silicon rubber decreases.However,in the early ageing stage,improvements in tensile strength,elongation at break,and frictional performance are caused by crosslinking density increments.Moreover,the addition of cerium oxide remarkably improves the re-cross linking degree during ageing process,which in turn decreases the number of holes on the friction surface and endows the silicon rubber with better mechanical and frictional properties,as well as thermo-oxidative ageing resistance.展开更多
基金Project supported by the National Natural Science Foundation of China(52274355)the National Key Research and Development Program of China(2022YFC2905305)+1 种基金the Gansu Province Science and Technology Major Special Project,China(22ZD6GD061)the Inner Mongolia Autonomous Region Science and Technology Revitalization of Inner Mongolia Cooperation Project,China(2022YFXM0001)。
文摘To solve the problem of ammonia wastewater pollution generated from preparing rare earth carbonate using the ammonium bicarbonate precipitation method,an eco-friendly precipitant,magnesium bicarbonate,was used to prepare lanthanum cerium carbonate.The lanthanum cerium sulfate solution obtained from the smelting and separation of Baotou mixed rare earth ore was used as the raw material.The influence of pH on the content of impurities,including SO^(2-)_(4)and magnesium,and the existing states of SO^(2-)_(4)n lanthanum cerium carbonate products,as well as the thermal decomposition behavior of the products,were deeply explored.SO^(2-)_(4)mainly exists in the form of rare earth sulfate complex salts in lanthanum cerium carbonate products.The fo rmation of the salts can be effectively avoided by adjusting the pH of the precipitation process.Then the content of SO^(2-)_(4)in the product is controlled.When the pH ranges from 6.00 to 7.12,the content of SO^(2-)_(4)in the product ranges from 0.42 wt%to 0.99 wt%.The content of MgO is lower than 0.04 wt%.Both contents meet the requirements of the national standard GB/T 16479-2020.In this study,lanthanum cerium carbonate products with low-content SO^(2-)_(4)were prepared.In addition,the existing states of SO^(2-)_(4)in the products are revealed.The research provides a new method for controlling the impurity content in preparing lanthanum cerium carbonate.
文摘BACKGROUND Inflammatory bowel disease(IBD)is a common chronic intestinal inflammatory disease.High oxidative stress is a treatment target for IBD.Cerium oxide(CeO2)nanomaterials as nanozymes with antioxidant activity are potential drugs for the treatment of colitis.AIM To synthesize hollow cerium(H-CeO2)nanoparticles by one-step method and to validate the therapeutic efficacy of H-CeO2 in IBD.METHODS H-CeO2 was synthesized by one-step method and examined its characterization and nanoenzymatic activity.Subsequently,we constructed dextran sulfate so-dium(DSS)-induced colitis in mice to observe the effects of H-CeO2 on colonic inflammation.The effects of H-CeO2 on colon inflammation and reactive oxygen species(ROS)levels in IBD mice were detected by hematoxylin and eosin staining and dichlorofluorescein diacetate staining,respectively.Finally,the biological sa-fety of H-CeO2 on mice was evaluated by hematoxylin and eosin staining,blood routine,and blood biochemistry.RESULTS H-CeO2 nanoparticles prepared by the one-step method were uniform,monodi-sperse and hollow.H-CeO2 had a good ability to scavenge ROS,∙OH and∙OOH.H-CeO2 reduced DSS-induced decreases in body weight and colon length,colonic epithelial damage,inflammatory infiltration,and ROS accumulation.H-CeO2 administration reduced the disease activity index of DSS-induced animals from about 8 to 5.H-CeO2 had no significant effect on body weight,total platelet count,hemoglobin,white blood cell,and red blood cell counts in healthy mice.No significant damage to major organs was observed in healthy mice following H-CeO2 administration.CONCLUSION The one-step synthesis of H-CeO2 nanomaterials had good antioxidant activity,biosafety,and inhibited deve-lopment of DSS-induced IBD in mice by scavenging ROS.
基金Project supported by Rumah Program 2023 and Net Zero Emission Program(1507/Ⅱ.7/HK.01.00/6/2023)a research facility from the National Research and Innovation Agency of Republic of Indonesia。
文摘Recycling rare earth elements(REEs)from waste is necessary for an environmentally sustainable reuse and wastewater management approach.Na-A zeolite was synthesized from coal fly ash(CFA)and applied for Ce^(3+)adsorption.Fourier transform infrared(FTIR)spectra show peaks at 790,500 and 467 cm^(-1),which are bond vibrations of Si-O-Si,Si with Al-O and Si-O-.The surface area is 15.88 m^(2)/g,with a pore size of 2.14 nm.SEM images show a cubic shape,which indicates the formation of zeolite.Field emission and energy disperse spectroscopy(EDS)shows the formation of Si,Al,Na,and O.Na-A zeolite was applied for Ce^(3+)adsorption.The optimum conditions for Ce^(3+)adsorption are 50 ppm concentration,360 min,and pH 6.The maximum adsorption capacity is 176.49 mg/g.Based on the results,it is found that the adsorption of Ce^(3+)by Na-A zeolite is pseudo-second-order.The desorption test using HNO_(3) is more effective than using HCl and H_(2)SO_(4).A desorption efficiency of 97.22%is obtained at 4 cycles.Adsorption test using real sample wastewater demonstrates an adsorption efficiency of 83.35%.
基金supported by Graduate Innovation Project of Shanxi Normal University(Grant No.2021Y443).
文摘Enhanced UV-B radiation represents a major environmental factor impacting global cereal production.Researchers have explored various approaches to reduce the detrimental impact of UV-B radiation on crops.Recently,engineered nanoparticles,particularly cerium oxide nanoparticles(CeO_(2)-NPs),have attracted widespread interest for their ability to boost plant tolerance to a range of abiotic stresses.This study investigates how CeO_(2)-NPs application affects the morphology,physiology,biochemistry,and transcriptomics profiles of wheat seedling roots subjected to enhanced UV-B stress.The findings demonstrate that CeO_(2)-NPs notably promoted root length,fresh and dry weights,and root activity(p<0.05)under enhanced UV-B stress.CeO_(2)-NP treatment reduced the content of hydrogen peroxide<(H_(2)O_(2))and malondialdehyde(MDA)in wheat,alleviating oxidative damage in seedling roots and partially restoring the root phenotype.Under non-UV-B stress conditions,CeO_(2)-NP treatment triggered the difference of 237 transcripts in plants relative to the control group.Under enhanced UV-B stress,CeO_(2)-NP treatment exhibited differentially expressed genes(DEGs)linked to the antioxidant defense mechanism responsible for reactive oxygen species(ROS)scavenging,compared to the non-nanoparticle control.This suggests that ROS scavenging may be a key mechanism by which CeO_(2)-NPs enhance wheat resistance to enhanced UV-B radiation.This study elucidates a potential molecular mechanism through which CeO_(2)nanoparticles may enhance wheat tolerance to UV-B stress.
文摘Cerium(Ce) compounds have attracted considerable attention as key components in functional coatings due to their many outstanding properties.This work provides a comprehensive review of recent advances in the application of Ce in functional coatings.The role of Ce in the improvement of functional properties such as corrosion-resistance,self-healing,superhydrophobicity,wear-resistance,and UV shielding is reviewed from the perspective of functional mechanism and applied research.Furthermore,the strategies,processes,practical problems,and current challenges in the research of functional coatings containing Ce are summarized and discussed.The objective is to highlight the great potential of Ce in functional coatings,and to explore new applications of Ce in the development of novel coatings.Thus,this work aims to enhance the application value of Ce,solving the problem of unbalanced application of rare-earth elements.
基金Project supported by the National Natural Science Foundation of China(92262301)。
文摘Enlarging the steric hindrance to the molecular structures of extractants is a common way to improve their selectivity.To improve the separation factor of thorium(Ⅳ)and cerium(Ⅳ),cyclic groups having large steric hindrance such as phenyl,cyclohexyl,and benzyl were introduced into theα-aminophosphonate extractant molecules.Bis(2-ethylhexyl)((phenylamino)methyl)phosphonate(PAMP),bis(2-ethylhexyl)((cyclohexylamino)methyl)phosphonate(CAMP),and bis(2-ethylhexyl)((benzylamine)methyl)phosphate(BAMP)were synthesized and applied in the separation and recovery of thorium(Ⅳ)and cerium(Ⅳ)from sulfuric acid solution.The separation ability between cerium(Ⅳ)and thorium(Ⅳ)descends in the order of CAMP>BAMP≈Cextrant230>DEHAMP>>PAMP,which is consistent with the decreasing order of steric hindrance.Nearly non-extraction of both cerium(Ⅳ)and thorium(Ⅳ)and the lowest separation ability for PAMP will be due to the conjugation of the lone pair of the amino N atom and benzene ring in PAMP.Furthermore,the extraction of REs(Ⅲ)by CAMP is lower than that of thorium(Ⅳ).Thermodynamic parameters(ΔG^(0),ΔH^(0),ΔS^(0))and extraction equilibrium constants were determined.An extraction process was developed to separate and retrieve thorium(Ⅳ)and cerium(Ⅳ)from a bastnaesite leaching solution.The final product purity of CeO2and ThO2is 99%and 98.4%,respectively,and the yields are 90.2%and 97.6%,respectively.
基金the National Natural Science Foundation of China(22308358,22208346,22421003)IPE Project for Frontier Basic Research(QYJC-2023-05)+1 种基金National Key Research and Development Program(2022YFC3902701)CAS Project for Young Scientists in Basic Research(YSBR-038).
文摘The purity of electronic-grade chemicals significantly impacts electronic components.Although crystallization has been used to purify cerium ammonium nitrate(CAN),the impurity removal mechanism underlying different crystallization parameters remains unclear.Traditional analytical methods of inductively coupled plasma mass spectrometry(ICP-MS)have problems in detecting trace Fe accurately,because of the high concentration of Ce and interference of polyatomic ions.Therefore,this study developed a new method integrating the standard addition and internal standard methods and explored the role of the kinetic energy discrimination mode.This new approach effectively overcomes Ce-related matrix interference and fills the gap in ultra-trace impurity detection.Furthermore,the study investigated the effects of cooling rate,seed mass loading and seed size on the removal of Fe impurity.The seed mass loading affects the average crystal size through regulating secondary nucleation and crystal growth.The removal of Fe in CAN is determined by surface adsorption and agglomeration.Under the condition of the cooling rate of 0.2 K·min^(-1),and addition of 0.5%(mass)600-680 μm seeds,the Fe content is the lowest,at only 0.24 mg·L^(-1),and the Fe removal rate reaches 92.28%.
基金Projects(2022YFC2905800,2021YFC2901000)supported by the National Key R&D Program of ChinaProject(52174242)supported by the National Science and Technology of ChinaProject(52130406)supported by the National Science and Technology Major Project of China。
文摘Roasting bastnaesite concentrates is a crucial process in extracting rare earths.This study explored an efficient suspension roasting technology and investigated the bastnaesite pyrolysis and cerium(Ce)oxidation.Relevant analytical tests were applied to evaluate the phase and surface property variations of bastnaesite,and isothermal kinetic analysis of bastnaesite pyrolysis and Ce oxidation was performed.The results revealed that bastnaesite decomposed rapidly and accompanied by Ce oxidation,and the gas-solid products were identified as CO_(2),Ce_(7)O_(12),La_(2)O_(3),CeF_(3) and LaF_(3),with Ce oxidation restricted by bastnaesite pyrolysis.As roasting time prolonged,cracks and pores appeared on bastnaesite surface;the BET specific surface and pore diameter increased.In later roasting period,the pore diameter continued to increase but the specific surface decreased,assigned to particle fusion agglomeration and pore consolidation.Additionally,the surface C content reduced and Ce(Ⅳ)content increased gradually as roasting progressed.The reaction kinetics all followed Avrami-Erofeev equations,the reaction orders of bastnaesite pyrolysis and Ce oxidation decreased with decreasing reaction temperature.The calculated activation energies at lower temperatures were higher than those calculated at higher temperatures.This study analyzed the bastnaesite reaction mechanism to supply a reference for the application of suspension roasting technology in bastnaesite smelting.
基金supported by the National Natural Science Foundation of China(No.22278097)Heilongjiang Province Universities Basic Scientific Research Business Fee Project(Nos.2022-KYYWF-0568 and 2023-KYYWF-0527)+2 种基金the Natural Science Foundation of Heilongjiang Province(No.YQ2021B004)the Postdoctoral fellowship of Heilongjiang Province(No.LBH-Z23156)the Postdoctoral Fellowship Program of CPSF(No.GZC20233449).
文摘Construction of elaborate configuration to enhance the intrinsic activity of NiMo-based catalyst candidates holds promise for accelerating the hydrogen evolution reaction(HER)kinetics.Herein,a novel cerium-doped NiMo phosphate(labeled as Ce-NiMo(PO_(4))_(0.66))is designed and fabricated via a facile hydrothermal and phosphatization method.A comprehensive characterization reveals that the introduction of the rare metal element cerium with an enriched 4f electronic distribution near the Fermi level modulates the hybridization of the 3d-2p orbitals and optimizes the electronic structure of the NiMo-based phosphate catalysts,which leads to the synergy between the nickel-molybdenum dual sites and the phosphate active unit to synchronously enhance the water dissociation and proton dehydrogenation transfer of the HER process.Consequently,Ce-NiMo(PO_(4))0.66 exhibits excellent alkaline HER performance with overpotentials at 10 and 500 mA·cm^(-2)current densities being only 40 and 295 mV,respectively,and desirable long-term durability at industrial current densities of 500 mA·cm^(-2).An overall hydrazine splitting(OHzS)constructed with Ce-NiMo(PO_(4))_(0.66)as a hydrazine oxidation reaction(HzOR)and HER bifunctional electrocatalyst has been constructed to achieve industrial current densities at the low voltage of 0.92 V,verifying its practical feasibility for sustainable hydrogen production and degradation of hydrazine pollutants.This work highlights that regulating the 3d-2p hybridization state through the inducing 4f orbital electronic state is a feasible means for enhancing the HER activity of transition metal compound catalysts.
基金Project supported by the National Key Research and Development Program(2021YFB3501101)Beijing Nova Program(20220484827)+2 种基金National Natural Science Foundation of China(52304370)Central Government Guidance Local Science and Technology Development Fund Project of Hebei Province(236Z4102G)Natural Science Foundation of Hebei Province(E2022103012)。
文摘Rare earth carbonates are essential precursors for the synthesis of oxide materials.In this study,we utilized in situ monitoring equipment to explore the alterations in the crystallization during the coprecipitation synthesis of cerium carbonate.By controlling the crystallization pathway and in the absence of any te mplating agents,we successfully synthesized a unique sphe rical self-assembled cerium oxide particle(Ceria-S).The Ceria-S exhibits excellent polishing performance.The crystallization process of cerium carbonate at 50℃persists for roughly 50 min.During the initial stages of crystallization from 0 to t_(3),the precipitated particles are amorphous.This is followed by a plateau phase of crystal growth from t_(3)to t_(5).Subsequently,during the burst crystallization phase from t_(5)to t_(6),Ce_(2)(CO_(3))_(3)·6H_(2)O and Ce_(2)O(CO_(3))_(2)·nH2O are formed,exhibiting a rod-like crystal morphology.By rapidly drying the precipitated particles at 60℃for 10 min and calcining,Ceria-S is obtained.The Ceria-S,with an average diameter of 180 nm,is assembled from primary cerium oxide nanoparticles of approximately 15 nm.Owing to the self-assembly structure of cerium oxide spherical nanoparticles,they exhibit a significantly larger specific surface area,resulting in an elevated concentration of Ce^(3+)as high as 35.5%.The Ceria-S exhibits a polishing removal rate of 420 nm/min,effectively decreasing the surface roughness(S_(a))of K9 glass from 1.605 to 0.404 nm.
文摘Correction to:J.Iron Steel Res.Int.https://doi.org/10.1007/s42243-025-01460-1 The publication of this article unfortunately contained mistakes.The revised and accepted dates were not correct.The corrected dates are given below.
基金Project(51571134)supported by the National Natural Science Foundation of ChinaProject(2014TDJH104)supported by the SDUST Research Fund+1 种基金the Joint Innovative Centre for Safe and Effective Mining Technology and Equipment of Coal Resources,Shandong Province,ChinaProject(cstc2012jj A50034)supported by the Natural Science Foundation of Chongqing,China
文摘Zinc calcium phosphate （Zn-Ca-P） coating and cerium-doped zinc calcium phosphate （Zn-Ca-Ce-P） coating were prepared on AZ31 magnesium alloy. The chemical compositions, morphologies and corrosion resistance of coatings were investigated through energy-dispersive X-ray spectroscopy （EDS）, X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, electron probe micro-analysis （EPMA） and scanning electron microscopy （SEM） together with hydrogen volumetric and electrochemical tests. The results indicate that both coatings predominately contain crystalline hopeite （Zn3（PO4）2·4H2O）, Mg3（PO4）2 and Ca3（PO4）2, and traces of non-crystalline MgF2 and CaF2. The Zn-Ca-Ce-P coating is more compact than the Zn-Ca-P coating due to the formation of CePO4, and displays better corrosion resistance than the Zn-Ca-P coating. Both coatings protect the AZ31 Mg substrate only during an initial immersion period. The micro-galvanic corrosion between the coatings and their substrates leads to an increase of hydrogen evolution rate （HER） with extending the immersion time. The addition of Ce promotes the homogenous distribution of Ca and formation of hopeite. The Zn-Ca-Ce-P coating has the potential for the primer coating on magnesium alloys.
文摘The co-doping of iron and cerium into TiO2 was studied by means of X-ray diffraction, Raman spectroscopy, UV Vis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy, when separately doping via the sol-gel method, iron was introduced in the fralnework of anatase TiO2 whereas cerium was not; interestingly, both iron and cerium were introduced in tile framework when co-doping by the sol-gel method. The co-doped TiO2 behaves much more intense surface hydroxyl concentration than the separately-doped and pure TiO2. This observation demonstrates for the first time a cooperative effect in the co-doping of transitional metals in the framework of TiO2.
文摘This work presents an investigation of solvent extraction parameters in order to obtain high purity cerium from a mixture containing other rare earths elements, as an alternative to oxidation and selective precipitation or dissolution. The study was carried out using a sample of sulfuric liquor obtained from the leaching of monazite rich in light rare earth elements (La, Ce, Pr, Nd) provided by INB (Indústrias Nucleares do Brasil S.A.). Experiments were carried out in chloridric, nitric and sulfuric media. The nitric and hydrochloric solutions were prepared by precipitation of the REE from the sulfuric liquor as rare earths oxalate, calcining the precipitate and dissolving it with nitric or hydrochloric acid. The separation of cerium was investigated in its trivalent and tetravalent forms. The parameters investigated were: type and concentration of extractant, type and amount of the oxidizing agent, liquor acidity, and volumetric ratio between organic and aqueous phases. The preference of the organic phase to extract cerium in its oxidized form (IV) over the other rare earths elements was confirmed, allowing the obtainment of a high purity cerium solution. The best results were achieved in nitric medium, with cerium in its tetravalent form, using cationic extractants (P507 or D2EHPA) and a mixture of potassium persulfate and silver chloride as oxidizing agents, yielding over 99% of cerium extraction with over 99% of purity.
基金the Science and Technology Development Planning Project of Jilin Province (20040125, 20060504, 20070402)the Scien-tific Research Planning Project of the Education Department of Jilin Province (2005109, 2006YJT05)the Scientific Research Project of En-vironment Protection Bureau of Jilin Province(2006-24)
文摘Electrospinning technique was used to fabricate PVP/Ce（NO3）3 composite microfibers. Different morphological CeO2 nanofibers were obtained by calcination of the PVP/Ce（NO3）3 composite microfibers and were characterized by scanning electron microscopy （SEM）, Transmission electron microscopy （TEM）, X-ray diffraction （XRD）, thermal gravimetric and differential thermal analysis （TG-DTA）, and （FTIR）. SEM micrographs indicated that the surface of the composite fibers was smooth and became coarse with the increase of calcination temperatures. The diameters of CeO2 hollow nanofibers （300 nm at 600 ℃ and 600 nm at 800 ℃ ） were smaller than those of PVP/Ce（NO3）3 composite fibers （1-2 um ）. CeO2 hollow nanofibers were obtained at 600 ℃ and CeO2 hollow and porous nanofibers formed by nanoparti- cles were obtained at 800 ℃. The length of the CeO2 hollow nanofibers was greater than 50 um. XRD analysis revealed that the composite microfibers were amorphous in structure and CeO2 nanofibers were cubic in structure with space group O^5H - FM3m when calcination tem- peratures were 600-800 ℃. TG-DTA and FTIR revealed that the formation of CeO2 nanofibers was largely influenced by the calcination temperatures. Possible formation mechanism of CeO2 hollow nanofibers was proposed.
文摘s: The influences of cerium and cerium carbide on the strength, plasticity, impact toughness and other mechanical properties of steels were investigated by means of metallography, scanning electron microscopy, impact test, tensile test and other experimental methods. The results show that cerium in solid solution of the steel matrix can inhibit the grain growth of austenite and enhance the temperature of grain coarsening by fifty degrees at least. An excess of cerium addition will segregate to grain boundaries, and considerably reduce the impact toughness of the steel. The cerium carbide can obviously improve the plasticity and toughness of steels, but does not noticeably affect the yield strength of steels.
文摘it was found by XPS and XRD that cerium existed as CeO_2 in iron based catalyst for dehydrogenation of ethylbenzene to styrene. and CeO_2 can be partly reduced under the reaction conditions to create Ce(3+)/Ce(4+) redox couples in the catalyst. The experiment of XPS and TPR-GC showed that there is an interaction between Ce oxide and Fe oxide, resulting in the shift of negative charge from iron to cerium and in the difficulty of Fe_2O_3 reduction to Fe_3O_4 in Fe_2O_3-CeO_2 system.The role of cerium promoter in the catalytic process was supposed to enhance the electron transfer among neighboring Fe active-sites of the catalyst and to improve the redox process of ethylbenzene dehydrogenation in the presence of steam by transferring oxygen from water to the active phase of the catalyst.
基金funding agency University Grants Commission (UGC),Government of India,for giving a fellowship and other financial assistance for her Ph.D.thesis study。
文摘Cerium tartrate(CeTar),produced in this study by precipitating cerium nitrate with potassium sodium tartrate(KNaTar),was examined as a corrosion inhibitor.Weight loss tests show inhibition efficiency of 71.7% with Ce(NO_(3))_(3) and 88.7% with CeTar inhibitor for one-month exposure to mild steel in 7 g/L NaCl solution.The inhibition efficiency drops to 28.6% with the fo rmer and remains around 8 7% with the latter inhibitor after six months of exposure.Similar results from electrochemical testing indicate that the inhibition efficiency decreases by adding cerium nitrate.Still,the cerium tartrate inhibitor demonstrates a nearly constant inhibition efficiency for up to 30 d,i.e.,≈90%.Electrochemical impedance spectroscopy(EIS) performed in these cases shows the following results:(ⅰ) with cerium nitrate,a film of iron and cerium oxide,which on prolonged exposure diminishes,and(ⅱ) with cerium tartrate,the formation of a bimetallic film(Fe-tartrate-Ce) and a mixture of cerium hydroxide and iro n oxide that protects steel for a longer duration.These inferences are based on the analyses of scanning electron microscopy/energydispersive X-ray analysis(SEM/EDAX),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron(XPS),and Raman spectroscopy results.
基金Project(51404038)supported by the National Natural Science Foundation of China
文摘Organic?inorganic hybrid coating on the surface of aluminum-tube used in refrigeration equipment using cerium ion (III) as the additive was fabricated by sol?gel method, and the structure of the coating was confirmed by FT-IR. The results of the characterization show that the corrosion resistance of the coating with 1.5 mmol/L cerium ion (III) gains significant improvement, in which the colour retention time of CuSO4 extends to 500 s, the anti-acid and alkali corrosion rates reduce by 67% and 70% compared with the blank one, respectively, and the salt spray tests also show good corrosion resistance. The electrochemical tests demonstrate that the self-corrosion current density and potential of the sample with hybrid coating are about 2.877×10?7 A/cm2 and?0.550 V, respectively. The metallographic and SEM images show that the hybrid coating is uniform and dense, and the EDS analysis confirms that the coating is mainly composed of Al, Si and Ce elements.
基金Project supported by the Development Plan for Academics in Huanshui,the Natural Science Foundation of the Henan Province(182300410169,182102210201)the Support Project of Scientific and Technological Innovation Talents of Universities in Henan Province(19HASTIT023).
文摘Cerium oxide/silicon rubber was prepared via mechanical blending.Mechanical and frictional properties,as well as thermal stability after thermo-oxidative ageing were investigated in this rubber composite.3D surface profilometry,scanning electron microscopy(SEM)and thermogravimetry analysis(TGA)were used to study the friction surface characteristics,friction mechanism and thermal stability,respectively.Additionally,swelling experiments were carried out to investigate the variation of crosslinking density.After thermo-oxidative ageing,the tear strength of cerium oxide/silicon rubber decreases.However,in the early ageing stage,improvements in tensile strength,elongation at break,and frictional performance are caused by crosslinking density increments.Moreover,the addition of cerium oxide remarkably improves the re-cross linking degree during ageing process,which in turn decreases the number of holes on the friction surface and endows the silicon rubber with better mechanical and frictional properties,as well as thermo-oxidative ageing resistance.
