As a common precursor for supercritical CO_(2)(scCO_(2))deposition techniques,solubility data of organometallic complexes in scCO_(2)is crucial for the preparation of nanocomposites.Recently,metal acetylacetonates hav...As a common precursor for supercritical CO_(2)(scCO_(2))deposition techniques,solubility data of organometallic complexes in scCO_(2)is crucial for the preparation of nanocomposites.Recently,metal acetylacetonates have shown great potential for the preparation of single-atom catalytic materials.In this study,the solubilities of iron(Ⅲ)acetylacetonate(Fe(acac)3)and nickel(Ⅱ)acetylacetonate(Ni(acac)2)were measured at the temperature from 313.15 to 333.15 K and in the pressure range of 9.5–25.2 MPa to accumulate new solubility data.Solubility was measured using a static weight loss method.The semi-empirical models proposed by Chrastil and Sung et al.were used to correlate the solubility data of Fe(acac)3 and Ni(acac)2.The equations obtained can be used to predict the solubility of the same system in the experimental range.展开更多
The utility of nickel/iron in the remediation of atrazine-contaminated water was investigated. The experimental results showed that nickel/iron had effective catalytic activity in dechlorinating atrazine under acidic ...The utility of nickel/iron in the remediation of atrazine-contaminated water was investigated. The experimental results showed that nickel/iron had effective catalytic activity in dechlorinating atrazine under acidic conditions. The dechlorination reaction approximately followed the first-order kinetics under the experimental conditions(nickel/iron:1.0 g/250 ml;C atrazine=20.0 mg/L), the reaction rate increased with decreasing pH value of the reaction solution and increasing the proportion of Ni:Fe within 2.95%. For condition with 2.95% nickel/iron, the reaction rate constants were 0.07518(R=0.9927), 0.06212(R=0.9846) and 0.00131 min -1(R=0.9565) at pH=2.0, 3.0 and 4.0, respectively. HPLC analysis was used to monitor the decline of atrazine concentration.展开更多
Numerous studies have demonstrated that Na2SO4 can significantly inhibit the reduction of iron oxide in the selective reduction process of laterite nickel ore. FeS generated in the process plays an important role in s...Numerous studies have demonstrated that Na2SO4 can significantly inhibit the reduction of iron oxide in the selective reduction process of laterite nickel ore. FeS generated in the process plays an important role in selective reduction, but the generation process of FeS and its inhibition mechanism on iron reduction are not clear. To figure this out, X-ray diffraction and scanning electron microscopy analyses were conducted to study the roasted ore. The results show that when Na2SO4 is added in the roasting, the FeO content in the roasted ore increases accompanied by the emergence of FeS phase. Further analysis indicates that NaeS formed by the reaction of Na2SO4 with CO reacts with SiO2 at the FeO surface to generate FeS and Na2Si2Os. As a result, a thin film forms on the surface of FeO, hindering the contact between reducing gas and FeO. Therefore, the reduction of iron is depressed, and the FeO content in the roasted ore increases.展开更多
Iron nickel oxide catalysts were prepared using co-precipitation procedure and studied for the conversion of synthesis gas to light olefins.In particular,the effects of a range of preparation variables such as Fe/Ni m...Iron nickel oxide catalysts were prepared using co-precipitation procedure and studied for the conversion of synthesis gas to light olefins.In particular,the effects of a range of preparation variables such as Fe/Ni molar ratios of the precipitation solution,precipitate aging times,calcination conditions,different supports and loading of optimum support on the structure of catalysts and their catalytic performance for the tested reaction were investigated.It was found that the catalyst containing 40%Fe/60%Ni/40wt%Al 2O3 ,which was aged for 180 min and calcined at 600 ℃ for 6 h was the optimum modified catalyst.The catalytic performance of optimal catalyst has been studied in different operation conditions such as reaction temperatures,H2 /CO molar feed ratios and reaction total pressure.Characterization of both precursors and calcined catalysts was carried out by powder X-ray diffraction（XRD）,scanning electron microscopy（SEM）,Brunauer-Emmett-Teller（BET） surface area measurements,thermal analysis methods such as thermal gravimetric analysis（TGA） and differential scanning calorimetry（DSC）.展开更多
Detoxification of chlorinated organic compounds via reaction with nickel/iron powder was implemented in aqueous solution. Compared to iron, nickel/iron bimetallic powder had higher hydrodechlorination activities for b...Detoxification of chlorinated organic compounds via reaction with nickel/iron powder was implemented in aqueous solution. Compared to iron, nickel/iron bimetallic powder had higher hydrodechlorination activities for both atrazine (ATR) and p-chlorophenol (pCP); nickel/iron (2.96%, w/w) was shown to have the largest specific surface area and the optimum proportion for the dechlorination of both ATR and pCP. Electrochemical measurements showed that the adsorbed hydrogen atom on the nickel must have been the dominant reductive agent for the dechlorination of both ATR andpCP in this system.展开更多
A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At ...A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.展开更多
The electroactive materials used in the counter electrode(CE)are of great concern as they influence the photovoltaic performances of dye-sensitized solar cells.The main functions of CE materials are collecting electro...The electroactive materials used in the counter electrode(CE)are of great concern as they influence the photovoltaic performances of dye-sensitized solar cells.The main functions of CE materials are collecting electrons from the external circuit and transferring them to the electrolyte and realizing the catalytic reduction of the redox species(I3^– or Co^3+)present in the electrolyte.The research hotspot of CE materials is seeking functional materials that display high efficiency,low cost,and good electrochemical stability and can substitute the benchmark platinum electrode.Chalcogen compounds of cobalt,nickel,and iron have been widely applied as CE materials and exhibit excellent electrocatalytic performances owing to their unique electrical properties,similar energies of adsorption of I atoms as platinum,excellent catalytic activities,and good chemical stabilities.In this review,we trace the developments and performances of chalcogen compounds of iron,cobalt,and nickel as CE materials and present the latest research directions for improving the electrocatalytic performances.We then highlight the optimization strategies for further improving their performances,such as fabrication of architectures,regulation of the components,synthesis of composites containing carbon materials,and elemental doping.展开更多
The highly-dispersed iron element decorated Ni foam was prepared by simple immersion in a ferric nitrate solution at room temperature without using acid etching, and characterized by X-ray powder diffraction(XRD), sca...The highly-dispersed iron element decorated Ni foam was prepared by simple immersion in a ferric nitrate solution at room temperature without using acid etching, and characterized by X-ray powder diffraction(XRD), scanning electron microscopy(SEM), EDAX spectrum(EDAX mapping) and Raman spectroscopy. The EDAX spectrum illustrated that iron element was highly-dispersed over the entire surface of nickel foam, and the Raman spectroscopy revealed that both Ni-O and Fe-O bonds were formed on the surface of the as-prepared electrode. Moreover, the iron element decorated Ni foam electrode can be used as non-enzymatic glucose sensor and it exhibits not only an ultra-wide linear concentration range of 1-18 mmol/L with an outstanding sensitivity of 1.0388 m A·mmol/(L·cm2), but also an excellent ability of stability and selectivity. Therefore, this work presents a simple yet effective approach to successfully modify Ni foam as non-enzymatic glucose sensor.展开更多
The over-consumption of fossil fuels resulted in the large quantity emission of carbon dioxide （CO2）, which was the main reason for the climate change and more extreme weathers. Hence, it is extremely pressing to ex...The over-consumption of fossil fuels resulted in the large quantity emission of carbon dioxide （CO2）, which was the main reason for the climate change and more extreme weathers. Hence, it is extremely pressing to ex- plore efficient and sustainable approaches for the carbon-neutral pathway of CO2 utilization and recycling. In our recent works with this context, we developed successfully a novel ＂chemical vapor deposition integrated process （CVD-IP）＂ technology to converting robustly CO2 into the value-added solid-form carbon materials, The monometallic FeNi0-Al2O3 （FNi0） and bimetallic FeNix-Al2O3 （FNi2, FNi4, FNi8 and FNi20） samples were synthesized and effective for this new approach. The catalyst labeled FNi8 gave the better performance, exhibited the single pass solid carbon yield of 30%. These results illustrated alternative promising cases for the CO2 capture utilization storage （CCUS）, by means of the CO2 catalytic conversion into the solid-form nano carbon materials.展开更多
With the aid of thermomagnetic analysis (TMA) up to 800ºС the composition and distribution of particles of native iron and Fe-Ni alloy was studied in 15 sections, Gams (Austria), Verhorechie and Selbuhra (Cr...With the aid of thermomagnetic analysis (TMA) up to 800ºС the composition and distribution of particles of native iron and Fe-Ni alloy was studied in 15 sections, Gams (Austria), Verhorechie and Selbuhra (Crimea), Kvirinaki and Tetritskaro (Georgia), Aimaki, Bass, Dzhengutaj, Madzhalis and Gergebil (North Caucasus, Russia), Klyuchi and Tep-lovka (Volga Region, Russia), Koshak (Kazakhstan), Kara-Kala and Khalats (Turkmenistan). The age of sediments varies from Miocene to Early Cretaceous. Iron particles are present at 521samples out of 921studied. Their percentage varies from 10-5% to 0.05%. The distribution consists of two groups: 1) “zero” group (iron is not found by TMA);2) group of logarithmic normal distribution with a differing modes. The global enrichment by iron particles in synchronous deposits of Miocene, Maastrichtian-Danian, Santonian and Cenomanian was discovered. With respect to nickel content, the iron particles fall into two groups: 1) nearly pure iron without nickel;and 2) iron with nickel content up to 20%, with modal value of 5%. The source of iron particles is the cosmic dust. Particles of pure nickel and the alloy containing more of 20% of nickel are very rare. Possibly, such particles are related mainly with impact events. A peak of elevated iron content with nearly constant nickel of 5-6% was found in almost all studied sections. It is a global effect which is not dependent of place and time of deposition of iron particles.展开更多
The iron-doped nickel oxide films used as oxygen evolution catalysts in the photoelectrochemical production of hydrogen from solar energy were deposited by means of RF reactive magnetron sputtering from a Ni-Fe alloy ...The iron-doped nickel oxide films used as oxygen evolution catalysts in the photoelectrochemical production of hydrogen from solar energy were deposited by means of RF reactive magnetron sputtering from a Ni-Fe alloy target in oxygen and argon atmosphere.The effects of processing parameters on the film properties,such as overpotential,composition,surface morphology and preferred orientation,were investigated.The electrochemical experiment,structural and compositional measurements indicate that the relative lower substrate temperature,higher RF power,higher working pressure and oxygen content are necessary to gain lower overpotential.The lowest overpotential of 251 mV is obtained at a current density of 80 mA/cm2.The existence of iron,which acts as activity site,and Ni3+ ion is responsible for lowering overpotential.By analyzing SEM and XRD data,it is also noticed that an improvement in crystallinity,appropriate grain size and less crystalline phase contribute to an increased electrocatalytic activity in oxygen evolution reaction.These results mentioned above indicate that iron-doped nickel oxide is promising as an oxygen catalyst.展开更多
Nickel-iron type cast iron electrodes are widely used for welding QT600-3 nodular iron.Nevertheless,the research work has demonstrated that the strength of these heterogeneous welded joints is low.In this paper,the un...Nickel-iron type cast iron electrodes are widely used for welding QT600-3 nodular iron.Nevertheless,the research work has demonstrated that the strength of these heterogeneous welded joints is low.In this paper,the uni- axial tension of the joints is studied by the Moire fringe method,and the dis- placement,strain and stress in the total fields are obtaind.Based on the uneven distribution of strain and stress,the reason of crack initiation and propagation is discussed.Through examining the appearance of the fracture by scanning elec- tron microscope,a lot of spherical substances distributed on the fracture surface are found,which may be another reason leading to cracking of the welded joint under the lower tensile stress.These new findings will help to improve the properties of nickel-iron type cast iron electrodes and the strength of the welded joint.展开更多
According to the chemical and phase composition of the nickel-copper-iron matte containing precious metals and the progress in enrichment of precious metals from the nickel-copper-iron matte containing precious metals...According to the chemical and phase composition of the nickel-copper-iron matte containing precious metals and the progress in enrichment of precious metals from the nickel-copper-iron matte containing precious metals at home and abroad, this paper put forward the process route of enrichment of precious metals and selectively leaching of base metals from the nickel-copper-iron matte by sulfuric acid and sodium hypochlorite. The effects of particle size, leaching temperature, leaching time, amount of sulfuric acid and sodium hypochlorite on the leaching rate of nickel, cobalt, copper and iron are mainly discussed. The results show that raw material particle size has significantly effects on the leaching rate of base metals, high leaching rate of base metals and enrichment of precious metals are obtained with the suitable particle size. Through the experiments, the reasonable experiment parameters and conditions were determined as fellows: particle size of-200 to +250 mesh, leaching temperature 95℃ , leaching time 5 h, sulfuric acid concentration 30%, adding amount of sodium hypochlorite 3 times of matte weight. Under these experiment parameters and conditions, the leaching rate of nickel, cobalt, copper and iron were 97.39%, 96.24%, 98.30% and 99.01%, respectively. The content of nickel, cobalt, copper, iron in the leaching residues was 8.15%, 0.23%, 1.40% and 0.24%, respectively. The content of Pt, Pd, Au, Ag and Rh in the leaching residues was 247 g/t, 521 g/t, 112 g/t, 494 g/t and 24 g/t, respectively. The content of Pt, Pd, Au, Ag and Rh in the leaching solution was <0.0005 g/L, 0.0023 g/L, 0.0007 g/L, <0.0005 g/L and 0.00017 g/L, respectively. This process has advantages as follows: a small investment, simple technology, high enrichment efficiency.展开更多
X-ray diffraction was utilized to measure the residual stress of 45 mm UNS N08810 plates after post-weld heat treatment at temperatures of 680℃ and 900℃, which showed reductions of 86.9% and 71.6% in the residual st...X-ray diffraction was utilized to measure the residual stress of 45 mm UNS N08810 plates after post-weld heat treatment at temperatures of 680℃ and 900℃, which showed reductions of 86.9% and 71.6% in the residual stress, respectively. This indicates that post-weld heat treatment can play a significant role in reducing residual stress, while no significant effects on tensile stress and micro-hardness of the welding joint were observed after treatment.展开更多
Fixed-bed operating experimental column conditions were studied to evaluate the performance of brick from Bangui Region (in Central African Republic), coated with iron oxyhydroxide (ferrihydrite) for the removal of ir...Fixed-bed operating experimental column conditions were studied to evaluate the performance of brick from Bangui Region (in Central African Republic), coated with iron oxyhydroxide (ferrihydrite) for the removal of iron(II) from aqueous solution. The prediction of theoretical breakthrough profiles using Bohart and Adams sorption model was employed to achieve characteristic parameters such as depth of exchange zone, time required for exchange zone to move vertically, moving rate for the exchange zone and adsorption capacity useful for fixed-bed column reactor was investigated under varying operating conditions. The effects of bed depth and flow rate on iron(II) adsorption were studied. Our finding revealed that the Brick from Bangui Region (in Central African Republic), coated with ferrihydrite was a very efficient media for the removal of Fe(II) ions from water. The experimental data showed that the depth and the moving rate (10.3 ± 0.6 cm) and (0.208 ± 0.006 cm/min) respectively of the exchange zone (adsorption zone) were independent of variability of the height of the adsorbent bed column, however the variations of the flow rate affect the moving rate of the exchange zone. The bed depth service time (BDST) model was used and permitted us to predict the service times of columns operated at various flow rates and bed depths and these predicted values were compared with the experimental values.展开更多
基金financial support from the National Key Research and Development Program of China(2020YFA0710202)the National Natural Science Foundation of China(21978043,U1662130)+1 种基金Inner Mongolia University of Technology Scientific Research Initial Funding(DC2300001240)Talent Introduction Support Project of Inner Mongolia(DC2300001426).
文摘As a common precursor for supercritical CO_(2)(scCO_(2))deposition techniques,solubility data of organometallic complexes in scCO_(2)is crucial for the preparation of nanocomposites.Recently,metal acetylacetonates have shown great potential for the preparation of single-atom catalytic materials.In this study,the solubilities of iron(Ⅲ)acetylacetonate(Fe(acac)3)and nickel(Ⅱ)acetylacetonate(Ni(acac)2)were measured at the temperature from 313.15 to 333.15 K and in the pressure range of 9.5–25.2 MPa to accumulate new solubility data.Solubility was measured using a static weight loss method.The semi-empirical models proposed by Chrastil and Sung et al.were used to correlate the solubility data of Fe(acac)3 and Ni(acac)2.The equations obtained can be used to predict the solubility of the same system in the experimental range.
文摘The utility of nickel/iron in the remediation of atrazine-contaminated water was investigated. The experimental results showed that nickel/iron had effective catalytic activity in dechlorinating atrazine under acidic conditions. The dechlorination reaction approximately followed the first-order kinetics under the experimental conditions(nickel/iron:1.0 g/250 ml;C atrazine=20.0 mg/L), the reaction rate increased with decreasing pH value of the reaction solution and increasing the proportion of Ni:Fe within 2.95%. For condition with 2.95% nickel/iron, the reaction rate constants were 0.07518(R=0.9927), 0.06212(R=0.9846) and 0.00131 min -1(R=0.9565) at pH=2.0, 3.0 and 4.0, respectively. HPLC analysis was used to monitor the decline of atrazine concentration.
基金the Specialized Research Fund for the Doctoral Program of Higher Education of China (No.20130006110017) for the financial support for this research
文摘Numerous studies have demonstrated that Na2SO4 can significantly inhibit the reduction of iron oxide in the selective reduction process of laterite nickel ore. FeS generated in the process plays an important role in selective reduction, but the generation process of FeS and its inhibition mechanism on iron reduction are not clear. To figure this out, X-ray diffraction and scanning electron microscopy analyses were conducted to study the roasted ore. The results show that when Na2SO4 is added in the roasting, the FeO content in the roasted ore increases accompanied by the emergence of FeS phase. Further analysis indicates that NaeS formed by the reaction of Na2SO4 with CO reacts with SiO2 at the FeO surface to generate FeS and Na2Si2Os. As a result, a thin film forms on the surface of FeO, hindering the contact between reducing gas and FeO. Therefore, the reduction of iron is depressed, and the FeO content in the roasted ore increases.
文摘Iron nickel oxide catalysts were prepared using co-precipitation procedure and studied for the conversion of synthesis gas to light olefins.In particular,the effects of a range of preparation variables such as Fe/Ni molar ratios of the precipitation solution,precipitate aging times,calcination conditions,different supports and loading of optimum support on the structure of catalysts and their catalytic performance for the tested reaction were investigated.It was found that the catalyst containing 40%Fe/60%Ni/40wt%Al 2O3 ,which was aged for 180 min and calcined at 600 ℃ for 6 h was the optimum modified catalyst.The catalytic performance of optimal catalyst has been studied in different operation conditions such as reaction temperatures,H2 /CO molar feed ratios and reaction total pressure.Characterization of both precursors and calcined catalysts was carried out by powder X-ray diffraction（XRD）,scanning electron microscopy（SEM）,Brunauer-Emmett-Teller（BET） surface area measurements,thermal analysis methods such as thermal gravimetric analysis（TGA） and differential scanning calorimetry（DSC）.
基金Project (No. 30270767) supported by the National Natural Science Foundation of China
文摘Detoxification of chlorinated organic compounds via reaction with nickel/iron powder was implemented in aqueous solution. Compared to iron, nickel/iron bimetallic powder had higher hydrodechlorination activities for both atrazine (ATR) and p-chlorophenol (pCP); nickel/iron (2.96%, w/w) was shown to have the largest specific surface area and the optimum proportion for the dechlorination of both ATR and pCP. Electrochemical measurements showed that the adsorbed hydrogen atom on the nickel must have been the dominant reductive agent for the dechlorination of both ATR andpCP in this system.
文摘A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.
基金supported by the National Science Fund for Distinguished Young Scholars(21425729)from the National Natural Science Foundation of Chinathe National Special S&T Project on Water Pollution Control and Treatment(2017ZX07107002)+1 种基金China Postdoctoral Science Foundation(2018M640209)the Tianjin Science and Technology Support Key Projects(18YFZCSF00500)~~
文摘The electroactive materials used in the counter electrode(CE)are of great concern as they influence the photovoltaic performances of dye-sensitized solar cells.The main functions of CE materials are collecting electrons from the external circuit and transferring them to the electrolyte and realizing the catalytic reduction of the redox species(I3^– or Co^3+)present in the electrolyte.The research hotspot of CE materials is seeking functional materials that display high efficiency,low cost,and good electrochemical stability and can substitute the benchmark platinum electrode.Chalcogen compounds of cobalt,nickel,and iron have been widely applied as CE materials and exhibit excellent electrocatalytic performances owing to their unique electrical properties,similar energies of adsorption of I atoms as platinum,excellent catalytic activities,and good chemical stabilities.In this review,we trace the developments and performances of chalcogen compounds of iron,cobalt,and nickel as CE materials and present the latest research directions for improving the electrocatalytic performances.We then highlight the optimization strategies for further improving their performances,such as fabrication of architectures,regulation of the components,synthesis of composites containing carbon materials,and elemental doping.
基金Project(2019zzts684)supported by the Fundamental Research Funds for the Central Universities,China。
文摘The highly-dispersed iron element decorated Ni foam was prepared by simple immersion in a ferric nitrate solution at room temperature without using acid etching, and characterized by X-ray powder diffraction(XRD), scanning electron microscopy(SEM), EDAX spectrum(EDAX mapping) and Raman spectroscopy. The EDAX spectrum illustrated that iron element was highly-dispersed over the entire surface of nickel foam, and the Raman spectroscopy revealed that both Ni-O and Fe-O bonds were formed on the surface of the as-prepared electrode. Moreover, the iron element decorated Ni foam electrode can be used as non-enzymatic glucose sensor and it exhibits not only an ultra-wide linear concentration range of 1-18 mmol/L with an outstanding sensitivity of 1.0388 m A·mmol/(L·cm2), but also an excellent ability of stability and selectivity. Therefore, this work presents a simple yet effective approach to successfully modify Ni foam as non-enzymatic glucose sensor.
基金support for this project from the National Natural Science Foundation of China (21476145)the National 973 Program of Ministry of Sciences and Technologies of China (2011CB201202)
文摘The over-consumption of fossil fuels resulted in the large quantity emission of carbon dioxide （CO2）, which was the main reason for the climate change and more extreme weathers. Hence, it is extremely pressing to ex- plore efficient and sustainable approaches for the carbon-neutral pathway of CO2 utilization and recycling. In our recent works with this context, we developed successfully a novel ＂chemical vapor deposition integrated process （CVD-IP）＂ technology to converting robustly CO2 into the value-added solid-form carbon materials, The monometallic FeNi0-Al2O3 （FNi0） and bimetallic FeNix-Al2O3 （FNi2, FNi4, FNi8 and FNi20） samples were synthesized and effective for this new approach. The catalyst labeled FNi8 gave the better performance, exhibited the single pass solid carbon yield of 30%. These results illustrated alternative promising cases for the CO2 capture utilization storage （CCUS）, by means of the CO2 catalytic conversion into the solid-form nano carbon materials.
文摘With the aid of thermomagnetic analysis (TMA) up to 800ºС the composition and distribution of particles of native iron and Fe-Ni alloy was studied in 15 sections, Gams (Austria), Verhorechie and Selbuhra (Crimea), Kvirinaki and Tetritskaro (Georgia), Aimaki, Bass, Dzhengutaj, Madzhalis and Gergebil (North Caucasus, Russia), Klyuchi and Tep-lovka (Volga Region, Russia), Koshak (Kazakhstan), Kara-Kala and Khalats (Turkmenistan). The age of sediments varies from Miocene to Early Cretaceous. Iron particles are present at 521samples out of 921studied. Their percentage varies from 10-5% to 0.05%. The distribution consists of two groups: 1) “zero” group (iron is not found by TMA);2) group of logarithmic normal distribution with a differing modes. The global enrichment by iron particles in synchronous deposits of Miocene, Maastrichtian-Danian, Santonian and Cenomanian was discovered. With respect to nickel content, the iron particles fall into two groups: 1) nearly pure iron without nickel;and 2) iron with nickel content up to 20%, with modal value of 5%. The source of iron particles is the cosmic dust. Particles of pure nickel and the alloy containing more of 20% of nickel are very rare. Possibly, such particles are related mainly with impact events. A peak of elevated iron content with nearly constant nickel of 5-6% was found in almost all studied sections. It is a global effect which is not dependent of place and time of deposition of iron particles.
基金Project(2003CB214501) supported by the National Basic Research Program of ChinaProject(48010) supported by the Excellent Doctor’s Science and Technology Innovation Foundation of Beijing Jiaotong Univsersity,China
文摘The iron-doped nickel oxide films used as oxygen evolution catalysts in the photoelectrochemical production of hydrogen from solar energy were deposited by means of RF reactive magnetron sputtering from a Ni-Fe alloy target in oxygen and argon atmosphere.The effects of processing parameters on the film properties,such as overpotential,composition,surface morphology and preferred orientation,were investigated.The electrochemical experiment,structural and compositional measurements indicate that the relative lower substrate temperature,higher RF power,higher working pressure and oxygen content are necessary to gain lower overpotential.The lowest overpotential of 251 mV is obtained at a current density of 80 mA/cm2.The existence of iron,which acts as activity site,and Ni3+ ion is responsible for lowering overpotential.By analyzing SEM and XRD data,it is also noticed that an improvement in crystallinity,appropriate grain size and less crystalline phase contribute to an increased electrocatalytic activity in oxygen evolution reaction.These results mentioned above indicate that iron-doped nickel oxide is promising as an oxygen catalyst.
文摘Nickel-iron type cast iron electrodes are widely used for welding QT600-3 nodular iron.Nevertheless,the research work has demonstrated that the strength of these heterogeneous welded joints is low.In this paper,the uni- axial tension of the joints is studied by the Moire fringe method,and the dis- placement,strain and stress in the total fields are obtaind.Based on the uneven distribution of strain and stress,the reason of crack initiation and propagation is discussed.Through examining the appearance of the fracture by scanning elec- tron microscope,a lot of spherical substances distributed on the fracture surface are found,which may be another reason leading to cracking of the welded joint under the lower tensile stress.These new findings will help to improve the properties of nickel-iron type cast iron electrodes and the strength of the welded joint.
基金The National Basic Research Program (973 Plan)of China (2012CB724201)
文摘According to the chemical and phase composition of the nickel-copper-iron matte containing precious metals and the progress in enrichment of precious metals from the nickel-copper-iron matte containing precious metals at home and abroad, this paper put forward the process route of enrichment of precious metals and selectively leaching of base metals from the nickel-copper-iron matte by sulfuric acid and sodium hypochlorite. The effects of particle size, leaching temperature, leaching time, amount of sulfuric acid and sodium hypochlorite on the leaching rate of nickel, cobalt, copper and iron are mainly discussed. The results show that raw material particle size has significantly effects on the leaching rate of base metals, high leaching rate of base metals and enrichment of precious metals are obtained with the suitable particle size. Through the experiments, the reasonable experiment parameters and conditions were determined as fellows: particle size of-200 to +250 mesh, leaching temperature 95℃ , leaching time 5 h, sulfuric acid concentration 30%, adding amount of sodium hypochlorite 3 times of matte weight. Under these experiment parameters and conditions, the leaching rate of nickel, cobalt, copper and iron were 97.39%, 96.24%, 98.30% and 99.01%, respectively. The content of nickel, cobalt, copper, iron in the leaching residues was 8.15%, 0.23%, 1.40% and 0.24%, respectively. The content of Pt, Pd, Au, Ag and Rh in the leaching residues was 247 g/t, 521 g/t, 112 g/t, 494 g/t and 24 g/t, respectively. The content of Pt, Pd, Au, Ag and Rh in the leaching solution was <0.0005 g/L, 0.0023 g/L, 0.0007 g/L, <0.0005 g/L and 0.00017 g/L, respectively. This process has advantages as follows: a small investment, simple technology, high enrichment efficiency.
文摘X-ray diffraction was utilized to measure the residual stress of 45 mm UNS N08810 plates after post-weld heat treatment at temperatures of 680℃ and 900℃, which showed reductions of 86.9% and 71.6% in the residual stress, respectively. This indicates that post-weld heat treatment can play a significant role in reducing residual stress, while no significant effects on tensile stress and micro-hardness of the welding joint were observed after treatment.
文摘Fixed-bed operating experimental column conditions were studied to evaluate the performance of brick from Bangui Region (in Central African Republic), coated with iron oxyhydroxide (ferrihydrite) for the removal of iron(II) from aqueous solution. The prediction of theoretical breakthrough profiles using Bohart and Adams sorption model was employed to achieve characteristic parameters such as depth of exchange zone, time required for exchange zone to move vertically, moving rate for the exchange zone and adsorption capacity useful for fixed-bed column reactor was investigated under varying operating conditions. The effects of bed depth and flow rate on iron(II) adsorption were studied. Our finding revealed that the Brick from Bangui Region (in Central African Republic), coated with ferrihydrite was a very efficient media for the removal of Fe(II) ions from water. The experimental data showed that the depth and the moving rate (10.3 ± 0.6 cm) and (0.208 ± 0.006 cm/min) respectively of the exchange zone (adsorption zone) were independent of variability of the height of the adsorbent bed column, however the variations of the flow rate affect the moving rate of the exchange zone. The bed depth service time (BDST) model was used and permitted us to predict the service times of columns operated at various flow rates and bed depths and these predicted values were compared with the experimental values.
