JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
He Sun,Jiaming Chen,Yusheng Yang,Min Qiu,Milin Zhang
A low-grade ore containing 4 % niobium and 7 % titanium has been extracted from Bayan Obo tailing, but its potential has not been fully utilized. This study aims to recover the niobium and titanium elements from this low-grade ores in the form of their carbides. The process involves reducing niobium and titanium to (Nb,Ti)C through a carbothermal process. During this process, iron and silicon are also reduced to Fe-Si intermetallic compounds, allowing (Nb,Ti)C to diffuse into them. Subsequently, selective electrochemical oxidation is used to separate (Nb,Ti)C from the Fe-Si intermetallic compounds in an aqueous ferrous sulfate solution. The Fe-Si intermetallic compounds are first oxidized to the Fe 3 Si phase, and then to the Fe 5 Si 3 phase in the solution with pH 0.35. The (Nb,Ti)C/matrix interfaces are identified as the preferred site of electrochemical pitting corrosion. By exploiting the electrochemical oxidation reaction of iron in the matrix, (Nb,Ti)C powders are separated along these interfaces. The by-products of this process are FeSi alloys, which are evaluated for their electrocatalytic properties in oxygen evolution reactions. It is found that the Fe 5 Si 3 alloy by-product exhibits good electrocatalytic activity and kinetics in the oxygen evolution reaction, demonstrating its potential for practical applications.
研究领域:
冶金学
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材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2023
·
IF 4.5
Miao TIAN,Qiong-qiong WANG,Qin-meng WANG,Wei LI,Xue-yi GUO
The effect of MgO on the phase equilibria between matte and tridymite-saturated FeO x −SiO 2 −MgO slag was investigatedusing high-temperature equilibration and microanalysis technique. The results showed that at 1300 °C and p (SO 2 ) of 10 kPa, the presence of MgO reduced the FeO activity of the slag, leading to the decrease in the oxygen partial pressure ( p (O 2 )) over the slag and the Cu solubility in the slag. Due to the lower FeO activity, FeS was oxidized from matte into slag, increasing the Cu concentration of the matte. In high-SiO 2 concentrationslags, excessive MgO in the liquid slag recrystallized as solid olivine (Mg 2 SiO 4 −Fe 2 SiO 4 ), increasing the slag viscosity and copper losses in the slag. The maximum MgO solubility in the FeO x −SiO 2 −MgO slag increased from 3 wt.% to 8 wt.% when the temperature raised from 1200 to 1300 °C under p (O 2 ) of 10 −6 kPa. At higher MgO content, the slag composition could be optimized by increasing temperature and adding SiO 2 flux to maintain a fully molten slag or avoid high proportions of solids.
研究领域:
冶金学
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材料科学
✓ 已验证
DOI
高影响因子
Materials Today Energy
·
2021
·
IF 7.311
Qiang Ma,Yan Zhao,Zuojun Hu,Jiakang Qu,Zhuqing Zhao,Hongwei Xie,Pengfei Xing,Dihua Wang,Huayi Yin
Low-cost silicon (Si) feedstocks and a facile method to downsize the particle size are two determinants for the application of Si for the lithium-ion battery anode. Among various Si feedstocks, the industrial bulk ferrosilicon (b-Si/FeSi 2 ) alloy is a promising Si resource, but decreasing the particle size and increasing the utilization of Si remain challenging. Herein, we report a self-driven alloying-electrochemical dealloying approach to converting the b-Si/FeSi 2 to nano-sized Si/FeSi (n-Si/FeSi) in molten salts using Mg to extract one Si atom from one FeSi 2 molecule by breaking down the FeSi–Si chemical bond and simultaneously forming Mg 2 Si. Subsequently, the obtained FeSi and Mg 2 Si are converted to nano Si and FeSi by electrochemically removing Mg from the Mg 2 Si anode to the cathode, making a circular use of Mg and increasing the electroactive Si content. Moreover, the polydopamine-coated n-Si/FeSi (n-Si/FeSi@C) anode exhibits a high capacity of 1449.7 mAh g −1 after 500 cycles at 0.4 A g −1 , and an extremely stable reversible capacity of 846.8 mAh g −1 is retained even after 1500 cycles at 2 A g −1 . Overall, this work provides an efficient method to convert industrial bulk Si/FeSi 2 to nano-sized Si/FeSi by leveraging the chemical bonds of Fe–Si and Mg–Si.
研究领域:
材料科学
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电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2024
·
IF 2.4
Zhang Xu,Zhang Liqi,Huang Bowen,Yang Yusheng,Zhao Zengwu
Materials like metallic iron and its alloys are essential to daily living and industrial production. The benefits of using electrolysis technology to prepare iron and its alloys are great efficiency, controllability, and environmental protection. This study focuses on the feasibility of the electrochemical method for the direct preparation of metallic iron and Si–Fe alloys in iron ores with high fluoride content. The electrochemical behavior of Fe(II) and Fe(III) in molten SiO 2 –CaO–CaF 2 slag on tungsten electrodes was investigated by using cyclic voltammetry and square wave voltammetry methods. It was determined that the reduction of Fe(II) ions follows a one-step two-electron transfer process: Fe(II) + 2e − → Fe(0). The reduction of Fe(III) involves a two-step electron transfer process: Fe(III) + e − → Fe(II) and Fe(II) + 2e − → Fe(0), respectively. The Fe(II)/Fe(0) process is an irreversible reaction controlled by diffusion. The diffusion coefficient of Fe(II) is D Fe(II) = 1.5 × 10 −6 cm 2 s −1 . The cathodic deposits of iron were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) combined with energy dispersive X-ray spectroscopy (EDS). The findings indicate that the production of Fe 2 Si alloy through electrolysis is more favorable when Fe(II) is present in the slag, while the production of metallic iron is more favorable when Fe(III) is present in the slag. This work provides a basis for the electrochemical direct preparation of Fe–Si alloy and metallic iron in high fluorine iron ore.
研究领域:
冶金学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2021
·Vol. 50
·期 25
·8917-8926
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IF 4.39
Xingyu Chen,Yifu Zhang,Chen Wang,Xueying Dong,Changgong Meng
The design and preparation of electrode materials with excellent performance is particularly important due to the current global scarcity of energy supplies, especially those using sustainable and renewable materials. In this work, it is first proposed to apply iron silicate (FeSi), which is synthesized using environmentally friendly biomass as a raw material, as an electrode material for supercapacitors (SCs). FeSi is derived from the calcination of reed leaves (RLs) in combination with a hydrothermal method, and spherical FeSi retains the porosity of the RL precursors and shows remarkable electrochemical performance. The specific capacitance of FeSi as a SC electrode can reach 575 F g−1 at 0.5 A g−1 in the voltage window from −1 to −0.5 V. Simultaneously, the FeSi electrode exhibits favorable cycling stability with 76% capacitance retention after 10 000 cycles and outstanding electrical conductivity. This finding provides a novel method of preparing a kind of untapped electrode material, porous FeSi nanoparticles derived from RLs, and the resulting FeSi material shows enormous potential for energy storage via high-performance SCs.
研究领域:
材料科学
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能源技术
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Qi Sun,Limin Qi
Solar water splitting as a promising way to convert solar energy into hydrogen energy has been largely limited by the low efficiency of photoanodes in photoelectrochemical water oxidation. In this work, through deliberately employing a indium tin oxide (ITO) underlayer as an electron transport layer (ETL) and a Fe 2 TiO 5 overlayer as a hole transport layer (HTL), a novel triple-layer ITO/BiVO 4 /Fe 2 TiO 5 heterojunction photoanode was prepared by solution-processed sequential deposition. Owing to the unique ETL/BiVO 4 /HTL heterojunction structure, the photocurrent density at 1.23 V RHE was significantly increased from 1.70 mA/cm 2 for the pristine BiVO 4 photoanode to 4.60 mA/cm 2 for the ITO/BiVO 4 /Fe 2 TiO 5 photoanode. After iron silicate (Fe-Sil) was deposited as a new and efficient cocatalyst, the resultant quaternary ITO/BiVO 4 /Fe 2 TiO 5 /Fe-Sil photoanode achieved an extremely high photocurrent density of 6.19 mA/cm 2 and an ABPE value as high as 2.55%, indicating an outstanding performance toward solar water oxidation. The high performance of the quaternary ITO/BiVO 4 /Fe 2 TiO 5 /Fe-Sil photoanode may be attributed to the desired ETL/BiVO 4 /HTL heterojunction structure in combination with the utilization of the Fe-Sil as an efficient oxygen evolution cocatalyst.
研究领域:
材料科学
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能源科学
·
化学
✓ 已验证
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2021
·Vol. 19
·期 2
·813-827
·
IF 1.968
Cong Zhou,Shuang Li,Zhaoju Yu
Iron-containing PSO precursors (FePSO) were synthesized by modification of polysiloxane with different amounts of ferric acetylacetonate [Fe(acac) 3 ], then porous SiFeCO ceramics were successfully prepared by subsequent pyrolysis. The chemical modification and ceramization process of PFSO precursors were studied by FT-IR and TGA measurements. XRD patterns imply that the SiC crystalline can be easily observed when PFSO was exposed to 1200℃ in nitrogen atmosphere, while pure PSO exhibited broad diffraction peaks of SiC at 1500℃, meaning that the grain coarsening of SiC was accelerated by adding iron. The crystallization behavior of ferric silicide (Fe x Si y ) is complex due to the variation of iron content in feed and annealing temperature, and Fe x Si y /SiC@SiOC nanocomposites were produced after annealing. Because of the in-situ formation of SiC, Fe x Si y , and carbon strips in nanocomposites, PFSO-derived ceramics demonstrate enhanced microwave absorption performance. The best effective absorption bandwidth (<−10 dB) and the minimum reflection loss are 2.6 GHz and −38 dB, respectively, which are achieved in the sample PFSO-3–1300℃. Fe x Si y /SiC@SiOC nanocomposites synthesized in this work exhibit potential application in the field of electromagnetic interference, the carbon content and the crystallization behavior of Fe x Si y are the critical factors for the performance optimization.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Lan Wang,Chen Hou,Lingfeng Luo,Biao Xiang,Zhiqiang Zhu,Chuanyi Wang
The sluggish Fe(III)/Fe(II) conversion in the Fenton reaction strongly restrains the continuous generation of reactive oxygen species towards the oxidation of refractory pollutants. Herein, an ultrathin 2D/2D FeSi/GLC hybrid architecture is constructed by confining graphite-like carbon (GLC) in the layered-nanospace of Fe-bearing beidellite (FeSi) silicate for efficient photo-Fenton-like catalytic degradation of refractory pollutants. The 2D space-confinement effect of FeSi realizes the graphitization of carbonated glucose, in turn enhancing the electrical conductivity and visible-light harvesting ability of FeSi. By integrating the experimental and DFT calculation results, two pathways of Fe(II) recovery for enhancing Fenton oxidation are proposed: 1) GLC as electron-transfer channels significantly accelerates the photogenerated electrons transfer for Fe(II) reduction from Fe(III), as well as enhances electron shuttle from Fe(II) sites to H 2 O 2 , thus strongly promoting the cleavages of H 2 O 2 into •OH; 2) GLC mediates electron transfer from H 2 O 2 to Fe(III), boosting the regeneration of Fe(II) accompanied by •O 2 − production. As a demonstration, the hybrid FeSi 1.0 /C0.3–500 exhibits high-efficiency performance in photo-Fenton reaction with impressive catalytic activity (0.82 min −1 ), over 410 and 150 times faster than its analogue carbon-free system and commercial Fe 3 O 4 using phenol as the probe, respectively, accompanied by the mineralization of 74.4 % in 60 min. Additionally, the reaction system could remove 80 % of chemical oxygen demand (COD) from real coal chemical wastewater (200 mg·L −1 ) during 300 min of continuous operation. This study offers a new perspective for developing high-performance photo-Fenton catalysts, also confirms a promising practical application potential in industrial wastewater treatment.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Minghui Liu,Yutong Zhao,Ming Tian,Kejia Liu,Guoping Hu,Jian Zhang,Tianyan Xue,Tao Qi,Hui Zhang
Platinum group metals (PGMs) are scarce critical materials, and recovering PGMs from spent automotive catalysts (SAC) is economically and ecologically important. However, dissolving the Fe-Si-PGMs alloy derived from SAC is challenging, impeding PGMs recovery. This study aims to develop a more sustainable, efficient, and scalable leaching scheme. We demonstrate efficient leaching of Fe-Si-PGMs alloy using a thermochemical combined with mechanochemical leaching method with a HCl + FeCl 3 + H 2 O 2 solution. Kinetics parameters studies optimize the leaching process. The main obstacles to leaching are the chemical inertness of the alloy and the SiO 2 encapsulation formed. Ultimately, efficient dissolution of 99 % Pd, 95 % Pt and 88 % Rh was achieved, increasing PGMs leaching by 17 % compared to single thermochemical leaching. Additionally, this work remedies the scalability limitations of mechanochemical leaching and provides valuable insights for PGMs recovery.
研究领域:
冶金工程
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环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2024
·
IF 9.7
Zhihui Shen,Tiantian Wu,Jianlong Wang,Song Mao,Xianchen Wang
Efficient pretreatment of fine-disseminated gold ore is a challenge in effective gold extraction due to the invisible occurrence of the most encapsulated gold. In this study, we investigated the mechanism of co-pretreatment with eco-friendly CaO and Na 2 CO 3 to improve gold extraction from fine-disseminated gold ore using element content and valence measurement, phase composition analysis, micromorphology and structure characterization, and thermodynamic calculation . The results indicated that more than 75% of gold was encapsulated in pyrite, quartz and calcite . The gold leaching rate evidently increased with the reagent content and slurry temperature of the pretreatment , reaching a maximum of 86.55% at 60 °C and CaO and Na 2 CO 3 concentrations of 16 and 32 g/L, respectively. At lower concentrations of OH − or CO 3 2− , pyrite oxidation and quartz corrosion were both limited. Interestingly, at higher concentrations of OH − and CO 3 2− , pyrite was ultimately converted to Fe 2 O 3 and SO 4 2− under aerobic conditions ; meanwhile, partial dissolution products of quartz reacted with the intermediates of pyrite oxidation, generating a new phase of Fe 2 SiO 4 . In addition, the soluble intermediate ferric carbonate complexes, formed by the induction of sufficient CO 3 2− , inhibited the accumulation of the passivation layer on the pyrite surface, resulting in constant oxidation of pyrite. Furthermore, the oxidation of pyrite was the maximum at 60 °C, but limited at 90 °C due to the hindrance of oxidation product coating. As a result, the phase transition of gold-bearing pyrite and quartz could be enhanced by the synergistic pretreatment of CaO and Na 2 CO 3 , resulting in an approximately 30% increase in both exposed gold content and gold leaching rate. This research proposes a promising green pretreatment with cost benefits for fine-disseminated gold ore and provides significant insights into phase transition regulation to improve gold leaching.
研究领域:
矿物加工工程
·
冶金学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Healthcare Materials
·
2024
·
IF 10
Shuairu Zhu,Hongwei Xu,Wanying Guo,Mei Yang,Huiling Tan,Shaosong Hou,Jie Yao,Han Luo,Yongchao Yao,Jingxiang Zhao,Yonggang Wei,Xuping Sun,Binwu Ying
The versatile element composition and multifunctional properties of biodegradable silicates have attracted significant attention in cancer therapeutics. However, their application as nanozymes is often limited by suboptimal catalytic efficiency and insufficient intratumoral retention. In this study, the hydrothermal synthesis of iron silicate (FeSi) nanosheets are reported exhibiting exceptional peroxidase (POD)-like activity (136.7 U mg −1 ), outperforming most reported iron-based nanozymes. Density functional theory calculations revealed that the introduction of Si into the catalyst enhances H 2 O 2 adsorption and dissociation of Fe sites, leading to superior POD performance. Furthermore, the FeSi nanosheets are modified with Indocyanine Green (ICG) to facilitate targeted aggregation-potentiated therapy. The integration of ICG improved tumor penetration and retention of the FeSi nanosheets, significantly increasing their reactive oxygen species production and bolstering therapeutic efficacy.
研究领域:
生物医学工程
·
癌症治疗
·
纳米医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2016
·
IF 1.207
Liang Wang,Anqi Liu,Zhaohui Zhang,Bin Zhao,Yingming Xia,Yun Tan
In this work, a novel catalyst of Fe 3 O 4 @SiO 2 @Yb 2 O 3 was prepared and the degradation of thymol in reverse osmosis concentrate using ozonation was explored. The operational parameters, such as ozone dosage (8–48 mg·min − 1 ), initial thymol concentration (20–100 mg·L − 1 ), initial pH value (3–11), and catalyst Fe 3 O 4 @SiO 2 @Yb 2 O 3 dosage (0.2–1.0 g), were studied focusing on the thymol degradation and COD removal. The results indicated that the increase in ozone dosage, initial pH value, and Fe 3 O 4 @SiO 2 @Yb 2 O 3 dosage accelerated the thymol degradation and COD removal, while the increase in initial thymol concentration hampered the effect of ozonation. A pathway of thymol degradation by catalytic ozonation was proposed based on the intermediates detected by gas chromatography-mass spectrometer and ion chromatography . This paper can provide basic data and technical alternative for pollutant removal from reverse osmosis concentrate by ozonation.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）