METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2025
·
IF 3.1
Lv Tingting,Song Jianwei,An Yunfei,Hu Tu,Tian Huan,Dou Dehao
Metallic iron influences the carbothermic reduction of titanium oxides in ilmenite, thereby affecting the carburizing rate of the product. This study employs a CH 4 -H 2 mixed gas to reduce various types of ilmenite and for the first time systematically investigates the mechanism by which iron impacts the carburizing rate during the reduction process. The results demonstrate that iron can catalyze the cracking of methane to generate more carbon and hydrogen, which enhances the reduction of ilmenite. Additionally, iron can dissolve carbon, leading to a phase change that modifies the aggregation state of iron. This alteration promotes volume contraction of the reduced ilmenite, subsequently affecting the carburizing rate of the product. From 1150 °C to 1225 °C, the increased solubility of carbon in iron facilitates its conversion from a solid state to an interconnected molten state, obstructing pore spaces. Concurrently, the high viscosity of molten iron hinders the effective utilization of dissolved carbon, leading to a reduced carburizing rate. As the temperature continues to rise, the fluidity of the molten iron increases, causing it to reaggregate and resulting in the reappearance of cavities. Moreover, molten iron can act as a diffusion pathway for carbon, improving the contact area between carbon and titanium oxides, which in turn promotes the formation of carbides.
研究领域:
冶金学
·
材料科学
✓ 已验证
DOI
高影响因子
Nanoscale Advances
·
2024
·Vol. 6
·期 4
·1135-1144
·
IF 4.6
Xin Ke,Bingqing Xie,Jingguo Zhang,Jianwei Wang,Weiying Li,Liqing Ban,Qiang Hu,Huijun He,Limin Wang,Zhong Wang
High-purity, monodisperse, and low-oxygen submicron copper powder particles with particle sizes in the range of 100–600 nm were synthesized under alkaline conditions using ascorbic acid (C6H8O6) as a reductant and copper chloride (CuCl2·2H2O) as a copper source. The redox potential of the Cu–Cl–H2O system was obtained by calculations and plotted on pH–E diagrams, and a one-step secondary reduction process (Cu(II) → CuCl(I) → Cu2O(I) → Cu(0)) was proposed to slow down the reaction rate. The commonalities and differences in the nucleation and growth process of copper powders under methionine (Met), hexadecyl trimethyl ammonium bromide (CTAB), and sodium citrate dihydrate (SSC) as protectants and without the addition of protectants are compared, and the reaction mechanism is discussed. Among them, methionine (Met) showed excellent properties and the Cu2O(I) → Cu(0) process was further observed by in situ XRD. The synthesized copper powder particles have higher particle size controllability, dispersibility, antioxidant properties, and stability, and can be decomposed at lower temperatures (<280 °C). The resistivity can reach 21.4 μΩ cm when sintered at a temperature of 325 °C for 30 min. This green and simple synthesis process facilitates industrialization and storage, and the performance meets the requirements of electronic pastes.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2021
·Vol. 21
·期 1
·715-719
·
IF 0
Zhao Dong,Pei Wenli,Wang Xiaoyang,Zheng Jian,Liu Chunhong,Wang Jianjun
NdFeB magnetic nanoparticles with a main phase of Nd2Fe14B have successfully been synthesized. The preparation includes the following processes. First, the NdFeB intermediate was synthesized by a wet-chemical method. The NdFeB intermediate was annealed at 800 °C,
which resulted in the formation of an NdFeB oxide. Then, the NdFeB oxide was reduced into NdFeB nanoparticles by a second-step reduction annealing with a CaH2 reductant. The second-step reduction annealing temperature was a key factor in preparing the NdFeB nanoparticles. A lower
reduction temperature of 900 °C could not completely reduce the NdFeB oxide into Nd2Fe14B. There were some residual unreduced nonmagnetic phases in the prepared materials, which resulted in obvious decreases of coercivity. A sufficiently high second-stage reduction
temperature resulted in an increased reduction, and more of the Nd2Fe14B phase could be obtained. In this work, nanoparticles with a uniform morphology and an increased Nd2Fe14B phase could be obtained at an optimum reduction temperature of 940 °C,
achieving a high coercivity of 5.4 kOe.
研究领域:
材料科学
·
磁学
✓ 已验证
DOI
PubMed
Silicon
·
2019
·Vol. 12
·期 7
·1575-1584
·
IF 1.21
Zhou Shichao,Chen Zhengjie,Ma Wenhui,Li Shaoyuan,Li Chen,Wu Jijun,Yang Xi
The effect of K 2 CO 3 as an additive agent in the carbothermic reduction process of silicon production is investigated in this study. Using a thermogravimetric analyzer (TGA) in argon atmosphere, different proportions of petroleum coke (PC) and pomelo peel (PP) are used as the carbonaceous reducing agent. Findings show that the additive displays catalytic activities for reductant composition of PC and PP in solid state under high temperature. The maximum mass loss rate of samples with additive is found to increase by 13.7% in the same conditions, compared to samples without the additive. In addition, a homogenous model (HM) is studied as a kinetic model using the Coats-Redfern method to observe and determine the kinetic parameters of all samples. High correlation coefficient values for the pyrolysis stages (R 2 > 0.99) and the carbothermic reduction stage of silicon dioxide (R 2 > 0.98) are obtained for all samples, illustrating that the kinetic model is applicable to this reaction process. According to findings in this study, the additive K 2 CO 3 is determined to positively impact reaction activity, speeding up the rate of pyrolytic reaction and the carbothermic reduction of silica.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Magnetochemistry
·
2024
·Vol. 10
·期 5
·34
·
IF 2.6
Han Zhou,Zaitian Cheng,Zhiqiang Ai,Xinyao Li,Lin Hu,Fapei Zhang
The development of novel synthesis and assembly strategies is critical to achieving a ferromagnetic organic semiconductor with high Curie temperature. In this study, we report a high magnetic field (HMF)-modified solvothermal approach for the reduction in neutral perylene diimide (PDI) into the dianion species to prepare the PDI magnets comprising radical anions after subsequent oxidation processes. The PDI materials, assembled from the dianion solution by an HMF-modified reduction, exhibit a smaller crystallite size and an enlarged distance of the π-π stacking in the PDI aggregates. Furthermore, the PDI magnets obtained from the process under a 9T field reveal weakened ferromagnetism and the rapid degradation of electrical conductivity compared to those prepared without a magnetic field. Based on spectral and structural characterizations, such performance deterioration originates from the enhanced instability of the radical anions exposed to air, as well as the decreased crystallinity for the radical PDIs synthesized from the HMF-modified reduction process. This work demonstrates that magnetic fields offer an effective way in the material synthesis process to manipulate the structure and magnetic properties of the radical-based organic magnets.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 77
·73156-73159
·
IF 3.289
Wu Yi,Ding-Bang Xiong,Wang Zhang,Huilan Su,Qinglei Liu,Jiajun Gu,Shenmin Zhu,Di Zhang
Ge photonic crystals were synthesized by replicating butterfly wings with GeO2 via a facile liquid phase deposition followed by a reducing process. The reflectance spectra of the Ge photonic crystals show a broad peak at wavelengths of 700–800 nm and angle-dependent peak positions.
研究领域:
材料科学
·
生物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Jing Liang,Xinyu Li,Yujing Zheng,Yingnan Pang,Yunxing Zhao,Yao Wang,Jiejing Zhang,Jianfeng Zhang
Advanced reduction processes (ARPs) have become hotspot because of their fast and efficient features in pollutant treatment. In this study, a novel ARP was raised through the assistance of biological wastewater degradation solutions (PDs), to completely reduce Cr(VI). Enterobacter cloacae YN-4, which could completely degrade 1500 mg/L phenol within 72 h, was isolated and identified. While, the content of organic acids and their derivatives in PDs was extremely high (74.76 %). After the combination of PDs with Fe(III) and UV, 10 mg/L Cr(VI) was completely reduced within 66 min, whose reduction rate of Cr(VI) was stable at various concentrations (10–100 mg/L), which was applicable on electroplating wastewater. In addition, Cr(VI) could be reduced stably (71.63 %) after 10 cycles. Compared with the reported ARPs, herein, the components was complex, which was firstly proposed that simultaneous action of polycarboxylic acids, monocarboxylic acids, amino acids and alcohols could promote and ensure the stable reduction of Cr(VI). Among them, the multispecies radicals·CO 2 - and·O 2- generated in PDs were combined with Fe(II), to co-reduce Cr(VI). This strategy produces a wide variety of radicals, which can provide an alternative pathway for remediation of various heavy metals and organic pollutants.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2018
·Vol. 32
·期 8
·e4428
·
IF 3.581
Songfang Zhao,Haobo Jiang,Jinhui Li,Xiangying Meng,Tianyu Chao,Zhe Zhang,Peng Zhang,Yongju Gao,Duxia Cao
Efficient and reusable nanocatalysts fabricated via a facile assembly are highly desirable for the cost-effective hydrogenation reduction. Inspired by a fishing process with a fishnet, multifunctional nanostructured catalysts are rationally designed to combine interesting features via the self-redox assembly of Fe 3 O 4 -Ag composites on reduced graphene oxide (rGO) (Fe 3 O 4 -Ag/rGO). In detail, Fe 3 O 4 nanoparticles (NPs) endow the ternary hybrids with superparamagnetism (21.42 emu g −1 ), facilitating catalysts to be separated from the reaction system. rGO could provide electron transfer pathways, enhancing catalytic activity. More interestingly, GO and Ag + could behave as oxidants to oxidize Fe 2+ for the in situ assembly of Fe 3 O 4 -Ag/rGO without any addition of reductant/oxidant or organic solvents, and AgNPs endow the ternary hybrids with excellent catalytic behaviour. Meaningfully, the bioinspired process enables the ternary hybrids to possess more abundant micro−/nanopores, larger surface area, and more amorphization. They exhibit exceptional catalytic performance, and could be recycled with excellent activity by means of convenient magnetic separation (at least 7 times). Moreover, the ternary hybrids could degrade methylene blue under UV light due to different valence states of Fe in Fe 3 O 4 . Therefore, the proposed bioinspired assembly and structure design for hierarchical catalysts would pave a promising way to assemble other catalysts.
研究领域:
材料科学
·
纳米生物学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2023
·Vol. 15
·期 9
·4477-4487
·
IF 6.7
Meng Tian,Shanshan Wu,Yang Hu,Zhaori Mu,Zhi Li,Yichao Hou,Pinxian Xi,Chun-Hua Yan
Electrocatalytic reduction of CO2 to formate is considered as a promising method to achieve carbon neutrality, and the introduction of heteroatoms is an effective strategy to improve the catalytic activity and selectivity of catalysts. However, the structural reconstruction behavior of catalysts driven by voltage is usually ignored. Therefore, we used Cu/Bi2S3 as a model to reveal the dynamic reduction process in different atmospheric environments. The catalyst showed an outstanding faradaic efficiency of 94% for formate and a long-term stability of 100 h, and exhibited a high current density of 280 mA cm−2 in a flow cell. The experimental results and theoretical calculations show that the introduction of copper enhances the adsorption of CO2, accelerates the charge transfer and reduces the formation barrier of *OCHO, thus promoting the formation of formate. This work draws attention to the effects of saturated gases in the electrolyte during structural evolution and provides a possibility for designing catalysts with high catalytic activity.
研究领域:
材料科学
·
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Feifei Wang,Haiting Zhang,Weiran Qin,Chiquan He,Sung Kyu Maeng,Jan Hofman,Wenhai Chu
Disinfection by-products (DBPs) in chlor(am)inated drinking water and wastewater pose risks to human health and ecological safety. Studies on the degradation of the formed DBPs, especially aromatic DBPs, are quite limited. Recently, advanced reduction processes (ARPs), generating highly reactive reductive radicals to break the carbon-halogen bonds, as an emerging technology for refractory organic compound degradation has attracted attention. This study, for the first time, explored the degradation of a representative nitrogenous and aromatic DBP, 2-chlorophenylacetonitrile (2-CPAN), by VUV/UV/sulfite-based ARP system, and investigated the underlying mechanisms and influencing factors. The results demonstrated that VUV/UV/sulfite system achieved over 98.6 % and 86.8 % degradation of 2-CPAN from tap water and wastewater within 60 minutes although inorganic ions existing in real waters slightly inhibited its degradation, highlighting its potential for practical application in real waters. Due to VUV direct photolysis and the generation of more reactive species, VUV/UV/sulfite exhibited superior performance in 2-CPAN degradation (98 %) than UV/sulfite (81 %). Furthermore, VUV/UV/sulfite system maintained a stable degradation efficiency across a wide range of pH (5−11) and sulfite dosages (0.25–5.0 mM), and achieved 90 % degradation even under oxic conditions. Mechanism studies confirmed the presence of hydrated electrons (e aq − ), hydroxyl radicals, and hydrogen radicals in VUV/UV/sulfite system, with e aq − identified as the primary contributor to 2-CPAN degradation. Chlorine in 2-CPAN was primarily released as chloride ions, achieving 94 % dehalogenation within 15 minutes. The above findings revealed that VUV/UV/sulfite could be a promising technology for aromatic DBP degradation in real waters.
研究领域:
环境科学
·
水处理工程
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Shangding Yang,Xiaoke Yan,Shitai Shen,Li Wu,Bolin Li,Liuyang He,Lijuan Wu,Zulin Zhang,Lie Yang
Although advanced reduction processes (ARPs) based on UV/S(IV) (UV/sulfite) processes could achieve higher dechlorination and degradation efficiencies for organic pollutants , the mineralization and detoxification efficiencies still need to be further improved. In this study, post-reoxygenation was employed to improve the mineralization and detoxification of chloramphenicol (CAP) in UV/S(IV)-ARPs. The effects of initial pH and aeration rate on the dechlorination and mineralization efficiency of CAP were investigated. At the optimized conditions (pH 3.0, aeration rate of 0.3 L min −1 ), 92.75 % of dechlorination efficiency and 29.3 % of COD removal were obtained after 2 h of reoxygenation. Meanwhile, the effects of inorganic anions (Cl - , SO 4 2- , HCO 3 – , NO 3 – , and HPO 4 2- ) on the removal of COD and dechlorination efficiency were also evaluated. Furthermore, the electron paramagnetic resonance analysis disclosed that SO 4 •- and HO • mainly contributed to the mineralization of CAP. Further degradation and mineralization of CAP were confirmed in the post-reoxygenation UV/S(IV)-ARPs (PRO-UV/S(IV)-ARPs) and the intermediates were identified. The ecotoxicity prediction and residual toxicity assessment revealed that the ecotoxicity of CAP solution was significantly reduced after the treatment of post-reoxygenation. Overall, the PRO-UV/S(IV)-ARPs provides a promising choice with straightforward operation for the purification and detoxification of CAP wastewater.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Xuefeng Liu,Guoshuai Liu,Shijie You
Advanced reduction process (ARP) has drawn an increasing interest as a new manner for removing oxidative pollutants in water. In this paper, we demonstrate the possibility of in-situ reduction of Cr(VI) by CO 2 ·- produced from formate originally existing in leather wastewater by visible-light-driven ARP containing black TiO 2 photocatalyst. The prepared black TiO 2 with nanotube structure achieves remarkable enhanced the reduction rate of Cr(VI) as high as 96.2% (k = 0.0114 min −1 ) in the presence of formate, which is approximately 4.75 times than that of 56.3% (k = 0.0024 min −1 ) in the absence under 120 min visible-light irradiate at unadjusted pH. The results exhibit a distinct contrast with commercial TiO 2 (P25). A series of control experiments are also performed, indicating that formate is able to convert the oxidative environment into a highly reductive one, and the formate concentration, black TiO 2 dosage and pH may greatly impact on the Cr(VI) reduction rate. According to the electron spin resonance (ESR) measurement, CO 2 ·- radicals can be directly verified as dominate radical in this system. Moreover, this system appears to be attractive for creating photochemical systems where in-situ production of CO 2 ·- radicals may be realized by using formate. Then this in-situ ARP system will provide a new perspective for the Cr(VI) removing, which makes leather wastewater treatment much easier and more sustainable in the future.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）