Inorganic Chemistry Frontiers
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2024
·Vol. 11
·期 10
·3036-3046
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IF 6.1
Shiheng Liang,Liugang Wu,Yiming Wang,Yuqi Shao,Hongyuan Song,Ziliang Chen,Weiju Hao
The construction of high-efficiency long-stable catalytic electrodes for hydrogen by seawater splitting is a huge challenge in the field of green hydrogen generation. Herein, a matrix-type titanium dioxide nanorod (Ti/TiO2) is constructed on the titanium plate (Ti) by one-step oxidative etching, and a two-dimensional self-supporting electrode with good stability and “local photothermal effect” strategy is constructed as a self-supporting electrode by carbon quantum dots (CDs) “inserted” self-growing iron boron (CDs-FeBx@TiO2). Based on the microstructure regulated by CDs, the in situ growth of FeB with high conductivity and high authenticity activity, the effective separation of electron–hole pairs in the TiO2 structure is promoted, and efficient photothermal seawater electrolysis is realized. The performance of hydrogen/oxygen evolution reaction (HER/OER) and overall seawater splitting of the highly active CDs-FeBx@TiO2 electrode increased by 14.7%, 16.2% and 4.4% at 10 mA cm−2 in alkaline simulated seawater. The CDs-FeBx@TiO2 electrode remains durable for 70 days at 100 mA cm−2 and even at industrial current density, and the catalytic activity remained at 93.5%. This work provides a simple way for the preparation of catalytic electrodes with high activity and excellent stability and provides theoretical support for the practical application of high purity hydrogen from seawater.
研究领域:
材料科学
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可再生能源
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电化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
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2024
·Vol. 14
·期 13
·8641-8651
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IF 3.9
Li Xiaoya,Ma Yongcun,Peng Shusen,Tian lixi
The traditional aqueous electroplating of zinc film causes significant corrosion of NdFeB during the electroplating process, which is accompanied by hydrogen evolution reactions. In this study, electroplating zinc film is carried out from a chloride-free nonaqueous bath using zinc acetate (Zn(OAc)2) as the main salt, sodium acetate (NaOAc) as the conducting salt, and ethylene glycol (EG) as the solvent. The electrochemical properties of the EG bath with Zn(OAc)2 and NaOAc are characterized by means of cyclic voltammetry (CV) and linear sweep voltammetry (LSV) together with a Hull cell test on brass. The results of the experiment show that the Zn(OAc)2 concentration, current density, and temperature significantly impact the deposition behavior of zinc. Moreover, the open circuit potential (OCP) test and scanning electron microscopy (SEM) results demonstrated that the corrosion of NdFeB in the EG bath containing 0.7 M Zn(OAc)2 and NaOAc is effectively inhibited compared to when using the traditional aqueous zinc plating bath. A dense zinc film with a metallic appearance is successfully deposited on the NdFeB surface from the EG bath containing 0.7 M Zn(OAc)2 and NaOAc at 6 mA cm−2 and 60 °C. Comparative experiments demonstrate that the as-deposited Zn film exhibits superior protective performance and exerts less damage to NdFeB compared to the aqueous electroplating film.
研究领域:
材料科学
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电化学
·
表面工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Yusheng Yang,Chaoqun Lan,Yingcai Wang,Zengwu Zhao,Baowei Li
In this work, a simple and sustainable approach is proposed to recover rare earths and iron from an ultrafine NdFeB waste. Rare earths are directly recovered by one-step precipitation in hydrofluoric acid and the dissolved iron by electrodeposition. The rate constant and activation energy of the reaction of rare earth hydroxide with hydrofluoric acid are investigated to understand the kinetics of iron leaching and rare earth precipitation. The rare earth precipitation is much faster than the iron leaching, enabling the rare earths separation from iron after a complete iron dissolution. The cathodic deposits of iron were characterized by X-ray photoelectron spectrometer (XPS) and scanning electron microscope (SEM). The nano-scale FeF 2 (s) and Fe(s) were deposited on Pt electrode in hydrofluoric acid solution with pH 2.3 and pH 2.89, respectively. The reduction of Fe(III) to Fe(0) was investigated by cyclic voltammetry, chronopotentiometry and open circuit chronopotentiometry. This reduction was a quasi-reversible process which was controlled by diffusion. The temperature dependence of the diffusion coefficient was established as lnD = −9.84 − 1805.43/ T and the activation energy value of the diffusion process was calculated to be −15.01 kJ mol −1 . The relationship between the Gibbs energy of intermetallic Fe-Pt formation and the temperature was established to be Δ G = −487.53 + 0.936 T . The hydrofluoric acid after the electrodeposition could be recycled for the leaching of the ultrafine NdFeB waste again.
研究领域:
材料科学
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环境工程
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电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2023
·
IF 6.2
Hongxing Chen,Renquan Wang,Jun Li,Chang Liu,Xiaojiao Yang,Ying Liu
The combination of high coercivity and resistivity is a strong requirement for permanent magnets to resist thermal demagnetization under complex operating conditions. However, this still remains a challenge for conventional strategies, which always sacrifice the maximum energy product as the coercivity or resistivity increases. In this work, we report a unique strategy of introducing only 0.1 wt% of insulating nano-diamonds (NDs) into the hot-deformed Nd-Fe-B magnets to significantly and simultaneously improve both magnetic properties ( H ci , B r , (BH) max and H k / H cj ) and resistivity. In particular, the coercivity increased by 60% from 746 to 1193 kA/m. Further microstructure observations indicate that this exceptional effect stems from NDs can effectively inhibit the formation of coarse grains and optimize the distribution of Nd-rich phases, ensuring a strong pinning effect to enhance hard magnetic performance. Meanwhile, the presence of additional grain boundaries and NDs can also lead to higher resistivity by preventing the movement of free electrons. Our work provides a distinctive strategy for interface modification with excellent comprehensive performance in permanent magnets.
研究领域:
材料科学
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磁学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Huayu Chen,Shuxin Ouyang,Ming Zhao,Yunxiang Li,Jinhua Ye
Water splitting has been greatly limited by the sluggish kinetics of the oxygen evolution reaction (OER). High-oxidation-state metal species are required as the favorable active sites in OER. Here, amorphous Cox–Fe–B (x is the molar ratio of Co/Fe), Co–B, and Fe–B compounds were successfully synthesized as the oxygen evolution electrocatalysts. The calculation of turnover frequency (TOF) indicates that both the Co and Fe sites are active for OER. Cyclic voltammetry, X-ray photoelectron spectroscopy, and long-term stability curves were used to demonstrate that Fe can stabilize Co in a higher oxidation level and meanwhile promote the generation of OOH-like species (the key intermediates for OER). The reduced impedance for Co2–Fe–B (compared with that for Fe–B and Co–B) obtained from the electrochemical impedance spectra confirms the enhanced conductivity for the Co2–Fe–B. This optimal sample on Cu substrate shows a low overpotential of 0.298 V at the current density of 10 mA cm–2 with a decreased overpotential of 42 mV compared to that of Co–B. The Co2–Fe–B catalyst also exhibits a small Tafel slope of 62.6 mV/dec and good stability. The enhanced performance could be attributed to the synergistic effect of the increased population of high-oxidation-state metal–OOH species and the promoted conductivity of the catalyst. A solar-to-hydrogen energy conversion efficiency of 4.2% and a Faradaic efficiency of 97.2% can be achieved by connecting the HER and as-prepared OER electrodes to a crystalline silicon solar cell.
研究领域:
材料科学
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电化学
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可再生能源
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Chang Du,Shuai Ma,Meiying Xie,Fan Yang,Zhigang Zhao,Yun Chen,Ying Ma
This paper proposes a new integrated method for recycling permanent magnet waste by betaine hydrochloride ([Hbet]Cl) solution extraction. The orthogonal experiment method was used to analyze four factors in the leaching process to explore the primary and secondary factors influencing the leaching results. The following optimum leaching conditions were obtained: leaching temperature of 200 ℃, leaching time of 8 h, lixiviant [Hbet]Cl concentration of 0.2 mol/L, and solid–liquid ratio of 1:150 g/ml. These conditions yielded the optimum leaching results of 99.81 % Pr, 97.05 % Nd, 95.51 % Gd, 56.24 % Ce and 0.20 % Fe, and almost all iron oxide remained in the residue. Compared with the results for common lixiviants, the proposed method showed a better leaching rate and selectivity, and the leaching sequence was in line with established chemical properties. The method is characterized by a high recovery rate, strong selectivity, environmental friendliness and low cost. The leaching mechanism was analyzed, and the crystal lattice energy U values of ionic crystal decomposition were calculated to explain the dissolution sequence and solubility difference of metal oxides, laying a foundation for the recovery process.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
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2021
·
IF 3.712
He Sun,Tuoyao Wang,Chengxiang Li,Yusheng Yang
Ultrafine NdFeB waste is a relatively clean waste produced during NdFeB magnet processing. Fluorine-containing wastewater is a common type of industrial wastewater, such as stainless steel pickling wastewater. In this work, rare earth element neodynium was recycled from ultrafine NdFeB waste by capturing fluorine ions in the fluorine-containing wastewater and prepared into neodynium oxyfluoride. The reaction process was investigated through UV-Vis-NIR, thermogravimetry/differential thermogravimetry (TG/DTG), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The neodymium hydroxide in the ultrafine NdFeB waste reacted with fluorine ions to form Nd(OH) 2 F, and Nd(OH) 2 F was then transformed into neodymium oxyfluoride after decomposition. The formed neodymium oxyfluoride is found to be particles with rhombohedral structure and a particle size of around 50 nm. The reaction kinetics of forming Nd(OH) 2 F was investigated. The reaction kinetic equation was established and the reaction activation energy was calculated. The effect of fluorine ion concentration on the reaction rate and products was evaluated. The results show that the reaction rate increases with the increase of fluorine ion concentration in the range of 0.01 – 1.5 mol/L, but it has little effect. In addition, the fluorine ion concentration affects the crystallinity of formed neodymium oxyfluoride. The recycling process not only realizes the sustainable utilization of rare earths, but also reduces the concentration of fluorine ions in the fluorine-containing wastewater, achieving two goals with one stone.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
DOI
高影响因子
Small
·
2025
·
IF 12.1
Zhen Shi,Chenxi Fang,Jiaqian Li,Sateesh Bandaru,Muwen Liu,Lizhong Zhao,Xuefeng Zhang
In spite of superior magnetic properties, neodymium–iron–boron (Nd-Fe-B) applications in harsh environments have been greatly hindered by their susceptibility to corrosion, humidity, mechanical, and temperature attacks. Herein, a construction strategy of robust slippery liquid-infused porous surfaces (SLIPS) coatings is proposed via the multi-dimensional design of surface, bulk coating, and interface. The manipulation of colloidal states of silica particles by chemical hydrophobization allows for building a dense polymer network, enhancing interfacial adhesion and locking lubricant film effectively. The resulting coating is demonstrated to be extremely stable, endowing the magnet with excellent liquid repellency, anti-corrosion, and anti-icing properties. Strikingly, no trace of corrosion is detected after 136-day immersion in 3.5 wt.% NaCl solution and the impedance modulus at 0.1 Hz can be maintained as the initial of 3.31 × 10 8 Ω·cm 2 even after 132-day immersion, which is far superior to that of commercial Ni-Cu-Ni, Zn, and EP coatings. Additionally, anti-icing performance at low temperatures is evidenced by the delayed icing time and decreased ice adhesion strength. Importantly, the self-healing property offers the surface intensified durability even after mechanical damage. This work demonstrates a construction strategy of robust SLIPS coatings with a multi-dimensional design, enabling the practical applications of Nd-Fe-B magnets in extreme environments like offshore wind turbines.
研究领域:
材料科学
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表面工程
·
腐蚀防护
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CATALYSIS TODAY
·
2021
·
IF 6.766
Mabrook S. Amer,Prabhakarn Arunachalam,Abdulaziz M. Alsalman,Abdullah M. Al-Mayouf,Zeyad A. Almutairi,Saba A. Aladeemy,Mahmoud Hezam
The development of greatly stable and cost-effective electrocatalysts for urea electro-oxidation reactions (UERs) is urgent and challenging for promoting urea removal in the wastewater and advanced energy conversion devices. We demonstrated that nickel-iron borate (NiFe-B) electrocatalysts supported on carbon paper (CP) for UERs through a one-pot solvothermal method. NiFe-B electrocatalysts were obtained with numerous Ni/Fe molar ratios in the precursors, and the physicochemical features of the NiFe-B were examined by X-ray diffraction, scanning and transmission electron microscope, and X-ray photoelectron spectroscopy. The optimized NiFe-B/CP exhibited a low onset potential (E onset = 0.287 V vs. SCE) with a Tafel slope of 27.9 mV/dec on CP, demonstrating much greater performance UERs. Furthermore, the NiFe-B/CP catalysts have shown a superior activity for the UERs in alkaline solution and exhibit more than two-fold enhancement in activity than Ni-B. Facile, cost-effective fabrication and highly efficient urea oxidation create the NiFe-B electrodes as attractive materials for UERs.
研究领域:
材料科学
·
环境科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2020
·
IF 3.99
Xunwen Su,Liqun Zhu,Weiping Li,Haining Chen,Rui Cao,Huicong Liu
Alumina sol was prepared with ascorbic acid (also known as Vitamin C, Vc) as peptizer instead of the traditional used HCl. The prepared sol was then used for the anti-corrosion protection of NdFeB magnets. After substitution, the protective ability of the alumina sol film on NdFeB magnets improved significantly. Systematic comparison of the two alumina sol film were taken. Result showed that the Vc peptized alumina sol (AS-Vc) film showed a more uniform and complete surface which can help repair the defects on NdFeB surface without causing other damages. The electrochemical test showed the corrosion current density of NdFeB with AS-Vc film further reduced to 7.682 × 10 −8 A cm -2 , which is almost one-third of that in AS-Cl film. Along with the salt-water immersion test result, the data showed the corrosion is obviously suppressed after substitution. What’s more, the differences of the film formation mechanism between the two alumina films were investigated. By comparison, NdFeB in AS-Vc showed an about 200 mV more positive open circuit potential than it in HCl peptized alumina sol (AS-Cl), which means less redox reaction during the film formation process. Above all, the Vc peptized alumina sol provides higher corrosion resistance ability for NdFeB, which is wery suitable for the simple protection of NdFeB materials.
研究领域:
材料科学
·
腐蚀与防护
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2020
·
IF 3.104
Zhengyu Liu,Jiaming Wu,Xinyu Liu,Wen Wang,Ziwei Li,Ruijing Xu,Yue Ding,Junlian Wang
Rare earths (REs) and Co are critical strategic resources. Their recovery is crucial for ensuring that their supplies are adequate and for reducing environmental pollution. End-of-life NdFeB magnets are important secondary RE sources. The separation of Dy, Nd, and Co from NdFeB leachate using a relatively new extractant (2,3-dimethylbutyl) (2,4,4′-trimethylpentyl)phosphinic acid (INET-3), was investigated in this study. The separation parameters, such as equilibrium pH, phase ratio, INET-3 concentration, and number of counter-current extraction stages, were optimised. The results show that INET-3 can separate Dy, Nd, and Co efficiently. For the preferential extraction of Dy from synthetic iron-free NdFeB leachate, the optimum equilibrium pH is 2.60. Under this condition, separation of Dy from the leachate requires four counter-current extraction stages at A/O (volume ratio of aqueous to organic) = 1:2. This is demonstrated by a simulated four-stage counter-current extraction process. At equilibrium pH = 2.52 and A/O = 1:2, 98% of Dy is recovered with 95% purity. As to the subsequent separation of Nd from the leachate, nearly 100% is recovered with 99% purity through a simulated three-stage counter-current extraction process at equilibrium pH = 5.33 and A/O = 1:1. Approximately 95% of Co remains in the raffinate with 99.98% purity.
研究领域:
资源回收
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Chenchen Qiang,Liang Zhang,Hengli He,Yangyang Liu,Yueying Zhao,Tian Sheng,Shoujie Liu,Xilin Wu,Zhen Fang
Developing an efficient bifunctional catalyst for Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) in water splitting technology is very attractive for clean energy. Here, a new Co-Fe-B ternary catalyst with improved crystallinity is successfully synthesized by combining the chemical reduction and subsequent solid-state reaction method. Synchrotron-based X-ray absorption near-edge structure (XANES) and X-ray photoelectron spectroscopy (XPS) indicate the electronic structure redistribution is favor for the improved performance. The overpotential is only 129 mV and 280 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline condition, the corresponding Tafel slope is 67.3 mV dec −1 and 38.9 mV dec −1 . Density functional theory calculations distinguish that the ternary crystalline Co-Fe-B catalysts are thermodynamically favorable for HER and OER. The actual active species of the ternary catalyst in OER is the CoOOH and FeOOH as indicated in ex situ Raman spectra. The present work may introduce promising crystallinity borides material for the anode and cathode of water splitting device.
研究领域:
材料科学
·
催化化学
·
清洁能源
✓ 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）