SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Zhiwen Chen,Youbin Wang,Qingya Wen,Shunyan Ning,Xinpeng Wang,Yuezhou Wei
Industrial waste solutions are rich in precious metals, which are valuable secondary resources. In order to realize the separation and recovery of ruthenium by electrodeposition, this work used a combination of cyclic voltammetry (CV), chronoamperometry (I-t), and electrochemical quartz crystal microbalance (EQCM) to study the electrochemical behavior and electrodeposition mechanism of ruthenium in HCl solution. The results show that the reduction of ruthenium in HCl solution is influenced by hydrogen evolution reaction (HER) and chlorine evolution reaction, and the reduction process of ruthenium varies at different potentials. The reduction currents of Ru(VIII)/Ru(0) and Ru(IV)/Ru(III) are observed at 0.88 V and 0.6 V. The reduction of Ru(III) to Ru(0) at negative potentials starts at −0.2 V, with peak cathodic currents between −0.2 V and −0.5 V accompanied by a significant mass increase, which is confirmed to be the electrodeposition of metallic ruthenium by SEM and EDS. The microscopic morphology of the ruthenium coating is spherical particles, and the nucleation mode of electrodeposition is progressive nucleation. The HER leads to a macroscopic morphology of a cleaved lamellar structure, which is not tightly adhered to the substrate. The metallic ruthenium starts to oxidize and dissolve rapidly after 1.12 V, leading to a rapid degradation of the electrode surface quality.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2020
·
IF 4.189
Jin Wang,Fudi Wang,Bing Yang,Jiang Wu,Mengtao Tian,Jiani Zhu,Xudong Wang,Lei Wang
A lamellar membrane assembled by parallel restacking of two-dimensional nanosheets provides a novel platform for studying the electrostatic manipulation of ion mobility under angström-scale confinement. The membrane nanostructure in aqueous solution is unstable due to intercalation. However, because accurate measurements of structural changes under different charged conditions are difficult, their effect on the ion modulation was seldom fully addressed, and the electrostatic modulation mechanism was not good. Here, we report the efficient manipulation of ion diffusion in the confined channels through a Ti3C2Tx membrane and gain insight into the mechanism by an in situ measurement of the lamellar nanostructure using an electrochemical quartz crystal microbalance with dissipation (EQCM-D). By precisely tuning the external potential directly applied to the membrane, the ion permeation rate can be effectively and reversibly increased by 6 times or decreased by 15 times. The EQCM-D measurement provides empirical evidence to demonstrate that the anomalous ion-flow modulation is determined by both the channel diameter and an ion rearrangement in the electrical double layers (EDLs), particularly, in the Stern layers. Although the channel expanded at low negative voltage, the ion permeation rate decelerated due to the counterion distribution in the Stern layers.
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Min Xue,Mufan Cao,Chengyang Xu,Dewei Xiao,Xiaogang Zhang
Polymer-based materials with the incorporation of redox-active dopants serve as promising electrodes for Li-ion batteries but their use is restricted by the limited doping level and inevitable dissolution behavior of the dopants. Here, we proposed a conjugated polymer-based electrode with an assistant dopant to realize the reversible capacity contribution of a redox-active dopant. By employing phosphate anion (PO) as the assistant dopant to stable the polymer matrix, the reversible capacity was improved by introducing indigo carmine (IC) into the polymer electrode. Based on the real-time monitoring of the electrochemical quartz crystal microbalance toward the mass change, the charge storage behavior of the redox-active dopant IC was observed and the stabilizing effect of the assistant dopant PO was revealed. The modified electrode delivered an increased capacity of 191 mA h g–1, and the reversible capacity remained 56% higher than that of the PO-undoped electrode after 200 cycles. The dual-doping strategy with the assistant dopant and the redox-active dopant is used to develop advanced polymer-based electrodes for high-capacity and long-cycling batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xun Liu,Danyal Rehman,Yufei Shu,Bei Liu,Li Wang,Li Li,Mengxia Wang,Kunkun Wang,Qi Han,Linlin Zang,John H. Lienhard,Zhongying Wang
Selective capacitive deionization (SCDI) is a promising process for preferentially removing specific ions from waters with complex compositions. The selectivity towards certain species in CDI is most frequently achieved through novel electrode materials with high affinities towards targeted species. In this study, we investigate the selective removal of fluoride ions from groundwater containing concentrated co-existing chloride ions. A carbon nanotube-CeO 2 (CNT-CeO 2 ) electrode is employed for the electro-sorption of fluoride ions. Our findings are compelling: when processing a mixed F − /Cl − solution comprising 10 mg/L F − and 100 mg/L Cl − , the CNT-CeO 2 electrode is seen to reduce the concentration of F − ions to 1.5 mg/L in just 150 min, amounting to an 85 % F − removal efficiency, while the Cl − removal efficiency remains below 2 %. Importantly, this translates to a F − /Cl − separation factor of up to 4.16 when using the CeO 2 -based electrodes, which is 40 times higher than that achieved with conventional activated carbon (AC) electrodes. Furthermore, the energy consumption for treating actual groundwater using scaled-up equipment is impressively low at approximately 0.2 kWh/m 3 . The high affinity of CNT-CeO 2 towards fluoride is attributed to the intercalation Faraday capacitance initiated by the reaction between F − with CeO 2 , as verified by the electrochemical quartz crystal microbalance (EQCM). Moreover, EQCM results show a substantial increase in both mass and current as the potential increased beyond 0.8 V vs Ag/AgCl, implying that the current surge is not a result of water splitting but rather the adsorption of F − onto the CNT-CeO 2 electrode. The addition of CNTs substantially increases the conductivity of CeO 2 electrodes and restricts the aggregation of CeO 2 , thereby accelerating ion diffusion and promoting selective adsorption characteristics. Importantly, our electro-driven approach demonstrates excellent adsorption–desorption over 20 cycles. This comprehensive study advances the technological development of selective CDI, while providing new insights for fluoride removal in groundwater.
研究领域:
环境工程
·
水处理
·
电化学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）