Journal of Energy Chemistry
·
2020
·
IF 7.216
Liutao Huang,Lei Yang,Siwei Guo,Yang Li,Lihua Zhao,Lifang Jiao
Nickel-iron layered double hydroxides (NiFe LDHs) have been identified as one of the best promising electrocatalysts-candidates for oxygen evolution reaction (OER). However, the catalytic activity effected by interlayer water molecules is ignored and rarely reported. Herein, Ni(OH) 2 , NiFe LDHs vertically aligned Ni foam are designed for OER. As a contrast, the corresponding electrocatalysts with the removal of the interlayer water molecules (Ni(OH) 2 -AT, NiFe LDHs-AT) are developed to probe into the influence of the interlayer water molecules towards OER. As expected, NiFe LDH nanoplates exhibit excellent catalytic performance and durability for water electrolysis in alkaline conditions with lower overpotential and smaller Tafel slope compared to those of NiFe LDHs-AT, which are influenced mainly by stability of crystal structure due to the existence of interlayer water molecules. The discovery opens up a similar pathway by controlling the amount of water molecules to boost catalytic performance for studying other electrocatalysts with heteroatom dopant.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2025
·
IF 5
Jingqi Zhang,Yaoli Peng,Chuanjia Wang,Wenhao Zhang,Xiaoman Luo
In this study, kaolinite, Ca-montmorillonite, and Na-montmorillonite were used as research objects to study the adsorption behavior of water molecules in clay minerals. The adsorption behavior of water molecules on the surface and interlayers of clay minerals was studied by density functional theory, XRD, Einstein viscosity theory, surface morphology, TG/DSC, and molecular dynamics. The experimental results show that under the same number of water molecules, the interlayer spacing of Na-montmorillonite increases slowly. After high-temperature dehydration, the interlayer spacing change of Na-montmorillonite is small. In the water-saturated state, the interlayer spacing of Na-montmorillonite is larger than that of Ca-montmorillonite. High-temperature removal of interlayer water has a small effect on the interlayer spacing of kaolinite. The thickness of the surface hydration film and the degree of hydration of Ca-montmorillonite are greater than those of Na-montmorillonite. The thickness of the surface hydration film of kaolinite (00-1) is greater than that of kaolinite (001), and the thickness of the surface hydration film and the degree of hydration of kaolinite are less than those of montmorillonite. The higher water absorption rate of Na-montmorillonite interlayers is the main reason for its higher water content than Ca-montmorillonite.
研究领域:
粘土矿物学
·
表面化学
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材料科学
·
计算化学
·
地质学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Zhongjun Zhao,Yiran Sun,Yihao Pan,Jing Liu,Jingkai Zhou,Mei Ma,Xiaozhong Wu,Xiangyan Shen,Jin Zhou,Pengfei Zhou
Layered Mn-based cathode (K x MnO 2 ) has attracted wide attention for potassium ion batteries (PIBs) because of its high specific capacity and energy density. However, the structure and capacity of K x MnO 2 cathode are constantly degraded during the cycling due to the strong Jahn-Teller effect of Mn 3+ and huge ionic radius of K + . In this work, lithium ion and interlayer water were introduced into Mn layer and K layer in order to suppress the Jahn-Teller effect and expand interlayer spacing, respectively, thus obtaining new types of K 0.4 Mn 1-x Li x O 2 ·0.33H 2 O cathode materials. The interlayer spacing of the K 0.4 MnO 2 increased from 6.34 to 6.93 Å after the interlayer water insertion. X-ray photoelectron spectroscopy studies demonstrated that proper lithium doping can effectively control the ratio of Mn 3+ /Mn 4+ and inhibit the Jahn-Teller effect. In-situ X-ray diffraction exhibited that lithium doping can inhibit the irreversible phase transition and improve the structural stability of materials during cycling. As a result, the optimal K 0.4 Mn 0.9 Li 0.1 O 2 ·0.33H 2 O not only delivered a higher capacity retention of 84.04 % compared to the value of 28.09 % for K 0.4 MnO 2 ·0.33H 2 O, but also maintained a greatly enhanced rate capability. This study provides a new opportunity for designing layered manganese-based cathode materials with high performance for PIBs.
研究领域:
储能材料
·
电化学
·
电池技术
·
材料科学
·
无机化学
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2021
·Vol. 32
·期 14
·2108267
·
IF 18.808
Ang Gao,Jiannian Xia,Min Li,Xia Lu,Feng Wang,Ru Yang
Crystal water mediated ion hydration and transport is a fundamental physicochemical process in a wide range of applications and natural processes, such as crystal water containing battery materials. In this context, K-Birnessite with interlaminar H 2 O (K 0.21 MnO 2 ⋅0.31H 2 O) is reported for nonaqueous potassium-ion storage with enhanced capacity and rate performance. It is clarified that the water–solid interface plays an important role in building and stabilizing the K-Birnessite layered structure and facilitating the K + diffusion for the K-ion battery system. In addition to the enlarged ionic channel dimensions and effective shielding of the electrostatic interaction with K + , the concerted diffusion of K + /H 2 O with the rotation of H 2 O molecules is further revealed to account for the quite low activation energies by first-principles simulations. Moreover, the interlayer H 2 O exerts on the electronic structures, and thus on the electrochemical voltage to result in the competition between the split of crystal field (“∇ JT ”) and the electronic superexchange interaction (“O w -K-O”) in the K-Birnessite structure. The results provide new insights into hydrated ion kinetics and open an exciting direction for battery material design.
研究领域:
材料科学
·
电化学
·
储能
·
计算材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）