JOM
·
2019
·Vol. 72
·期 4
·1687-1693
·
IF 2.305
Xia Yang,Zhao Jinlong,Dong Zhaowang,Guo Xueyi,Tian Qinghua,Zhang Siwen,Liu Yong
Ultra-high pure metallic zirconium powder was successfully obtained through a two-step gradient reduction of nano-ZrO 2 in Ar atmosphere. The first reduction by Mg was to remove ~ 85% oxygen, followed by a heat-treatment step to control the particle size and specific surface area of the powder, and the final reduction by calcium was to further purify the powder and decrease oxygen to an extremely low level (0.068 wt.%). The oxygen level in the final powder meets the standard specification of Zr sponge (ASTM B349/B349M-16). Processing parameters, including the reduction temperature, the amount of Mg and MgCl 2 and the heat treatment temperature, were investigated. Thermodynamic modeling with the assistance of HSC Chemistry software was carried out to understand the reduction reaction. This study offers a novel process for producing ultra-high pure metallic zirconium powder with the potential to replace the conventional Kroll process.
研究领域:
材料科学
·
冶金学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Hao Zhang,Nan Tang,Xia Yu,Zhongkai Guo,Zhen Liu,Xiaoming Sun,Min-Hui Li,Jun Hu
To date, flexible sensors derived from hydrogel materials have been popularly adopted in the field of wearable electronic devices. It is urgent and prospective to create a high-performance and multi-functional hydrogel by simple and green methods to satisfy the various demands for long-term direct human contact. Herein, a sustainable physical double network hydrogel is prepared by natural glycyrrhizic acid (GL) and biocompatible polyvinyl alcohol (PVA) in water/glycerol solvent, which exhibits high mechanical properties, good biocompatible, anti-freezing and anti-drying ability. Inspired by the reducing abilities of GL, a gradient silver nanoparticles layer can be constructed in situ on the hydrogel surface without additional reducing agents. It not only affords the UV-light shielding and antibacterial effect for the hydrogel, but also effectively improves the sensing performance. The simultaneous realization of desired properties enables the hydrogel to be assembled into a sensor to detect all-dimensional human motion with high sensitivity, stability and durability. Benefiting from the renewable raw material, non-toxic reagent and facile preparation process, this work provides new insight and inspiration for the design of flexible sensors with high performance, multi-functionality and sustainability.
研究领域:
材料科学
·
生物医学工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2025
·
IF 9.2
Xue Bai,Yanzhi Sun,Jiahong Xie,Huayi Yin,Rui He,Zhenfa Liu,Xifei Li,Junqing Pan
The sluggish leaching kinetics and low separation efficiency of Li/Co/Ni ions with high chemical consumption greatly hindered the recovery efficiency and cost of spent Li-ion batteries. Herein, we propose a self-generated H2 drives gradient reduction of spent cathode via surface enrichment of Li+ from retired Li-ion batteries, achieving a facile, efficient extraction of Li (>99.3%) by water as a leaching agent without chemicals. Characterizations and calculations reveal the adsorption and electron transfer mechanism between H2 and LiCoO2, the new phase transition mechanism of the layered structure and the changes in the electronic bonding and coordination environment of elemental Co during H2 precise reduction. Economic and environmental analyses showed that this work exhibits 22.6% energy consumption with 0% CO2 emissions and chemical consumption than hydrometallurgy, respectively, fully demonstrated its green and energy saving prospects for recycling spent Li-ion batteries.
研究领域:
材料科学
·
环境科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2020
·
IF 7.888
Yanru Zhu,Jian Zhang,Xiaodan Ma,Zhe An,Shaowei Guo,Xin Shu,Hongyan Song,Xu Xiang,Jing He
Complexity of chemical linkages (C-C/C-H/C-O, C=C/C=O, or C-O-H/C-O-C) in biomass-derived molecules makes the selective activation of targeted bonds much more challenging, expecting well-defined catalysts and definite catalytically-active sites. This work demonstrates an effective gradient reduction strategy to control the definite structure of catalytically-active sites, affording defects-rich nano-twin Cu particles. This strategy just involves the reduction (calcination under H 2 ) of Cu II -containing layered double hydroxides (LDHs) simply with controlling the reduction gradient (interval time) of Cu II species in two chemical micro-environments (Cu II -O-Cu II and Cu II -O-M II/III/IV (M ≠ Cu)) in the brucite-like layer of LDHs. The nano-twin Cu particles efficiently promote the target activation of C-O and C=C in the conversion of furfural to cyclopentanone (CPO). With ~100% furfural conversion, the defects-rich nano-twin Cu particles afford a CPO selectivity of 92%, 50% higher than regular spherical Cu particles. The multi-stepped defect sites, originating from the planar defects, play a decisive role in promoting the CPO selectivity by facilitating the hydro-deoxygenation to C-O of 4-hydroxycyclopentenone (HCP) and hydrogenation to C=C of HCP or cyclopentenone.
研究领域:
催化化学
·
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）