MINERALS ENGINEERING
·
2020
·
IF 3.795
Peilun Shen,Dianwen Liu,Xiaohui Xu,Xiaodong Jia,Xiaolin Zhang,Kaiwei Song,Jinpeng Cai
In this study, for the first time, we applied ammonium phosphate to pre-treat chrysocolla prior to sulfidization flotation. In addition, we investigated the structural characteristics of the copper sulfide film formed on the chrysocolla surfaces and its response to flotation. Micro-flotation experiments revealed that the addition of (NH 4 ) 3 PO 4 prior to sulfidization greatly improves the floatability of chrysocolla and its recovery increased from 8.71% to 87.97% with butyl xanthate as the collector. The results of the field emission scanning electron microscopy analysis showed that numerous regular fragments appeared on the chrysocolla surfaces after the addition of (NH 4 ) 3 PO 4 . The X-ray diffraction and X-ray photoelectron spectrometry analysis confirmed that these fragments were newly formed copper sulfide covering the chrysocolla surfaces, during this process a chemical reaction occurred in the slurry system, i.e. the Cu 2+ were reduced to Cu + , the S 2− were mainly oxidized to S − , (S 2 ) − , (S 2 ) 2− . The copper sulfide species primarily in the form of crystalline covellite (Cu + 3 (S 2 ) 2− S − ), which is the key to obtaining good flotation recovery. As a specific activator, (NH 4 ) 3 PO 4 participates in the liquid-solid phase chemical reaction between the sulfidizing reagent and the chrysocolla, which promotes the sulfidization reaction of chrysocolla.
研究领域:
矿物加工工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2014
·Vol. 16
·期 38
·9054-9062
·
IF 3.858
Zongjian Liu,Yuanyuan Chen,Yifan Zheng
We propose a novel strategy for the synthesis of materials with a hierarchical structure. This strategy is based on in situ combination of two processes, namely, capping agent-mediated oriented growth and stirring-induced aggregation, and the growth of Cu crystals in the presence of linear alkyl diamines of short carbon chain length under vigorous stirring is shown to demonstrate its feasibility. Our experimental results have shown that the oriented growth of Cu nanowires can be significantly disturbed by vigorous stirring, resulting in large-scale growth of hierarchical dendritic Cu crystals. The morphology of grown dendritic Cu crystals has been found to vary with the stirring rate, type of diamine, and diamine concentration, which makes it possible to prepare hierarchical Cu structures of various morphologies. The growth mechanism of these hierarchical Cu structures is proposed based on the experimental observations. The present unique strategy offers a fresh way to fabricate materials with a hierarchical structure.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry B
·
2017
·Vol. 5
·期 44
·8686-8694
·
IF 4.543
Jian Lv,Chuncai Kong,Xuanxuan Hu,Xiaojing Zhang,Ke Liu,Shengchun Yang,Jinglei Bi,Xiaoyan Liu,Ge Meng,Jianhui Li,Zhimao Yang,Sen Yang
Morphology control is expected to be an effective method to enhance the electrochemical properties of materials. In this work, zinc cation-mediated growth of Cu2O crystals was achieved via an aqueous chemical route at room temperature. Thus, by simply increasing the concentration of Zn2+, concave cube-like (C-Cu2O), porous (P-Cu2O), and hierarchical (H-Cu2O) Cu2O crystals were selectively obtained. The morphologies and structures of the as-prepared Cu2O crystals were characterized by SEM, TEM, XRD and XPS. The three materials were subsequently employed as active materials for the non-enzymatic detection of glucose. The H-Cu2O-based electrode exhibited the highest sensitivity (3076 μA mM−1 cm−2) in virtue of its highest surface area, while the P-Cu2O-based electrode showed the widest linear range (up to 24 mM). The reliability of the Cu2O-based glucose sensors was proved by determining their detection limit, response time, selectivity, and stability characteristics on human serum samples. This work provides a novel strategy for the morphology-controlled Zn2+-mediated fabrication of Cu2O crystals with different glucose sensing performances depending on their structures.
研究领域:
材料科学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 63
·36831-36837
·
IF 3.049
Xiaodong Yang,Shupeng Zhang,Lei Zhang,Bo Zhang,Tianrui Ren
Compared with low-index {100} or {111} planes of Cu2O crystals, rhombic dodecahedra (RD) Cu2O crystals exposing 12 {110} facets exhibit the most superior photodegradation of organic pollutants. Herein, a series of RD Cu2O crystals with different sizes were successfully synthesized by precisely adjusting the reaction temperature ranging from 40 °C to 100 °C. The results revealed that truncated rhombic dodecahedra (TRD) Cu2O crystals were fabricated when the temperatures was 40 °C. More importantly, on raising the temperature to above 40 °C, Cu2O architectures dynamically evolved from TRD to RD. Meanwhile, the sizes gradually decreased with elevation of the temperature, while the RD morphology of Cu2O crystals remained, demonstrating the importance of temperature for determining the morphology and size of Cu2O crystals. In addition, we also carefully investigated the visible-light photodegradation performance of Cu2O crystals for methyl orange (MO). RD Cu2O crystals exhibited superior photocatalytic activity compared with TRD, and showed size-dependent photocatalytic activity for MO. The photocatalytic activity of RD Cu2O crystals can be greatly improved by decreasing the size. In particular, RD-60 with the minimum size achieved the best photocatalytic properties compared to the other RD and TRD Cu2O crystals, and still displayed high photocatalytic efficiency even after three cycles. Such results advance the understanding that temperature modulation serves as an effective means to fabricate RD Cu2O crystals.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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