摘要
采用热重分析、原子力显微镜以及第一性原理密度泛函理论系统地研究了孔雀石表面水化特性及水分吸附作用机理。结果表明:亲水矿物孔雀石表面存在大量的吸附水,单位表面水分子的吸附数量为28.41个/nm^(2)。吸附水的存在促使孔雀石表面发生重构,水化后的矿样显示出较强的非范德华力形式的引力。理论计算结果进一步证实了水分子在孔雀石表面的吸附在热力学上是有利的,且在孔雀石主要解理面(201)晶面同一断裂区内,水分子在四方形场构型的Cu_(c4)位点的吸附较邻近拉伸八面体场构型的Cu_(c6)位点具有明显的优势,Cu_(c6)位点对水分子的约束能力远不及Cu_(c4)位点。此外,受Cu_(c6)位点约束的水分子与矿物表面及键合在Cu_(c4)位点上的水分子形成立体的复杂氢键网络结构。
The adsorption mechanism of water molecules on malachite surface and its hydration characteristics were systematically investigated by thermogravimetric analysis,atomic force microscopy and first-principles density functional theory.The results show that there is a large amount of adsorbed water on the surface of the hydrophilic mineral malachite,and the adsorbed number of water molecules per unit surface is 28.41/nm^(2).The presence of adsorbed water promotes the reconstruction of the malachite surface,and the hydrated malachite sample shows strong adhesion rather than van der Waals force.The theoretical calculation results further confirm that the adsorption of water molecules on the malachite surface is favorable in thermodynamics.Moreover,in the same fracture region on the malachite(201)surface,and the adsorption of water molecules at the Cu_(c4)sites with tetragonal field configuration is obviously superior to that of the adjacent Cu_(c6)sites with stretched octahedral field configuration.The constraint capacity of the Cu_(c6)site to water molecules is far less than that of the Cu_(c4)sites.In addition,the water molecules constrained by the Cu_(c6)sites form a three-dimensional complex hydrogen bonding network structure with the mineral surface and the nearby water molecules bound at the Cu_(c4)sites.
作者
张洪亮
孙伟
周琪琪
许志杰
陈代雄
张晨阳
ZHANG Hong-liang;SUN Wei;ZHOU Qi-qi;XU Zhi-jie;CHEN Dai-xiong;ZHANG Chen-yang(School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China;Key Laboratory of Hunan Province for Comprehensive Utilization of Complex Copper-Lead Zinc Associated Metal Resources,Hunan Research Institute for Nonferrous Metals,Changsha 410001,China)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2023年第7期2318-2329,共12页
The Chinese Journal of Nonferrous Metals
基金
国家重点研发计划资助项目(2022YFC2904503,2019YFC040303)
国家自然科学基金资助项目(52074356,U20A20269)
湖南省自然科学优秀青年基金资助项目(2021JJ20069)
中国博士后科学基金资助项目(2020T130188,2018M642988)
长沙市科技计划(杰出创新青年培养计划)资助项目(KQ2106016)
省部共建复杂有色金属资源清洁利用国家重点实验室开放基金资助项目(CNMRCUKF2101)。
关键词
孔雀石
水分子
吸附机制
DFT
malachite
water molecule
adsorption mechanism
DFT
