Confinement induces stable calcium carbonate formation in silica nanopores
Confinement induces stable calcium carbonate formation in silica nanopores
复制标题
限制诱导二氧化硅纳米孔中稳定碳酸钙的形成
DOI：
10.1039/d2nr01834a
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发表时间：
2022
期刊：
影响因子：
6.7
通讯作者：
Gadikota, Greeshma
中科院分区：
文献类型：
--
作者：
Asgar, Hassnain;Mohammed, Sohaib;Gadikota, Greeshma
通过形成耐用的碳酸盐来消除人为二氧化碳的可扩展努力要求我们利用硅质纳米多孔地质材料来储存碳。虽然碳酸钙在块状流体中的形成已有广泛的报道，但对于纳米受限流体对硅质材料中特定的稳定和亚稳态碳酸钙形成的影响的了解有限，因为硅质材料中存在丰富的地下环境。为了应对这一挑战，设计了直径为3.7 nm的二氧化硅纳米通道，并利用X射线衍射(XRD)和分子动力学(MD)模拟研究了特定碳酸钙相的形成。在二氧化硅纳米通道中发现了稳定的碳酸钙(或方解石)的形成。与大块流体相比，封闭状态下钙离子的第一水化壳层中的水分子较少，有助于碳酸钙的稳定形成。这些研究表明，纳米多孔硅质环境有利于形成稳定的碳酸钙形成。
Scalable efforts to remove anthropogenic CO2via the formation of durable carbonates require us to harness siliceous nanoporous geologic materials for carbon storage. While calcium carbonate formation has been extensively reported in bulk fluids, there is a limited understanding of the influence of nanoconfined fluids on the formation of specific stable and metastable polymorphs of calcium carbonates in siliceous materials that are abundant in subsurface environments. To address this challenge, silica nanochannels with diameters of 3.7 nm are architected and the formation of specific calcium carbonate phases is investigated using X-ray diffraction (XRD), and molecular dynamics (MD) simulations. The formation of stable calcium carbonate (or calcite) is noted in silica nanochannels. The presence of fewer water molecules in the first hydration shell of calcium ions in confinement compared to in bulk fluids contributes to stable calcium carbonate formation. These studies show that nanoporous siliceous environments favor the formation of stable calcium carbonate formation.