Nanogeosciences are the international frontier field for the recent cross-development of geosciences and nanotechnology, also are the combination of nanometer and earth. It is possible to research the morphology, structures, and components of the earth on a nanoscale and further reveal the nanoscale information recorded by the substances on the earth, relying on research means, experience, and achievements of fast-developing nanotechnology and in combination with geoscience. Based on the summarization of the existing academic achievements in ultra-microscopic reasearch on geosciences, the concept of nanogeosciences is put forward. Nanogeosciences are a series of geosciences, taking the matters on different layers of the earth as a research target, to reveal the information of nanoparticles and nanopores and their relationship with geoscientific phenomena and especially genetic types during the geoscientific processes on the basis of nanoscience and geoscience, as well as nanotechnology and geoscientific tools. Nanotechnology has been introduced in various branches of geosciences, at first nanogeology since the 1980s. From the nanogeology to nanogeosciences, nanogeosciences have witnessed three major developmental stages: exploratory research, development of several research directions, and the preliminary formation of the subject based on comprehensive research. Among them, relevant nanophenomena found in the field of geoscience have been observed and relevant geoscientific issues have been explored. In the

This research delved into the influence of mesoporous silica’s surface charge density on the adsorption of Cu²⁺. The synthesis of mesoporous silica employed the hydrothermal method, with pore size controlled by varying the length of trimethylammonium bromide (C_nTAB, n = 12, 14, 16) chains. Gas adsorption techniques and transmission electron microscopy characterized the mesoporous silica structure. Surface charge densities of the mesoporous silica were determined through potentiometric titration, while surface hydroxyl densities were assessed using the thermogravimetric method. Subsequently, batch adsorption experiments were conducted to study the adsorption of Cu²⁺ in mesoporous silica, and the process was comprehensively analyzed using Atomic absorption spectrometry (AAS), Fourier transform infrared (FTIR), and L3 edge X-ray absorption near edge structure (XANES). The research findings suggest a positive correlation between the pore size of mesoporous silica, its surface charge density, and the adsorption capacity for Cu²⁺. More specifically, as the pore size increases within the 3–4.1 nm range, the surface charge density and the adsorption capacity for Cu²⁺ also increase. Our findings provide valuable insights into the relationship between the physicochemical properties of mesoporous silica and the adsorption behavior of Cu²⁺, offering potential applications in areas such as environmental remediation and catalysis.