Based on the considerable progress in high-performance functional nanomaterials, there is a growing cognition that macroscopic quantitative composition-structure-property relationship (QCSPR) in functional materials design or structure-activity relationship (SAR) in catalytic materials both depends on the interfacial dynamics/reactions at a microscopic level. Here, the greatest challenge is how to effectively deliver the excellent properties of nano-functional units to the macroscale characteristics of materials/devices. The typical examples include host-guest recognition system, capacitors, controllable self-assemblies, micro-/nano-fluids and photoelectrical performance based on electrode-electrolyte interactions.

Interfaces mainly consist of a fluid phase, where the interactions acting on the particles possess different properties from that in bulk states. In many classical theories, the interface is treated as a mathematical surface where the fluid properties have sudden changes. Physically, several concepts, like surface free energy, surface tension and boundary slip length, are used to describe its effect on the particulate behaviors; chemically, its importance is closely linked with the size, shape and morphology of the system: the smaller size, the bigger specific surface the system has, the greater effect the interface will have.

Besides, the quantity(content), spatial distribution, component and structure of interfaces also affect the nature and mechanism of the reactions, thereby adjusting the practical performance of the system. For example, in the hydrogen/oxygen evolution reactions of electrocatalysis, the transferable abilities of electrons, ions and molecules are mentioned. The surface/interface of the electrode material is closely connected with the number of exposed active sites, the charge transfer efficiency and the adsorption capacity of the intermediates, which has become an important entry point for the control of the electric catalyst performance.

What’s more, the revelation of micro-level mechanisms and descriptions of the corresponding interactions at interfaces can revolutionize the in-situ tracking and characterization system. Specifically, more accurate morphological structure, like plane, edge, side and facet, even atomic structure can be clearly seen via in-situ observation; clearer graph-based information about oxidation state of intermediates and more precise crystal structural analysis can be obtained via in-situ X-ray techniques.

Finally, better understanding of the role of surface/interface will contribute to the discovery, optimal design, modification and computation of functional nanomaterials by providing a system of targeted strategies. The critical step here is how to establish a reliable, explicit mapping between the micro-level interface-related features and macro-level practical performance via optimizing the interfacial reactions.

The aim of this proposal is to provide a better understanding of the mechanism and a more universal methodology for macroscope performance analysis and optimization based on structural or composition-based analysis at the nano-level. Moreover, a more profound aim is for the better optimal design of functional nanomaterials.