Construction of model platforms to probe the confinement effect of nanocomposite-enabled water treatment

To overcome the bottleneck of aggregation of nanomaterials as the main obstacle for their application in water decontamination processes, it is a promising strategy to confine the nanoparticles inside the pores or channels of supporting substrates. Moreover, significantly improved performance of the resultant nanocomposites induced by the nanoconfinement effect has been sporadically reported. However, the underlying mechanisms behind such nanoconfinement effect are far from clearly understood, thus impeding the rational design of the nanocomposites for more efficient water decontamination. The construction of model systems with nanoconfinement structures is of fundamental significance to further mechanistic investigations into the nanoconfinement effect, whereas such methodologies have not been systematically reviewed. Herein, this article provides an overview of the methods for preparations of composites with nanoconfinement structures in terms of physical, physicochemical, and chemical routes, with the illustration of the fundamental principles and application examples of the methods of concern. The applied support materials for model systems construction were focused on those with shapeable framework and processability, such as carbon nanotubes, homoporous membranes, ordered mesoporous materials, and two-dimensional materials. Furthermore, we elucidated the key factors in maximizing nanoconfinement efficiency and the synthesis of nanoparticles with controllable size and morphology. On such a methodological basis, this review is believed to shed new light on both fundamental studies and technological innovation on nanoconfined materials for water decontamination.