The recovery processes of critical metals from multiple sources have turned more and more attention due to the increasing demand and consumption of them in modern industry. Many metals are used as significant components in manufacturing of a variety of products and equipment, playing significant roles in the economic security and national security; those metals involve rare earth elements (REEs), precious metals which include gold, silver, and platinum group metals (PGMs), and other valuable metals such as lithium, uranium, nickel, et al. The traditional approach to obtaining the above metals is by hardrock mining of natural ores via chemical and physical processes. However, this method of mining and refining metals from minerals is usually energy-consuming, costly, and environmental-destructive. Thus, various approaches to extracting or recycling target metals from the seawater or the solution of secondary resources as an alternative to traditional hardrock mining have been developed, and thereinto, using functional porous adsorbents to selectively capture specific metal ions from the aqueous resources has attracted increasing attention due to its outstanding merits such as high efficiency, energy-saving process, low cost, and reduced environmental impacts