Mesoporous activated carbon as a kind of non-silica-based mesoporous functional material is widely used in many fields such as catalysis, electrochemistry, supercapacitors, biomedicine, and adsorption due to its small pore size (i.e., 2-50 nm), high specific surface area, large pore size and volume of porosity, easy to modify the surface, and good hydrothermal stability. The development of mesoporous materials benefits from the rapid application of mesoporous activated carbon as an adsorbent in the field of adsorption. However, mesoporous carbon is not as widely utilized as mesoporous silica, and mesoporous carbon materials become popular just in recent years.

This review represented recent development on the synthesis and preparation of mesoporous activated carbon materials by physical activation method, chemical activation method, hard template method, soft template method and sol-gel method. The common types of templating agents in the preparation of hard template method and soft template method were enumerated. Silica is widely used as a template, and a class of low-cost, easy-to-remove and environmentally friendly templating agents were derived. The application of excellent magnetic biochar in sol-gel method was analyzed. The physical properties of carbon materials synthesized from different carbon precursors under the condition of H₃PO₄ as an activator were summarized. The control of pore size structure and morphology during the preparation of mesoporous carbon materials obtained by different methods were discussed. The current status of various methods in the preparation of mesoporous activated carbon materials was introduced. The advantages and disadvantages of the various methods in the synthesis of mesoporous activated carbon materials were analyzed. The four types of methods for structural modification and functionalization of mesoporous activated carbon materials by elemental doping of nitrogen, boron, phosphorus and sulfur in non-metals, transition metal doping led by iron, lanthanum, neodymium and cerium-dominated rare metal doping and oxidative modification of surface functionalization were described. The physical properties of carbon materials synthesized from some of the metal doped carbon precursor templates were discussed. The key role of introduction in mesoporous activated carbon materials undergoing structural modification was indicated via the introduction of functional groups through catalytic oxidation by chemical reagents to overcome the intrinsic limitation of limited adsorption capacity. Also, recent development on the adsorption of heavy metal ionsin was mentioned. In addition to some common metal elements, some niche metals (i.e., cobalt) were utilized in doping. In the adsorption of heavy metal ions by mesoporous carbon materials, the sources of heavy metals in water body were introduced, and the application of mesoporous activated carbon materials before and after modification for the removal of heavy metal ions (i.e., mercury, lead, and chromium) in wastewater was briefly described. Compared to the conventional activated carbon adsorbents on the removal of organic pollutants (i.e., dyes, phenols and volatile organic compounds), the mesoporous carbon materials have advantages in the removal of mercury by mercury-sulphur binding, and heavy metals (i.e., lead and hexavalent chromium, etc.). The mechanisms (i.e., electrostatic interaction, ion exchange and surface complexation) in the adsorption process of mercury, lead, and chromium ions were summarized.