Conventional synthesis methods of functional materials are usually time- and energy consuming and contribute to the accumulation of waste solvents. An alternative solution is the use of environmentally friendly recipes such as mechanochemical synthesis, which may be employed for large-scale production of materials. Mechanochemistry has been applied in various areas, such as metallurgy, mineral processing, construction and synthesis of organic compounds, and currently it is experiencing a renaissance because of its successful implementation for the synthesis of diverse organic, inorganic and organic–inorganic hybrid nanomaterials. Here mechanochemical synthesis of highly porous materials is reviewed with special emphasis on novel sorbents. Mechanochemically-assisted methods are well suited for the preparation of highly porous carbons (such as lignin- or tannin-derived carbons), metal–organic frameworks (e.g., MOF-5, MIL-101 and U-67) or covalent organic frameworks with specific surface areas up to 3500 m² g⁻¹. Recently, ball milling was also utilized for the synthesis of ordered coordination polymers and perfectly ordered mesoporous carbons. Nowadays, mechanochemistry has become a powerful and quite universal method for the preparation of various materials. Hence, there is a need for a review summarizing the current accomplishments in this field. Most of the mechanochemically obtained porous materials reported so far have been designed for adsorption, catalysis and energy storage related applications.

Ultrasounds are commonly used in medical imaging, solution homogenization, navigation, and ranging, but they are also a great energy source for chemical reactions. Sonochemistry uses ultrasounds and thus realizes one of the basic concepts of green chemistry, i.e., energy savings. Moreover, reduced reaction time, mostly using water as a solvent, and better product yields are among the many factors that make ultrasound-induced reactions greener than those performed under conventional conditions. Sonochemistry has been successfully implemented for the preparation of various materials; this review covers sonochemically synthesized nanoporous materials. For instance, sonochemical-assisted methods afforded ordered mesoporous silicas, spherical mesoporous silicas, periodic mesoporous organosilicas, various metal oxides, biomass-derived activated carbons, carbon nanotubes, diverse metal-organic frameworks, and covalent organic frameworks. Among these materials, highly porous samples have also been prepared, such as garlic peel-derived activated carbon with an apparent specific surface area of 3887 m²/g and MOF-177 with an SSA of 4898 m²/g. Additionally, many of them have been examined for practical usage in gas adsorption, water treatment, catalysis, and energy storage-related applications, yielding satisfactory results.

Metal–organic structures have great potential for practical applications in many areas. However, their widespread use is often hindered by time-consuming and expensive synthesis procedures that often involve hazardous solvents and, therefore, generate wastes that need to be remediated and/or recycled. The development of cleaner, safer, and more sustainable synthesis methods is extremely important and is needed in the context of green chemistry. In this work, a facile mechanochemical method involving water-assisted ball milling was used for the synthesis of MOF-303. The obtained MOF-303 exhibited a high specific surface area of 1180 m²/g and showed an excellent CO₂ adsorption capacity of 9.5 mmol/g at 0 °C and under 1 bar.

Highly porous activated carbons were synthesized via the mechanochemical salt-templating method using both sustainable precursors and sustainable chemical activators. Tannic acid is a polyphenolic compound derived from biomass, which, together with urea, can serve as a low-cost, environmentally friendly precursor for the preparation of efficient N-doped carbons. The use of various organic and inorganic salts as activating agents afforded carbons with diverse structural and physicochemical characteristics, e.g., their specific surface areas ranged from 1190 m²·g⁻¹ to 3060 m²·g⁻¹. Coupling the salt-templating method and chemical activation with potassium oxalate appeared to be an efficient strategy for the synthesis of a highly porous carbon with a specific surface area of 3060 m²·g⁻¹, a large total pore volume of 3.07 cm³·g⁻¹ and high H₂ and CO₂ adsorption capacities of 13.2 mmol·g⁻¹ at −196 °C and 4.7 mmol·g⁻¹ at 0 °C, respectively. The most microporous carbon from the series exhibited a CO₂ uptake capacity as high as 6.4 mmol·g⁻¹ at 1 bar and 0 °C. Moreover, these samples showed exceptionally high thermal stability. Such activated carbons obtained from readily available sustainable precursors and activators are attractive for several applications in adsorption and catalysis.

A facile mechanochemical method was used for the synthesis of ordered mesoporous carbons (OMCs) with well-dispersed metal nanoparticles. The one-pot ball milling of tannins with a metal salt in the presence of a block copolymer followed by thermal treatment led to Ni- or Pt-embedded OMCs with high specific surface areas (up to 600 m²·g⁻¹) and large pore volumes (up to ~0.5 cm³·g⁻¹). The as-prepared OMC-based samples exhibited hexagonally ordered cylindrical mesopores with narrow pore size distributions (average pore size ~7 nm), which implies sufficient long-range copolymer-assisted self-assembly of the tannin-derived polymer upon milling even in the presence of a metal salt. The homogenous decoration of carbons with small-sized metal (Ni or Pt) particles was essential to provide H₂ storage capacities up to 0.33 wt.% at 25 °C and under 100 bar. The presented synthesis strategy seems to have great potential in the practical uses of functionalized polymers and carbons for applications in adsorption and catalysis.