Adsorption Mechanisms for Volatile Organic Compounds

Adsorption mechanisms for volatile organic compounds (VOCs) centre on the interplay between surface energetics and pore architecture of adsorbent materials. Physical adsorption is driven by van der Waals forces, hydrogen bonding and π–π interactions, whereas chemisorption entails stronger chemical bonds at reactive surface sites. The distribution and size of micropores, mesopores and macropores govern diffusion rates and capacity, often characterised by adsorption isotherm models such as Langmuir and Freundlich, and kinetic descriptions by pseudo-order equations. Surface functionalisation—through hydrophobic coatings, metal oxide nanoparticles or organic modifiers—tunes selectivity, enhances uptake under humid conditions and facilitates regeneration by temperature or vacuum swings. Material classes under active investigation include activated carbons, zeolites, mesoporous silicas, carbonaceous composites and organoclays, each offering distinct adsorption profiles for different VOC chemistries. This research is motivated by air quality regulations, industrial solvent recovery and environmental health concerns, driving the development of adsorbents with high capacity, rapid kinetics and robust recyclability for applications ranging from indoor air purification to industrial emission control.

Research from Nature Portfolio

Recent studies have demonstrated the potential of mesoporous graphene powders with high specific surface area and transformed surface chemistry to achieve exceptional adsorption efficiencies for aromatic VOCs such as toluene and xylene at ambient concentrations. The non-polarised graphene network exploits π–π interactions to reach removal efficiencies in excess of 90 per cent across a range of concentrations. Importantly, thermal expansion protocols render the material hydrophobic, mitigating competitive water adsorption and enabling at least five cycles of reuse with minimal loss of capacity. These advances highlight the interplay between nanostructure design and surface modification in driving high-performance VOC capture.

Adsorption Mechanisms for Volatile Organic Compounds publication trend

The graph below shows the total number of articles in adsorption mechanisms for volatile organic compounds across all publications each year (not limited to Nature Index journals).

Technical terms

Physisorption: Adsorption involving weak van der Waals forces without chemical bond formation.

Chemisorption: Adsorption requiring the formation of chemical bonds between adsorbate and surface.

Specific surface area: The total surface area of an adsorbent per unit mass, determining available active sites.

Breakthrough time: The elapsed time in dynamic adsorption before effluent concentration reaches a defined fraction of the inlet.

Mesoporous materials: Solids characterised by pore diameters between 2 and 50 nm, balancing diffusion and capacity.

Adsorption isotherm: A curve describing the equilibrium relationship between adsorbate concentration in fluid and amount adsorbed at a constant temperature.

References

1. Mesoporous graphene adsorbents for the removal of toluene and xylene at various concentrations and its reusability. Scientific Reports (2019).
2. Synthesis of ZSM-5/Siliceous Zeolite Composites for Improvement of Hydrophobic Adsorption of Volatile Organic Compounds. Frontiers in Chemistry (2019).
3. Activated carbons modified by magnesium oxide as highly efficient sorbents for acetone. RSC Advances (2018).
4. Styrene removal by surfactant-modified smectite group minerals: Efficiency and factors affecting adsorption/desorption. Chemical Engineering Journal (2022).