<p>Volatile organic compounds (VOCs) pose environmental and health problems, underscoring the need to develop effective methods for their capture. This study produced activated biochar from biomass and evaluated its ability to capture different VOCs, including dichloromethane, chloroform, toluene, and cyclohexane, with the best results observed for dichloromethane (301&#xa0;mg&#xa0;g⁻¹). The temperature swing adsorption (TSA) process was used in the studies, which employed thermogravimetric analysis, taking advantage of the ease of this technique. The biomass used to produce the activated carbons was the invasive aquatic plant <i>Eichhornia crassipes</i>, a fast-growing aquatic plant chosen for its ecological reasons and low cost. The biomass was characterized by immediate analysis using ASTM methods and thermogravimetric analysis for comparative purposes. Initial characterization showed a fixed carbon content ranging from 28 to 40%, a crucial parameter for activated carbon production. In the activation process, KOH was used in different molar ratios of 1:1, 1:2.5, and 1:4. After production, the BET analysis indicated a surface area of the activated carbons ranging from 333 to 950 m² g⁻¹. VOC capture capacities were evaluated by thermogravimetric analysis, and it was observed that the adsorption capacity decreased with increasing temperature, a characteristic of physisorption. The adsorption curves were correlated with mathematical models, highlighting the pseudo-first-order model (<i>r</i>² = 0.9562–0.9915) as the dominant one, indicating a predominant physical adsorption mechanism. Meanwhile, the Avrami-Erofeev model (<i>r</i>² = 0.9899–0.9955) also suggested a contribution from chemical adsorption. VOC vapor capture studies by thermogravimetry applying TSA process are suitable, accurate, and easy to operate for these studies.</p> Graphical abstract <p></p>