Amino Acid-Modified Porous Carbon Foams Derived from Wheat Powder with Enhanced Adsorption Performance for VOCs

Porous carbon foam (PCF), known for its high surface area and abundant functional groups, is considered to exhibit superior adsorption capacity and wide applicability for gases. Wheat, being a widely cultivated and easily accessible crop globally, contains abundant carbon elements. In this study, wheat powder served as the carbon precursor, and β-alanine, rich in amino and carboxyl groups, was introduced into the hierarchical pore structure of wheat powder. Subsequently, the material underwent secondary hydrothermal treatment with the activation agent potassium hydroxide (KOH), resulting in hydrothermal wheat powder PCF (HWPCF) rich in a three-dimensional interconnected structure with layered pores as the representative feature. This structural treatment increased the specific surface area (2278 m²·g⁻¹) and total pore volume (1.17 cm³·g⁻¹) of PCF, accelerating the rapid mass transfer of gas molecules and significantly enhancing the utilization of adsorption sites in the modified PCF. HWPCF exhibited outstanding adsorption performance for acetone (608.7 mg g⁻¹) and n-hexane (517.6 mg g⁻¹). In addition, the modified PCF showed good adsorption capacity for CO₂ (4.99 mmol·g⁻¹). This study highlights the effective modification of expired wheat powder with β-alanine, reducing the overall carbon footprint of the production process and achieving the reuse of waste in an environmentally friendly manner.