Engineering Microporous Bamboo-Derived Carbons via Alkaline Activation for Formaldehyde Adsorption in Building Environments

Abstract

This study presents a systematic evaluation of bamboo-derived activated carbons (ACs) prepared using three alkaline activating agents-KOH, KHCO3, and K2CO3-for efficient formaldehyde adsorption. The pore structures of the resulting ACs were modulated by varying the alkali-to-carbon (A/C) ratio from 1:1 to 4:1, and the effects on microstructure and adsorption performance were thoroughly investigated. Among all samples, AC-MB@KOH(3) demonstrated superior performance, featuring a high specific surface area of 2141.77 m2/g and a removal efficiency of 90%, attributed to its rich microporous texture and well-developed hierarchical porosity. Comparative analysis revealed that the activation strength and decomposition behavior of different alkaline agents critically influenced pore formation dynamics and gas diffusion pathways. Correlation analysis indicated a strong linear relationship between formaldehyde removal efficiency and micropore volume (R2 = 0.87), emphasizing the pivotal role of micropores in gas molecule capture. These findings underscore the advantages of strong alkaline activation and offer a theoretical foundation for designing high-efficiency, biomass-derived porous adsorbents for indoor air purification applications.