Facile Control of Corncobs-based Carbons with Eutectic Salt ZnCl2/NaCl Templated for the Adsorption of Organic Aldehyde.

Corncob, a renewable biomass waste, has been successfully explored as a low-cost crude carbon source to prepare controlled morphology, and result in higher value-added carbons through a ZnCl2/NaCl treatment and direct pyrolysis process. The synthesis route is simple, green, and results in carbons with different morphology and porous structures by varying the ratio of the eutectic salt ZnCl2/NaCl. Moreover, the adsorption capacities of different carbon materials for formaldehyde and butyraldehyde were tested further. It was demonstrated that NaCl and ZnCl2 could be utilized as a mesopore template, and as a micropore activation agent for carbon materials, respectively. Although the mesopores can provide a fast diffusion channel, and the micropores can enhance adsorption ability, the specific surface area originating from the mesopores was proportional to the amount of butyraldehyde adsorption, and the specific surface area of the micropores was beneficial to the amount of formaldehyde adsorption taking place. The adsorption isotherms follow Langmuir and pseudo first-order kinetic modeling. Additionally, the whole process belongs to physical adsorption. [ABSTRACT FROM AUTHOR]