Porous carbon materials based on Physalis alkekengi L. husk and its application for removal of malachite green

Abstract

Physalis alkekengi L. husk (PH) is a waste product discarded during agricultural production. Improper disposal of large amounts of PH can lead to environmental pollution of water and air. In this work, a porous carbon material was prepared for the first time from PH and denoted as PCPH. The structures and surface properties of PCPH were characterized using TGA, SEM, XRD, FT-IR, N2 adsorption/desorption, Raman spectroscopy, and XPS. The specific surface area of PCPH was as high as 3502 m2/g, and the total pore volume was 2.24 cm3/g. Malachite green (MG) was used as a model dye for evaluating the adsorption performance of PCPH. When the pH was 9, the maximum adsorption capacity of PCPH reached 1989 mg/g. Fast adsorption of MG reached 1016 mg/g in the first 5 min. The adsorption data of PCPH was fitted with kinetics and isotherm models, and the thermodynamics were analyzed. The adsorption mechanism of MG was also analyzed. The removal rate of MG still reached 89% after 10 cycles. In summary, PCPH has excellent application potential in environmental water pollution treatment.