In-situ synthesis of duster-like hollow mesoporous copper silicate composites for high-efficiency adsorption of aflatoxin B1 from water

Abstract

Aflatoxin B1 (AFB1) is one of the pollutants widely distributed in wastewater, which easily causes serious harm to human health and ecosystem. Mesoporous silicate materials are often used as adsorbents attributed to their well-controlled structures and high surface area. Herein, copper silicate composites (MCSCs) with novel duster-like hollow mesoporous structure were synthesized in situ on an acid-etched sepiolite substrate, and used as adsorbents for removal of AFB1 from water. The resultant MCSCs exhibited high specific surface area (439 m2/g), consequently exposing abundant functional groups (e.g., Si–OH, Cu–OH and Si–O–Cu), which contributed to improved adsorption performance. As expected, the MCSCs showed excellent AFB1 adsorption capacity, and the maximum adsorption capacity, obtained from the Langmuir model, was 24.99 mg/g. Analyses of the kinetic data revealed that the adsorption process of AFB1 onto MCSCs were fitted well with the pseudo-second-order and Weber-Moris intra-particle diffusion models. The FTIR and XPS analysis confirmed that the adsorption mechanisms were mainly electron donor-acceptor interaction and hydrogen bonding. These results in this work will provide valuable information for the development of green and efficient strategy for synthesizing other silicate materials, which are expected to applied as highly efficient adsorbents to remove AFB1 from wastewater.