Lotus stem-inspired directional channel structured graphene oxide/collagen composite aerogels with high capillary effect for the adsorption of methylene blue dye.

Frequent water pollutants caused by organic dyes in the textile industry pose a serious threat to ecosystems, and there is a high demand for rapid cleanup and degradation of these pollutants. Inspired by the structure of the natural lotus stem and the self-assembly behavior of collagen (COL), we designed a composite aerogel with rapid organic dye adsorption driven by the capillary effect. Briefly, COL molecules were rapidly in situ self-assembled on the graphene oxide (GO) surface through a simple pretreatment process, aiming to achieve strong interfacial interactions between COL fibrils and GO. Then, the unidirectional freeze-drying technology was used to prepare GO/COL composite aerogels with directional channels for rapid dye adsorption. The resulting GO/COL composite aerogels achieved significantly increased structural stability under the synergistic effect of strong interfacial interactions and directional channel structure, which can not only obviously enhance the mechanical properties of GO/COL composite aerogels, but also endow them with a capillary effect, making them have an encouraging dye adsorption effect. This work provides a new type of GO composite aerogel based on the self-assembly behavior of COL, which has the advantages of high structural stability, environmental friendliness, strong adsorption capacity, and is a promising dye adsorbent in the textile industry.