Environmental Pressure Drying Facilitates the Preparation of Highly Elastic Graphene/Cellulose Composite Aerogels for Efficient Dye Adsorption

Three-dimensional graphene-based aerogel possess unique advantages in the field of dye wastewater treatment due to their high porosity, large specific surface area, and strong mechanical properties. However, the existing drying methods for graphene-based aerogels primarily focus on vacuum freeze-drying, making it highly challenging to achieve the controlled preparation of highly elastic graphene-based aerogels under low-cost and easily industrialized ambient pressure. Here, a strategy of freeze-thaw treatment, low surface tension solvent replacement and one-dimensional linear cellulose scaffold reinforcement was carefully designed, successfully preparing a series of highly compressible and resilient graphene/cellulose composite aerogels (RGA/CMC) under ambient pressure conditions. Various characterization techniques were utilized to analyze RGA/CMC, and its adsorption performance was evaluated using methylene blue (MB) in water as a typical pollutant. The results indicate that the equilibrium adsorption capacity of RGA/CMC for MB can reach 127.92 mg·g-1, with a removal rate of MB in solution exceeding 99%. The adsorption process primarily involves monolayer chemical adsorption, conforming to the Langmuir model and pseudo-second-order kinetics. Additionally, an increase in temperature is beneficial for the adsorption of MB. Furthermore, after 500 compression cycles at 80% strain, RGA/CMC maintained approximately 95% of its original height. This study provides a new perspective for the large-scale preparation of graphene-based aerogels with excellent mechanical properties, which are expected to be applied in dye wastewater treatment and other fields.