From coconut water to hydrophobic three-dimensional carbon aerogels: A recyclable and sustainable platform for oil recovery

Phuoc M. Huynh; Vy N.T. Nguyen; Quan H. Nguyen; Duy K. Trang; Phu V. Luu; Khoi M. Tran; Thanh C. Ly; Kien A. Le; Anh N. Pham; Khanh H.M. Tran; Hoang Phuoc Ho; Huy X. Le; Khoa D. Nguyen; Ha V. Le

doi:10.1016/j.biteb.2026.102669

From coconut water to hydrophobic three-dimensional carbon aerogels: A recyclable and sustainable platform for oil recovery
Journal article, 2026

Sustainable, recyclable carbon aerogels were fabricated from coconut water-derived bacterial cellulose via an environmentally benign route involving alkali/urea pretreatment, freeze-drying, and controlled carbonization. The process produced an ultralight three-dimensional carbon network with hierarchical interconnected porosity. After the carbonization, the surface area increased significantly, reaching approximately 534 m²/g at 700 °C, together with higher micropore and total pore volumes. TEM analysis showed the transition from a disordered cellulose framework to layered, partially graphitized carbon sheets, while XPS revealed reduced oxygen- and nitrogen-containing groups and increased C-C bonding, indicating effective carbonization and enhanced hydrophobicity. The aerogel exhibited high adsorption capacities for oils and organic solvents (115–266 g/g) with rapid uptake, achieving near-maximum adsorption within minutes. Importantly, good recyclability was demonstrated with 83% of its initial capacity at the tenth cycle. These findings present a green and efficient valorization pathway for agricultural by-products into potential materials for oil remediation in water.

Hydrophobic liquids

Carbon aerogel

Coconut water

Oil recovery

Recycling