Cellulose Derived Hierarchical Nanopore-Spaced Membranes by Murray’s Law for Gas Capture and Storage

Nanoporous membranes with two-dimensional materials such as graphene oxide have attracted attention in volatile organic compounds (VOCs) and H₂ adsorption due to their unique molecular sieving properties and operational simplicity. However, the agglomeration of graphene sheets and low efficiency remains challenging. Cellulose, the most prevalent biopolymer, is derived from plants and agricultural wastes. The capture and conversion of carbon from the atmosphere into biomass also produces oxygen as the byproduct. Emulating optimum natural systems following Murray’s law, we designed a novel and controllable 2D nanostructured hierarchical nanopore-spaced membranes (HNM) from cellulose, a class of micropore-dominated carbon spaced graphene oxide-based nanocomposites via controlled-pyrolysis and “doctor blade” coating method. Hierarchical carbon spheres, prepared following Murray’s Law using chemical activation incorporating microwave heating, act as spacers and adsorbents. Hierarchical carbon spheres preclude the agglomeration of graphene oxide, while graphene oxide sheets physically disperse, ensuring structural stability. The obtained HNM contain micropores that are dominated by a combination of ultramicropores and mesopores, resulting in high VOCs/H₂ adsorption capacity, up to 235 and 352 mg/g at 200 ppmv and 3.3 wt% (77 K and 1.2 bar), respectively. This work opens a new vista for the development of efficient sustainable 2D composites for applications in both human health and global climate.