Flexible cage-like carbon spheres with ordered mesoporous structures prepared via a soft-template/hydrothermal process from carboxymethylcellulose

Abstract

Novel carbon microspheres with tunable mesoporous structures and surface morphologies (CSF_n) were synthesized via hydrothermal carbonization using carboxymethylcellulose (CMC) as carbon source and the triblock copolymer Pluronic F127 as a soft template. The obtained carbon microspheres changed from smooth spheres when no F127 was added to walnut-like, strawberry-like, and cage-like structures when 0.5, 0.7, and 1.0 g, respectively, of F127 were added. Linear polymerization and cycloaddition of F127 with the CMC hydrothermally carbonized intermediate products enabled formation of carbon skeletons with higher thermal stabilities. After carbonization, the F127 in the carbon skeleton decomposed, leading to mesopore formation. In addition to the morphology, the mesoporous structure and specific surface area of the carbon microspheres can also be controlled by varying the mass of F127; the pore structure changed from a stripe-like 2-D hexagonal mesostructure to cubic mesoporous to disordered worm-like pores. The unique ordered mesoporous structure resulted in the carbon spheres exhibiting high adsorption capacity for Vitamin B₁₂.