Sugarcane bagasse as the scaffold for mass production of hierarchically porous carbon monoliths by surface self-assembly

The hierarchically porous carbon materials (HPCMs) with micro- and meso-porosity were prepared by surface coating and solvent evaporation-induced self assembly (EISA) using sugarcane bagasse as the scaffold. The triblock copolymer F127 and phenol-formaldehyde resin were used as mesostructural directing agent and carbon precursor, respectively. The microstructures in terms of morphology, pore texture, degree of graphitization, and thermal stability were characterized by scanning and transmission electron microscopy, nitrogen adsorption analysis, X-ray powder diffraction, and thermogravimetric analysis, respectively. The bulk morphology of HPCMs with hierarchically porous architecture can be retained after calcination at 1000 degrees C. Small and wide angel XRD patterns show 2-D hexagonal mesostructures and enhanced degree of graphitization. The specific surface areas of monolithic carbon materials are in the range 487-544 m(2) g(-1) with the micropore percentages of 66-67%. The thermal stability of HPCMs is enhanced by the strong interaction of hydroxyl groups of sugarcane bagasse with phenol-formaldehyde resins, and subsequently retains the highly ordered structures with pore size distributions centered at 0.5 and 3.2 nm. In addition, the bagasse-based HPCMs show good electrochemical property and the specific capacitances are in the range 190-234 F g(-1) at the scan rate of 5-50 mV s(-1). Results clearly show that the use of surface coating and EISA with sugarcane bagasse as the scaffold is an easy, effective and mass productive strategy for fabrication of HPCMs. (C) 2011 Elsevier Inc. All rights reserved.