Preparation and Application of Hierarchical Porous Carbon Materials from Waste and Biomass: A Review

Hierarchical porous carbon (HPC) materials contain organized pores having different scales of diameters. These materials exhibit surprisingly high performance in various applications due to the functional combination of hierarchical pores. This paper reviews the preparation of HPC from waste and biomass, and their potential applications. Biomass with naturally organized hierarchical structure, such as wood, grass and nut shell, have been widely used as raw materials, from which, hierarchical porosity can be formed through simple pyrolysis-activation. Influences of the types and dosages of activating agent, as well as the pyrolysis/activation conditions on the specific surface area, pore volume and hierarchical porous structure of the structured biomass-based HPC are discussed. For non-structured raw materials such as sucrose, pitch and plastics, novel technologies have been developed to prepare HPC; these include hard-/soft-template methods, hydrothermal carbonization, chemical vapor deposition, spray pyrolysis and autogenic pressure carbonization. The approaches to design or control the structures and properties of HPC made from non-structured materials are also reviewed. Moreover, advanced applications of HPC in energy storage, deionization, adsorption and catalysis are summarized.