Hierarchical mesoporous carbon nanosheets for efficient organic pollutants removal

Hierarchical mesoporous carbon nanosheets were synthesized by using gallic acid and zinc organic-inorganic (Zn-GA) hybrids as templates. After carbonization and removal of ZnO nanoparticles by diluted HCl, carbon nanosheets with a thickness of 11–16 nm were formed and arranged like a completely-opened-erected book. The carbon nanosheets possessed mesopores (centered at 6.5 and 23.4 nm) and macropores and had high surface areas (786 m2 g−1) and large pore volumes (1.57 cm3 g−1). The thin thickness and high amount of mesopores of the carbon nanosheets ensured short diffusion path and largely available inner and outer adsorptive sites of the carbon nanosheet. The hierarchical structure of the carbon nanosheets avoided the thin nanosheets from aggregation during adsorption of organic pollutants in water solution. The obtained hierarchical mesoporous carbon (HMC) nanosheets were used as adsorbents to remove 2,4,6-trichlorophenol (TCP) from water. As a result, the HMC nanosheets showed fast adsorption rate and significantly higher adsorption capacity (833 mg g−1) to TCP than other mesoporous carbon materials.