Activated carbon derived from hydrothermal treatment of sucrose and its air filtration application

Abstract

As air pollution problems become increasingly serious and the environmental awareness continues to rise, a source of cheap and simple air filtration active material is also required. Here, we demonstrated the use of hydrothermal carbonization-derived activated carbon for such an application. By doing so, we hope to develop a biodegradable filtering material which can combine filtering capability with biodegradable functionalities. To this end, an air filtration paper using activated carbon and pulp as materials was synthesized. Activated carbon was prepared by hydrothermal carbonization of sucrose and further activation. Hydrochar synthesis parameters including reaction time, reaction temperature, sucrose concentration, pH effect of hydrothermal solution, and nitrogen doping were investigated. The air filtration application was demonstrated using activated carbon obtained from a dramatic chemical reaction with KOH at 800 °C as the biodegradable active filler material. The morphology of hydrochar and activated carbon was characterized by scanning electron microscopy (SEM). Gas chromatography-mass spectrometry (GC-MS) was used to investigate the mechanism of hydrochar formation with different pH of hydrothermal solution. Fourier-transform infrared spectrometer (FTIR) was used to confirm activation. The results of elemental analysis showed evidence of nitrogen doping. Surface area and pore size analysis results allow for comparison of the degree of activation. The highest surface area of activated sample obtained in this study is up to 3026 m² g⁻¹ and the filtering abilities of our samples were measured by TSI model 8130 testing method with results of filtering efficiency achieving a quarter of that of the commercial air filter product.