Preparation and characterization of nano silver immobilized hydrochar derived from hydrothermal carbonization of tobacco stem

In this present study, silver nanoparticles (AgNPs) immobilized hydrochar was prepared through a facile one-pot co-hydrothermal carbonization of tobacco stem and silver nitrate. The effect of concentration of silver precursor, hydrothermal temperature and reaction time on the chemical compositions, structural property, combustion performance, as well as gaseous products release behavior of the resultant AgNPs immobilized hydrochar were evaluated. The co-hydrothermal treatment decreased the volatile matter while increased the ash content of hydrochar. Single-phase AgNPs were successfully generated and evenly immobilized onto the hydrochar during the hydrothermal process. The immobilized AgNPs played a notable catalytic role during the char combustion stage, thereby decreased the ignition temperature, burnout temperature and maximum rate temperature for char combustion. Meanwhile, TG-FTIR analysis suggested that the emission amount of harmful gas CO during hydrochar combustion was reduced due to the catalytic effect of AgNPs. This phenomenon may indicate the appropriate amount of nanoparticles immobilization could enhance the combustion behavior of hydrochar fuel.