Enhancement of lignin-based carbon quantum dots from poplar pre-hydrolysis liquor on photocatalytic CO2 reduction via TiO2 nanosheets

Abstract Reasonable utilization of lignin in pre-hydrolysis liquor (PHL) is very important for the economic benefit of papermaking industry. In this paper, lignin in poplar pre-hydrolysis liquor (PHL) was effectively adsorbed by TiO2 nanosheets, realizing the purification of PHL. Subsequently, lignin was carbonized via thermal desorption for forming the carbon quantum dots immobilized on TiO2 nanosheets surface, which can improve both the separation efficiency of photogenerated carrier and CO2 adsorption capacity of TiO2, as a result the efficiency of photocatalytic CO2 reduction of C/TiO2 increased 300 % compared to the TiO2.