Photocatalytic lignin oils and CO2 upgradation to diesel precursors and syngas over engineered CdSe quantum dots

Abstract

Photocatalytic lignin oils and CO2 upgradation for diesel precursors and H2/syngas production were explored over electrostatic self-assembled CdSe QDs/B-SiO2. The preparation of fuel precursors and H2 from lignin oils could be efficiently realized with noble metal free heterogeneous photocatalytic system in green solvent H2O (diesel precursors: 71–96%, H2: 6.0–7.3 mmol gcat-1). Moreover, lignin oils and CO2 could be simultaneously transformed to diesel precursors and syngas with good to excellent yield (diesel precursors: 64%-87%, H2: 5.1–6.7 mmol gcat-1, CO: 5.2–5.6 mmol gcat-1). In the CdSe QDs/B-SiO2 system, spherical SiO2 carrier was conducive for the dispersion of CdSe QDs to provide more active sites; the light absorption and utilization ability enhancement for CdSe QDs could be achieved by the scattered light recycling in the near field of SiO2, thereby realizing photocatalytic surface photoredox ability elevation and photocatalytic activity enhancement; the solvent assisted light scattering ability enhancement further promoted the heterogeneous photocatalytic performance.