NH2-UiO-66/ g -C3N4/CdTe composites for photocatalytic CO2 reduction under visible light

Abstract

To boost the photocatalytic activity of NH2-UiO-66 toward CO2 under visible light, CdTe quantum dots and g-C3N4 nanocrystals were introduced to form NH2-UiO-66/g-C3N4/CdTe composites via a two-step synthetic strategy. g-C3N4 and CdTe in different visible light ranges possessed a strong absorption ability, and, thereby, greatly extended the range of photoresponsive wavelength of the composites. Mott-Schottky analysis revealed that the energy level of the conduction band of g-C3N4 and CdTe was higher than the LUMO level of NH2-UiO-66, benefiting for the photogenerated carriers separation and electron injection from g-C3N4 and CdTe to NH2-UiO-66, leading to a high concentrated Zr (iii) formation. Finally, the NH2-UiO-66/g-C3N4/CdTe composites exhibited the superior photocatalytic performance for CO2 conversion in the acetonitrile/ethanol system upon visible light irradiation (≥400 nm) with a HCOOH generation rate of 24.6 μmol g-1 h-1 that was ∼7.5 times higher than that of NH2-UiO-66 alone.