Light-induced degradation of rhodamine B by tellurium quantum dots.

Abstract

Tellurium quantum dots (Te QDs) were prepared using bulk tellurium as the precursor. Te QDs can be a highly active photocatalyst for boosting the photocatalytic degradation of rhodamine B (RhB) under visible light irradiation. The morphology and composition of Te QDs were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that in the presence of H2O2, the photocatalytic efficiency of Te QDs on RhB could achieve a good degradation effect within a very short time (30 min). The effects of initial dye concentration, pH value, light intensity, catalyst dosage and H2O2 concentration on dye degradation were successively studied. The effects of inorganic ions (NO3-, Cl-, SO42-, Ca2+, Mg2+ and Fe3+) on photocatalytic degradation were also discussed. Experimental results of free radical capture showed that OH• and O2•- played important roles in photocatalytic degradation. More importantly, Te QDs efficiency still remained above 85% after four cycles of use, indicating good stability, recyclability and utility. This work may inspire further design of other semiconductor QDs for highly efficient dye degradation.