Light-induced degradation of rhodamine B by tellurium quantum dots

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^-, SO₄^2-, 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.