One-step hydrothermal synthesis of cobalt and potassium codoped CdSe quantum dots with high visible light photocatalytic activity

The effect of metal ion doping on the electronic structure and optical properties of CdSe quantum dots has been investigated by various characterization techniques and experiments. Various cation codoped CdSe quantum dot photocatalysts were synthesized via a hydrothermal method. The prepared quantum dots were examined using X-ray diffraction, fluorescence spectroscopy, X-ray photoelectron spectroscopy, high resolution transmission electron microscopy, and UV–vis diffuse reflectance spectroscopy. The activities of the photocatalysts were evaluated with respect to the photodegradation of tetracycline hydrochloride solutions under simulated sunlight irradiation. 3%Co–4%K/CdSe quantum dots showed a higher photocatalytic activity than others within 30 min of visible light irradiation. Furthermore, there was hardly any decrease in the catalytic efficiency after the fourth experimental cycle. Identification data illustrate that Co and K codoping may cause improvement in the photocatalytic performance of CdSe quantum dots, which is crucial for tetracycline hydrochloride degradation under simulated sunlight irradiation. Therefore, this study demonstrates a promising strategy for the design of highly efficient photocatalysts for the remediation of aqueous pollutants.