Carbon dot-boosted catalytic activity of CaO2 by tuning visible light conversion

Abstract

External auxiliary methods, including UV illumination, Fenton reagent addition and O₃ aeration, are broadly used to activate self-generated H₂O₂ from CaO₂ for toxic chemical removal, wastewater remediation, and even cancer therapy. However, these techniques are commercially unfeasible or bring new contaminants into the environment when used. Herein, we present a novel method of tuning visible light conversion to facilitate the release and activation of H₂O₂ by virtue of the integration of CaO₂ with biocompatible carbon dots (CaO₂/CDs). This totally green catalyst can be facilely synthesized in solution without heating or extra pressure, and exhibits a 2.1 times higher catalytic activity compared to single CaO₂. The incorporation of CDs not only induces more photogenerated carriers but also tunes their reactions to activate the H₂O₂ generated from CaO₂, giving rise to a high yield of the superoxide radical instead of the hydroxyl radical during the catalytic process. Thus, the CDs significantly enhance the catalytic performance of the H₂O₂ released from CaO₂ with the help of light energy.