A high-performance composite CDs@Cu-HQCA/TiO2 flower photocatalyst: Synergy of complex-sensitization, TiO2-morphology control and carbon dot-surface modification

A CDs@Cu-HQCA/TiO2 flower composite photocatalyst (CDs: carbon dots, HQCA: 8-hydroxyquinoline-5-carboxylic acid) was constructed by exploiting the synergy of complex-sensitization, TiO2-morphology control, and carbon dot-surface modification. The photocatalytic degradation of phenol, norfloxacin, tetrabromobisphenol A and Cr (VI) by Cu-HQCA/TiO2 particle, tube, diamond and flower-like show that the Cu-HQCA complex effectively extends the visible light absorption range of composite photocatalysts, and the flower morphology of TiO2 not only improves the adsorption of pollutants but also enhances the photoelectric response of the composite photocatalyst. In this manner, a CDs@Cu-HQCA/TiO2 flower catalyst that demonstrates excellent performance for the removal of dexamethasone, which does not degrade well naturally, was prepared, which delivered a rate of degradation of 99.4% and a degree of mineralization of 77.4% for dexamethasone. Possible degradation sites and dexamethasone degradation products were studied by combining computational chemistry with high-resolution mass spectrometry, and a possible mechanism for photogenerated carrier transmission and separation in the CDs@Cu-HQCA/TiO2 flowers is proposed.