Study on preparation and photocatalytic performance of mint carbon dots/TiO2 composite photocatalyst
In this study,mint powder was employed as biological carbon source to prepare mint carbon dots(mint-CDs)/TiO2 composite photocatalyst by a one-step hydrothermal method.The structure,mor-phology,specific surface area and photogenerated charges separation characteristics were carefully in-vestigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transform in-frared spectroscopy(FT-IR),Brunauer-Emmett-Teller(BET)method,and surface photo voltage spectro-scopy(SPS).Rhodamine B(RhB)was employed as model pollutant to study the photocatalytic activit-ies of mint-CDs/TiO2 photocatalysts.The results show that mint-CD improve the photocatalytic activity of TiO2,and superoxide free radical·O2-is the main active free radical in the photocatalytic degrada-tion reaction.When the mass ratio of mint-CDs/TiO2 is 2%,the composite photocatalyst demonstrates the maximum photogenerated charges separation efficiency and degradation activity for RhB,and the photocatalytic activity was increased by 2.24 times compared with reference TiO2.