The carbon quantum dots prepared by chemical oxidation method were added to tetrabutyl titanate,and TiO2/CQDs composite materials were prepared by sol-gel hydrolysis method.The as-prepared TiO2/CQDs samples were characterized by a series of techniques.The properties of TiO2/CQDs composite materials were studied with rhodamine B (Rh B) as a degradation target.The results showed that the light absorption intensity of TiO2/CQDs increased compared with that of TiO2.Moreover,its absorption wavelength was red-shifted towards the visible light region.When the content of CQDs in composite was 5%,the photocatalytic degradation rate of Rh B by the TiO2/CQDs was 85.47%,which was about 6 times higher than that of pure TiO2.Even after being recycled for 4 times,its catalytic degradation rate for Rh B remained above 82%.It could be seen from the photocatalytic reaction mechanism that superoxide anion radical (·O-2) had the largest oxidation effect in the photocatalytic Rh B degradation process,followed by hole (h+),then hydroxyl radical (·OH),and hydrogen peroxide molecule (H2O2) was the weakest.
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基金资助
国家自然科学基金(51972242);煤基精细化工河南省工程实验室开放课题项目(C202006)
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