LAUSR

A series of sensitized TiO2 NPs with enhanced photocatalytic activity were prepared by different sized CdTe QDs with bifunctional ligand interlinking. The microstructures and morphologies of four different sizes of CdTe QDs and CdTe QDs sensitized TiO2 NPs were characterized systematically by fluorescence spectroscopy, UV‐Vis diffuse reflectance spectroscopy, FT‐IR, XRD, XPS, FE‐SEM, HRTEM, BET, and positron annihilation lifetime spectroscopy (PALS). The photocatalytic performance of CdTe QDs sensitized TiO2 NPs was investigated by degrading MO and MB in aqueous solution under visible light irradiation. The process of degradation complied with the first‐order reaction kinetics. Four different sized CdTe QDs sensitized TiO2 exhibited higher photocatalytic activities than TiO2. Particularly, yellow emitting CdTe QDs (3.28 nm) sensitized TiO2 (CT_1.5) showed the best photocatalytic performance, which may be attributed to the optimal NP size, and has a moderate light absorption and electron injection. The effect of microstructural defects on CdTe QDs sensitized TiO2 has been confirmed effectively by positron lifetime measurements.