In this work, a sol-gel method was used to load TiO 2 nanoparticles on three clays (kaolinite, halloysite and palygorskite) with different morphologies (plates, tubes, and rods with micro tunnels), and then the photocatalytic performance of obtained clay-TiO 2 composites for degradation of methyl orange was comparatively investigated. The results surprisingly show that the trend of photocatalytic performance of composites is opposite to that of special surface area of corresponding clays. By concentrated analysis of the loading status of TiO 2 , the lowest photocatalytic efficiency of palygorskite-TiO 2 composite is mainly ascribed to (1) the aggregation of TiO 2 nanoparticles on Pal surface, not the amount of TiO 2 and (2) the relatively weak adsorption of Pal to methyl orange. The additional adsorption of hydroxyl surface of Kaol to methyl orange and little TiO 2 in the lumen of Hal tube leads to the better photocatalytic performance of kaolinite-TiO 2 composite than halloysite-TiO 2 composite. Finally, kaolinite is proved to be an excellent carrier to support nano TiO 2 resulting in a good photocatalytic performance and cycle stability, and the study can provide a direct guidance to select appropriate clay-photocatalyst composites for different practical applications. Unlabelled Image • Comparative photocatalytic study of loading nano TiO 2 on three clays with distinct morphologies • Opposite trend between photocatalytic performance of clay-TiO 2 composites and special surface area of clays • TiO 2 aggregation on palygorskite, little TiO 2 in halloysite and MO adsorption on kaolinite hydroxyl surface cause the trend [ABSTRACT FROM AUTHOR]