•TiO2 nanocrystal seeds was loaded on fly ash substrates by surface modification.•One-dimensional porous TiO2 was synthesized on fly ash carriers.•The floating photocatalyst presented better catalytic activity and recyclability.By modification of silane coupling agent, the TiO2 nanocrystal seeds layer was loaded on the surface of fly ash carriers. Based on that, the hydrothermal method was adopted to synthetize the one-dimensional (1-D) TiO2 which were loaded on the carriers densely under the condition of a low concentration TiO2 precursor. Because of the calcination residual of modifier, the transmission and diffusion of ions on the surface of TiO2 would be hindered, and the 1-D TiO2 with porous surface can be obtained. The specific surface area of porous TiO2/fly-ash composite particles reaches 174.8 m2/g. HRTEM and XRD results suggested that the TiO2 prepared was a single-crystalline structure featuring the (110) plane, but the plane had some structural defects for being bended and interrupted. Results of photocatalytic degradation of Rhodamine B showed that the catalytic activity of 1-D porous TiO2 was higher than that without a porous structure.Download high-res image (471KB)Download full-size image