As illustrated in Fig. 1, the present HS TiO2 is featured by bipyramid agglomerate (BPA). We propose that distinct structural features of BPA may enhance the photocatalytic activity for the following reasons. Firstly, uniformly packed dense agglomerates promote an efficient charge pair separation through the interparticle charge transfer and provide accessible mesopores for the A 582941 of substrates. Furthermore, the bipyramidal shape enhances the electron transfer between primary particles by increasing the contact area. Secondly, the exposed 1 0 1 facets on the bipyramidal TiO2 further reduce the recombination rate because the photo-generated electrons are preferentially accumulated at the 1 0 1 facets with retarding the recombination rate  and . Finally, the high crystallinity of bipyramidal particles with fewer defect sites can minimize the defect-induced recombination. The superior activities of 1 0 1 -oriented BPAs were demonstrated and discussed for photocatalytic and PEC performances.