Figure 1.

a SEM image, b TEM image, c XRD patterns, d Nitrogen absorptionā€“desorption isotherms and corresponding pore size distribution of TiO2 hollow spheres synthesized at 180Ā°C for 48 h

Yang et al. Nanoscale Research Letters 2010 5:1437-1441   doi:10.1007/s11671-010-9658-2