The SEM images of DFNS and the composite 0.75-CNNS@CdS are given in Fig. 2a and 2b, respectively. DFNS shows a porous spherical morphology. After decoration, 0.75-CNNS@CdS maintains a spherical and porous morphology. As seen in the TEM image (Fig. 2c and 2e), the pristine silica shows fibrous morphology with sharp edges. From the TEM image (Fig. 2d), 0.75-CNNS@CdS are wrapped by a thin layer g-C3N4 and some rod-shaped CdS are distributed on the surface of the spherics. Fig. 2f shows that the
