Figure 1

SEM images of clam shell samples: (a,b) uncalcined; (c,d) treated at 800 °C; (e,f) treated at 900 °C; (g,h) treated at 1000 °C; and TEM image (i–k) treated at 1000 °C.

SEM images of clam shell samples: (a,b) uncalcined; (c,d) treated at 800 °C; (e,f) treated at 900 °C; (g,h) treated at 1000 °C; and TEM image (i–k) treated at 1000 °C.