Nanoscale Res Lett (2010) 5:1408–1417 1415 Fig. 4 X-ray diffraction to synthesis of nanoparticles SiO2 obtained with bioprocess and without bioprocess using as precursors: rice husk (a–b) sugarcane bagasse (c–d) and coffee husk (e–f) to two temperatures of calcinations: 500 and 700 C. It shows a change in the crystallinity of the nanoparticles synthesized, since the different precursors used and varying the temperature of calcination and employing or not employing the bioprocess 123