Another method of improving the light-harvesting properties of TiO2 within the visible-light range is to dope some elements as N, S and C or metallic nanoparticles as Au or Ag. Among all element-doped method, N-doped method is considered to be effective as it could form a localized state slightly above the valence band in the band gap which could cause band narrowing, and it could also reduce the formation energy of oxygen vacancies. There could be two types of N-doped: organic and inorganic. The former includes urea and other organic compounds ; the latter includes ammonia and other inorganic compounds. These methods usually need to introduce additional source of nitrogen, which are complex and cumbersome. Moreover, mixed-oxide system containing TiO2 has attracted more and more attention in the field of photocatalyst, such as TiO2/SiO2, TiO2/Al2O3, TiO2/ZrO2, which has enhanced photocatalytic performance. Among all mixed-oxide system containing TiO2, titaniumsilicon oxides have been found to enhance photocatalytic activity more efficiently, because silica has a good property in lightharvesting within visible range. As agricultural bioresource, rice husk contains large mounts of silicon, so we try to develop a new method to synthesize titaniumsilicon oxides by utilizing rice husk with calcination method. On the other hand, most biomass including rice husk contains abundant non-metallic elements such as C, H, O and N, which indicates that nitrogen in rice husk could be self-doped into mixed-oxide system during synthesis. Furthermore, the biological structure is hierarchical in nature, and rice husk is a typical example of which with large surface area and porosity, so the structure of that could contribute to adsorption. Such structural features of rice husk inspire us to replicate them on functional materials with special functional properties. Thus, we except to find a new way in utilizing rice husk effectively for inheriting its advantages of both chemical composition and microstructure. In addition, the products are expected to contribute to environmental protection. In this study, we propose rice husk as non-metallic precursor to synthesize TiO2, because silicon is contained in rice husk, we expect it could be converted to SiO2 with calcination to synthesize mixed-oxide system as TiO2/SiO2. Besides, nitrogen in rice husk is expected to be self-doped into the mixed-oxide system during ICI 182780 synthesis as well as the inheritance of its hierarchical porous structure, resulting in biogenic hierarchical TiO2/SiO2, hereafter refer to BH-TiO2/SiO2. The sol-gel coating is employed for the replication of the porous framework of the rice husk. The BHTiO2/SiO2 samples are used for dye degradation, which is an example of pollutants degradation. This work is a combination of bioresource engineering and applied chemistry, and would develop a new method to protect the natural environment by utilizing useful biomass in the vast environment. This work employed rice husk as prototype to demonstrate its potential application in synthesizing hierarchical TiO2/SiO2.