title: Biogenic hierarchical TiO₂/SiO₂ derived from rice husk and enhanced photocatalytic properties for dye degradation.
abstract: BACKGROUND
  Rice husk, an agricultural bioresource, is utilized as a non-metallic bio-precursor to synthesize biogenic hierarchical TiO₂/SiO₂ (BH-TiO₂/SiO₂) and the products are applied to dye degradation.
  
  
  RESULTS
  The as-prepared BH-TiO₂/SiO₂ samples are characterized by X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), nitrogen-adsorption measurement, UV-vis spectroscopy and electronic paramagnetic resonance (EPR). The results show that BH-TiO₂/SiO₂ possesses both anatase and rutile phases with amorphous SiO₂ as background, which contains mesopore structure, and nitrogen derived from original rice husk is self-doped into the lattice. Besides, the light-harvesting within the visible-light range of BH-TiO₂/SiO₂ has been enhanced. Moreover, the catalytic activity of BH-TiO₂/SiO₂ has been proven by EPR, and both the photocatalytic activity and stability of BH-TiO₂/SiO₂ are improved as well, which has been illustrated by cycled degradation of methylene blue dye under irradiation.
  
  
  CONCLUSIONS
  This work provides a good way to combine natural hierarchical porous structure with synthetic material chemistry based on available biomass in the vast natural environment for the sustainable development of human society, and extends potentials of biomass in applications such as photocatalysts, sunlight splitting water and so forth.
authors.affiliation: State Key Lab of Composites, Shanghai Jiaotong University, Shanghai, People's Republic of China.
authors.forename: Dalong
authors.initials: D
authors.lastname: Yang
authors.forename: Tongxiang
authors.initials: T
authors.lastname: Fan
authors.forename: Han
authors.initials: H
authors.lastname: Zhou
authors.forename: Jian
authors.initials: J
authors.lastname: Ding
authors.forename: Di
authors.initials: D
authors.lastname: Zhang
mesh_terms: D004396:Coloring Agents / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D012275:Oryza / Q000737:chemistry*; D010777:Photochemistry / Q000379:methods*; D056951:Photoelectron Spectroscopy; D012822:Silicon Dioxide / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D004396:Coloring Agents; C507641:TiO2-SiO2; D012822:Silicon Dioxide; D014025:Titanium