title: Porous ZnO-ZnSe nanocomposites for visible light photocatalysis.
abstract: We report the synthesis of porous ZnO-ZnSe nanocomposites for use in visible light photocatalysis. Porous ZnO nanostructures were synthesized by a microwave-assisted hydrothermal reaction then converted into porous ZnO-ZnSe nanocomposites by a microwave-assisted dissolution-recrystallization process using an aqueous solution containing selenium ions. ZnO and ZnSe nanocrystallites of the nanocomposites were well-mixed (rather than forming simple core-shell (ZnO-ZnSe) structures), particularly, in the outer regions. Both ZnO and ZnSe were present at the surface and exposed to the environment. The porous ZnO-ZnSe nanocomposites showed absorption bands in the visible region as well as in the UV region. The porous ZnO-ZnSe nanocomposites had much higher activities than the porous ZnO nanostructures. Control experiments using cutoff filters revealed that the main photocatalytic activity of the synthesized nanostructures arose from photo-excitation of the semiconductor (ZnO or ZnSe) via absorption of light of an energy equal to or exceeding the band gap energy.
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-Dong, Nam-Gu, Pohang, Gyungbuk, Korea.
authors.forename: Seungho
authors.initials: S
authors.lastname: Cho
authors.forename: Ji-Wook
authors.initials: JW
authors.lastname: Jang
authors.forename: Jae Sung
authors.initials: JS
authors.lastname: Lee
authors.forename: Kun-Hong
authors.initials: KH
authors.lastname: Lee
mesh_terms: D002384:Catalysis; D003460:Crystallization / Q000379:methods*; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D010316:Particle Size; D010777:Photochemistry / Q000379:methods; D016062:Porosity; D018036:Selenium Compounds / Q000737:chemistry* / Q000528:radiation effects; D012666:Semiconductors; D013499:Surface Properties; D017967:Zinc Compounds / Q000737:chemistry* / Q000528:radiation effects; D015034:Zinc Oxide / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D046911:Macromolecular Substances; D018036:Selenium Compounds; D017967:Zinc Compounds; C044696:zinc selenide; D015034:Zinc Oxide