title: Self-assembled double-shelled ferrihydrite hollow spheres with a tunable aperture.
abstract: Novel double-shelled hierarchical ferrihydrite hollow spheres (Fe(10)O(14)(OH)(2).4H(2)O) were successfully synthesized on a large scale by using a facile medicine-inspired solution-phase approach. Sodium nitroprusside (SNP), an ordinary and inexpensive medicine for expanding blood vessels, served as both a ferric source and an in situ formed gas-bubble template with the presence of sodium dihydrogen phosphate as a pH regulator, coordinator, and stabilizer. A twice-gas-bubble template model has been proposed for the formation of the double-shelled hollow spheres to take advantage of the dissociation and hydrolyzation of the two kinds of ligands in the SNP precursor. The size of the double-shelled ferrihydrite hollow spheres can be tuned by varying the experimental parameters. As-obtained ferrihydrite is highly sensitive to ethanol gas, which indicates potential applications in the field of sensing devices.
authors.affiliation: Department of Nanomaterials and Nanochemistry, Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui, China.
authors.forename: Zhengcui
authors.initials: Z
authors.lastname: Wu
authors.forename: Miao
authors.initials: M
authors.lastname: Zhang
authors.forename: Kuai
authors.initials: K
authors.lastname: Yu
authors.forename: Shudong
authors.initials: S
authors.lastname: Zhang
authors.forename: Yi
authors.initials: Y
authors.lastname: Xie
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry*; D005740:Gases / Q000737:chemistry; D010316:Particle Size; D011312:Pressure; D012680:Sensitivity and Specificity; D013696:Temperature; D013816:Thermodynamics
chemical_list: D005290:Ferric Compounds; D005740:Gases; C092844:ferric oxyhydroxide