Photocatalytic synthesis of copper colloids from CuII by the ferrihydrite core of ferritin.
The iron-storage protein ferritin encapsulates a nanoparticle of iron oxide. The size and properties of these nanoparticles can be adjusted by controlled oxidative hydrolysis reactions of Fe(II). This mineralized ferritin protein cage has previously been shown to act as an effective photocatalyst for reduction of Cr(VI). In the present work, we demonstrate that Fe(O)OH-mineralized ferritin catalyzes the photoreduction of Cu(II) to form a stable, air-sensitive, colloidal dispersion of Cu(0). In addition, the particle sizes of the Cu colloids can be controlled by varying the ratio of Cu(II) to ferritin. This illustrates an important principle, namely that the properties of one preformed material can be utilized for the specific synthesis of a second material, thus tailoring the desired physical properties of the final products. This procedure represents a multistep materials synthesis: the formation of a new nanomaterial from a catalytic precursor.
Ensign
Daniel
D
Department of Chemistry and Biochemistry, Department of Plant Sciences, and Center for Bio-Inspired Nanomaterials, Montana State University, Bozeman, MT 59717, USA.
Young
Mark
M
Douglas
Trevor
T
D002384:Catalysis; D003102:Colloids / Q000138:chemical synthesis*; D003300:Copper / Q000737:chemistry*; D019327:Copper Sulfate; D005290:Ferric Compounds / Q000737:chemistry; D005293:Ferritins / Q000737:chemistry*; D008854:Microscopy, Electron; D036103:Nanotechnology; D010084:Oxidation-Reduction; D010316:Particle Size; D010782:Photolysis; D013053:Spectrophotometry; D013997:Time Factors
D003102:Colloids; D005290:Ferric Compounds; C000499:ferric oxide; D003300:Copper; C092844:ferric oxyhydroxide; D005293:Ferritins; D019327:Copper Sulfate; C000520:cuprous oxide