A method for synthesizing ZnO–carbonaceous species nanocomposites, and their conversion to quasi-single crystal mesoporous ZnO nanostructures

Abstract

We report a method for synthesizing quasi-single crystal mesoporous ZnO nanostructuresvia a self-generated templating approach. ZnO–carbonaceous species nanocomposites (average diameter of ∼500 nm) were synthesized using a microwave-assisted hydrothermal reaction. The nanocomposites consisted of quasi-single crystalline ZnO regions and amorphous carbonaceous regions, which formed a self-generated nanotemplate. These nanocomposites were converted into quasi-single crystalline mesoporous ZnO nanostructures during combustion of the amorphous carbonaceous species (the template removing step). The adsorption properties and photocatalytic activities of the mesoporous ZnO structures were evaluated. The mesoporous ZnO structures showed better adsorption than the commercial ZnO nanostructures with similar dimensions or the 3D ZnO structures composed of nanoplates with {20} planar surfaces (benchmark materials) even though the BET surface area of the 3D ZnO structures was larger than that of the mesoporous ZnO structures. The quasi-single crystal mesoporous ZnO structures exhibited a high photocatalytic activity.