ZnO long fibers: large scale fabrication, precursor and the transformation process, microstructure and catalytic performance

Abstract

The development of effective and low-cost catalysts for the synthesis of chemical energy and for the photo-assisted elimination of pollution is of great importance for the sustainable development of human society. This work designs a fibrous ZnO catalyst, which was composed of stacked ZnO nanoparticles. Photocatalysis investigations demonstrated that the fibers possess higher catalytic ability compared to their powder counterparts. Moreover, the fibrous form is more suitable for application in a continuous mode and simple separation operation. The ZnO fibers were fabricated by the centrifugal-spinning of a molecular precursor sol into gel fibers, followed by heat treatment. The viscous precursor sol was synthesized by concentrating a zinc citrate aqueous solution, which was made from citric acid and ZnO powders. The mechanism of formation of the organozinc sol was investigated by a series of characterizations of the precursor solution, gel precursor, and the decomposition of the gel precursor. The results indicate that zinc citrate monomers in precursor solution were assembled into a multinuclear structure induced by solvent evaporation.