Polyoxometalate-assisted synthesis of the ZnO polyhedra in an alkali solution and their photoelectrical properties

With the assistance of polyoxometalates (POM), ZnO polyhedra with the mean length of 200 nm and mean diameter of 100 nm are synthesized by a simple solvothermal route in an alkali solution. Parallel experiments without POM were carried out to investigate the formation process of ZnO polyhedra and the results showed that POM played a key role in the formation of ZnO polyhedra. A possible formation mechanism was also proposed. Meanwhile, the as-prepared ZnO powder was used to assemble dye-sensitized solar cells (DSSC) photoanodes, the overall solar-to-electric energy conversion efficiency was up to 2.45%, which were obtained using TiCl4 post-treatment.

ZnO polyhedrons were synthesized by a simple solvothermal route with the assistance of K7HNb6O19. ZnO nanoclusters generated at the beginning of the reaction. POMs adsorb on the surface of the nanoclusters, inhibiting their further growth into nanorods and facilitating them gather into the relatively stable polyhedral structure.Figure optionsDownload as PowerPoint slideHighlights
► ZnO polyhedra were synthesized with the assistance of isopolyoxometalates.
► K7HNb6O19 was first introduced into the preparation of ZnO.
► A possible formation mechanism was proposed.
► Polyoxometalate-assisted synthesized ZnO was first introduced into the field of DSSC.
► Conversion efficiency was significantly improved by TiCl4 post-treatment.