Controllable preparation, growth mechanism and the properties research of ZnO nanocrystal

•Large scales of ZnO nanocrystals were grown on ZnO-seed-coated substrate by electrochemical deposition method.•We had controlled the structure and morphology of ZnO nanocrystals by changing the preparation parameters.•The ZnO nanocrystals which grow along the c-axis are uniform and well-aligned arrays with hexagonal wurtzite structure.•Its photo-degradation rate of methylene blue can reach to 91% which is almost two times than the ZnO powder.

Large scale of ZnO nanocrystals were grown on the ITO glass substrate by a electro deposition method. The obtained nanocrystals were characterized by SEM, XRD, PL and photo-decomposition test. It is shown that ZnO nanocrystals grown on ZnO-seed-coated substrate are uniform and well-aligned arrays of hexagonal ZnO nanorods of 100 nm in diameter. All the ZnO nanocrystals have a very good crystallinity with hexagonal wurtzite structure and grow along the c-axis. We found that the preparation of the structure and morphology of ZnO nanocrystal can be controlled by changing the preparation parameters. While the electrode position voltage is the main factor that controls the morphology of nanocrystals, the electrochemical deposition time, the electrochemical deposition temperature and the annealing temperature also have an effect on the morphology. Its photo-degradation rate of methylene blue can reach 91% which is almost two times than the ZnO powder.