Straightforward Approach for Epitaxial Growth of CuO over ZnO Nanorods: Heterostructure Study and Photoelecterochemical Water Splitting Performance

摘要

Optimization of the band gap in semiconductors through tailored heterojunctions has received immense research interests for advancement in photovoltaic and photoelectochemical hydrogen production. Heteroepitaxial superstructures are considered as crucial for charge carrier flow at the semiconductor interface. The present research attempt disclosed the method of facile fabrication of perfectly aligned ZnO nanorods, followed by their uniform decoration with CuO nanoparticles. In consequence, heterojuction was developed, which was studied through XPS and TEM. High resolution TEM images provides the evidence of coherent epitaxial growth due to overlapping lattices of both materials across the interface by highlighting the lattice mismatch of 7%. The 7 degree plane loss is expected due to less matching of lattice constants and misorientation of the planes at the interface. This assembly provided better collection of photo-generated charge carriers in extended light absorption range, resulting in better performance of photelectrochemical (PEC) water oxidation device.