Sreed Sharma Kanakkillam, Bindu Krishnan, Selene Sepulveda Guzman, Josue Amilcar Aguilar Martinez, David Avellaneda Avellaneda, Sadasivan Shaji
Abstract
Zinc oxide (ZnO) is a wide bandgap semiconductor for energy applications while the spectral absorption only in UV region limits the use as a visible light absorber. Here, visible light absorbing modified ZnO (black) is prepared by creating surface defects and vacancies using pulsed laser irradiation in liquid. The modified ZnO nanoparticles have spherical morphology and they are free from impurity phases. The optical bandgap of this modified material is narrowed by increased irradiation time with a morphological transformation to mostly nanospheres. XPS analysis confirmed the oxygen vacancies contribution and the valance band study showed a reduction in the band edge. With the results of Raman and photoluminescence spectra, the oxygen defects and vacancies were confirmed. Thin films were fabricated using these materials via doctor blade method and their photocatalytic studies showed enhanced activity in organic dye decay under visible light. Results of this study show a facile method for fabrication of defects rich metal oxide nanomaterials by pulsed laser irradiation in liquid.
