Optical properties of porous nano-composites of zinc (hydr)oxide with graphite oxide

The optical properties of zinc (hydr)oxide and the composites of zinc (hydr) oxide with 2% and 5% graphite oxide were investigated by three spectroscopic techniques: absorption, fluorescence and photocurrent techniques. The obtained energy gaps (from 2.85 eV to 2.95 eV) of the composites were smaller than that for zinc oxide (similar to 3.2 eV) and zinc (hydr)oxide (similar to 3.00 eV). The band gap narrowing of the composite materials is due to presence of defects, less confinement, and larger particles. The bonds between zinc (hydr)oxide lattice and the carbon of graphene phase also contribute to this phenomenon.