Rapid visualization of fingerprints on various surfaces using ZnO superstructures prepared via simple combustion route

Abstract

A simple solution combustion route has been used to prepare ZnO nanopowders (NPs) using different barbiturates (Barbituric acid, 1, 3-dimethyl barbiturates and 2-thiobarbiturates) as fuels. The obtained product was well characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM), ultraviolet-visible Spectroscope (UV-Vis) and Photoluminescence (PL). The PXRD results confirm the hexagonal phase of the material. The detailed structural analysis is performed by Rietveld refinement method. The energy band gap of NPs is found to be in the range of 3.31 - 3.49 eV. The growth mechanism for the formation of 3D micro-architectures is discussed in detail. The PL emission spectrum shows a broad emission peak at 502 nm upon an 406 nm excitation wavelength. The ZnO NPs can be used for the visualization of latent finger prints (LFPs) under normal light on various porous and non-porous surfaces. In this case, the visualized LFPs are found to be excellent compared to the commercially available powders. Keywords: Zinc oxide, Barbiturates, Photoluminescence, Latent fingerprint