Growth and influence of Gd doping on ZnO nanostructures for enhanced optical, structural properties and gas sensing applications

Undoped and Gd-doped ZnO nanorods and nanoflowers were successfully prepared by one step hydrothermal method. The effect of Gd concentration on the formation of different morphology has been investigated. The X-Ray Diffraction analysis showed that the prepared ZnO nanostructures exhibits hexagonal wurtzite phase. The morphology of the nanostructures of ZnO was analyzed by FE-SEM and TEM. ZnO nanoparticles were transformed into nanorods and nanoflowers with increasing the wt% of Gd. UV-Visible spectroscopic studies showed that the presence of Gd in the ZnO matrix leads to tuning of bandgap. Where 6 wt% of Gd incorporation in ZnO matrix showed decrease in bandgap compared to undoped ZnO. The significant peak shift was observed in the electronic state of Zn at the higher concentration of Gd, which confirms the presence of Gd in ZnO matrix. Significant enhancement of xylene sensitivity was achieved by Gd doping in ZnO. These findings indicate that Gd-doped ZnO (GZ4) can be considered as good xylene sensing element at room temperature.