Novel ZnO nanostructures on Philippine natural zeolite (PNZ) framework designed via thermal decomposition process of solution-based ZnCl2 precursor

ZnO nanostructures were successfully grown inside Philippine natural zeolite (PNZ) micropores for the first time via a simple thermal decomposition of solution-based ZnCl2 precursor. The surface morphological, structural and thermal properties of the ZnO-PNZ composite were investigated through SEM/EDX, XRD, XPS, TGA/DTA and DSC analysis. Nanofibers and nanorods developed inside the micropores of the zeolite matrix after calcination of Zn-exchanged PNZ at 550 °C for 5 h. XRD analysis revealed that the nanostructures have ZnO wurtzite crystal structure with a (101) preferred growth orientation or along the a-xis. XPS results further confirmed the formation of ZnO and the presence of unreacted ZnCl2 in the zeolite matrix. Additionally, O1s fitting result showed that the ZnO-PNZ composite have higher amount of chemisorbed oxygen species. Finally, thermal analysis demonstrated that the composite sample is highly stable at high temperatures. These results highlight the potential of our ZnO-PNZ composite sample for high-temperature catalyst applications.