Comparison of ZnO Nanoparticles Prepared by Precipitation and Combustion for UV and Sunlight-Driven Photocatalytic Degradation of Methylene Blue

ZnO nanoparticles (NPs) were comparatively synthesized via precipitation and combustion techniques. The ZnO NPs synthesized via precipitation and combustion exhibited similar polycrystalline hexagonal wurtzite structures. The large crystal sizes of ZnO NPs were obtained from the ZnO precipitation in comparison with those from the ZnO combustion, while the particle sizes were in the same range. The functional analysis implied that the ZnO structures had surface defects. Moreover, absorbance measurement showed the same absorbance range in ultraviolet light. In the photocatalytic degradation of methylene blue, ZnO precipitation exhibited higher degradation performance than ZnO combustion. This was attributed to the larger crystal sizes of ZnO NPs, which provided an enduring carrier movement at semiconductor surfaces and reduced electron-hole recombination. Thus, the crystallinity of ZnO NPs can be considered an important factor in photocatalytic activity. Furthermore, precipitation is an interesting synthesizing method for preparing ZnO NPs with large crystal sizes.

Automated summary

ZnO nanoparticles were synthesized using precipitation and combustion techniques. The precipitation method resulted in larger crystal sizes compared to the combustion method, while the particle sizes were similar. The functional analysis revealed surface defects in the ZnO structures. In the photocatalytic degradation of methylene blue, ZnO precipitation exhibited better degradation performance due to its larger crystal sizes, which facilitated carrier movement and reduced electron-hole recombination. The crystallinity of ZnO nanoparticles is thus an important factor in photocatalytic activity. Furthermore, precipitation is an interesting method for synthesizing ZnO nanoparticles with large crystal sizes.