Mesoporous ZnO nanorods array with a controllable area density for enhanced photocatalytic properties

Synthesis of Poly(vinyl alcohol)-Aided ZnO/Mn2O3 Nanocomposites for Acid Orange-8 Dye Degradation: Mechanism and Antibacterial Activity

Zinc oxide is one of the novel metal oxides utilized for diverse applications. The sol-gel and unintended self-propagation procedures were applied to synthesize the porous and high surface area ZnO-based metal oxide nanocomposite. The p-type manganese(III) oxide was successfully coupled with n-type ZnO. The physical property characterization results revealed the surface area, porosity, and charge transfer capability improvement on the poly(vinyl alcohol) (PVA)-aided binary nanocomposite (PVA-ZnO/Mn2O3), compared to ZnO. The XRD patterns and TEM image analysis validated the nanometer size range for the materials (15-60 nm). The SEM micrographs and BET spectral details have confirmed the porous nature of the PVA-ZnO/Mn2O3 nanocomposite. The supporting results were obtained from the HRTEM (IFFT) and SAED pattern analyses. The EDX and HRTEM analyses were used for the confirmation of elemental composition and reality of the PVA-ZnO/Mn2O3 composite, respectively. The presence of the improved charge transfer property for PVA-ZnO/Mn2O3, compared to ZnO, was evidenced from acid orange-8 dye degradation. The highest zone of inhibition (14 mm) was recorded on Escherichia coli bacteria for the uncalcined PVA-ZnO/Mn2O3 nanocomposite compared to PVA, yet, less zone of inhibition compared to the calcined PVA-ZnO/Mn2O3 nanocomposite. The authors recommend the formation of the couple between metal oxides by electrochemical technique analyses as a future work.

Morphology-controlled Fabrication of SnO2 /ZnO Nanocomposites with Enhanced Photocatalytic Performance

In this work, a series of novel SnO₂ /ZnO nanocomposites with different morphologies were fabricated via a facile hydrothermal technique followed by calcination in air. The morphological, structural and photocatalytic properties of the SnO₂ /ZnO nanocomposites were studied using different methods. The results showed that the synthesized nanocomposites possessed crystal phases of wurtzite hexagonal phase ZnO and tetragonal rutile phase SnO₂ . In addition, the morphologies of SnO₂ /ZnO nanocomposites strongly depended on the molar ratios of Sn and Zn. Compared with ZnO and SnO₂ , the SnO₂ /ZnO nanocomposites exhibited considerably higher degradation efficiency for the photodegradation of methylene blue and quinolone antibiotics under mercury lamp irradiation. The SZ-2 nanospheres exhibited the highest degradation efficiency of 95.81%, which was about 2.63 times higher than that of ZnO nanoparticles. Moreover, the trapping experiments confirmed that ˙OH played the dominant role in MB degradation. Finally, the charge carriers potential transfer pathway and photocatalytic degradation mechanism were put forward. This study provides an economical way to prepare hybrid nanocomposites with controlled morphology for practical applications in the photocatalytic degradation of organic dyes and residual antibiotics.