Abstract
We developed utilization models of supported electrospun TiO(2)-ZnWO(4) photocatalytic nanofibrous membranes for air and water purifications using a noncomplex system with facile adaptation for large-scale processes. For this uniquely designed and multimode catalyst, ZnWO(4) is selected for a visible light activity, while TiO(2) is incorporated to enhance physical stability. Morphological structures of the TiO(2)-ZnWO(4) membrane are characterized by scanning electron microscopy and scanning electron microscopy-energy-dispersive X-ray spectroscopy. The distinguished growth of ZnWO(4) nanorods at the surface of the TiO(2)-ZnWO(4) membrane is revealed by transmission electron microscopy (TEM). The relaxation process and charge transfer mechanism are proposed following the examination of interface and band gap (2.76 eV) between TiO(2) and ZnWO(4) particles via HR-TEM and UV-vis spectrophotometry. For the gas-phase reaction, a transparent photocatalytic converter is designed to support the pleated TiO(2)-ZnWO(4) membrane for toluene decomposition under visible light. To obtain a crack-free and homogeneous fiber structure of the pleated TiO(2)-ZnWO(4) membrane, 1 h of nanofibrous membrane fabrication via a Nanospider machine is required. On the other hand, a fiberglass-supported TiO(2)-ZnWO(4) membrane is fabricated as a fixed-bed photocatalyst membrane for methylene blue decomposition under natural sunlight. It is observed that using the calcination temperature at 800 °C results in the formation of metal complexes between fiber glass and the TiO(2)-ZnWO(4) membrane. The TiO(2)-ZnWO(4) membrane successfully decomposes toluene vapor up to 40% under a continuous-flow circumstance in a borosilicate photocatalytic converter and 70% for methylene blue in solution within 3 h. Finally, the mechanically robust and supported TiO(2)-ZnWO(4) nanofibrous membranes are proven for an alternate potential in environmental remediation.