We developed utilization models of supported electrospun
TiO2-ZnWO4 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, ZnWO4 is selected for a visible light
activity, while TiO2 is incorporated to enhance physical
stability. Morphological structures of the TiO2-ZnWO4 membrane are characterized by scanning electron microscopy
and scanning electron microscopy–energy-dispersive X-ray spectroscopy.
The distinguished growth of ZnWO4 nanorods at the surface
of the TiO2-ZnWO4 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 TiO2 and ZnWO4 particles
via HR-TEM and UV–vis spectrophotometry. For the gas-phase
reaction, a transparent photocatalytic converter is designed to support
the pleated TiO2-ZnWO4 membrane for toluene
decomposition under visible light. To obtain a crack-free and homogeneous
fiber structure of the pleated TiO2-ZnWO4 membrane,
1 h of nanofibrous membrane fabrication via a Nanospider machine is
required. On the other hand, a fiberglass-supported TiO2-ZnWO4 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 TiO2-ZnWO4 membrane. The TiO2-ZnWO4 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 TiO2-ZnWO4 nanofibrous membranes are proven for an alternate potential in environmental
remediation.