Supported TiO2-ZnWO4 Photocatalytic Nanofibrous Membranes for Flow-Through and Fixed-Bed Reactors

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.

Wet Spinning of Graphene Oxide Fibers with Different MnO2 Additives

We present the fabrication of graphene oxide (GO) and manganese dioxide (MnO₂) composite fibers via wet spinning processes, which entails the effects of MnO₂ micromorphology and mass loading on the extrudability of GO/MnO₂ spinning dope and on the properties of resulted composite fibers. Various sizes of rod and sea-urchin shaped MnO₂ microparticles have been synthesized via hydrothermal reactions with different oxidants and hydrothermal conditions. Both the microparticle morphology and mass loading significantly affect the extrudability of the GO/MnO₂ mixture. In addition, the orientation of MnO₂ microparticles within the fibers is largely affected by their microscopic surface areas. The composite fibers have been made electrically conductive via chemical or thermal treatments and then applied as fiber cathodes in Zn-ion battery prototypes. Thermal annealing under an argon atmosphere turns out to be an appropriate method to avoid MnO₂ dissolution and leaching, which have been observed in the chemical treatments. These rGO/MnO₂ fiber cathodes have been assembled into prototype Zn-ion batteries with Zn wire as the anode and xanthan-gum gel containing ZnSO₄ and MnSO₄ salts as the electrolyte. The resulted electrochemical output depends on the annealing temperature and MnO₂ distribution within the fiber cathodes, while the best performer shows stable cycling stability at a maximum capacity of ca. 80 mA h/g.

Rice flour-based nanostructures via a water-based system: transformation from powder to electrospun nanofibers under hydrogen-bonding induced viscosity, crystallinity and improved mechanical property

Rice flour is a naturally abundant and renewable biodegradable and biocompatible material.

Starch-based and multi-purpose nanofibrous membrane for high efficiency nanofiltration

The objective of the present work is to develop nanofibrous membranes from rice-flour based nanofibers containing PVA for high efficiency filtration.

Mechanically robust, multifunctional and nanofibrous membranes for tuberculosis elimination

Mechanically robust and potent antibacterial membranes are fabricated for total elimination of water- and airborne tuberculosis (TB) bacteria.

Thermal relaxation in combination with fiberglass confined interpenetrating networks: a key calcination process for as-desired free standing metal oxide nanofibrous membranes

Using Pd/Pt-decorated solar light active ZnWO₄/mixed-phased TiO₂ nanofibers as a model subject, we investigate the prerequisites for the construction of mechanically stable metal oxide nanofibrous membranes.