Investigating the role of microwave thermal and non-thermal effects on WO(3)-graphene oxide composite synthesis

The effects of microwave-assisted synthesis on the morphology and crystalline structure of WO(3)-graphene oxide (GO) composites have been investigated. Using two different microwave reactors, evidence supports that thermal and non-thermal effects significantly influence the properties of the synthesized materials. The findings reveal that the microwave cavity geometry affects how the microwaves are “delivered” to the reactional cavity as a function of time; it also orientates the growth process of the WO(3) particles. Consequently, the crystalline structure and morphology are affected. As a result, the WO(3)-GO composites produced using a CEM reactor exhibit a rounded shape and hexagonal phase of WO(3), besides enhanced reduction of GO. Whereas the composites made using an Anton-Paar reactor are composed of sheets and flowers of WO(3) with hexagonal, triclinic and/or WO(3) hydrate structures and cause a lower reduction on the GO.