Investigating the role of microwave thermal and non-thermal effects on WO₃-graphene oxide composite synthesis

Author(s)

Rodrigues, Barbara S. ; Vicente, Marcos R. S. ; Souza, Juliana S.

• Document type: Journal article
• Source: RSC ADVANCES; v. 13, n. 38, p. 10-pg., 2023-09-04.

Abstract

The effects of microwave-assisted synthesis on the morphology and crystalline structure of WO3-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 WO3 particles. Consequently, the crystalline structure and morphology are affected. As a result, the WO3-GO composites produced using a CEM reactor exhibit a rounded shape and hexagonal phase of WO3, besides enhanced reduction of GO. Whereas the composites made using an Anton-Paar reactor are composed of sheets and flowers of WO3 with hexagonal, triclinic and/or WO3 hydrate structures and cause a lower reduction on the GO. (AU)

• FAPESP's process: 21/05958-4 - Modulation of physical-chemical properties of metal semiconductors through the control of the parameters of microwave-assisted synthesis
• Grantee: Juliana dos Santos de Souza Silva
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/26010-9 - Photoactive devices based on heterojunctions of bismuth vanadate and tungsten oxide over graphene
• Grantee: Bárbara Scola Rodrigues
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)