A Novel in situ Wetting Method to Develop Biodegradable Ag+Fe<sub>2</sub>O<sub>3</sub>@GO/Zn Biocomposites with Ameliorated Interfacial Properties and Substantial Antibacterial Activity

In recent years, Zn-based biodegradable metals were considered as one of the most promising candidates for medical implantable metals. Developing biodegradable Zn matrix composites not only could resolve the problem of insufficient mechanical properties of pure Zn, but also could give materials better biocompatibility. However, the easily agglomerative reinforcement and the poor interfacial bonding between matrix and reinforcement would greatly affect the performance of composites. Therefore, based on the above issues, we designed an innovative in situ wetting strategy to strengthen interfacial bonding and improve biocompatibility by using Ag and Fe2O3 modified graphene oxide (Ag+Fe2O3@GO) as the reinforcement of Zn-based composites. During the subsequent spark plasma sintering (SPS), Fe2O3 induced an in-situ redox reaction with Zn matrix, simultaneously resulting in an in-situ generated ZnO interlayer and the elemental Fe. Then, due to the elevated temperature and stress of the SPS process, elemental Fe and Ag could further alloy with Zn matrix contributing to the precipitation of secondary phase and solid solution in the Zn matrix, thereby garnering ZnO@GO/Zn-Ag-Fe biocomposites through only one-step sintering process. Refined microstructure, unique interfacial structure, enhanced mechanical properties were confirmed in the Ag+Fe2O3@GO/Zn biocomposites. This work could provide an inspiring and creative approach for the interfacial design and biofunctionalization of advanced Zn matrix biocomposites.