Facile Green Synthesis of Titanium Dioxide Nanoparticles by Upcycling Mangosteen (Garcinia mangostana) Pericarp Extract

In the present report, green synthesis of titanium dioxide nanoparticles (TiO(2) NPs) was performed by upcycling mangosteen (Garcinia mangostana) pericarp extract (methanol and ethyl acetate extracts). Field emission scanning electron microscopy images revealed an aggregated structure with a highly porous network of TiO(2) NPs. TiO(2) NPs synthesized with ethyl acetate extract (EtOAc-TiO(2) NPs) exhibited more monodispersity and possessed smoother surfaces than the control TiO(2) NPs (Con-TiO(2) NPs) and TiO(2) NPs synthesized with methanol extract (MeOH-TiO(2) NPs). High-resolution X-ray diffraction patterns clearly confirmed that TiO(2) NPs had a crystalline nature. A mixture of anatase and rutile was observed in Con-TiO(2) NPs and MeOH-TiO(2) NPs, while EtOAc-TiO(2) NPs had only anatase with the smallest size (12.50 ± 1.81 nm). Ethyl acetate extract contained the highest amount of α-mangostin; thus, the surface of TiO(2) NPs was functionalized with ethyl acetate extract. The functionalized TiO(2) NPs synthesized with ethyl acetate extract (EtOAc-TiO(2)-αm) showed the highest 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH) radical scavenging activity. In vitro cell viability on mouse fibroblast cells (NIH3T3) indicated that the newly synthesized TiO(2) NPs did not show any significant cytotoxicity. Therefore, the TiO(2) NPs in the present report have the potential to be used in cosmetic applications such as sunscreens. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s11671-022-03678-4.