Sustainable hydrogen production and potential anticancer applications of biofuel-derived silver decorated BiFeO3 nanostructures.

Multifunctional perovskite nanostructures capable of addressing sustainable energy and biomedical challenges are of great interest to researchers. In this study, BiFeO3 (BFO), Ag-modified BFO (BFO-Ag), fuel-assisted α-BFO, and biofuel-assisted Ag-modified α-BFO (α-BFO-Ag) nanostructures were synthesized via solution combustion using Ravenia spectabilis leaf extract as fuel to investigate the effects of compositional and synthetic modifications on structural, magnetic, anticancer, and electrochemical properties. The evaluated band gap (3.09 and 3.15 eV) suggests effective charge-transport. The formation of rhombohedral BiFeO3 (JCPDS #01-074-2016) was confirmed by PXRD analysis in all samples with distinct diffraction planes. Conversely, the weak secondary reflections of Bi2O3 observed in pristine BFO were significantly diminished in the Ag-modified and fuel-assisted samples, indicating enhanced phase purity. Also, the same was affirmed by conducting Rietveld refinements for the obtained pattern. Morphological analysis revealed densely packed, agglomerated, and polyhedral nanostructures with distinct grain boundaries and compact surface features, characteristic of combustion-derived materials. BET studies revealed the mesoporous feature of the synthesized α-BFO-Ag nanostructure. Magnetic measurements indicated an enhanced magnetic response for α-BFO-Ag compared to the other synthesized samples, which may be associated with Ag incorporation and defect-induced modifications in the magnetic ordering. The nanostructures also exhibited dose-dependent cytotoxicity against MDA-MB-231 triple-negative breast cancer cells, with α-BFO-Ag demonstrating comparatively higher anticancer activity among the investigated samples. Based on electrochemical investigations, the BiFeO3@Ag + Fuel electrode demonstrated low overpotentials of 82 mV at 10 mA cm- 2 and low charge-transfer resistance (11.97 Ω) along with enhanced hydrogen evolution reaction (HER) efficiency. Ag incorporation and fuel-assisted synthesis led to enhanced charge transport, surface activity, and biological response, making these nanostructures promising dual-functional materials for sustainable hydrogen production and anticancer applications.