Enhanced catalytic degradation of organic pollutants by multi-stimuli activated multiferroic nanoarchitectures

Smart catalysts that can simultaneously utilize multiple energy sources will have a significant positive impact on the inefficiencies of conventional environmental remediation approaches, and will address their high energy demands. In this work, we have manufactured multiferroic magnetoelectric photocatalysts that can be simultaneously activated using multiple energy sources for the degradation of organic pollutants. The catalysts are composed of CoFe2O4@BiFeO3 (CFO@BFO) nanooctahedrons (NOs), CFO@BFO nanocubes (NCs), and CFO@BFO nanowires (NWs), and were successful in harnessing energy from three different energy sources, including UV-vis light, acoustically mediated mechanical vibrations and magnetic fields. The CFO@BFO NOs displayed the most enhanced degradation, reaching 93%, 96%, and 99% degradation of RhB dye within 1 h under light, ultrasound, and magnetic fields, respectively. When these energy sources were used simultaneously, significantly increased reaction rates were observed compared to the single-energy source stimulation. Results of radical trapping experiments indicate that radical species i.e., OH center dot and O-2 center dot(-) play a dominant role in catalytic degradation of organic pollutant, RhB, under all three stimuli. These results will contribute significantly to the development of new environmental technologies that are highly versatile in nature and able to adapt to changing environments to deliver efficient environmental remediation.