Insight into the interaction of magnetic photocatalysts with the incoming light accelerating bacterial inactivation and environmental cleaning

This report presents an up-to-date review on the interaction of light with magnetic semiconductors during photocatalysis leading to bacterial inactivation and pollutant degradation. The acceleration in the photocatalytic reactions mediated by wide-band gap semiconductors like TiO2 and ZnO by doping/decorating them with Fe/Fe-magnetic oxides is documented in this study. The design, synthesis and testing of some magnetized FeOx semiconductors is presented for some selected magnetic photocatalyst. Insight is provided for the mechanism by magnetic materials in the dark and under light in environmental relevant reactions. The experimental data found is related to the underlying theory for paramagnetic and superparamagnetic materials whenever possible. The significant effects observed upon addition of Fe-magnetic oxides absorbing solar/visible light extending the photo-response of wide-band semiconductors absorbing in the UV-range is addressed. The material presented in this report topic discusses for the first time the faster kinetics observed for magnetic catalysts compared to their non-magnetic counterparts during disinfection and pollutant degradation processes. The intervention of magnetic photocatalyst composites in environmental processes is compared to similar non-magnetic materials. Some features of the magnetic catalyst properties responsible for the observed effect are discussed. The accelerated photocatalysis by wide-band gap semiconductors where Fe-oxides or Fe-intra-gap states have been added presented is discussed in a detailed way. The actual limitations to obtain quantitative data for the light-catalyst interaction during photocatalytic processes for this kind of materials is addressed. The potential practical application in environmental cleaning by magnetic materials warrants further research in this field since the low-cost one step separation of reactants and residual products is feasible at the end of the process.