Solar driven self-sustainable photoelectrochemical bacteria inactivation in scale-up reactor utilizing large-scale...

Here we present photoelectrochemical (PEC) bacterial inactivation properties of large-scale fabricable Ti/MoS₂/MoO_x photoanode with a strong solar light absorbance capacity. Specifically, by thermal oxidation of the as-prepared MoS₂/Ti film at 250 °C for 15 min in aerobic condition, the visible light performance of photocurrent generation and Escherichia coli (E. coli) inactivation are markedly enhanced. Complete inactivation of 10⁶ CFU/mL E. coli in NaCl electrolyte is achieved with 0.5 V bias in 2 h under visible light irradiation, and H₂O₂ and O₂^- have been found as key reactive oxidative species to destroy E. coli. The bacteria inactivation performance of present photoanode is comparable with reported visible light photoanodes such as Cu₂O or N-doped TiO₂. The markedly improved PEC performance and inhibited photocorrosion could be attributed to the formation of heterojunction of MoS₂/MoO_x on the surface due to thermal oxidation. Furthermore, the PEC E. coli inactivation performance and stability of the large dimensional electrode are evaluated in a scale-up reactor. As an example of self-sustainable PEC water treatment system powered by only solar panels, wastewater containing inorganic, organic, macromolecule and microbial pollutants is attempted to be treated employing the developed electrodes under illumination of LED lamps.