Rational design of a bismuth oxyiodide (Bi/BiO1-I) catalyst for synergistic photothermal and photocatalytic inactivation of pathogenic bacteria in water

In this study, bismuth oxyiodide with coexistence of plasmonic Bi and oxygen vacancy (Bi/BiO1-xI) was successfully prepared and used towards photothermal and photocatalytic disinfection of pathogenic bacteria containing water. Plasmonic Bi and oxygen vacancies in Bi/BiO1-xI induced a surface plasmon effect under the irradiation of simulated solar light from 500-900 nm and promoted the generation of hot electrons and reactive species (1O2, h+ and •O2−). The catalyst showed promising performance for inactivation of E. coli K-12, with a 7.2 log inactivated achieved under the optimum conditions. A synergy between photothermal and photocatalytic inactivation was identified and discussed. The mechanisms of E. coli K-12 destruction were investigated. The destruction of extracellular antioxidant enzymes of E. coli K-12 was identified after inactivation. Moreover, the E. coli's membrane and its intracellular contents were attacked by the reactive species (1O2, h+ and •O2−) and the thermal effects. This work provides useful insights into the rational design of semimetal bismuth-mediated photocatalysts towards effective and sustainable water disinfection.