Rapid Catalytic Water Disinfection from Earth Abundant Ca2Fe2O5 Brownmillerite

Abstract Water disinfection is a crucial challenge for humanity. Approaches that are effective, cheap, environmentally friendly, and do not promote gene exchange between bacteria are urgently required. Strongly oxidizing radicals are highly promising to achieve this as they lead to bacterial activation at high efficiencies. However, sources to consistently generate these radicals are limited to high energy UV/H 2 O 2 treatments requiring a large energy input. Here the use of abundant, cheap, brownmillerite (Ca 2 Fe 2 O 5 ) is demonstrated as an efficient radical generation material under dark conditions, showing a seven order of magnitude decrease in bacterial concentration over 10 min. This decrease is attributed to the release of interlayer Ca 2+ from the layered structure of Ca 2 Fe 2 O 5 and hydroxyl radical generation. The efficacy of Ca 2 Fe 2 O 5 is demonstrated by disinfecting turbid sewage sludge. The identification of this cheap, abundant, and nontoxic antibacterial material will provide an opportunity for broad scale clean water generation globally, and address the United Nations’ Sustainable Development Goal of clean water and sanitation.