Perovskites based on earth-abundant elements as robust catalysts for photo-driven oxygen production

• Earth-abundant perovskites catalysts for photo-driven oxygen production were investigated. • CaMn 0.7 Fe 0.3 O 3-δ0 is a robust and cost-effective catalyst with intriguing performance for oxygen evolution. • CaMn 0.7 Fe 0.3 O 3-δ0 appears as a highly stable compound, making it a reusable catalyst. • Fe doping of CaMnO 3 strongly enhances its photocatalytic activity. The oxygen evolution step is still the bottleneck in the architecture of an artificial photosynthetic system. Nowadays, several catalysts for photo-induced water oxidation have been investigated. However, the challenge consists of designing catalysts that are robust, efficient, and, at the same time, composed of elements that are non-toxic and widely available on the Earth's crust. We prepared a robust and cost-effective catalyst with intriguing performance for oxygen evolution through simple doping. The synthesis, characterisation, and photocatalytic studies on two perovskites based on earth-abundant elements, CaMnO 3 and CaMn 0.7 Fe 0.3 O 3-δ0 , are reported. Both perovskites act as productive catalysts for water oxidation, and specifically, doping CaMnO 3 oxide with iron increases its photocatalytic activity. Remarkably, as a further advantage, CaMn 0.7 Fe 0.3 O 3-δ0 appears as a stable compound, which remains unmodified after five consecutive oxygen evolution cycles, thus making it a reusable catalyst for more than one photocatalytic process.