Cation-deficiency induced spin regulation enhancement photo-assisted electrocatalytic wastewater splitting

Achieving improved energy efficiency, a green economy and degradation of environmental pollutants are important challenges to achieving sustainable development strategies. Herein, we have designed and synthesized a series of LaFe1-xO3 (LaFeO3, LaFe0.95O3, and LaFe0.9O3) crystals with Fe vacancies for photo-assisted electrocatalysis (PAEC). These catalysts are used for both the anodic and cathodic reactions, where the anode efficiently removes persistent organic pollutants such as methylene blue (MB), and the cathode converts water into hydrogen gas. We observed that the presence of Fe vacancies leads to rearranging the electronic structure on the surface, enhancing the photo-assisted electrocatalytic activity. The rate constant for the photo-assisted electrocatalytic LaFe0.90O3 was measured to be 0.996 min−1, which is 2.37 times and 2.74 times higher than that of the electrocatalytic (0.420 min−1) and photocatalytic (0.363 min−1) processes, respectively. The hydrogen production efficiency reached 1.42 μmol min−1. This study provides the first evidence of the photo-assisted electrocatalytic mechanism and potential applications of LaFeO3-based catalysts in enhancing the electro-oxidation of pollutants. It offers additional insights for the rational design and construction of more efficient PAEC catalysts for effective wastewater purification and energy recovery.