Synthesis of Mn-doped ErFeO3 with enhanced photo and vibration catalytic activities

In this paper, a series of ErFe1−xMnxO3 (x = 0, 0.1, 0.3, 0.5) were readily prepared by the sol–gel method, with citric acid as the combustion agent. The powder gradually changes from the orthorhombic phase (ErFeO3, space group Pbnm) to the hexagonal phase (ErFe0.5Mn0.5O3, space group P63cm). Reduction in the optical band gap from 2.10 eV of ErFeO3 to 1.69 eV of ErFe0.5Mn0.5O3 is observed. Photocatalytic study on methylene blue (MB) by visible light irradiation showed that the photocatalytic activities are greatly enhanced for Mn-substituted ErFeO3, due to the narrower band gap and smaller particle size. Interestingly, ErFe0.5Mn0.5O3 also behaves complete degradation of MB within 120 min vibration, indicating the existence of piezo-electrochemical coupling. The possible photocatalytic and vibration catalytic mechanism of this system was also proposed. The results indicates that this system will be a good candidate for the decomposition of organic pollutant through utilizing both the natural vibration and solar energy.