Bi-functional LaMxFe1-xO3 (M = Cu,Co, Ni) for photo-fenton degradation of methylene blue and photoelectrochemical water splitting

Due to growing concern over environmental remediation and the energy crisis, perovskite nanoparticles have gained wide interest in converting solar energy to sustainable fuel and also in degrading organic effluents. Herein, we report the synthesis and bi-functional activity of one-pot-glycine combustion derived LaM_xFe_1-xO₃ (M = Cu, Co, Ni; x = 0, 0.01) for photo-Fenton degradation of Methylene Blue (MB) and photoelectrochemical water splitting. When used as a photocatalyst, with partial substitution of Cu even at a lower concentration, LaCu_0.01Fe_0.99O₃ has exhibited excellent degradation efficiency of 96.4% in 90 min, which is 2.5 times better than the LaFeO₃. On the other hand, Co and Ni modified LaFeO₃ photocatalysts have demonstrated prominent activities with degradation efficiency of 93.8% and 74.8% respectively within 180 min of visible light irradiation. The retention and reusability analysis showed that LaCu_0.01Fe_0.99O₃ is stable against photo corrosion and remains unchanged after 5 consecutive cycles of MB dye degradation. In addition, LaCu_0.01Fe_0.99O₃ is complimented as a single catalyst for dual functions such as photocatalysis and electrocatalysis, both of which are assisted by visible light. Under illumination, the overpotential (η) improved from 507.6 mV vs RHE (dark) to 498.1 mV vs RHE (light) for O₂ evolution and 220.5 mV vs RHE (dark) to 182.8 mV vs RHE (light) for H₂ generation respectively. The light response of the catalyst and improvement in activity is validated by the significant enhancement in current density under exposure at both half cycle of chronoamperometry.