Enhanced photocatalytic degradation of tetracycline over magnetic La0.7Sr0.3MnO3/g-C3N4 p-n heterojunction arising from the synergistic effects of oxygen vacancy defects and high-potential photogenerated electrons

A novel, magnetic, p-n heterojunction-structured La0.7Sr0.3MnO3/g-C3N4 (LS/CN) photocatalyst was de-signed by hybridizing p-type La0.7Sr0.3MnO3 with n-type g-C3N4 . Several characterizations showed that the as-preparedLS/CN-0.5 nanoparticles possessed a saturation magnetization of 27.3 emu/g, coercivity of 60.3 Oe, specific surface area of 25.68 m(2)/g, and average particle size of 23 nm. The photocatalytic in-vestigation determined a degradation efficiency of 95.0% for a 10 0-mL tetracycline solution with an initial concentration of 50 mg/L within 210 min over 0.05 g of the LS/CN-0.5. Experiments showed that LS/CN-0.5 exhibited good reusability, where a degradation efficiency of 88.6% was obtained after six cycles. It was found that the p-n heterojunction realized the excitation of photogenerated electrons in the high-potential conduction band of La0.7Sr0.3MnO3. Furthermore, the synergistic effects of oxygen vacancies and high-potential photogenerated electrons induced the generation of more superoxide radicals, leading to the high photocatalytic activity of LS/CN. This study demonstrates a new strategy to design and construct highly efficient, magnetic, p-n heterojunction photocatalysts. (C) 2022 Elsevier B.V. All rights reserved.