Enhanced degradation of tetracycline hydrochloride by activated peroxymonosulfate through Ni-doped LaFeO3

Abstract

To achieve efficient degradation of tetracycline hydrochloride (TC), we employed a straightforward hydrothermal method to enhance the physicochemical properties of the initial lanthanum ferrite by substituting different ratios of Ni for Fe. Ni doping significantly reduced the energy band band gap of LFNO-5 from 1.93 eV to 1.76 eV, enhanced the visible light response range and photocurrent response, reduced the impedance, and generated more oxygen vacancies. The photocatalytic activity of the target materials was investigated using tetracycline hydrochloride as a model pollutant under the activation of a minute amount of potassium persulfate (PMS) and visible light. After 60 min of exposure to light, LFNO-5/PMS achieved a 90% degradation of TC (k = 0.03374 min−1), surpassing PMS (k = 0.00710 min−1) by a factor of 4.75 and LFO/PMS (k = 0.01781 min−1) by a factor of 1.89. The redox cycling of FeIII/FeII and NiIII/NiII in LFNO-5 facilitated an effective synergistic photocatalytic process. Vacancies (h+) and sulphate radicals (SO4−) played a crucial role in pollutant degradation within the LFNO/PMS system. Furthermore, the LFNO-5/PMS system exhibited excellent resistance to various inorganic ions and humic acids, while delivering noteworthy performance even in the presence of environmental disturbances. The degradation efficiency of the catalyst did not decrease significantly after several cycles, and the metal leaching rate was low, with good stability and reusability. Furthermore, Ni-doped LFO not only improved the activation efficiency for PMS, but also demonstrated the superiority of the LFNO-5 catalyst as a promising activator for PMS effluent remediation.