Novel n–n Type CoCr<sub>2</sub>O<sub>4</sub>/NiFe<sub>2</sub>O<sub>4</sub> Heterojunction Photocatalyst: Internal Magnetic Field Control of Photocatalytic Activity, Mechanism Insight and Pathway for Tetracycline Hydrochloride Degradation
Huajing Gao, V. Jagadeesha Angadi, Shifa Wang, Xianju Zhou, Li Li, Hua Yang, Mohd Ubaidullah, Dengfeng Li, Chander Prakash, Shoyebmohamad F. Shaikh, Nipa Roy, Sang Woo Joo
Abstract
Abstract Herein, a series of CoCr 2 O 4 /wt%NiFe 2 O 4 (CCO/wt%NFO) composites are successfully synthesized by a simple solution combustion method combined with mechanical grinding techniques. The preparation of CCO/wt%NFO composites result in an estimation of its photocatalysis performance by removing tetracycline hydrochloride (TC) as a model of antibiotic pollutants. The results show that the percentage of NFO by mass have a great influence on the morphology and the photocatalysis performance of CCO/wt%NFO composites. Superior photocatalysis performance is observed in CCO/25%NFO composites prepared at percentage of NFO is 25%. The photocatalyst used with CCO/25%NFO composites result in a removal ratio of 81% for TC. The generation of hydroxyl radical (•OH), superoxide anion radical (•O 2 − ) and holes (h + ) is largely responsible for degrading TC through photocatalysis in the presence of CCO/wt%NFO composites. The optimal operating conditions involve the initial concentration of TC and pH of TC being 50 mg L −1 and pH = 13, respectively. Furthermore, CCO/wt%NFO is highly reusable and stable during the photocatalytic removal process. The degradation pathway, toxicity, and photocatalytic mechanism of CCO/25%NFO composites for the degradation of TC are extensively examined through mass spectrometry, toxicity analysis, and energy band theory.