1. Engineering Research Center for Waste Oil Recovery Technology and Equipment, Ministry of Education, Chongqing Technology and Business University, Chongqing 400067, China
2. Department of Materials Science and Engineering, College of Environment and Resources, Chongqing Technology and Business University, Chongqing 400067, China
3. Magnetism Key Laboratory of Zhejiang Province, China Jiliang University, Hangzhou 310018, China