1. School of Physics and Mechanical & Electrical Engineering, Institute for Functional Materials, Hubei University of Education, Wuhan, P.R. China
2. School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou, P.R. China
3. Institute of Materials Research and Engineering, Hubei Engineering Technology Research Center of Environmental Purification Materials, Hubei University of Education, Wuhan, P.R. China