1. Faculty of Science Kunming University of Science and Technology Kunming 650093 China
2. Faculty of Metallurgical and Energy Engineering Kunming University of Science and Technology Kunming 650093 China
3. Shenzhen Research Institute City University of Hong Kong Shenzhen 518072 China
4. Department of Chemical and Biological Engineering Energy Institute and Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong 999077 China