Shengli Zhang1, Zhong Yan1, Yafei Li2, Zhongfang Chen3,* and Haibo Zeng1,*
1 Institute of Optoelectronics & Nanomaterials, Herbert Gleiter Institute of Nanoscience, College of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094 (China)
2 College of Chemistry and Materials Science, Jiangsu Key Laboratory of Biofunctional Materials, Nanjing Normal University, Nanjing, 210023 (China)
3 Department of Chemistry, Institute for Functional Nanomaterials, University of Puerto Rico, Rio Piedras, San Juan, PR 00931 (USA)