* Corresponding authors

^a Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0698, USA
E-mail: banglin.chen@utsa.edu
Web: http://www.utsa.edu/chem/faculty/ChenLab
Fax: +1 210-458-7428

^b Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China

^c NIST center for neutron research, National Institute of Standards & Technology, Gaithersburg, Maryland 20899-6102, USA

^d School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University, Tianjin 300350, China