1. Tianjin Key Laboratory of Environmental Remediation and Pollution Control College of Environmental Science and Engineering Nankai University Tianjin 300350 P. R. China
2. Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) and the Tianjin key Lab and Molecule‐based Material Chemistry College of Chemistry Nankai University Tianjin 300071 P. R. China
3. Dept. of Civil & Environmental Engineering Rice University 6100 Main Street Houston TX 77005 USA