K. Sun, J. Y. Luo, X. Zhang, Z. J. Wu, Y. Wang*, H. K. Yuan, Z. H. Xiong, S. C. Li, Q. K. Xue*, and J. Z. Wang*, Supramolecular Motors on Graphite Surface Stabilized by Charge States and Hydrogen Bonds. ACS Nano 11, 10236 (2017).