Can doping graphite trigger room temperature superconductivity? Evidence   for granular high-temperature superconductivity in water-treated graphite   powder
  Trying to dope graphite flakes we found that the magnetization of pure, several tens of micrometers grain size graphite powder and after a simple treatment with pure water shows clear and reproducible granular superconducting behavior with a critical temperature above 300K. The observed magnetic characteristics as a function of temperature, magnetic field and time, provide evidence for weakly coupled grains through Josephson interaction, revealing the existence of superconducting vortices. 
T. Scheike, W. B\"ohlmann, P. Esquinazi, J. Barzola-Quiquia, A.   Ballestar, A. Setzer
cond-mat.supr-con cond-mat.mtrl-sci cond-mat.str-el