Dissociation of water over Ti-decorated C60

Using first-principles calculations we have studied the reactions of water over Ti-decorated C-60 in order to assess the possibility of using this system as a catalyst for water dissociation. Our results show that a single water molecule dissociates exothermically with a small energy barrier on a single Ti atom adsorbed on C-60. After dissociation, both H+ and OH-ions bind strongly to the Ti atom, which serves as an effective reactive center that facilitates further water splitting. When a second water molecule is introduced, we observe the formation of a hydrogen molecule with a comparably small activation barrier. When the coverage of Ti on C-60 is increased, the formation of Ti dimer does not change the catalytic effect of Ti/C-60 complex very much. Our results provide fundamental insights into the mechanisms of water dissociation on such a prototypical nanostructure and suggest that Ti-decorated C-60 could be exploited as a catalyst for water splitting to generate hydrogen. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3469813]