Methane formation in graphite and boron-doped graphite under simultaneous O+ and H+ irradiation

Boron-doped graphite specimens (∼15 at.% B) exposed to simultaneous O+/H+ irradiation were found to have higher methane yields than when exposed to H+ ions alone. This finding is opposite to the case of pure graphite where simultaneous O+/H+ irradiation leads to a decrease in methane yield when compared to the H+-only case. It appears that the mechanism leading to CH4 yield reduction for B-doped graphites is partially nullified by the presence of oxygen ions. Possible mechanisms are proposed.