We developed a novel and facile method to hydrogenate grapheme by using a conditioning upstream of the graphene sample to generate atomic hydrogen
Inspired by the elegant idea to create graphane,1there have been some efforts to decorate the graphene lattice with hydrogen atoms to transform it from a highly conductive zero-overlap semimetal into a nonzero gap semiconductor and thus tune its electric properties to suit wider practical applications.234 However, these attempts have been merely limited to cold hydrogen plasma treatment5 in which the hydrogen plasma bombardment also creates numerous undesired defects in the graphene structure. Since graphene conduction proves to be very challenging. To date, the chemical hydrogenation graphene to modulate its conduction has never been reported.
In this communication, we report a novel and facile method to hydrogenate graphene by using bulk amounts of catalyst placed upstream of the graphene flake films in the hydrogen flow as depicted in Scheme 1. Raman scattering and FTIR investigation are presented to study the hydrogenated graphene. Additionally, we looked into the wettability of the hydrogenated graphene surface because the C-H groups could dramatically decrease the surface energy5 and hence considerably enhance the hydrophobicity, which would further substantiate the successful hydrogenation of graphene.
We adopted radio frequency catalytic chemical vapor deposition (rf-cCVD) method6 to hydrogenate the graphene films, and the schematic diagram of the rf-CVD system is depicted (Fig. S1, ESI†). After the pretreatment (see ESI† for details) of both the catalyst and the sample, a graphite boat with Ni(8 wt%)/ Al2O3 was put at the upstream of the graphene sample, and heated to 820 0C for about 3 h under hydrogen flow (20 mL/min) at the center of the induction coil. Two inches distance between these boats was kept in order to prevent the sample from being overheated when