Facile fabrication of crumpled graphene oxide nanosheets and its Platinum nanohybrids for high efficient catalytic activity.

Crumpled graphene oxide nanosheets have drawn large attentions due to its compressibility and self-avoiding stacking as flat graphene sheets trend to aggregate and restack. Up to now, most of the synthesis approaches were relied on external substrates, such as elastic substrates or ultrasonic atomizer, and the crumpled structures were obtained in a solid state directly. Here we report a facile method to produce crumpled dispersive nanosheets in solution through general base-washing treatment by taking advantage of the amphipathy of GO nanosheets. With the dissociation of oxygen-functional groups on nanosheets in alkaline environment, highly water-soluble oxidative debris (OD) would fall off from the nanosheets due to the increase of electrostatic repulsions, and resulted in the crumple of the flat sheets, while the covalent oxygen-functional groups on the nanosheets were reserved. As a result, the nanosheets remained dispersible in solution, and could be used directly for surface modifications. Pt nanoparticles could be directly deposited onto both sides of the sheets through common nucleation and growth from precursor ions process. Compared with flat graphene-based hybrid, the catalytic performance of crumpled-graphene-Pt (CG-Pt) is more excellent and attractive, and corresponding apparent kinetic rate constant (k) of CG-Pt toward 4-nitrophenol reduction is enhanced by 2.7-4.6-fold. This study provides a new and facile way to fabricate crumpled nanosheets and demonstrates to be easy modified for various purpose.