Low temperature preparation of the monolayer-graphene/diamond heterostructure with superior mechanical properties

There is increasing interest in the preparation of graphene-on-diamond (GOD) hybrids since it is expected to reveal a new horizon of mechanical applications if the beneficial properties of diamond and graphene are effectively combined. Herein, we demonstrated the atomistic scale events leading to the growth of graphene domains on the diamond during the annealing of the nickel catalyst and diamond substrate by combining experiments and theoretical calculations, including the mechanism transition from high-to low-temperature. Concurrently, the high-quality heterostructure of monolayer graphene on diamond was prepared at a low temperature (760 °C) by rapid thermal annealing technique under the guidance of theoretical insights, and an extraordinarily low coefficient of friction (0.021) was exhibited, representing a 91.1 % reduction against the pristine diamond. The adhesion tests confirmed that such an excellent self-lubricity benefited from the adhesion shield effect of as-grown graphene and the consequent reduction in adhesion energy. Furthermore, the corresponding hardness and elastic modulus were also improved by 14.1 % and 32.5 %, respectively. This investigation presents a great potential of the preparation/integration and application of the GOD heterostructure.