▎ 摘　　要

Reduced graphene oxide (rGO) supported palladium nanopartides (Pd NPs) with a size of similar to 3 nrn were synthesized using one-pot photoassisted citrate reduction. This synthetic approach allows for the formation and assembly of Pd NPs onto the rGO surface with a desired size and can be readily used for other metal NP preparation. The prepared rGO-Pd exhibited 5.2 times higher mass activity for ethanol oxidation reaction than the commercial platinum/carbon (Pt/C). In the oxygen reduction reaction tests, rGO-Pd exhibited comparable activity compared with Pt/C and maintained its high performance after 4000 cycles of potential sweep. These results demonstrate that our synthetic approach is effective for preparing graphenesupported metal NPs with excellent activity and stability in ethanol oxidation and oxygen reduction reactions.