Synthesis of self-assembled and hierarchical palladium-CNTs-reduced graphene oxide composites for enhanced field emission properties

•Microwave assisted synthesis of hierarchical palladium-CNTs-reduced graphene oxide composite.•Pd catalyst assisted growth of CNTs on rGO nanosheets surfaces.•The hierarchical structure shows enhanced field emission properties with good stability.•The mechanisms for the enhanced field emission are proposed and discussed.

We report the synthesis of palladium-graphene oxide based (Pd-rGO) composite and its enhanced electron field emission studies. The palladium nanoparticles decorated reduced graphene oxide (Pd-NPs-rGO) and Pd catalyst assisted grown CNTs on reduced graphene oxide (Pd-CNTs-rGO) composite have been synthesized employing microwave. The hierarchical Pd-CNTs-rGO composite shows enhanced field emission performance due to the synergestic effect of Pd catalyst assisted grown CNTs on rGO nanosheets (rGO-NSs) and its proper contact on rGO surfaces. The enhanced field emission behavior of Pd-CNTs-rGO composite is attributed to the easy electron tunneling from the one-dimensional CNTs, which increases the emission sites and hence the field emission current density. The Pd-CNTs-rGO composite exhibits lower turn-on field, lower threshold field, larger field enhancement factor and high emission current stability as compared to Pd-NPs-rGO composite.

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