Monodispersed, highly interactive facet (111)-oriented Pd nanograins by ALD onto free-standing and flexible electrospun polymeric nanofibrous webs for catalytic application

An atomic layer deposition (ALD) of monodispersed palladium (Pd) nanograins (≈2 nm) onto electrospun polymeric nanofibers (NF) is presented. By ALD, monodispersed Pd nanograins with (111) exposed facets are decorated on the surface of the free-standing flexible nanofibrous webs (NW). The Pd nanograin-decorated free-standing NW exhibit catalytic reduction of 4-nitrophenol to 4-aminophenol. Even under low loading capacity (≈20 µg mg−1), Pd nanograins manifest effective catalytic performance which can be referred to direct exposure of Pd single crystalline highly interactive (111) plains with high surface area on the NW. The Pd nanograins and the interactive sites along with the high surface area NW yield effective catalytic reduction of 4-nitrophenol to 4-aminophenol with the catalytic reduction rate of 0.0531 min−1. Pd nanograins display thermally tunable effective catalytic reduction properties with activation energy (Ea) of 1.705 J mol−1 on varying the reaction temperature from 12 to 42 °C. Moreover, Pd nanograin-decorated NW are exhibited the effective reusable behavior with stable structural integrity even after repeated catalytic reactions. The approach of this study opens up synthesis and surface decoration of metal nanostructures onto NF through ALD with controlled size and facet orientation for designing reusable and free-standing flexible catalytic nanofibrous materials.