Facile synthesis of nitrogen-doped carbon coated Fe3O4/Pd nanoparticles as a high-performance catalyst for Cr (VI) reduction

A novel facile and cost- effective approach was developed to fabricate Fe3O4/Pd nanoparticles encapsulated in a nitrogen-doped carbon (NC) shell (Fe3O4/Pd@N-C) through a layer-by-layer assembly method coupled with high-temperature annealing. The Fe3O4/Pd@N-C nanocomposites acted as a high-performance catalyst for the catalytic reduction of Cr (VI) to Cr (III) using formic acid (HCOOH) as the reducing agent. Due to conductive and protective functions of the NC shell, the catalyst had a high stability and catalytic activity, and only needed 3 min were required to convert Cr(VI) to Cr(III). Furthermore, catalytic conditions such as annealing temperature, reaction temperature and Pd loading were optimized. The excellent catalytic performance of Fe3O4/Pd@N-C can be attributed to the following reasons: the thin NC shell, the high disperse of Pd NPs loaded on the Fe3O4, the high content of pyridinic nitrogen and graphitic nitrogen, as well as high surface area up to 110.77 m(2) g(-1). (C) 2020 Elsevier B.V. All rights reserved.