Electronic interaction between platinum nanoparticles and nitrogen-doped reduced graphene oxide: effect on the oxygen reduction reaction

Abstract

Confirmed by DFT, a significant amount of platinum atoms are chemically bound to N of N-doped RGO.

One step synthesis of chlorine-free Pt/Nitrogen-doped graphene composite for oxygen reduction reaction

“…The 2D and the D+G bands are also visible with small intensity at around 2700 and 2930 cm −1 , respectively. The results are consistent with previously reported Raman spectra of graphene oxide and nitrogen-doped graphene sheets [28]. The ID/IG ratio slightly increased after the thermal treatment of GO from 0.91 to 1.05 due to the increase in the number of structural defects caused by the incorporation of nitrogen atoms into the carbonaceous framework.…”

“…There is a considerable amount of oxidized platinum, which is likely the result of the smaller size of the platinum nanoparticles. A high percentage of Pt atoms on the nanoparticle surface in contact with air gives rise to different oxide phases [28]. This kind of interaction could increase the electrocatalytic activity and durability of ORR catalysts.…”

“…It was also showed that a stronger electronic interaction is formed between the nitrogen doped support and the platinum nanoparticles due to the increased electron affinity of the former. This further facilitates the electron donation behavior of platinum nanoparticles [28]. Using nitrogen doped graphene as a support instead of undoped graphene to improve ORR performance has already been suggested in the literature.…”

“…N-doping was typically achieved by the thermal treatment of the carbon support (graphene or GO) in the presence of a nitrogen source, e.g. dicyanidamide [31], polyanline [32], polypyrrol [33], pyrrol [34], urea [30], nitrogen plasma [29] or ammonia [28], and Pt nanoparticles were synthesized in a subsequent step by the in situ reduction of e.g. hexachloroplatinic acid or platinum carbonyl complexes.…”

A facile strategy for ultrasmall Pt NPs being partially-embedded in N-doped carbon nanosheet structure for efficient electrocatalysis

“…Although they could lead to excellent durability performance via stabilizing and steric effect, the confined Pt NPs in carbon surface layer will sacrifice a large proportion of active sites [19,20]. It is reported that the carbon support containing nitrogen groups can allow for the homogenous embedding of Pt NPs, facilitating electrons to transfer from Pt to carbon support, and the robust interaction between Pt and N atoms endows the catalysts with enhanced electrochemical activity and even durable catalytic performance [16,21]. Therefore, achieving Pt NPs homogeneously embedded in N-doped carbon materials through a facile and environment-friendly method is important for the electrochemical catalysts in energy conversion and storage technologies.…”