Highly dispersed nanocrystallines WC supported on microwave exfoliated RGO by ionic liquid and its catalytic performance in electroreduction of nitrobenzene

Tungsten carbide (WC) nanocrystallines were loaded onto the surface of microwave-exfoliated reduced graphene oxide (RGO) using program-controlled reduction–carbonization technique and modified impregnation method in the presence of ionic liquid (IL). The characterization results show that WC nanocrystallines with a size of ca.80 nm were highly dispersed on RGO with the assistance of IL. The electrocatalytic activity of the prepared WC/RGO (IL) was evaluated in the nitrobenzene reduction reaction. It was found that the WC/RGO (IL) gave better activity and stability than single RGO or WC/RGO that were prepared in the absence of IL. The high activity of WC/RGO (IL) can be explained to be the result of the synergistic function between WC and RGO. It was also proved that the pre-treatment of GO by microwave-exfoliated method was an effective way to form the graphene-based intercalation materials. Our study demonstrated that WC/RGO (IL) could be a promising alternative catalyst toward the nitrobenzene electroreduction because of its higher performance and lower cost.

Tungsten carbide (WC) nanocrystallines were loaded onto the surfaces of microwave-exfoliated reduced graphene oxide (RGO) using program-controlled reduction–carbonization technique and modified impregnation method in the presence of ionic liquid (IL) as shown below. The interaction of IL will make great impact on the nucleation and growth of nanocrystallines. Therefore, it is not difficult to anticipate that WC nanocrystallines, which were obtained from the reduction and carbonization steps, will be more dispersive on RGO and be much smaller in size. The prepared WC/RGO (IL) was used as the electrocatalyst for nitrobenzene reduction reaction. It was found that the WC/RGO (IL) gave the better activity and stability than single RGO or WC/RGO which were prepared in the absence of IL.Figure optionsDownload high-quality image (214 K)Download as PowerPoint slideHighlights
► GO was pre-treated by microwave irradiation exfoliation, which could increase its volume and interlayer space to a large extent.
► Participating of ionic liquid (IL) will disperse WCl6 effectively in solution and make smaller W-containing group size, which would lead to smaller WC.
► WCl6 was reduced to WC by program-controlled reduction–carbonization technique.
► WC/RGO (IL) electrocatalyst shows better performance for nitrobenzene reduction.