Filling carbon nanotubes with Ni-Fe alloys via methylbenzene-oriented constant current electrodeposition for hydrazine electrocatalysis

► A novel method is presented to fill multiwalled carbon nanotubes with Ni-Fe alloys. ► The method is methylbenzene-oriented constant current electrodeposition. ► The method is based on the different conductivity of MWCNTs inside and outside. ► The process is simple, environment friendly and proceeds at low temperature. ► The Ni85Fe15-filled MWCNTs showed high electrocatalytic activity for hydrazine.