Facile synthesis of novel Cu2O-g-C3N4/Vulcan carbon composite as anode material with enhanced electrochemical performances in urea fuel cell

Abstract

A novel g-C3N4/VC composite was prepared by adopting simple hydrothermal treatment without using any additives from bulk g-C3N4 and Vulcan XC-72R (VC) in different ratios. Further, the resulting composite materials were used as a support for the synthesis of Cu2O NPs. The use of g-C3N4/VC not only acts as a support for the Cu2O NPs but also it forms a new type of novel composite materials, i.e., Cu2O-g-C3N4/VC. Various ratios (1:1, 1:2 and 2:1) of g-C3N4 and VC were used for the synthesis of three different types of the composite materials such as Cu2O-g-C3N4/VC(1:1), Cu2O-g-C3N4/VC(1:2), and Cu2O-g-C3N4/VC(2:1). The structures, surface properties, elemental compositions, and morphologies of synthesized materials were analyzed by various instrument methods such as FTIR, XRD, FESEM, Raman, EDS, BET, etc. Then the electrochemical activity of those resulting Cu2O-g-C3N4/VC composite materials were examined towards urea oxidation. The catalytic activity of Cu2O-g-C3N4/VC composite materials were found to be influenced by the variation of the g-C3N4 to VC ratio. The Cu2O-g-C3N4/VC(1:2) composite presented a higher current density (25.3 mAcm−2) as compared to that of Cu2O-g-C3N4/VC(1:1) (21.2 mAcm−2) and Cu2O-g-C3N4/VC(2:1) (13.5 mAcm−2) at 0.6 V using 2 M urea. The observed higher catalytic activity of this Cu2O-g-C3N4/VC (1:2) composite material compared to Cu2O-g-C3N4/VC (1:1) and Cu2O-g-C3N4/VC (2:1) is due to its higher surface area arising from different morphology compared to that of others. The Chronoamperometric measurements of the composite materials demonstrated their high stability upto 2 h without any degradation in the current density.