Sn‐based chi‐rGO/SnO2 Nanocomposite as an Efficient Electrocatalyst for CO2 Reduction to Formate

Abstract

Abstract Designing efficient and cost‐effective electrocatalysts in simple ways is very important for energy efficiency. In this sense, nano‐sized materials have been extensively utilized for the development of efficient electrodes for electrochemical CO2 reduction. In the present study, we have developed a Sn/chitosan‐reduced graphene oxide (chi‐rGO)/SnO2 composite electrode via only electrochemical techniques and tested it for electrochemical reduction of CO2 to formate. A bare Sn plate was modified with a reduced graphene oxide layer in the presence of chitosan to get a stable Sn/chi‐rGO composite structure and to get more active sites, thus an efficient reduction process was performed. The surface of the Sn/chi‐rGO composite was further modified by SnO2 nanoparticles via the potentiostatic electrodeposition method at a fixed applied potential of −0.6 V for varying periods. The calculated double‐layer capacitance (Cdl) of the Sn/chi‐rGO/SnO2 electrode was about 80 times larger than the bare Sn plate implying that the coexistence of SnO2 nanoparticles on the (chi‐rGO) structure enhanced the electrochemically active sites. The maximum Faradaic efficiency was recorded as 88 % towards the production of formate at an average current density of −7.36 mAcm−2 at −1.8 V. Electrochemical measurements and the stability test revealed that the resultant Sn/chi‐rGO/SnO2 composite structure behaves as a potential electrode material for efficient CO2 conversion to formate.The study presents a simple and low‐cost electrode preparation procedure including only electrochemical techniques which can be conducted within a very short time and without using extra energy and chemicals/additives.

Keywords

• Electrochemical CO2 reduction
• reduced graphene oxide (rGO)
• tin-oxide
• nanocomposite
• formate/formic acid