Collective Use of Deep Eutectic Solvent for One-Pot Synthesis of Ternary Sn/SnO₂@C Electrode for Supercapacitor

Abstract

Scalable and simple preparation of metal/metal oxide-carbon composite with high specific surface areas and designated properties are essential for their large scale practical applications. In view of this, we report an ecofriendly deep eutect solvents (DESs) assisted synthesis of Sn/SnO2@C hybrid composite. Herein, we have investigated the crucial role of DESs which collectively acts as solvent-precursor-reactant system offering an interesting and exciting physicochemical properties and alternative for the conventional solution-based synthesis methods. TEM images reveal that the massive Sn/SnO2 nano-particles with average size of 15-20 nm, are uniformly confined in highly layered porous carbon sheets leading to the carbonaceous composite with large surface area of 500 m(2)/g after thermal treatment. It is noteworthy that the excellent electrochemical performance of Sn/SnO2@C hybrid composite for supercapacitor electrode material (109.70 mAh/g at 1.42 mA/cm(2) and almost 100% capacitance retention for 5000 cycles) can be attributed to the higher surface area and synergic properties of Sn and SnO2. Nevertheless, the carbon matrix with a low degree of graphitization can establishes a good electrical contact and also prevents the detachment of nanoparticles during the course of long-term electrochemical reactions. In addition, selection of less toxic component is possible by virtue of compositional versatility of DESs. Thus the use of DESs can bring froth the twin benefits of solvent-precursor-reactant system and cost effective eco-friendly synthesis route which can be applicable for the synthesis of various metal/metal oxide-carbon composites.