Silver-loaded carbon sphere-in-rod 3D nano-architectures as electrode material for supercapacitors

Abstract

Carbon spheres (SCs) with hydrophilic shells consisting of nano-sized building blocks are of great interest for the next generation of electrochemical capacitors. In this study, silver-loaded carbon sphere-in-rod 3D architectures were synthesized by in situ hydrothermal carbonization of sucrose and silver nitrate. Silver loading improves the electrical conductivity of the hybrid electrode by developing nanoscale ligaments between the grown SCs. The obtained sphere-in-rod 3D architectures were characterized using field emission scanning electron microscopy, transmission electron microscopy, dynamic light scattering, energy-dispersive X-ray spectroscopy, elemental mapping, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, Thermogravimetric analysis, and Brunauer-Emmett-teller methods. The electrochemical evaluation revealed that silver-loaded carbon sphere-in-rod 3D architectures exhibited high specific capacitance of 421 mF cm−2 at 1 mA cm−2 and wide operating potential window because of being able to work in both negative and positive voltages. The present work demonstrates a green, low-cost, and scalable approach for constructing a hybrid electrode material using saccharide and noble metal building blocks.