CoS2 nanodots anchored into heteroatom-doped carbon layer via a biomimetic strategy: Boosting the oxygen evolution and supercapacitor performance

Abstract

Development of efficient and durable electrocatalysts and electrode materials are significantly important to enhance the electrochemical performance for oxygen evolution reaction and supercapacitor applications. Herein, we design a hydrothermal-assisted biomimetic strategy to anchor CoS2 nanodots on heteroatom-doped carbon layer (CoS2@HADC). Numerous CoS2 nanodots and heteroatoms rich in N and S are in situ hybridized into the carbon layer in a homogeneously dispersed manner. The preparation procedure is quite simple and moderate, avoiding the high-temperature annealing step. The optimized hybrid not only act as effective electrocatalyst, in which overpotential of 226 mv is enough to drive a current density of 10 mA cm−2 with a Tafel slope of 56 mV Dec−1 during the OER process, but also serve as electrode material with specific capacitance of 565 F g−1 at a current density of 1 A g−1 for high-performance supercapacitor, compared with CoS2 (176 F g−1). Also, it exhibits superior cycling activity (~100% capability retention after 10000 cycles at 2 A g−1 in 6.0 M KOH) and remains a 57% high rate capability (320 F g−1 at 5 A g−1). The rational design concept for cobalt sulfides/heteroatom-doped carbon hybrid provide a simple strategy towards superior energy conversion and storage devices.