Synthesis of tungsten disulfide for electrochemical energy applications

One-dimensional tungsten disulfide (WS2) was synthesized by a simple hydrothermal method for electrochemical energy applications, such as hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalysts and flexible supercapacitors. The synthesized WS2 exhibits a low overpotential of −230 mV at −10 mA cm−2 and 290 mV at 10 mA cm−2 with low Tafel slopes of 127 mV dec-1 and 163 mV dec-1 for HER and OER, respectively. In addition, the synthesized WS2 performed high specific capacitance of 152F g−1 at a current density of 1 A g−1 with an energy density of 13.5 Wh kg−1 and power density of 408 W kg−1 for the flexible supercapacitor. Ultimately, high specific capacitance retention (93 %) and coulombic efficiency (87 %) after 5,000 cycles with reliable flexibility were shown. These results demonstrated that the synthesized WS2 could be used for electrocatalysts and flexible supercapacitor electrodes with high performance.