Cobalt/titanium nitride@N-doped carbon hybrids for enhanced electrocatalytic hydrogen evolution and supercapacitance

In this work, we demonstrate the synthesis of a composite architecture that is composed of nitrogen-doped carbon encapsulating cobalt and titanium nitride nanoparticles on carbon cloth (Co-TiN@NG-x/CC) for hydrogen evolution reaction and supercapacitor applications. The optimized electrocatalyst, Co-TiN@NG-2/CC, shows a low overpotential of similar to 208 mV to drive a current density of 10 mA cm(-2) and long-term durability in 1 M KOH. For the supercapacitor (SC), Co-TiN@NG-2/CC exhibits a capacitance of up to 189 mF cm(-2) at a current density of 0.5 mA cm(-2) and good rate capability. The capacitance can retain ca. 70% of the initial specific capacitance even after 1000 cycles at a current density of 1 mA cm(-2). The enhanced hydrogen evolution reaction and supercapacitance are attributed to the synergistic effect between titanium nitride and Co nanoparticles in the N-doped carbon matrix, leading to increased active sites and electrical conductivity.