Phosphorus doped single wall carbon nanotubes loaded with nanoparticles of iron phosphide and iron carbide for efficient hydrogen evolution

Abstract

The development of low-cost and high-performance non-precious metal electrocatalysts for the hydrogen evolution reaction (HER) is highly desirable for the wide range of applications of molecular hydrogen as a clean renewable energy source. Here phosphorus doped single wall carbon nanotubes loaded with nanoparticles of iron carbide and iron phosphide are synthesized cost-effectively and time-efficiently using a one-pot and one-step chemical vapor deposition method, and exhibit superb catalytic activity for the HER. The nanohybrid electrocatalyst produces a current density of 20 mA cm⁻² at an overpotential of 157 mV in acid solution and 331 mV in basic solution. The Tafel slope is 60.8 mV dec⁻¹ in acid solution and 87.6 mV dec⁻¹ in basic solution. The catalyst can work stably in both acidic and basic solutions with 100% faradaic efficiency. The superb performance correlates with the doping of single wall carbon nanotubes with phosphorus, and the synergistic effect of iron phosphide and iron carbide.