Pressure-induced bimetallic carbon nanotubes from metal-organic frameworks as optimized bifunctional electrocatalysts for water splitting

Carbon nanotubes (CNTs) have attracted great interest in numerous applications due to their excellent electronic and structural properties. However, harsh synthesis conditions and high energy consumption limit the further application of CNTs. Herein, we developed a facile and innovative strategy to generate CNTs by physically pressurizing metal-organic frameworks (MOFs) and then pyrolyzing. The synthesized bimetallic nitrogen/sulfur double-doped carbon nanotubes are denoted as FexCo1-xP (x = 0.5, 0.6, 0.7, 0.8, 0.9). The introduction of pressure not only revolutionized the morphology of the electrocatalysts, but also enhanced the activity of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline solution. Fe0.6Co0.4-P exhibits superior OER and HER performances in 1.0 mol.L-1 KOH solution with overpotentials of 364 and 346 mV at 10 mA.cm(-2), which are 28 and 5 mV lower than unpressurized Fe0.6Co0.4.