Nanocomposites of 1D MoS₂ with Polymer-Functionalized Nanotubes of Carbon and Borocarbonitride, and Their HER Activity

Nanocomposites formed by carboxyl-functionalized MoS2 nanotubes with poly(diallyldimethylammonium chloride) (PDDA, described as P)-modified single-walled carbon nanotubes (SWCNT) and borocarbonitride nanotubes (BCNNT) have been prepared by a solution-phase flocculation of 1D nanotubes. The nanocomposites show higher photocatalytic and electrocatalytic HER activities compare to the individual constituents, where the H2 yield improves with the MoS2 nanotube proportion. The maximum H2 evolution rate achieved is 7475 μmol g–1 h–1 in the nanocomposite of MoS2–P.SWCNT with a MoS2–P.SWCNT proportion of 3:1, whereas the corresponding physical mixture exhibits only 3112 μmol g–1 h–1. The MoS2–P.SWCNT (3:1) nanocomposite also shows superior electrocatalytic H2 evolution with an onset potential of 80 mV (vs RHE). The MoS2–P.BCNNT composite exhibits a somewhat lower H2 evolution rate. Electrostatic stacking of 1D MoS2 nanotubes with SWCNT/BCNNT appears to be a valuable strategy for HER and related catalytic reactions.