Unraveling the effects of surface functionalization on the catalytic activity of ReSe2 nanostructures towards the hydrogen evolution reaction

Herein, the surface functionalization of ReSe2 nanostructures by surfactants was investigated. This was done to understand how the use of various surfactants affects the catalytic activity of ReSe2 nanostructures towards the hydrogen evolution reaction (HER), and to determine which surfactant would result in maximal exposure of the active edge sites without impeding the catalytic processes of the HER. Oleylamine (OLA), oleic acid (OA), and trioctylphosphine oxide (TOPO) were used as the surfactants. Powder X-ray diffraction confirmed the formation of ReSe2 nanostructures that crystallized in a distorted 1 T phase triclinic system with a P-1 space group. The FTIR, XPS, NMR, and computational studies revealed that the surfactants bind to the surface of the ReSe2 nanostructures through their respective head groups. The ReSe2 nanostructures synthesized using TOPO (ReSe2- TOPO) had the lowest on-set potential, Tafel slope, and overpotential at 10 mA/cm2 at 73 mV, 58 mV/dec, and 171 mV, respectively. The catalytic performance of the nanostructures was significantly affected by their interaction with the surfactants. A high degree of passivation by the surfactant resulted in poor catalytic activity, and a lower degree of passivation resulted in excellent catalytic activity towards the HER.

Automated summary

The surface functionalization of ReSe2 nanostructures by different surfactants significantly affects their catalytic activity towards the hydrogen evolution reaction (HER). Binding of surfactants to the surface of ReSe2 nanostructures was confirmed through various spectroscopic techniques. Among the surfactants used, ReSe2 synthesized with trioctylphosphine oxide (TOPO) exhibited the best catalytic performance with the lowest onset potential, Tafel slope, and overpotential. The interaction between the surfactants and nanostructures played a crucial role in determining the catalytic activity.