PbTe quantum dots as electron transfer intermediates for the enhanced hydrogen evolution reaction of amorphous MoS_x/TiO₂ nanotube arrays

Abstract

Amorphous molybdenum sulfides (a-MoSx) have been demonstrated as economic and efficient hydrogen evolution catalysts for water splitting. Further improvements of their hydrogen evolution reaction (HER) activities could be achieved by coupling them with appropriate electron transfer intermediates via interfacial engineering. In this study, a novel ternary composite electrode comprising PbTe quantum dots (QDs), a-MoSx and TiO2 nanotube arrays (TNAs) was successfully fabricated by a facile combination of successive ionic layer adsorption and reaction (SILAR) and electrodeposition routes. Investigation of the microstructures and electrocatalytic properties of the a-MoSx/PbTe QD/TNA hybrid material show that PbTe QDs can work as electron temporary storage and electron transfer intermediates between the electrocatalyst a-MoSx and electrode-based material TiO2 that significantly lower the impedance of electrode process, enhance the energy band bending at the interface between the electrolyte and electrode surface, and increase the electrochemically active surface area. The electron interphase crossing from a-MoSx to electrolyte and electron transport inside the electrode are greatly strengthened. The ternary PbTe@MoSx/TNA electrode demonstrates lowered onset potential and Tafel slope and superior electrocatalytic activity and cyclic stability towards HER.

Electrocatalytic Performance of Titania Nanotube Arrays Coated with MoS2 by ALD toward the Hydrogen Evolution Reaction

“…30 In the case of amorphous MoS 2 , as well, a number of studies have been devoted to nanostructuring aimed at increasing the surface area while maintaining sufficient electrical conductivity. 31−34 A highly porous structure typically features long electron transport distances, which can cause resistive (Ohmic) losses. 35,36…”

ZnS Nanotubes/Carbon Cloth as a Reversible and High‐Capacity Anode Material for Lithium‐Ion Batteries

“…Confronted with the increasing environmental pollution and exponential consumption of fossil fuels worldwide, clean and renewable energy and their storage devices are urgently sought after . In this regard, lithium‐ion batteries have gained tremendous attention due to its remarkable properties such as large energy density and environmental friendliness .…”

Stabilizing an ultrathin MoS2 layer during electrocatalytic hydrogen evolution with a crystalline SnO2 underlayer

“…Both of these values are comparable to the best featured in the literature (Table S2 †). 9,11,[40][41][42][43][44][45][46] What the system presented here offers as a signicant advantage is its control over the electrocatalyst stability. The agreement in the MoS 2 electrocatalysis community is that a-MoS 2 yields the best performance and c-MoS 2 the best stability.…”