Layer-by-Layer Construction of a Nanoarchitecture by Polyoxometalates and Polymers: Enhanced Electrochemical Hydrogen Evolution Reaction

Abstract

In this contribution, a nanoarchitectural approach was employed to produce a nanolayer of polyoxometalate (POM) on the surface of a glassy carbon electrode (GCE) to achieve a higher surface area with higher electrocatalytic activity toward the electrochemical hydrogen evolution reaction (HER). To accomplish this, the well-known layer-by-layer (LbL) technique was employed, which involved the alternate adsorption of the POM, Na 0, abbreviated as [(TBA)Mo 12 (AleThio) 4 ], and polyethyleneimine (PEI) polymer. This nanolayered electrode exhibited catalytic properties toward the HER in 0.5 M H 2 SO 4 with the resulting polarization curves indicating an increase in the HER activity with the increasing number of POM layers, and the overpotential required for this reaction was lowered by 0.83 V when compared with a bare GCE. The eighth PEI/[(TBA)Mo 12 (AleThio) 4 ] bilayer exhibited a significantly lower HER overpotential of −0.077 V at a current density of 10 mA cm −2 . Surface characterization of the LbL-assembled nanolayers was carried out using X-ray photoelectron spectroscopy, atomic force microscopy, and scanning electron microscopy. We believe that the synergetic effect of the positively charged PEI polymer and the catalytically active molybdate POM is the cause for the successful response to the electrochemical HER.

A multifunctional organophosphonic ligand-templated poly(polyoxotungstate) with potential in building a genosensor for thalassemia gene detection

“…[32][33][34] Nevertheless, the advancements of poly(POT) clusters in electrochemistry have been limited by their water-solubility. To break this bottleneck, more and more preparative methods for poly(POT)based composite materials have been put forward, for instance, physical adsorption, 21 chemical/electro-deposition, 35 layer-by-layer assembly, 36 and electropolymerization. 37 As the electropolymerization technology can provide uniform polymeric films with high chemical/electrochemical stability and remarkable conductivity, it has become a favored route to modify electrodes in constructing electrochemical sensors or devices.…”

Electron‐Sponge Nature of Polyoxometalates for Next‐Generation Electrocatalytic Water Splitting and Nonvolatile Neuromorphic Devices

“…The as obtained nanolayered electrode revealed higher electrocatalytic HER activity (−0.077 V at 10 mA cm −2 , and a low Tafel slope of 80 mV dec −1 ) in acidic electrolyte, which was attributed to the synergetic effect of the positively charged PEI polymer and the catalytically active Mo-POM. [59] H 2 production without oxygen impurity is a grand challenge. [139] Natural photosynthetic systems have ability to separately produce O 2 and H 2 gases via water splitting.…”

“…The as obtained nanolayered electrode revealed higher electrocatalytic HER activity (−0.077 V at 10 mA cm −2 , and a low Tafel slope of 80 mV dec −1 ) in acidic electrolyte, which was attributed to the synergetic effect of the positively charged PEI polymer and the catalytically active Mo‐POM. [ 59 ]…”

“…"Metal−DNA-origami−POV6" heterostructure permitting the application of memristive functions via multi-logic functions because of POV6 (violet) and a synaptic dynamic due to an interplay between the Au (dark yellow), DNA-origami (blue), and counter ions (green). Reproduced with permission [59]. Copyright 2023, American Chemical Society.…”

Construct of an Electrodeposited Cobalt–Molybdenum Film and Evaluation of Its Efficiency in Hydrogen Evolution

“…Because Co (d7) has a low hydrogen adsorption strength and Mo (d5) has a high hydrogen adsorption strength, the two alloys can draw on each other’s strengths to increase hydrogen adsorption strength and catalytic activity. − In addition, binary catalysts consisting of Mo and Co elements have been used as cathodes for hydroelectrolysis. They have demonstrated good catalytic properties due to either crystalline structure modification − or electronic formation. − Besides, the self-supporting electrode allows for better contact between the catalyst and the reactant on the surface. − …”