Halide-regulated growth of electrocatalytic metal nanoparticles directly onto a carbon paper electrode

Abstract

Direct growth of hierarchical micro/nanostructured metal arrays on a 3D substrate is a powerful tool to enhance the catalytic efficiency of metal particles towards a wide range of substrates.

Exploring the Optical and Morphological Properties of Ag and Ag/TiO2 Nanocomposites Grown by Supersonic Cluster Beam Deposition

“…Coatings based on metallic nanoparticles (NPs) films, NPs dispersed in host dielectric or conductive matrices or barrier layers and hierarchical three-dimensional nanomaterials, are attracting a lot of interest due to their applicability in fields spanning from electro-catalysis [1], fuel cells [2], to antimicrobial coatings [3,4,5,6] and nanojoining [7,8]. However, to tailor the properties of nanostructured systems, the synthesis of nanoparticle-matrix nanocomposite coatings may require complex multi-step approach, even after the NPs synthesis, where matrix embedding may require colloidal stabilization, cross-linking growth and substrate functionalization [9].…”

Nanostructured Inorganic Materials at Work in Electrochemical Sensing and Biofuel Cells

“…For low indexes, the reactivity of glucose over Au(hkl) surfaces increases in the order (111) < (110) < (100). Other studies have pointed out the likely role of higher crystallographic (hkl) facets such as (200) or (220) [58,64,75]. This plausible contribution needs a fundamental investigation using single crystals.…”

“…In 2015, Li et al [92] reported the first attempt in combining a Cu metal oxide and noble metal in a binder-free style for fabricating non-enzymatic glucose sensors. As is well discussed in Reference [58], the majority of existing synthetic methodologies require materials to be stabilized in a liquid or dispersed in a powder before using a binder, such as Nafion, to immobilize the NPs on a substrate (i.e., glassy carbon, carbon paper) prior to use. While the use of a Nafion ionomer contributes to the proton transport within the electrode materials, the use of such binders adds a layer of complexity to the fabrication process, and the degradation of binders results in the undesired loss of NPs and a subsequent decrease in the catalytic performance [58].…”

“…For electrodes comprising inorganic materials within their composition, their activity is often considered in terms of their roughness factor, in which the greater the surface roughness, the greater the electrochemical activity. In a recent attempt to grow electrocatalytic metal nanoparticles directly onto a carbon paper electrode employing halide anions as regulators, Holade et al demonstrated that flower-like rough surfaces exhibited higher catalytic activity than featureless smooth surfaces, about one order of magnitude greater [58]. Fundamentally, solid porous materials are classified according to their pore sizes (diameter) in three main categories which are macroporous (>50 nm), mesoporous (2-50 nm) and microporous (<2 nm) [65,66].…”

“…All these possible interferences should be taken into account when choosing a supporting electrolyte for non-enzymatic electrodes. An ideal catalytic material should have a high dispersion of the active sites, a controllable surface structure and morphology, and minimal metal loading which allow for optimizing the activity, selectivity, and durability [58]. For platinum group metals (PGMs), the old and most widely used approach of optimizing electrochemical performances towards organic molecules, electrooxidation relies on engineering materials with a tunable surface structure and composition, namely nanoalloys and core-shell materials with fascinating and exceptional properties.…”