Revealing the diverse electrochemistry of nanoparticles with scanning electrochemical cell microscopy.

The next generation of electroactive materials will depend on advanced nanomaterials, such as nanoparticles (NPs), for improved function and reduced cost. As such, the development of structure-function relationships for these NPs has become a prime focus for researchers from many fields, including materials science, catalysis, energy storage, photovoltaics, environmental/biomedical sensing, The technique of scanning electrochemical cell microscopy (SECCM) has naturally positioned itself as a premier experimental methodology for the investigation of electroactive NPs, due to its unique capability to encapsulate individual, spatially distinct entities, and to apply a potential to (and measure the resulting current of) single-NPs. Over the course of conducting these single-NP investigations, a number of unexpected ( rarely-reported) results have been collected, including fluctuating current responses, and carrying of the NP by the SECCM probe, hypothesised to be due to insufficient NP-surface interaction.

Five years of scanning electrochemical cell microscopy (SECCM): new insights and innovations.

Scanning electrochemical cell microscopy (SECCM) is a nanopipette-based technique which enables measurement of localised electrochemistry. SECCM has found use in a wide range of electrochemical applications, and due to the wider uptake of this technique in recent years, new applications and techniques have been developed. This minireview has collected all SECCM research articles published in the last 5 years, to demonstrate and celebrate the recent advances, and to make it easier for SECCM researchers to remain well-informed.

Drop-cast gold nanoparticles are not always electrocatalytically active for the borohydride oxidation reaction.

The next-generation of energy devices rely on advanced catalytic materials, especially electrocatalytic nanoparticles (NPs), to achieve the performance and cost required to reshape the energy landscape towards a more sustainable and cleaner future. It has become imperative to maximize the performance of the catalyst, both through improvement of the intrinsic activity of the NP, and by ensuring all particles are performing at the level of their capability. This requires not just a structure-function understanding of the catalytic material, but also an understanding of how the catalyst performance is impacted by its environment (substrate, ligand, ).

Structure-dependent CO reduction on molybdenite (MoS) electrocatalysts.

Scanning electrochemical cell microscopy (SECCM) is employed to directly identify the structure-dependent electrochemical CO reduction reaction (eCORR) activity of molybdenite (MoS) electrocatalysts in an aqueous imidazolium-based aprotic ionic liquid electrolyte. Nanoscale defects, where the edge plane (EP) is exposed, are directly targeted, revealing heightened overall activity (eCORR + the competing hydrogen evolution reaction, HER) over the relatively inactive basal plane (BP). In addition, certain types of defects (, step edges) only exhibit heightened activity under a CO atmosphere (, compared to N), indirectly confirming higher selectivity at these surface sites.

Direct electrochemical identification of rare microscopic catalytic active sites.

Local voltammetric analysis with a scanning electrochemical droplet cell technique, in combination with a new data processing protocol (termed data binning and trinisation), is used to directly identify previously unseen regions of elevated electrocatalytic activity on the basal plane (BP) of molybdenum disulfide (2H-MoS). This includes BP-like structures with hydrogen evolution reaction activities approaching that of the edge plane and rare nanoscale electrocatalytic "hot-spots" present at an areal density of approximately 0.2-1 μm.

Anticancer Activity and Cisplatin Binding Ability of -Quinoline and -Isoquinoline Derived [PdL] Metallosupramolecular Cages.

New quinoline ( ) and isoquinoline-based ( ) ligands have been synthesized, along with their respective homoleptic [Pd( or )] cages ( and ). The ligands and cages were characterized by H, C and diffusion ordered (DOSY) NMR spectroscopies, high resolution electrospray ionization mass spectrometry (HR-ESIMS) and in the case of the -quinoline cage, X-ray crystallography. The crystal structure of the architecture showed that the [Pd( )] cage formed a twisted isomer where the [Pd()] units at either end of the cage architecture adopt the opposite twists (left and right handed).