Laboratory of Physical and Analytical Electrochemistry

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High-Throughput Sizing, Counting, and Elemental Analysis of Anisotropic Multimetallic Nanoparticles with Single-Particle Inductively Coupled Plasma Mass Spectrometry

Ayush Agarwal, Natalia Gasilova, Cedric David Koolen, Mo Li, Wen Luo, Andreas Züttel

Nanoparticles (NPs) have wide applications in physical and chemical processes, and their individual properties (e.g., shape, size, and composition) and ensemble properties (e.g., distribution and homogeneity) can significantly affect the performance. However, the extrapolation of information from a single particle to the ensemble remains a challenge due to the lack of suitable techniques. Herein, we report a high-throughput single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS)-based protocol to simultaneously determine the size, count, and elemental makeup of several thousands of (an)isotropic NPs independent of composition, size, shape, and dispersing medium with atomistic precision in a matter of minutes. By introducing highly diluted nebulized aqueous dispersions of NPs directly into the plasma torch of an ICP-MS instrument, individual NPs are atomized and ionized, resulting in ion plumes that can be registered by the mass analyzer. Our proposed protocol includes a phase transfer step for NPs synthesized in organic media, which are otherwise incompatible with ICP-MS instruments, and a modeling tool that extends the measurement of particle morphologies beyond spherical to include cubes, truncated octahedra, and tetrahedra, exemplified by anisotropic Cu NPs. Finally, we demonstrate the versatility of our method by studying the doping of bulk-dilute (

2022

Water photo-oxidation on self-assembled organic/Co3O4 metal junctions in biphasic systems

Hubert Girault, Astrid Johana Olaya Avendano, Julieta Soledad Riva

A microwater vertical bar butyronitrile (W vertical bar BCN) interface was used to study the effect of the interfacial chemical polarization on the efficiency of the visible-light induced water oxidation reaction (WOR) by the electron acceptor/ photosensitizer TTF/TTF(center dot+)self-assembled on the surface of Co3O4 microparticles, acting as redox electrocatalysts. The polarized W|BCN interface acts as a selective platform for the separation of the products of the photoreaction, TTF and protons, which has a strong positive effect on the efficiency of the WOR. The resulting cobalt oxide-organic microwire junction is as efficient as its Pt analog.

PERGAMON-ELSEVIER SCIENCE LTD2022

Photo‐Electrochemical Conversion of CO 2 Under Concentrated Sunlight Enables Combination of High Reaction Rate and Efficiency

Etienne Boutin, Sophia Haussener, Mahendra Patel, Silvan Suter

Photo-electrochemical production of solar fuels from carbon dioxide, water, and sunlight is an appealing approach. Nevertheless, it remains challenging to scale despite encouraging demonstrations at low power input. Higher current densities require notable voltage input as ohmic losses and activation overpotentials become more significant, resulting in lower solar-to-CO conversion efficiencies. A concentrated photovoltaic cell is integrated into a custom-made heat managed photo-electrochemical device. The heat is transferred from the photovoltaic module to the zero-gap electrolyzer cell by the stream of anodic reactant and produce synergetic effects on both sides. With solar concentrations up to 450 suns (i.e., 450 kW m−2) applied for the first time to photo-electrochemical reduction of CO2, a partial current for CO production of 4 A is achieved. At optimal conditions, the solar-to-CO conversion efficiency reaches 17% while maintaining a current density of 150 mA cm−2 in the electrolyzer and a CO selectivity above 90%, representing an overall 19% solar-to-fuel conversion efficiency. This study represents a first demonstration of photo-electrochemical CO2 reduction under highly concentrated light, paving the way for resource efficient solar fuel production at high power input.

Wiley2022