A key challenge in the field of electrochemical carbon dioxide reduction is design catalytic materials featuring high product selectivity, stability, and a composition earth-abundant elements. In this work, we introduce thin films nanosized metal-organic frameworks (MOFs) as atomically defined nanoscopic that function catalysts for efficient selective to monoxide aqueous electrolytes. Detailed examination cobalt-porphyrin MOF, Al2(OH)2TCPP-Co (TCPP-H2 =...

TiO2 anatase plays a central role in energy and environmental research. A major bottleneck toward developing artificial photosynthesis with is that it only absorbs ultraviolet light, owing to its large bandgap of 3.2 eV. If one could reduce the visible region, TiO2-based photocatalysis become competitive clean source. Here, using scanning tunneling microscopy spectroscopy conjunction density functional theory calculations, we report discovery highly reactive titanium-terminated surface...

Significance Electrochemical conversion of CO 2 to carbon-based products, which can be used directly as fuels or indirectly fuel precursors, is suggested one the promising solutions for sustainability. Not only does this process allow using renewables such solar electricity energy input, but emitted from consumption recycled back into fuels. The success technology depends on value added product that forms , and therefore it important facilitate multicarbon generation. This work presents a...

Significance Semiconductor heterojunction is a key building block in modern electronics and optoelectronics. The accurate control over the composition, band gap, energy level (band bending), doping foundation of ideal functional heterojunctions. We demonstrate highly spatially resolved heterojunctions type semiconductor, halide perovskites, which show great potential photovoltaic solid-state lighting applications. accomplish this through combination facile anion-exchange chemistry with...

Significance Understanding and controlling the ion migration in a solid-state semiconductor is essential for device performance modern photonics, electronics, optoelectronics. Direct microstructural observation atomic-scale mechanism of intrinsic lattice diffusion are still highly challenging. Here, we report direct visualization halide anion interdiffusion CsPbCl 3 –CsPbBr single crystalline nanowire heterojunctions via nanoscale imaging, allowing measuring diffusivities. The diffusivities...

Electrochemical AFM is a powerful tool for the real-space characterization of catalysts under realistic electrochemical CO2 reduction (CO2 RR) conditions. The evolution structural features ranging from micrometer to atomic scale could be resolved during RR. Using Cu(100) as model surface, distinct nanoscale surface morphologies and their potential-dependent transformations granular smoothly curved mound-pit surfaces or structures with rectangular terraces are revealed RR in 0.1 m KHCO3 ....

Within the last several years, metal halide perovskites such as methylammonium lead iodide, CH3NH3PbI3, have come to forefront of scientific investigation defect-tolerant, solution-processable semiconductors that exhibit excellent optoelectronic properties. The vast majority study has focused on Pb-based perovskites, which limited applications because their inherent toxicity. To enable broad application these materials, properties lead-free must be explored. Here, two-dimensional, cesium tin...

We investigate the magnetic coupling of Ni centers embedded in two-dimensional metal-coordination networks self-assembled from 7,7,8,8-tetracyanoquinodimethane (TCNQ) molecules on Ag(100) and Au(111) surfaces. X-ray circular dichroism measurements show that single adatom impurities assume a spin-quenched configuration both surfaces, while atoms coordinating to TCNQ ligands recover their moment exhibit ferromagnetic coupling. The valence state strength coordination depend crucially underlying...

The formation of extended two-dimensional metal-organic coordination networks (2D-MOCNs) showing high adaptability to surface step edges and structural defects is revealed by scanning tunneling microscopy. Rod-like 4,4'-di-(1,4-buta-1,3-diynyl)-benzoic acid (BDBA) iron atoms assemble into 2D-MOCNs on Au(111) Ag(100) surfaces. Independent from the chosen substrate its symmetry MOCN grows continuously over multiple terraces through mutual in-phase structure adaptation network domains at as...

Dye-sensitized solar cells constitute a promising approach to sustainable and low-cost energy conversion. Their overall efficiency crucially depends on the effective coupling of photosensitizers photoelectrode details dye's levels at interface. Despite great efforts, specific binding prototypical ruthenium-based dyes TiO2, their potential supramolecular interaction, interrelation between adsorption geometry electron injection lack experimental evidence. Here we demonstrate...

Surface condition plays an important role in the optical performance of semiconductor materials. As new types semiconductors, emerging metal-halide perovskites are promising for next-generation optoelectronic devices. We discover significantly improved light-emission efficiencies lead halide due to surface oxygen passivation. The enhancement manifests close 3 orders magnitude as perovskite dimensions decrease nanoscale, improving external quantum from <0.02% over 12%. Along with about a...

A key challenge in electrocatalysis remains controlling a catalyst's structural, chemical, and electrical properties under reaction conditions. While organic coatings showed promise for enhancing the selectivity stability of catalysts CO

Rational innovation of electrocatalysts requires detailed knowledge spatial property variations across the solid-electrolyte interface. We introduce correlative atomic force microscopy (AFM) to simultaneously probe,

Magnetization curves of two rectangular metal-organic coordination networks formed by the organic ligand TCNQ (7,7,8,8-tetracyanoquinodimethane) and different (Mn Ni) 3d transition metal atoms [M(3d)] show marked differences that are explained using first principles density functional theory model calculations. We find existence a weakly dispersive hybrid band with M(3d) character crossing Fermi level is determinant for appearance ferromagnetic coupling between centers, as it case metallic...

Metal coordination assemblies of the symmetric bi-functional 4,4′-di-(1,4-buta-1,3-diynyl)-benzoic acid are investigated by scanning tunnelling microscopy on metal surfaces. The formation long-range ordered, short-range disordered and random phases depends competition between convergent divergent motifs individual functional groups is crucially influenced substrate.

Surface-confined molecular networks can serve as templates to steer the adsorption and organization of secondary ligands, metal atoms, clusters. Here, incorporation Ni atoms clusters into open two-dimensional robust metal–organic self-assembled from butadiyne dibenzoic acid molecules Fe on Au(111) Ag(100) surfaces is investigated by scanning tunneling microscopy. The substrate plays a crucial role in interaction with host networks. On template steers growth underneath network pattern near...

Extensive efforts have been directed toward identifying catalytic material composites for efficiently transforming CO2 into valuable chemicals. Within this longstanding scientific challenge, the investigation of model systems is particular interest to gain fundamental insight relevant processes and synergistically advance materials functionalities. Inspired by ubiquitous presence metal–organic active sites in conversion CO2, we study here interaction with a two-dimensional network...

Electrocatalytic reactions are vital for closing the anthropogenic carbon cycle by enabling conversion of sustainably-derived electrical energy into chemical energy.A wide array electrocatalytic have gained extensive attention, including hydrogen evolution (HER), oxygen (OER), and CO 2 electroreduction (CO RR).However, progress in enhancing catalyst activity, selectivity, stability is

Abstract Eine effiziente Charakterisierung der Katalysatoren im Realraum und unter realistischen Bedingungen elektrochemischen CO 2 ‐Reduktion (CO RR) gelang durch elektrochemische AFM. Die Entwicklung von Strukturmerkmalen konnte Mikrometer‐ bis hin zur atomaren Skala aufgelöst werden. Auf einer Cu(100)‐Modelloberfläche treten während RR in 0,1 m KHCO 3 ausgeprägte nanoskalige Oberflächenmorphologien auf, wobei sich granulare Strukturen potentialabhängig glatt geschwungene...

Microsensors for resolving local pH are versatile analytical tools studying reactions at solid-liquid interfaces in applications such as electrocatalysis and corrosion. However, the achievable temporal resolution is limited, hindering operando investigation of surfaces electrochemical reactions. Here, we present a methodology to achieve high time by deploying AC voltammetry with microsensor. The sensor composed gold ultramicroelectrode functionalized electropolymerized methylene blue its...

Unveiling the atomic-scale surface structure of electrocatalysts and nature electrochemical interfaces under reaction conditionsChristopher Kley a, ba Helmholtz Young Investigator Group Nanoscale Operando CO2 Photo-Electrocatalysis, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germanyb Department Interface Science, Fritz Haber Institute Max Planck Society, 14195 GermanyMaterials for Sustainable Development Conference (MATSUS)Proceedings MATSUS Spring 2024...

Keywords: scanning tunneling microscopy ; spectroscopy molecular self-assembly supramolecular architectures multi-component systems dye-sensitized solar cell titanium dioxide photosensitizer electrospray ion beam deposition density functional theory ultra high vacuum These Ecole polytechnique federale de Lausanne EPFL, n° 5884 (2013)Programme doctoral PhysiqueFaculte des sciences baseInstitut physique la matiere condenseeLaboratoire science a l'echelle nanometriqueJury: R. Houdre...