Free energy difference to create the M-OH* of the oxygen evolution reaction by time-resolved optical spectroscopy

April 19, 2021

Theoretical descriptors differentiate the catalytic activity of materials for the oxygen evolution reaction (OER) by the strength of oxygen binding in the reactive intermediate created upon electron transfer. Recently time-resolved spectroscopy of (photo)-electrochemically driven OER followed the vibrational and optical spectra of this intermediate, denoted M-OH*. However, these inherently kinetic experiments have not been connected to the relevant thermodynamic quantities. Here, we discover that picosecond optical spectra of the Ti-OH* population on lightly doped SrTiO3 are ordered by the surface hydroxylation.

Accuracy in Resolving the First Hydration Layer on a Transition-Metal Oxide Surface: Experiment (AP-XPS) and Theory

Oct. 25, 2020

Understanding the equilibrium conditions at the metal oxide/aqueous interface is a key component toward visualizing the structure of water in confined environments and differentiating the catalytic activity of transition-metal oxides. While ambient pressure X-ray photoelectron spectroscopy (AP-XPS) has been the primary technique to investigate the formation of a hydration layer on many surfaces, results over the extended relative humidity (RH) range accessible experimentally have not been compared quantitatively to theoretical predictions. With the use of first-principles theoretical methods and accumulated knowledge of AP-XPS spectral analysis, we do so here for a model surface, TiO2-terminated undoped SrTiO3(100) (STO).

The JPC Periodic Table

Feb. 13, 2020

In this Virtual Issue, we celebrate the International Year of the Periodic Table by presenting one paper in JPC that is concerned with each of the 118 elements.

Charting a Course for Chemistry

Feb. 13, 2020

To mark the occasion of Nature Chemistry turning 10 years old, we asked scientists working in different areas of chemistry to tell us what they thought the most exciting, interesting or challenging aspects related to the development of their main field of research will be — here is what they said.

Selecting between two transition states by which water oxidation intermediates on an oxide surface decay

July 18, 2019

While catalytic mechanisms on electrode surfaces have been proposed for decades, the pathways by which the product’s chemical bonds evolve from the initial charge-trapping intermediates have not been resolved in time. Here, we discover a reactive intermediate population with states in the middle of a semiconductor’s band-gap to reveal the dynamics of two parallel transition state pathways for their decay.

Probing Electric Double Layer Composition via in-situ Vibrational Spectroscopy and Molecular Simulations

July 18, 2019

The EDL guides electrode passivation in batteries, while in (super)capacitors, it determines charge storage capacity. Despite its importance, quantification of the nanometer-scale and potential-dependent EDL remains a challenging problem. Here, we directly probe changes in the EDL composition with potential using in-situ vibrational spectroscopy and molecular dynamics simulations for a Li-ion battery electrolyte (LiClO4 in dimethyl carbonate).

Forwarding the Molecular Design of Heterogeneous Catalysts

Aug. 22, 2018

Catalysis research has long been divided between homogeneous and heterogeneous catalysis. In this issue of ACS Central Science, the authors, building upon the previous breakthrough work, tether a dual-atom Ir molecular water oxidation catalyst to heterogeneous catalysts in various surface-bound geometries and demonstrate differences between these configurations.

Faradaic oxygen evolution from SrTiO3 under nano- and femto-second pulsed light excitation

June 7, 2017

During photocatalytic water oxidation, n-SrTiO3(100) demonstrated near 100% Faradaic efficiency for O2 evolution with nano- (30 ns) and femto- (150 fs) second pulsed laser excitation of the band gap, despite surface rearrangements attributed to the high peak power (300 MW cm−2).

One-electron intermediates of water oxidation & the role of solvation in their stability

April 26, 2017

The initial step of the electrochemically controlled water oxidation reaction on transition metal oxide surfaces localizes positive charge onto surface atoms, creating one-electron intermediates. For decades, the stability of this critical reaction intermediate has been used to predict catalytic activity, by a Sabatier analysis of the first bond (O–O) the intermediates catalyse within the O2 evolution cycle.

Detecting the Photo-excited Carrier Distribution across GaAs/Transition Metal Oxide Interfaces by Coherent Longitudinal Acoustic Phonons

Feb. 17, 2017

A prominent architecture for solar energy conversion layers diverse materials, such as traditional semiconductors (Si, III–V) and transition metal oxides (TMOs), into a monolithic device. The efficiency with which photoexcited carriers cross each layer is critical to device performance and dependent on the electronic properties of a heterojunction.

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