Dopant segregation, frequently observed in ionic oxides, is useful for engineering materials and devices. However, due to the poor driving force for ion migration and/or the presence of substantial grain boundaries, dopants are mostly confined within a nanoscale region. Herein, we demonstrate that core-shell heterostructures are formed by oriented self-segregation using one-step thermal annealing of metal-doped hematite mesocrystals at relatively low temperatures in air. The sintering of highly ordered interfaces between the nanocrystal subunits inside the mesocrystal eliminates grain boundaries, leaving numerous oxygen vacancies in the bulk. This results in the efficient segregation of dopants (~90%) on the external surface, which forms their oxide overlayers. The optimized photoanode based on hematite mesocrystals with oxide overlayers containing Sn and Ti dopants realises high activity (~0.8 μmol min cm) and selectivity (~90%) for photoelectrochemical HO production, which provides a wide range of application for the proposed concept.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8943161 | PMC |
| http://dx.doi.org/10.1038/s41467-022-28944-y | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Single atom alloys aggregation in the presence of ligands.
Nanoscale
January 2025
Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
Single atom alloys (SAAs) have gained tremendous attention as promising materials with unique physicochemical properties, particularly in catalysis. The stability of SAAs relies on the formation of a single active dopant on the surface of a metal host, quantified by the surface segregation and aggregation energy. Previous studies have investigated the surface segregation of non-ligated and ligated SAAs to reveal the driving forces underlying such phenomena.
View Article and Find Full Text PDFSurface Reconstructed NiPt/Si Photoelectrodes for Bias-free Hydrogen Evolution Coupled with 5-hydroxymethylfurfural Oxidation.
Chem Asian J
November 2024
Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Coupling hydrogen evolution reaction (HER) with biomass valorization using a photoelectrochemical (PEC) system presents a promising approach for effectively converting solar energy to chemical energy. A crucial biomass valorization reaction is the production of value-added 2,5-furandicarboxylic acid (FDCA) via 5-Hydroxymethylfurfural (HMF) oxidation reaction (HMFOR). To achieve efficient FDCA production, we demonstrate an effective photoanode strategy that combines metal silicidation, dopant segregation, and surface reconstruction to create a bimetallic silicide NiPtSi/n-Si photoanode.
View Article and Find Full Text PDFUnderstanding Defect-Mediated Ion Migration in Semiconductors using Atomistic Simulations and Machine Learning.
ACS Mater Au
November 2024
School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, United States.
Ion migration in semiconductor devices is facilitated by the presence of point defects and has a major influence on electronic and optical properties. It is important to understand and identify ways to mitigate photoinduced and electrically induced defect-mediated ion migration in semiconductors. In this Perspective, we discuss the fundamental mechanisms of defect-mediated ion migration and diffusion as understood through atomistic simulations.
View Article and Find Full Text PDFWave Function Localization Reduces the Bandgap of Disordered Double Perovskite CsAgBiBr.
J Phys Chem Lett
November 2024
HSE University, 101000 Moscow, Russia.
Double perovskite CsAgBiBr is a promising alternative to lead-based perovskites with excellent stability and attractive optoelectronic properties. However, a relatively large bandgap severely limits its performance in many applications such as solar cells and photodetectors. It has been reported that a random distribution of Ag and Bi atoms in CsAgBiBr effectively reduces its bandgap without introducing dopants or impurities, while the mechanism remains unclear.
View Article and Find Full Text PDFTemperature promotes selectivity during electrochemical CO reduction on NiO:SnO nanofibers.
J Mater Chem A Mater
December 2024
Mesoscale Chemical Systems, MESA+ Institute, University of Twente P. O. Box 217 Enschede 7500AE The Netherlands.
Electrolyzers operate over a range of temperatures; hence, it is crucial to design electrocatalysts that do not compromise the product distribution unless temperature can promote selectivity. This work reports a synthetic approach based on electrospinning to produce NiO:SnO nanofibers (NFs) for selectively reducing CO to formate above room temperature. The NFs comprise compact but disjoined NiO and SnO nanocrystals identified with STEM.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!