2020 New's Items

Mining Databases to Predict a Material's Properties

January 23, 2020
Sam Lemonick | c&en

One of the promises of the information age is that collecting and analyzing larges amounts of data will lead to new insights. Materials scientists have embraced that idea, creating several public databases of materials’ properties over the past decade. New software aims to put that data to use by mapping mathematical relationships between properties for the first time, helping scientists calculate property values not yet measured and potentially find new materials or new uses for existing ones (Matter2020, DOI:...

https://cen.acs.org/physical-chemistry/computational-chemistry/Software-mines-da…

Reticular Chemistry and Harvesting Water from Desert Air

Liu CH
Nguyen HL
Yaghi OM
2020

ALTHOUGH CHEMISTS IN general are concerned with the art and science of constructing molecules and understanding their behavior, for a long time the idea that such molecules can be linked together by strong bonds to make infinite, extended structures was fraught with failure. The notion of using molecular building blocks to make such structures invariably led to chaotic, ill-defined materials and therefore not only defying the chemists’ need to exert their will on the design of matter but also preventing them from deciphering the atomic arrangement of such products. The field remained...

Application of Single-Site Catalysts in the Hydrogen Economy

Chen L
Qi Z
Zhang S-C
Su J
Somorjai GA
2020

Catalysts development is an evolutionary process. The generation of new single-metal-site catalysts, with isolated metal atoms dispersed on the surface of substrates, offers maximum atom-utilization efficiency, high specific activity, and novel properties. The unique structure of single-site catalysts also enables their potential to bridge the gap between homogeneous and heterogeneous catalysis. This field is at an early stage, characterized by important discoveries and novel demonstrations of catalytic properties associated with the fine structure of single metal sites; however,...

A mini review of cobalt-based nanocatalyst in Fischer-Tropsch synthesis

Qi Z
Chen L
Zhang S
Su J
Somorjai GA
2020

Fischer-Tropsch (F-T) synthesis, converting syngas to hydrocarbons, provides a green alternative for fuel production. Cobalt is one of the most intensively studied F-T catalysts due to its great activity, high stability, and relatively low cost. In this mini review, we summarized some recent advancements in the development of cobalt-based F-T catalysts focusing on the effects of particle size, surface oxidation states, crystallography, and bimetallic particles, with emphasis on the research from our group. Furthermore, non-steady state conditions were investigated to access the...

Li5VF4(SO4)2: A Prototype High-Voltage Li-Ion Cathode

Vincent RC
Vishnoi P
Preefer MB
Shen J-X
Seeler F
Persson KA
Seshadri R
2020

A Li-rich polyanionic compound based on V3+ with a previously unknown structure, Li5VF4(SO4)2, has been developed as a high-voltage cathode material for Li-ion batteries. The solvothermal preparation of this material, crystal structure solution, and initial electrochemical characterization are presented. An analysis based on density functional theory electronic structure calculations suggests that a high voltage close to 5 V is required to extract two Li...

Evaluation of Amorphous Oxide Coatings for High-Voltage Li-Ion Battery Applications Using a First-Principles Framework

Cheng J
Sivonxay E
Persson KA
2020

Cathode surface coatings are widely used industrially as a means to suppress degradation and improve electrochemical performance of lithium-ion batteries. However, developing an optimal coating is challenging, as different coating materials may enhance one aspect of performance while hindering another. To elucidate the fundamental thermodynamic and transport properties of amorphous cathode coating materials, here, we present a framework for calculating and analyzing the Li+ and O2– transport and the stability against delithiation in...

Enumeration as a Tool for Structure Solution: A Materials Genomic Approach to Solving the Cation-Ordered Structure of Na3V2(PO4)2F3

Mattei GS, ,
Dagdelen JM
Bianchini M
Ganose AM
Jain A
Suard E
Fauth F
Masquelier C
Croguennec L
Ceder G
Persson KA
Khalifa PG
2020

While powder diffraction methods are routinely utilized to optimize structural models for compounds whose crystal structures are known, the determination of unknown structures is far more challenging. When the unknown structure is large, structure solution can become a virtually intractable problem using standard structure solution methodologies, especially when the space group cannot be unambiguously resolved. One such system is the promising Na-ion battery cathode material Na3V2(PO4)2...

Successes and Opportunities for Discovery of Metal Oxide Photoanodes for Solar Fuels Generators

Lan Zhou
Aniketa Shinde
Dan Guevarra
Joel A. Haber
Kristin A. Persson
Jeffrey B. Neaton
John M. Gregoire
2020

The importance of metal oxide photoanodes in solar fuels technology has garnered concerted efforts in photoanode discovery in recent decades, which complement parallel efforts in development of analytical techniques and optimization strategies using standard photoanodes such as TiO2, Fe2O3 and BiVO4. Theoretical guidance of high-throughput experiments has been particularly effective in dramatically increasing the portfolio of metal oxide photoanodes, motivating a new era of...

Solvent Mediated Excited State Proton Transfer in Indigo Carmine

Roy PP
Shee J
Arsenault EA
Yoneda Y
Feuling K
Head-Gordon M
Fleming GR
2020

Excited state proton transfer (ESPT) is thought to be responsible for the photostability of biological molecules, including DNA and proteins, and natural dyes such as indigo. However, the mechanistic role of the solvent interaction in driving ESPT is not well understood. Here, the electronic excited state deactivation dynamics of indigo carmine (InC) is mapped by visible pump–infrared probe and two-dimensional electronic–vibrational (2DEV) spectroscopy and complemented by electronic structure calculations. The observed dynamics reveal notable differences between InC in a protic...

Helicity-dependent photocurrents in the chiral Weyl semimetal RhSi

Dylan Rees
Kaustuv Manna
Baozhu Lu
Takahiro Morimoto
Horst Borrmann
Claudia Felser
J E Moore
Darius H Torchinsky
J Orenstein
2020

Weyl semimetals are crystals in which electron bands cross at isolated points in momentum space. Associated with each crossing point (or Weyl node) is a topological invariant known as the Berry monopole charge. The circular photogalvanic effect (CPGE), whereby circular polarized light generates a helicity-dependent photocurrent, is a notable example of a macroscopic property that emerges directly from the topology of the Weyl semimetal band structure. Recently, it was predicted that the amplitude of the CPGE associated with optical transitions near a Weyl node is proportional to its...