2 research outputs found
TiO<sub>2</sub> Photocatalysis–DESI-MS Rotating Array Platform for High-Throughput Investigation of Oxidation Reactions
We
present a new high-throughput platform for studying titanium
dioxide (TiO<sub>2</sub>) photocatalytic oxidation reactions by performing
reactions on a TiO<sub>2</sub>-coated surface, followed by direct
analysis of oxidation products from the surface by desorption electrospray
ionization mass spectrometry (DESI-MS). For this purpose, we coated
a round glass wafer with photocatalytically active anatase-phase TiO<sub>2</sub> using atomic layer deposition. Approximately 70 aqueous 1
μL samples can be injected onto the rim of the TiO<sub>2</sub>-coated glass wafer, before the entire wafer is exposed to UV irradiation.
After evaporation of water, the oxidation products can be directly
analyzed from the sample spots by DESI-MS, using a commercial rotating
sample platform. The method was shown to provide fast photocatalytic
oxidation reactions and analysis with throughput of about four samples
per minute. The feasibility of the method was examined for mimicking
phase I metabolism reactions of amodiaquine, buspirone and verapamil.
Their main photocatalytic reaction products were mostly similar to
the products observed earlier in TiO<sub>2</sub> photocatalysis and
in in vitro phase I metabolism assays performed using human liver
microsomes
Atomic Layer Deposition of Spinel Lithium Manganese Oxide by Film-Body-Controlled Lithium Incorporation for Thin-Film Lithium-Ion Batteries
Lithium
manganese oxide spinels are promising candidate materials
for thin-film lithium-ion batteries owing to their high voltage, high
specific capacity for storage of electrochemical energy, and minimal
structural changes during battery operation. Atomic layer deposition
(ALD) offers many benefits for preparing all-solid-state thin-film
batteries, including excellent conformity and thickness control of
the films. Yet, the number of available lithium-containing electrode
materials obtained by ALD is limited. In this article, we demonstrate
the ALD of lithium manganese oxide, Li<sub><i>x</i></sub>Mn<sub>2</sub>O<sub>4</sub>, from Mn(thd)<sub>3</sub>, Li(thd), and
ozone. Films were polycrystalline in their as-deposited state and
contained less than 0.5 at. % impurities. The chemical reactions between
the lithium precursor and the film were found not to be purely surface-limited
but to include a bulk component as well, contrary to what is usually
found for ALD processes. In addition, we show a process for using
Li(thd)/ozone and LiO<sup><i>t</i></sup>Bu/water treatments
to transform ALD-MnO<sub>2</sub> and ALD-V<sub>2</sub>O<sub>5</sub> into Li<sub><i>x</i></sub>Mn<sub>2</sub>O<sub>4</sub> and
Li<sub><i>x</i></sub>V<sub>2</sub>O<sub>5</sub>, respectively.
The formed Li<sub><i>x</i></sub>Mn<sub>2</sub>O<sub>4</sub> films were characterized electrochemically and found to show high
electrochemical capacities and high cycling stabilities