In Situ X-ray Absorption Spectroscopy of LaFeO and LaFeO/LaNiO Thin Films in the Electrocatalytic Oxygen Evolution Reaction.

We study the electrocatalytic oxygen evolution reaction using in situ X-ray absorption spectroscopy (XAS) to track the dynamics of the valence state and the covalence of the metal ions of LaFeO and LaFeO/LaNiO thin films. The active materials are 8 unit cells grown epitaxially on 100 nm conductive LaSrMnO layers using pulsed laser deposition (PLD). The perovskite layers are supported on monolayer CaNbO nanosheet-buffered 100 nm SiN membranes.

Direct and real-time observation of hole transport dynamics in anatase TiO using X-ray free-electron laser.

Carrier dynamics affects photocatalytic systems, but direct and real-time observations in an element-specific and energy-level-specific manner are challenging. In this study, we demonstrate that the dynamics of photo-generated holes in metal oxides can be directly probed by using femtosecond X-ray absorption spectroscopy at an X-ray free-electron laser. We identify the energy level and life time of holes with a long life time (230 pico-seconds) in nano-crystal materials.

Size-dependent interaction of plasma with anatase TiO nanoparticles.

We study the particle size distribution and phase changes of the anatase TiO2 nanopowder samples when they are subject to the plasma treatments of three different kinds of gases as nitrogen (N2), oxygen (O2), and argon (Ar). The plasma gas pressures vary as 0.1, 0.

A computational approach to interface engineering of lead-free CHNHSnI highly-efficient perovskite solar cells.

Perovskite solar cells (PSCs) based on organic-inorganic metal halide perovskites are a recent ground-breaking advancement in attaining power conversion efficiencies exceeding 21%. However, the toxicity of lead in these PSCs could be a deterrent for large-scale development due to the environmental concerns. The methylammonium tin triiodide (CH3NH3SnI3) perovskite has been successfully employed in lead-free PSCs as an alternative to CH3NH3PbI3 perovskite.