Phase Stability of High Entropy (Mg,Ni,Co,Cu,Zn)O from Temperature-Resolved Synchrotron Diffraction: Tetragonal Distortion and Guggenite Phase.

The temperature-resolved structure evolution of quinary and quaternary equimolar oxides containing Mg, Ni, Zn, Co, and Cu is investigated by in situ synchrotron diffraction. Important structural modifications occur already at mild temperatures and depend on the elements involved. All quaternary compounds with χ(Cu) = 0.

In Situ X-ray Absorption Spectroscopy Study of the Deactivation Mechanism of a Ni-SrTiO Photocatalyst Slurry Active in Water Splitting.

We used in situ X-ray absorption spectroscopy (XAS) to investigate the composition-performance correlation of Ni-SrTiO photocatalysts active for water splitting. After preparation and exposure to ambient conditions, the Ni particles on SrTiO consist of Ni(0) and Ni(II) phases, with a 4:1 at % ratio, in a metal/oxide core/shell configuration, as confirmed by XPS and TEM-EDX. In situ XAS experiments using an aqueous slurry of the Ni-SrTiO photocatalyst and simultaneous continuous exposure to 365 nm light with a power density of 100 mW cm and the X-rays do not reveal significant changes in oxidation state of the Ni particles.

Accurate prediction of the optical properties of nanoalloys with both plasmonic and magnetic elements.

The alloying process plays a pivotal role in the development of advanced multifunctional plasmonic materials within the realm of modern nanotechnology. However, accurate in silico predictions are only available for metal clusters of just a few nanometers, while the support of modelling is required to navigate the broad landscape of components, structures and stoichiometry of plasmonic nanoalloys regardless of their size. Here we report on the accurate calculation and conceptual understanding of the optical properties of metastable alloys of both plasmonic (Au) and magnetic (Co) elements obtained through a tailored laser synthesis procedure.

Single-Atoms on Crystalline Carbon Nitrides for Selective C─H Photooxidation: A Bridge to Achieve Homogeneous Pathways in Heterogeneous Materials.

Single-atom catalysis is a field of paramount importance in contemporary science due to its exceptional ability to combine the domains of homogeneous and heterogeneous catalysis. Iron and manganese metalloenzymes are known to be effective in C─H oxidation reactions in nature, inspiring scientists to mimic their active sites in artificial catalytic systems. Herein, a simple and versatile cation exchange method is successfully employed to stabilize low-cost iron and manganese single-atoms in poly(heptazine imides) (PHI).

Metastable Ni(I)-TiO Photocatalysts: Self-Amplifying H Evolution from Plain Water without Noble Metal Co-Catalyst and Sacrificial Agent.

Decoration of semiconductor photocatalysts with cocatalysts is generally done by a step-by-step assembly process. Here, we describe the self-assembling and self-activating nature of a photocatalytic system that forms under illumination of reduced anatase TiO nanoparticles in an aqueous Ni solution. UV illumination creates a Ni/TiO/Ti photocatalyst that self-activates and, over time, produces H at a higher rate.