Iridium-Based Nanohybrids: Synthesis, Characterization, Optical Limiting, and Nonlinear Optical Properties

Abstract

The present work reports on the synthesis and characterization of iridium (Ir)-based nanohybrids with variable chemical compositions. More specifically, highly stable polyvinylpyrrolidone (PVP) nanohybrids of the PVP-IrO2 and PVP-Ir/IrO2 types, as well as non-coated Ir/IrO2 nanoparticles, are synthesized using different synthetic protocols and characterized in terms of their chemical composition and morphology via X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM), respectively. Furthermore, their nonlinear optical (NLO) response and optical limiting (OL) efficiency are studied by means of the Z-scan technique, employing 4 ns laser pulses at 532 and 1064 nm. The results demonstrate that the PVP-Ir/IrO2 and Ir/IrO2 systems exhibit exceptional OL performance, while PVP-IrO2 presents very strong saturable absorption (SA) behavior, indicating that the present Ir-based nanohybrids could be strong competitors to other nanostructured materials for photonic and optoelectronic applications. In addition, the findings denote that the variation in the content of IrO2 nanoparticles by using different synthetic pathways significantly affects the NLO response of the studied Ir-based nanohybrids, suggesting that the choice of the appropriate synthetic method could lead to tailor-made NLO properties for specific applications in photonics and optoelectronics.

A-Site Modulation of Co–Ir Based Double Perovskite Oxides (A2CoIrO6, A = Sr, Nd, Pr, and Sm) for Maximization of Water Oxidation and Hybrid Electrolysis Derived Isopropanol Upconversion in Acid Medium

“…Figure shows the HRXPS data of Ir and Co of all the catalysts. As per the literature, Ir 4f spectra commonly fitted with two doublets refer to Ir 4f 7/2 and Ir 4f 5/2 . For metallic Ir, the Ir 4f 7/2 peak appears at around 60.3 eV and shifted to a little higher value of 61.8 eV for crystalline IrO 2 .…”