A reaction cell for time-resolvedin situXAS studies during wet chemical synthesis: the Cu₂(OH)₃Cl case

Abstract

The use of in situ time-resolved dispersive X-ray absorption spectroscopy (DXAS) to monitor the formation of Cu2(OH)3Cl particles in an aqueous solution is reported. The measurements were performed using a dedicated reaction cell, which enabled the evolution of the Cu K-edge X-ray absorption near-edge spectroscopy to be followed during mild chemical synthesis. The formed Cu2(OH)3Cl particles were also characterized by synchrotron-radiation-excited X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. The influence of polyvinylpyrrolidone (PVP) on the electronic and structural properties of the formed particles was investigated. The results indicate clearly the formation of Cu2(OH)3Cl, with or without the use of PVP, which presents very similar crystalline structures in the long-range order. However, depending on the reaction, dramatic differences were observed by in situ DXAS in the vicinities of the Cu atoms.

Formation of Bimetallic Copper–Gold Alloy Nanoparticles Probed by in Situ X‐ray Absorption Fine Structure Spectroscopy

“…In contrast, the final Cu‐ K edge spectrum is very different from those of metallic copper (Figure b) and bulk Au 0.75 Cu 0.25 alloy. In particular, the final Cu‐ K edge spectrum shows a prominent pre‐edge peak, which is a fingerprint of the presence of ionic Cu species in a planar geometry , . These results together reveal that, although the Au 1– x Cu x NP formation occurred, a large fraction of unreduced copper remained in solution and covered the typical features of the absorption spectrum of the bulk alloy.…”

“…Bimetallic gold–copper alloy nanoparticles (Au 1– x Cu x NPs) have attracted much attention not only from a scientific perspective but also from an applied one, especially in the field of catalysis . Extensive efforts have been devoted to building synthesis strategies for Au 1– x Cu x NPs with well‐controlled chemical compositions, crystalline structures,, sizes, and shapes (morphologies) .…”

“…For example, changes in oxidation states, coordination, and bond formation can be monitored at the initial nucleation and growth stages of the NP formation, and information can be obtained about the local environment with chemical sensibility, even in the absence of a crystalline phase , . Although several in situ studies have been performed to monitor the formation of bimetallic NPs, most of them have dealt with aqueous‐phase reactions, and only a few limited reports have dealt with the formation of bimetallic NPs in the organic phase …”

Mechanism of the formation of copper‐containing fractal‐like crystallites in metal‐organic thin films: Shape simulation and XANES analysis

“…As XRD analysis showed the formation of Cu 2 Cl(OH) 3 and CuO at different stages of crystallite formation, as the first step we have carried out comparison of the samples under study experimental XANES spectra with different forms of Cu 2 Cl(OH) 3 and copper oxides. Figure A shows the experimental XANES spectra of the films after treatment at 150, 250, 350, and 500 °C in comparison with reference samples: two forms of Cu 2 Cl(OH) 3 (atacamite and paratacamite ), CuO, Cu 2 O, and Cu. For the samples under investigation, it is clearly seen that there are two groups of spectra.…”

A dispenser–reactor apparatus applied forin situXAS monitoring of Pt nanoparticle formation

“…To enable acquiring time-resolved XAS data during reactions in liquid media, we recently developed a reaction cell which was employed for studying the formation of copper compounds by in situ DXAS (Boita et al, 2014b). To perform the present work, this cell was attached to a homemade liquid dispenser, which allows remote control of the dosing speed of solutions into the reaction cell.…”