2023 Volume 72 Issue 10.11 Pages 391-397
We have developed a heatable flow cell system for in situ XAFS measurements that continuously observes chemical state changes in a sample containing a solution. The system was applied to the analysis of electroless nickel-phosphorus plating reaction to evaluate its applicability. The flow cell and the heater were provided with windows for passing X-rays, and 20 sheets of polyester film with a catalyst were enclosed in the cell. The electroless nickel-phosphorus plating solution was pumped into the cell with the heater temperature set at 60 °C, and nickel was deposited on the film in the cell. The change in the chemical state of nickel on the deposition reaction was observed by continuous Ni K-edge XAFS measurements (at BL28B2 in SPring-8) from the start of feeding the plating solution. As a result, it was found that nickel sulfate, which is the source of nickel in the plating solution used, changed to metallic nickel and nickel phosphide over time. In addition, the analytical results of the chemical state changes based on the in situ XAFS measurements were in good agreement with those based on the ex situ XAFS measurements of nickel and phosphorus. Therefore, this flow cell system is considered effective for continuous observation of the chemical state changes in a sample containing a solution.
