Quantitative analysis of the PtO structure during photocatalytic water splitting by operando XAFS

Here, for the first time, we detect reversible structural changes of platinum oxide as an active site in photocatalytic water splitting by operando X-ray absorption fine structure spectroscopy. The platinum-oxygen bond length increases from 2.07 to 2.13 angstrom A and the coordination number reduces from 4.0 to 2.5 between the ex situ and operating photocatalysts.