Unveiling Dynamic Structure and Bond Evolutions in BiOIO₃ Photocatalysts during CO₂ Reduction

We have established a correlation between photocatalytic activity and dynamic structure/bond evolutions of BiOIO 3 ‐based photocatalysts during CO 2 reduction by combining operando X‐ray diffraction with photoelectron spectroscopy. More specifically, the selective photo‐deposition of PtO x species on BiOIO 3 (010) facets could effectively promote the electron enrichment on Bi active sites of (100) facets for facilitating the adsorption/activation of CO 2 molecules, leading to the formation of Bi sites with high oxidation state and the shrink of crystalline structures. With introducing light irradiation to drive CO 2 reduction, the Bi active sites with high oxidation states transformed into normal Bi 3+ state, accompanying with the expansion of crystalline structures. Owing to the dynamic structure, bond, and chemical‐state evolutions, a significant improvement of photocatalytic activity for CO evolution has been achieved on PtO x ‐BiOIO 3 (195.0 μmol g −1 ⋅ h −1 ), much higher than the pristine (61.9 μmol g −1 ⋅ h −1 ) as well as metal‐Pt decorated BiOIO 3 (70.3 μmol g −1 ⋅ h −1 ) samples. This work provides new insights to correlate the intrinsically dynamic structure/bond evolutions with CO 2 reduction activity, which may help to guide future photocatalyst design.