Unveiling the charge migration-induced surface reconstruction of Cu2MoS4 catalyst for boosted CO2 reduction into olefiant gas.

The dynamic evolutions of atomic and electronic structure on Cu 2 MoS 4 catalysts were firstly explored by combining synchronous-illumination X-ray photoelectron spectroscopy with X-ray diffraction. Benefitting from the above structure characteristics, Cu 2 MoS 4 nanosheets exhibit excellent activity enhancement (8.7 μmol g−1 h−1) for CO 2 reduction to C 2 H 4 under the visible light irradiation in comparison with the trace amount of Cu-doped MoS 2 and pure MoS 2. [Display omitted] • The dynamic evolutions of surface structures in Cu 2 MoS 4 nanosheets were observed. • The novel SI-XPS and SI-XRD technologies were first applied. • The Cu 2 MoS 4 nanosheets exhibited excellent photocatalytic CO 2 to C 2 H 4 activity. • A new and valuable insight into the photocatalysis for CO 2 reduction was put forward. Understanding the charge dynamic behavior of the catalyst is crucial to unravel the underlying mechanism for photocatalytic CO 2 reduction to C 2+ products. However, the structure–activity relationships are not intuitive because of the dynamic evolution of electronic and atomic structures for catalysts under the excitation state. Herein, modeling on layered Cu 2 MoS 4 nanosheets, we for the first time observe charge migration-induced evolution of electronic and atomic structure on Cu 2 MoS 4 catalyst during the CO 2 reduction process by combining synchronous-illumination X-ray photoelectron spectroscopy (SI-XPS) with X-ray diffraction (SI-XRD). During the dissociation of CO 2 molecules as well as the charge migration process under the visible light irradiation condition, the surface S atoms return back to the lattice phase, leading to the valence-state normalization of Cu, Mo and S atoms and the increases of the interlayer lattice spacing. By virtue of the above unique characteristic changes, Cu 2 MoS 4 nanosheets exhibit excellent activity enhancement (8.7 μmol g−1 h−1) for CO 2 reduction to C 2 H 4 under the visible light irradiation in comparison with the trace amount of Cu-doped MoS 2 and pure MoS 2. [ABSTRACT FROM AUTHOR]