Engineering defect-rich H-W18O49 nanowire/MIL-125(Ti) nanosheet S-scheme heterostructure for remarkable CO2 photoconversion

The rational construction of heterojunctions with surface defects and localized surface plasmon resonance (LSPR) effect is a promising strategy for improving CO2 photoreduction performance. Herein, the one-dimensional/twodimensional (1D/2D) S-scheme heterostructures integrated with non-stoichiometric 1D W 18 O 49 nanowires (HW 18 O 49 NWs) and 2D ultrathin MIL-125(Ti) nanosheets (MIL-125(Ti) NSs) were constructed by self-assembly for photocatalytic CO2 reduction. In situ X-ray photoelectron spectroscopy (XPS), electron spin resonance spectra (ESR), and photoluminescence (PL) spectroscopy characterizations confirm the construction of S-scheme heterojunction and the solid internal electric field at the heterointerface enables effective spatial charge separation while keeping a strong redox capability. The hot electrons generated from the LSPR effect of visible-near-infrared light-excited H-W18O49 NWs can be injected into MIL-125(Ti) NSs to increase the electron density and accelerate the reaction rate. Thus, the optimized H-W18O49 NW/MIL-125(Ti) NS heterostructure exhibited good performance, achieving a CO yield of 202.37 mu mol g-1h- 1 . This study enriches the diversity and architecture of available heterostructures for photocatalytic applications.