Simultaneously efficient light absorption and charge transport of phosphate and oxygen-vacancy confined in bismuth tungstate atomic layers triggering robust solar CO2 reduction

The fundamental catalytic limitations for the photoreduction of CO2 still remain: low efficiency, poor charge transport and short lifetime of catalysts. To address the critical challenges, an efficient strategy based on spatial location engineering of phosphate (PO4) and oxygen-vacancy (Vo) confined in Bi2WO6 (BWO) atomic layers is employed to establish and explore an intimate functional link between the electronic structures and activities of Vo-PO4-BWO layers. Both theoretical and experimental results reveal, the Vo-PO4-BWO layers not only narrow the band gap from the UV to visible-light region but also reduce the resistance. The time-resolved photoluminescence decay spectra exhibit the increasing carrier lifetime for Vo-PO4-BWO layers, indicating the improved charge separation and transfer efficiency. As expected, the Vo-PO4-BWO layers with the simultaneously efficient light absorption and charge transport properties achieve much higher methanol formation rate of 157 μmol g-1 h-1, over 2 and 262 times larger than that of BWO atomic layers and bulk BWO. This work may reveal that the light absorption and spatial charge transport over atomic layers could benefit CO2 conversion and shed light on the design principles of efficient photocatalysts towards solar conversion applications. Simultaneously efficient light absorption and charge transport in phosphate and oxygen-vacancy confined in bismuth tungstate atomic layers have been achieved for excellent visible-light-driven CO2 reduction. [Display omitted] •Phosphate and oxygen-vacancy confined in BWO atomic layers were achieved•Vo-PO4-BWO atomic layers exhibit efficient light absorption and charge transport•Vo-PO4-BWO layers present highest methanol formation by CO2 photoreduction•Mechanism of CO2 photoreduction over Vo-PO4-BWO atomic layers is proposed