Charge localization induced by Fe doping in porous Bi5O7I Micro-flower for enhanced photoreduction of CO2 to CO

Abstract

The bismuth-rich bismuth oxyhalide materials exhibit prominent photocatalytic CO2 reduction (PCR) performance owing to the considerable negative conduction band potential and unique intrinsic internal electric field. However, it possesses poor capture ability of CO2 molecule due to the intrinsically weak adsorption, greatly limiting its further PCR improvement. Herein, we modulate the spatial charge redistribution over hierarchically Bi5O7I micro-flower through a facile and cost-efficient iron doping strategy, achieving significantly enhanced CO2 capture capacity. Mechanistic studies indicate that the promoted adsorption ability originates from the localized electrons around the doped Fe sites. Benefiting from the resultant unique electronic structures, the Fe doped Bi5O7I micro-flowers also exhibit remarkably improved harvest of visible light and promoted charge separation and transfer capability, thus finally achieving a notably boosted photocatalytic CO evolution rate of 12.02 μmol·g−1·h−1 without any sacrifice agents.