Charge Modulation at Atomic-Level through Substitutional Sulfur Doping into Atomically Thin Bi WO toward Promoting Photocatalytic CO Reduction.

Photocatalytic reduction of CO has attracted enormous interest as a sustainable and renewable source of energy. In the past decade, numerous bulk-type semiconductors have been developed, but the existing designs suffer many limitations, namely rapid recombination of charge carriers and weak light absorption ability. Herein, a bottom-up approach was developed to design atomically thin sulfur-doped Bi WO perovskite nanosheets (S-BWO) with improved reduction ability, extended visible light absorption, prolonged lifetime of charge carriers, enhanced adsorption of CO , and reduced work function. Compared with pristine Bi WO (P-BWO), S-BWO nanosheets exhibited a 3-fold improvement in photocatalytic reduction of CO under simulated sunlight irradiation. Experimental studies and density functional theory calculations revealed the synergistic roles of atomically thin nanosheets and S atoms in promoting photocatalytic efficiency.