Charge Modulation at Atomic-Level through Substitutional Sulfur Doping into Atomically Thin Bi2 WO6 toward Promoting Photocatalytic CO2 Reduction.

Abstract

Photocatalytic reduction of CO2 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 Bi2WO6 perovskite nanosheets (S‐BWO) with improved reduction ability, extended visible light absorption, prolonged lifetime of charge carriers, enhanced adsorption of CO2, and reduced work function. Compared with pristine Bi2WO6 (P‐BWO), S‐BWO nanosheets exhibited a 3‐fold improvement in photocatalytic reduction of CO2 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.