Design of Ag2CrO4/Bi2WO6 S-scheme heterojunction photocatalyst with superior photothermal-assisted photocatalytic degradation and H2O2 production performance

S-scheme Ag2CrO4/Bi2WO6 heterojunction was created by the decoration of Ag2CrO4 nanoparticles on the surface of Bi2WO6 flower-like microsphere. The S-scheme Ag2CrO4/Bi2WO6 heterojunctions exhibit robust photocatalytic activity compared with bare Bi2WO6, which is attributed to the coupling of the S-type heterojunction and photothermal effect. [Display omitted] •S-scheme Ag2CrO4/Bi2WO6 heterojunction was established.•S-scheme Ag2CrO4/Bi2WO6 exhibit remarkable improved photocatalytic activity.•The photothermal-assisted photocatalytic mechanism of Ag2CrO4/Bi2WO6 is proposed. In this work, a photothermal-assisted S-scheme Ag2CrO4/Bi2WO6 heterojunction photocatalysts has been created. This S-scheme heterostructure was established by the attachment of Ag2CrO4 nanoparticles on the surface of Bi2WO6 flower-like microsphere. The photocatalytic degradation performance of the composite was evaluated by the remove of methylene blue (MB) under simulated sunlight irradiation, which indicates that the S-scheme Ag2CrO4/Bi2WO6 heterojunctions exhibit remarkable improved photocatalytic degradation activity compared with bare Bi2WO6. The optimal degradation rate was achieved by 10 %Ag2CrO4/Bi2WO6 sample, which is ∼3.1 times faster than that of individual Bi2WO6. More importantly, 10 %Ag2CrO4/Bi2WO6 sample also affords robust photocatalytic H2O2 generation rate under visible light irradiation without any trap agent and gas bubbling. The decomposition pathways of MB and corresponding toxicity analysis were performed according to the experimental detection and theoretical simulation. The construction of S-scheme heterojunction between Ag2CrO4 and Bi2WO6, confirmed by the in-situ XPS detection, can promote the photogenerated charges separation and maintain high photocatalytic redox capability of system. Particularly, Ag2CrO4 is also found to be a photothermal material. Its photothermal effect is able to further accelerate the photogenerated electrons migration across the S-scheme heterojunction interface, thereby boosting the photothermal-assisted photocatalytic activity. The possible mechanism of photothermal-assisted photocatalytic behavior of S-scheme Ag2CrO4/Bi2WO6 heterojunction was proposed.