Vacancy-dependent interfacial Mo-S bridge in S-scheme CdIn2S4/MoO3-x heterojunction for efficient photocatalytic overall water splitting

Here, we constructed S-scheme CdIn 2 S 4 /MoO 3-x (CISMO) photothermal catalyst with interface Mo-S bond for efficient overall water splitting. As expected, hydrogen (H 2 ) and oxygen (O 2 ) evolution rates of the optimized CISMO reached 554.71 and 277.88 μmol·g −1 ·h −1 , respectively, far higher than that of CdIn 2 S 4 (71.78 and 34.45 μmol·g −1 ·h −1 ) and MoO 3-x (0 and 21.83 μmol·g −1 ·h −1 ). Mechanism analysis revealed that the photogenerated carrier transfer followed an S-scheme route. More importantly, the photocatalytic performance of CdIn 2 S 4 /MoO 3-x was highly relevant with the oxygen vacancies (Ovs) in pristine MoO 3-x . In S-rich environment, the Ovs could be imbedded by sulfur (S) for the formation of interface Mo-S bond during CISMO fabrication. Interface Mo-S bridge facilitated the photogenerated carriers transfer between CdIn 2 S 4 and MoO 3-x . Moreover, the metal-free localized surface plasmon resonance effect, originating from the residual Ovs in CdIn 2 S 4 /MoO 3-x , could further enhance the water splitting performance through photothermal conversion. This work shed light on controllable interface chemical bond formation in heterojunction photocatalysts to signally promote the photocatalytic performance.