Novel MoSSe/Bi2WO6 S-scheme heterojunction photocatalysts for significantly improved photoelectrochemical and photocatalytic performance

Two-dimensional MoSSe nanoplates demonstrate low internal resistance and outstanding reduction potential, while Bi 2 WO 6 nanoparticles exhibit zero-dimensional appearance and high oxidation potential. Herein, novel MoSSe/Bi 2 WO 6 step-scheme (S-scheme) heterojunction photocatalysts (MSSB) were prepared to combine the properties of those two materials. These catalysts were confirmed to have lower internal resistance (as low as 0.07 kΩ), and higher carriers’ separation efficiency due to the well-contacted two-dimensional/zero-dimensional structure. More importantly, the heterojunction catalysts displayed both good oxidation and reduction performance which have been confirmed by the conducted catalytic tests. With an optimized Bi 2 WO 6 loading ratio, degradation rates ( k ) and photocurrent density of the MSSB2 sample were 2.09, and 8.31 times more than that of MoSSe, as well as 1.77, and 26.27 times more than that of Bi 2 WO 6 . Active species (superoxide radical •O 2 − and hydroxyl radical •OH) were detected by the electron spin resonance tool which could infer that a S-scheme heterojunction has already constructed between the Bi 2 WO 6 and MoSSe. Driven by the MoSSe and band edge bending, the e – on the conduction band of Bi 2 WO 6 readily slid toward MoSSe and recombines with the h + on the valence band of MoSSe, while retaining the powerful e – and h + with high redox potential on the CB of MoSSe and VB of Bi 2 WO 6 . This work further provided a novel strategy for developing S-scheme nano-heterojunction catalysts and revealed their prospects in photoelectrochemistry and photocatalysis. Novel MoSSe/Bi 2 WO 6 S-scheme heterojunction catalysts (MSSB) were obtained. With an optimized Bi 2 WO 6 loading ratio, degradation rates ( k ) and photocurrent density of the MSSB2 sample were 2.09, and 8.31 times more than that of MoSSe, as well as 1.77, and 26.27 times more than that of Bi 2 WO 6 , which displayed a promising application in photocatalysis and photoelectrochemistry. • Novel 2D MoSSe/0D Bi 2 WO 6 S-scheme heterojunction catalysts (MSSB) were obtained. • The photoelectrochemical and photocatalytic activity of the MSSB catalyst were largely enhanced. • The photocurrent of the MSSB catalyst has an enhancement of 26.27 times. • The photocatalytic degradation rate of the MSSB catalyst has an enhancement of 2.09 times.