Abstract
Solar‐driven overall water splitting based on metal sulfide semiconductor photocatalysts remains as a challenge owing to the strong charge recombination and deficient catalytic active sites. Additionally, significant inhibition of back reactions, especially the oxidation of sulfide ions during the photocatalytic water oxidation catalysis, is an arduous task that requires an efficient photogenerated hole transfer dynamics. Here, a ternary dumbbell‐shaped catalyst based on RuO2/CdS/MoS2 with spatially separated catalytic sites is developed to achieve simultaneous production of hydrogen and oxygen under simulated solar‐light without any sacrificial agents. Particularly, MoS2 nanosheets anchored on the two ends of CdS nanowires are identified as a reduction cocatalyst to accelerate hydrogen evolution, while RuO2 nanoparticles as an oxidation cocatalyst are deposited onto the sidewalls of CdS nanowires to facilitate oxygen evolution kinetics. The density functional theory simulations and ultrafast spectroscopic results reveal that photogenerated electrons and holes directionally migrate to MoS2 and RuO2 catalytic sites, respectively, thus achieving efficient charge carrier separation. The design of ternary dumbbell structure guarantees metal sulfides against photocorrosion and thus extends their range in solar water splitting.
Highlights
Photocatalysts remains as a challenge owing to the strong charge comparable to fossil-fuel-derived hydrogen recombination and deficient catalytic active sites
The quest for clean and renewable energy sources alternative to CdS nanorods with Pt nanoparticles (NPs) at the end of nanorods fossil fuels.[1,2,3]. It has been regarded as a simple and cost-effective can show impressive photocatalytic H2 evolution performance with a high quantum efficiency of 9.6% under the light illumination with the wavelength of 455 nm.[27]
Chai The Hong Kong Polytechnic University Shenzhen Research Institute benefits of interfacial charge separation between photogenerated electrons transferring to Pt cocatalyst and holes remaining on the CdS nanorods, resulting in longer electron lifetime
Summary
RuO2/CdS/MoS2 photocatalyst with nanodumbbells structure (Figure 2a). Amine-functionalized CdS nanowires with average diameter of 60–70 nm were first prepared through a solvothermal approach by using ethanediamine as the chelating agent, as confirmed by scanning electron microscope (SEM) The SEM and TEM images (Figure S4, Supporting Information) show that MoS2 NSs are selectively and symmetrically grown on the two tips of CdS nanowire to form a well-defined nanodumbbell structure. After MoS2 NSs affixed CdS nanowire tips, the surface-modified –NH2 groups still remain at the sidewalls of CdS nanowires, which is confirmed by Fourier transform infrared spectra (Figure S5, Supporting Information). The strong coordination between Ru3+ and –NH2 groups ensures that the dispersion of Ru3+ ions on the sides of CdS/MoS2.[38] Following a thermal treatment process, RuO2 NPs were selectively formed on the sidewalls of CdS nanowires. As displayed in Figure 2k,m, MoS2 NSs and RuO2 NPs are preferentially formed at the tips and sidewalls of CdS nanowires, respectively. RuO2/CdS nanowires were synthesized by depositing RuO2 onto the sidewalls of CdS nanowires, as confirmed by SEM, TEM, and XRD pattern (Figure S7, Supporting Information)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
