Abstract
Electrochemical hydrogen evolution reaction (HER) is a promising route to harvest high-purity hydrogen (H2). Efficient and selective energy transformations rely on the development of novel catalytic materials in terms of compositions and structures that survive under harsh conditions. This study focuses on a unique nanostructured CoMoS3 catalyst for HER under strong acidic and basic electrolyte. The morphologies of the catalysts are fine-tuned by altering reaction times in a hydrothermal reaction. Limited reaction time generates twisted thin-sheet CoMoS3 (12 h), which spins into a nanotube with an extended synthetic time (16 h). As the reaction time increases to 20 h, the CoMoS3 composite creates open-ended nanotubes, facilitating reactants to penetrate and react actively in the inner space of the nanotubes. Further, prolonged reaction time (24 h) results in the formation of the close-ended CoMoS3 nanotubes. We find out that the open-ended structure plays an important role in achieving fast kinetics as well as creating more active sites in HER reaction. The catalyst delivers a profound performance under both acidic and basic conditions, with overpotentials of 93 mV and 115 mV (at a current density of 10 mA/cm2) in the acidic and basic electrolytes, respectively. Moreover, it shows superior long-term durability in both solutions. This work will provide a great foundation for understanding the morphology effect with the same composited catalyst towards energy conversion reactions, not limited to HER.
Highlights
Hydrogen (H2), as a high energy density and environmentally friendly energy carrier plays a critical role in the sustainable hydrogen economy [1,2,3,4]
The inductively coupled plasma (ICP) results are listed in Table S1, where it shows that the ratios of Co : Mo : S for all samples are close to 1 : 1 : 3
The lattice spacings 2.72 Å, 1.94 Å, and 1.69 Å in the selected area electron diffraction (SAED) are found to be consistent with the lattice spacing of CoMoS3 (#16–0439) [43]. These results are consistent with the X-ray diffraction (XRD) results, which further confirm that the main chemical composition of the catalysts is CoMoS3
Summary
Hydrogen (H2), as a high energy density and environmentally friendly energy carrier plays a critical role in the sustainable hydrogen economy [1,2,3,4]. Electrocatalysts, which are cost-effective, durable and possessing a close-to-zero overpotential, are critically important for the development of H2-based economy [3,12,14,15,16]. Platinum and their alloys are probably the most recognizable model catalysts in HER [17,18,19,20]. There are two potential explanations for superior performance of open-ended CoMoS3: Firstly, the increased surface area of the open-ended structure compared to the other morphologies increase its HER activity; secondly, the nanotube structure might facilitate the reaction by the confinement effect when the reactants react in the confined nanotube environment. The close-ended structure, missing the above features, shows a downstream performance
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.
