1. Anchoring metal-organic framework-derived hollow CoV2O6 nanocubes onto lattice tensile strained V2CTx MXene for superior overall water splitting.
- Author
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Zhou, Yu, Wu, Yousen, Guo, Dongxuan, Li, Jinlong, Chu, Dawei, Na, Shengnan, Yu, Muran, Li, Daqing, Sui, Guozhe, and Chai, Dong-Feng
- Subjects
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HYDROGEN evolution reactions , *OXYGEN evolution reactions , *TRANSITION metal ions , *HYDROPHILIC surfaces , *ION exchange (Chemistry) , *CHEMICAL kinetics - Abstract
MXene is considered as a kind of promising two-dimensional layered carbide/nitride in the field of overall water splitting attributed to hydrophilic surface, controllable interlayer spacing, and desirable metal conductivity. Nevertheless, the re-stack effect still hinders its large-scale development. Therefore, in this work, metal-organic frameworks-derived hollow CoV 2 O 6 nanocubes anchored on the surface of lattice tensile strained V 2 CT x MXene (TS-V 2 CT x /CoV 2 O 6 HN) as electrocatalysts are prepared through ion exchange process and the following liquid nitrogen quenching treatment. Lattice tensile strain could boost ions transfer of transition metals due to the enlarger interlayer spacing. The heterostructure between CoV 2 O 6 and V 2 CT x MXene could optimize the adsorption energy of H- and O-containing intermediates to obtain the best ΔGH* for hydrogen evolution reaction (HER) and decrease the ΔG value of rate determining step for oxygen evolution reaction (OER). Besides, the CoV 2 O 6 components acting as intercalation agents could avoid the self-aggregation of MXene nanosheets. Simultaneously, the hollow structure also offers high active area to promote electrolyte permeation and accelerate electron/ion transfer. As a consequence, the TS-V 2 CT x /CoV 2 O 6 HN acquires extraordinary HER and OER performance with the overpotential of 32.2 and 235.0 mV at the current density of − 10 mA/cm2 and 10 mA/cm2, respectively, which is quite remarkable compared to the recent MXene-based electrocatalysts. Moreover, the overall water splitting device assembled by TS-V 2 CT x /CoV 2 O 6 HN demonstrates a low cell voltage of 1.358 V at 10 mA/cm2. Thence, this work donates an exciting avenue to overcome the re-stack issue of V 2 CT x MXene, constructing a superior electrocatalyst with high activity and desirable reaction kinetics. [Display omitted] • The hollow CoV 2 O 6 nanocubes anchored on the surface of lattice tensile strained V 2 CT x MXene are successfully prepared. • Lattice tensile strain could change the local atomic/electronic environment and widen interlayer spacing. • The hollow structure could offer rich active area and effectively avoid the self-aggregation of MXene sheets. • TS-V 2 CT x /CoV 2 O 6 HN acquires extraordinary hydrogen evolution reaction and oxygen evolution reaction activity. • This work could offer an exciting avenue for overcoming the re-stack issue of V 2 CT x MXene. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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