J. Energy Chem.｜La-doped NiFe-LDH-coupled MXenes for efficient total water splitting

已传文件：photo/1631586161.png Beiconn can provide La-doped NiFe-LDH coupled MXene (customizable)





Research abstract

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The development of catalysts with high stability and activity in alkaline electrolytes with high hydrogen production and oxygen production reaction activities is the key to sustainable energy conversion technology, namely electrochemical water splitting. In view of this, the research team of Professor Jiqi Zheng of Dalian University of Technology published the latest research results in the journal "Journal of Energy Chemistry", and proposed a new strategy for regulating water splitting electrocatalysts in alkaline electrolytes. Synergistic coupling between LDH and 3D vertically aligned MXene nanosheets enables the preparation of a composite catalyst, NiFeLa-LDH/v-MXene/NF, on a macroporous nickel foam substrate. The strong electronic interaction between the multi-metal centers and the unique vertically aligned porous MXene with more active surface area of the prepared catalyst can accelerate the reaction kinetics and enhance the water adsorption and dissolution ability. NiFeLa-LDH/v-MXene/NF exhibits reduced overpotentials at 233 and 255 mV for HER and OER, respectively, at a current density that meets commercial requirements (500 mA cm-2), and the stability is also very good. Excellent. Compared with Pt/C-RuO2, the assembled basic catalyst NiFeLa-LDH/v-MXene/NF exhibited a lower operating voltage of 1.71 V at a current density of 500 mA cm-2.

Graphical guide







Figure 1. Schematic diagram and SEM image of the synthetic route of NiFeLa-LDH/v-MXene/NF.





Figure 2. XRD and XPS spectra of NiFeLa-LDH/v-MXene/NF.





Figure 3. Electrocatalytic performance of NiFeLa-LDH/v-MXene/NF and comparative samples.





Figure 4. Nyquist image of NiFeLa-LDH/v-MXene/NF, capacitance comparison, contact angle test mass change during water adsorption and FTIR spectrum.





Figure 5. Analysis and comparison of electrocatalytic performance of NiFeLa-LDH/v-MXene/NF.

Summarize

The self-supporting electrodes prepared in this paper have a layered 3D structure. Benefiting from the synergistic effect between structure and composition, the enhancement of charge transport and the increase of electrochemical active sites are accompanied by the enhancement of water adsorption and decomposition properties. This results in improved kinetics of sluggish HER and OER reactions, resulting in lower overpotentials and Tafel slopes. The highly active NiFeLa-LDH/v-MXene/NF is an outstanding electrocatalyst for water splitting, requiring only 1.48 V at a current areal density of 10 mA cm-2 for 400 hours. This work provides a novel idea for the development of highly active bifunctional catalysts.


Literature link

https://doi.org/10.1016/j.jechem.2022.02.044

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