Professor Mu Shichun and Professor Tang Haolin, Small View: Iron-doped Ni/MoO2 hollow heterogeneous nanorod array promotes efficient alkaline water/seawater electrolysis
【Article information】
Iron-doped Ni/MoO2 hollow heterogeneous nanorod array promotes efficient alkaline water/seawater electrolysis
P 1 Author: Shi Wenjie
Corresponding author: Mu Shichun*, Tang Haolin*
Unit: Wuhan University of Technology
[Research background]
electrolyzed water During the process of water , water molecules are decomposed into oxygen and hydrogen through oxygen precipitation reaction (OER) and hydrogen precipitation reaction (HER). However, the current electrolytic water technology is limited by the slow kinetic processes of OER and HER, so it is urgent to develop highly active dual-function electrocatalysts to promote water decomposition kinetics. In nickel-molybdenum-based catalysts, Ni atoms have excellent hydrolysis activity, while Mo atoms have superior hydrogen adsorption energy; at the same time, the strong coupling effect of nickel and molybdenumide can cause electron transfer and change the electronic structure of the catalyst, so that it has basic HER activity similar to platinum group metal . However, the oxygen evolution reaction (OER) activity of nickel-molybdenum-based catalysts is low, resulting in the lack of reports of high-efficiency OER and HER bifunctional nickel-molybdenum-based catalysts. Therefore, waking up the OER activity of nickel-molybdenum-based catalysts is of great significance to promote their application in the field of water electrolysis.
[Article Introduction]
Based on this, the team of Professor Mu Shichun of Wuhan University of Technology and Professor Tang Haolin jointly published a paper titled "Fe-Incorporated Ni/MoO2 Hollow Heterostructure Nanorod Arrays for High-Efficiency Overall Water Splitting in Alkaline and Seawater Media" on Small.
This paper successfully constructed a unique NiFe/Fe-MoO2 hollow heterogeneous nanorod through a novel self-sacrificing template strategy. The catalyst exhibits superior OER and platinum-like HER activities in alkaline pure water and seawater.
Figure 1. NiFe/Fe-MoO2 catalyst structure and application scenarios
[Key points of this article]
Key points of the first: Building NiFe/Fe-MoO2 hollow heterogeneous nanorod
using novel The self-sacrificing template strategy is to grow Prussian blue analog (PBA) cubes in situ on NiMoO4; then, during the ion exchange , the nickel ions coordinate with the ferrocyan ions and the dissolution of some molybdate ions, forming a unique NiMoO4@PBA hollow nanorod structure; after high temperature calcination, NiFe/Fe-MoO2 heterostructure was obtained, and its hollow nanorod structure was still maintained.
Figure 2. Synthesis and Characterization of NiFe/Fe-MoO2 Catalyst
Key Point 2: NiFe/Fe-MoO2 has excellent OER and platinum-like HER activity
NiFe/Fe-MoO2 has excellent catalytic activity and stability in alkaline media (1 M KOH): the OER overpotential is only 213 mV@20 mA/cm2, which is better than most reported nickel-molybdenum-based catalysts (Figure 3); this catalyst also has platinum-like HER activity, and the current density of 10 mA/cm2 is only 33. The low overpotential of mV (Figure 4). In addition, after 70 h of constant current stability test, the OER/HER activity did not show significant attenuation, indicating excellent electrochemical stability.
Figure 3. Oxygen evolution reaction (OER) performance in 1 M KOH
Figure 4. NiFe/Fe-MoO2 catalyst at 1 M KOH Hydrogen evolution reaction (HER) performance in KOH
Key points 3: NiFe/Fe-MoO2 can efficiently drive alkaline pure water/sea electrolysis
Thanks to the unique hollow heterogeneous nanorod structure, the total hydrolysis reaction of NiFe/Fe-MoO2 in alkaline pure water and alkaline seawater electrolytes requires only a tank voltage of 1.48 and 1.51 V to drive the current density of 10 mA/cm2, which significantly exceeds the activity of commercial Pt/C||RuO2 precious metal electrode pairs, and exhibits excellent electrochemical stability and nearly 100% Faraday efficiency.
Figure 5. Full water-removing properties of NiFe/Fe-MoO2 catalyst in alkaline media and alkaline seawater
Key points 4: Prospective
This paper introduces iron atoms effectively stimulates the OER activity of nickel-molybdenum-based catalysts through self-sacrificing template strategy, and obtains a nickel-molybdenum-based bifunctional catalyst with excellent OER and platinum-like HER activities. This work has important implications for the design and construction of high-performance non-precious metal OER/HER dual-function catalysts, and will effectively promote the multi-scenario application of nickel-molybdenum-based catalysts for water electrolysis.
[Article link]
Fe-Incorporated Ni/MoO2 Hollow Heterostructure Nanorod Arrays for High-Efficiency Overall Water Splitting in Alkaline and Seawater Media
https://onlinelibrary.wiley.com/doi/10.1002/smll.202205683
[Introduction to the corresponding author]
Mu Shichun : Chief professor, doctoral supervisor, national high-level talent. We have long been committed to the research on hydrolyzing hydrogen production catalyst and proton exchange membrane fuel cell catalyst. As the first author or corresponding author, he published more than 270 high-quality academic papers in domestic and foreign journals such as Nat. Commun., Adv. Mater., J. Am. Chem. Soc., Angew. Chem. Int. Ed., Energy Environ. Sci., etc.
Tang Haolin : Chief professor, doctoral supervisor, national high-level talent. He has been engaged in research on key materials of fuel cells and lithium batteries for a long time. As the first author or corresponding author, he published more than 100 high-quality academic papers in domestic and foreign journals such as Adv. Mater., Adv. Energy Mater., Adv. Funct. Mater., Nano Energy, Adv. Sci. and other .
