Related Experiment Video
Updated: Aug 15, 2026
09:18
Simple Methods for the Preparation of Non-noble Metal Bulk-electrodes for Electrocatalytic Applications
Published on: June 21, 2017
Free-Standing High-Entropy Oxides for Efficient Electrocatalytic Nitrate-to-Ammonia
Hongjin Xia1, Mingtao Yang2, Yidong Hu2
1Institute of Advanced Wear & Corrosion Resistant and Functional Materials, Jinan University, Guangzhou, China.
Small (Weinheim an Der Bergstrasse, Germany)
|August 14, 2026
Summary
A novel zinc oxide nano-array decorated with high-entropy oxides (ZnO-HEOs) shows excellent electrocatalytic nitrate reduction reaction (NO3-RR) performance. This catalyst achieves high efficiency and stability for energy and environmental applications.
Area of Science:
- Materials Science
- Electrochemistry
- Catalysis
Background:
- Electrocatalytic nitrate reduction reaction (NO3-RR) is crucial for environmental remediation and sustainable ammonia production.
- Developing efficient and stable electrocatalysts for NO3-RR in neutral electrolytes remains a significant challenge.
Purpose of the Study:
- To introduce a novel free-standing high-entropy oxides (HEOs) catalyst based on zinc oxide nano-array decorated with iron, cobalt, nickel, copper, and zinc oxides (ZnO-HEOs).
- To evaluate the electrocatalytic performance and stability of ZnO-HEOs for NO3-RR.
- To investigate the underlying mechanism for the enhanced catalytic activity.
Main Methods:
- Fabrication of free-standing ZnO-HEOs catalyst.
- Electrochemical characterization including cyclic voltammetry and chronoamperometry.
- Performance evaluation in a membrane electrode assembly for NO3-RR.
- Analysis of ammonia yield and Faradaic efficiency.
- Investigation of zinc-nitrate battery performance.
- Electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy to study interfacial synergistic effects.
Main Results:
- The ZnO-HEOs catalyst achieved a Faradaic efficiency of ~99.42% and an ammonia yield of ~34.09 mg cm-2 h-1 for NO3-RR in a neutral electrolyte.
- The catalyst demonstrated a high open-circuit potential of ~1.55 V and a peak power density of ~5.33 mW cm-2 in a zinc-nitrate battery.
- The performance of ZnO-HEOs surpassed that of HEOs powder and previously reported catalysts, attributed to the interfacial synergistic effect between ZnO and HEOs.
- Exceptional stability was observed in both electrochemical systems, with ZnO effectively stabilizing the HEOs active sites.
Conclusions:
- The developed ZnO-HEOs catalyst offers a promising route for efficient and stable electrocatalytic nitrate reduction.
- The interfacial synergistic effect between ZnO and HEOs is key to enhancing charge transfer and reducing the energy barrier for NO3-RR.
- This work promotes the practical application of self-supporting HEOs in energy and environmental fields.
Keywords:
electrochemical ammonia synthesishigh‐entropy oxidemembrane electrode assemblynitrate reduction reactionzinc‐nitrate batteryMore Related Videos
Related Concept Videos
01:08Electrodeposition
Electrodeposition is a technique used to separate an analyte from interferents by electrochemical processes. Here, the analyte is a metal ion that can be deposited on an electrode immersed in the sample solution. The electrochemical setup consists of an anode and a cathode. When an electric current is applied to the setup, oxidation occurs at the anode. At the cathode, which consists of a large metal surface, metal ions undergo reduction and deposit onto the surface.
Electrodeposition can...
Electrodeposition can...
03:00Electrolysis
In a galvanic cell, the electrical work is done by a redox system on its surroundings as electrons produced by the spontaneous redox reactions are transferred through an external circuit. Alternatively, an external circuit does work on a redox system by imposing a voltage sufficient to drive an otherwise nonspontaneous reaction in a process known as electrolysis. For instance, recharging a battery involves the use of an external power source to drive the spontaneous (discharge) cell reaction in...
01:29Preparation of Amines: Reduction of Oximes and Nitro Compounds
Oximes can be reduced to primary amines using catalytic hydrogenation, hydride reduction, or sodium metal reduction. The reduction of aliphatic and aromatic nitro compounds to primary amines takes place by either catalytic hydrogenation or by using active metals like Fe, Zn, and Sn in the presence of an acid.
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...