Nanosheet arrays of iron oxide for enhanced ammonia synthesis via electrochemical nitrogen reduction for prospective algal membrane bioreactors

Muhammad Adnan Younis; Saira Manzoor; Amjad Ali; Fazal Haq; Tariq Aziz; Mehwish Kiran; Arshad Farid; Mohamed E El Sayed; Mohammad N Murshed; Zeinhom M El-Bahy; Muhammad Saeed Akhtar

doi:10.1016/j.chemosphere.2023.139621

Nanosheet arrays of iron oxide for enhanced ammonia synthesis via electrochemical nitrogen reduction for prospective algal membrane bioreactors

Chemosphere. 2023 Oct:338:139621. doi: 10.1016/j.chemosphere.2023.139621. Epub 2023 Jul 22.

Authors

Affiliations

¹ Shenzhen University. Institute of Microscale Optoelectronics, 518060, China. Electronic address: adnanyounis@zju.edu.cn.
² Shenzhen University. Institute of Microscale Optoelectronics, 518060, China. Electronic address: saira@bit.edu.cn.
³ Jiangsu University. Research School of Polymeric Materials, School of Materials Science and Engineering, Zhenjiang, 212013, China.
⁴ Institute of Chemical Sciences, Gomal University, D.I.Khan 29050, Pakistan.
⁵ School of Engineering, Westlake University, Hangzhou 310024, China.
⁶ Faculty of Agriculture, Gomal University, D.I.Khan 29050, Pakistan.
⁷ Gomal Center of Biochemistry and Biotechnology, Gomal University, D.I.Khan 29050, Pakistan.
⁸ Physics Department, Faculty of Science and Arts, King Khalid University, Muhayl Asser, Saudi Arabia.
⁹ Department of Chemistry, Faculty of Science, Al-Azhar University, Nasr City, 11884, Cairo, Egypt. Electronic address: zeinelbahy@azhar.edu.eg.
¹⁰ School of Chemical Engineering, Yeungnam University, Gyeongsan, 712-749, South Korea. Electronic address: msakhtar@yu.ac.kr.

PMID: 37487973
DOI: 10.1016/j.chemosphere.2023.139621

Abstract

The earth's nitrogen cycle relies on the effective conversion of nitrogen (N₂) to ammonia (NH₃). As a result, the research and development of catalysts that are earth-abundant, inexpensive, and highly efficient but do not need precious metals is of the utmost significance. In this investigation, we present a controlled synthesis technique to the fabrication of an iron oxide (Fe₂O₃) nanosheet array by annealing at temperatures ranging from 350 to 550 °C. This array will be used for the electrochemical reduction of atmospheric N2 to NH3 in electrolytes. The Fe₂O₃ nanosheet array that was produced as a result displays outstanding electrochemical performance as well as remarkable stability. When compared to a hydrogen electrode working under normal temperature and pressure conditions, the Fe₂O₃ nanosheet array produces an impressive NH3 production rate of 18.04 g per hour per mg of catalytically active material in 0.1 M KOH electrolyte, exhibiting an enhanced Faradaic efficiency (FE) of 13.5% at -0.35 V. This is accomplished by exhibiting an enhanced Faradaic efficiency (FE) of 0.1 M KOH electrolyte. The results of experiments and electrochemical studies reveal that the existence of cation defects in the Fe₂O₃ nanosheets plays an essential part in the enhancement of the electrocatalytic activity that takes place during nitrogen reduction reactions (NRR). This study not only contributes to the expanding family of transition-metal-based catalysts with increased electrocatalytic activity for NRR, but it also represents a substantial breakthrough in the design of catalysts that are based on transition metals, so it's a win-win. In addition, the use of Fe₂O₃ nanosheets as electrocatalysts has a lot of potential in algal membrane bioreactors because it makes nitrogen fixation easier, it encourages algae growth, and it makes nitrogen cycling more resource-efficient.

Keywords: Algal membrane bioreactors; Ambient condition; Ammonia synthesis; Electrocatalysis; Iron oxide nanosheets; Nitrogen reduction reaction.

MeSH terms

Ammonia*
Bioreactors*
Nitrogen
Prospective Studies

Substances

ferric oxide
Ammonia
Nitrogen