Solvothermal synthesis of hybrid nanoarchitectonics nickel-metal organic framework modified nickel foam as a bifunctional electrocatalyst for direct urea and nitrate fuel cell

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Vol. 34; no. 8; p. 104087
• Main Authors: Ravipati, Manaswini, Badhulika, Sushmee
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-08-2023
• Subjects: Ni-MOF catalyst; Nickel foam; Nitrate reduction; Solvothermal method; Urea oxidation; Urea oxidation; Ni-MOF catalyst; Solvothermal method; Nickel foam; Nitrate reduction
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2023.104087

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•Nickel-Metal Organic Framework was synthesized via one pot-solvothermal technique.•A novel organic linker (2,4,6-tri methoxy pyrimidine) was used as organic ligand.•Ni-MOF/NF catalyst was examined in the presence of simulated urine and tap water.•Ni-MOF/NF electrode exhibited bifunctional ability towards DUFC and DNFC.
Urea and nitrate-based fuel cells have emerged as promising electricity generation devices. However, most of these catalysts are expensive and limited in supply, which limits their practical applications. Hence, metal-organic frameworks (MOF) have been explored as catalysts due to their low cost, easy preparation, and high redox activity. Here, we synthesize nickel-based MOF (Ni-MOF) via one-pot solvothermal technique as bifunctional electrocatalyst for the direct urea and nitrate fuel cell. The as-synthesized Ni-MOF is deposited on nickel foam (NF) and used as working electrode (Ni-MOF/NF) which demonstrates a peak current density of 188 mA/cm2 for urea oxidation reaction (UOR) and −14 mA/cm2 for nitrate reduction reaction (NRR) at an onset potential of ∼ 1.58 V (vs RHE), and ∼ 1.12 V (vs RHE), respectively The enhanced functionality of the Ni-MOF/NF electrode can be attributed to the high catalytic efficacy of the Ni-MOF. This is mainly due to the presence of multiple oxidation states of N (i.e., Ni2+/3+) and excellent electronic conductivity of the organic ligands in MOF structure. Moreover, Ni-MOF/NF electrodes retain ∼ 71.2% and ∼ 83.9% capacity after 20000 s of UOR and NRR, respectively. This efficacy of the as-fabricated electrocatalyst proves MOF as a promising platform for direct fuel cell applications.