Interface-engineered nickel oxyhydroxide on carbon nanofibers for efficient urea oxidation and wastewater-to-energy conversion
PLOS ONE, cilt.21, sa.6 June, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 21 Sayı: 6 June
- Basım Tarihi: 2026
- Doi Numarası: 10.1371/journal.pone.0347020
- Dergi Adı: PLOS ONE
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, L'Année philologique, Aerospace Database, BIOSIS, Chemical Abstracts Core, EMBASE, Index Islamicus, Linguistic Bibliography, MEDLINE, Psycinfo, zbMATH, Directory of Open Access Journals, Zoological Record, Academic Search Ultimate (EBSCO), Natural Science Collection (ProQuest), Biological Science Database (ProQuest), Biomedical Reference Collection: Corporate Edition (EBSCO), Health Research Premium Collection (ProQuest), Materials Science & Engineering Collection (ProQuest), Pharma Collection (ProQuest), Technology Collection (ProQuest)
- Atatürk Üniversitesi Adresli: Hayır
Özet
Urea is a common nitrogenous pollutant in agricultural and industrial wastewaters, and its electrochemical oxidation in alkaline media enables simultaneous detoxification and energy recovery. Herein, we report an interface-engineering strategy based on P,N-modified nickel–carbon nanofibers prepared via a scalable electrospinning–carbonization process using ammonium phosphate as a multifunctional precursor. During thermal treatment, phosphorus and nitrogen heteroatoms are incorporated into the carbon framework while regulating the surface chemistry of embedded nickel nanoparticles, promoting the formation of a NiOOH-ready interfacial layer. Structural analyses (XRD, SEM/TEM) confirm the formation of metallic Ni domains uniformly dispersed within turbostratic carbon nanofibers. XPS reveals the coexistence of Ni0/ Ni+2/Ni+3 species along with phosphate- and nitrogen-derived functionalities that enhance electronic modulation and redox reversibility. In 1.0 M KOH, the optimized composition exhibits a Ni+2/Ni+3 redox charge of ~12.5 mC.cm−2. For urea electrooxidation (0.5 M urea), the catalyst delivers a maximum current density of ~115 mA.cm−2 with a low onset potential of 0.37 V (vs Ag/AgCl). The apparent activation energy is 9.82 kJ.mol−1, indicating a kinetically favorable NiOOH-mediated pathway. Chronoamperometry shows stable operation with ~70–80% current retention over 1000 s. When implemented as an anode in a membrane-less direct urea fuel cell, the material achieves a peak power density of ~1.1 W.m−2 at 35 °C, demonstrating practical wastewater-to-energy feasibility. This work highlights how dual heteroatom modification of carbon nanofibers can regulate nickel interfacial chemistry, enabling efficient urea remediation coupled with renewable power generation.