Elucidating the role of cobalt nanoparticles and Mn-phosphate in etched ZIF-67/phthalimide-NC and phthalimene oxide for supercapacitor and electrochemical oxygen evolution reaction applications
Artikel i vetenskaplig tidskrift, 2025

Electrochemical supercapacitors and the electrochemical oxidation of biomass-derived oxygenates have great significance for long-term high-performance devices. However, appropriate sites with redox features remain a bottleneck for electrochemical oxidation and capacitance retention. Herein, N-doped carbon sheets with Mn-phosphate-doping and Co-metal nanoparticles were synthesized via a facile one-pot activation and calcination of the layered potassium phthalimide salt without inclusion of any additional activators or template. The unique 2D-structure of the obtained microporous carbon flakes with a layered structure provides a sturdy N-C matrix for prolonged charging/discharging with abundant active adsorption sites and an effective route for rapid electrolyte ion transport with a shorter diffusion distance for the adsorption/desorption of ions. Through these merits, K-Ph-NC offers high capacitance and outstanding rate performance with an incredible energy density in capacitor devices, and the specific capacitance of the as-prepared K-Ph-NC is proportional to the number of micropores. K-Ph-NC was further transformed to a K-Ph-Oxide, a graphene oxide version of K-phthalimide, by using an improved Hummer's method by using Mn-salt and phosphoric acid, which resulted in a phthalimene oxide doped with Mn-phosphate. In addition, a composite of K-Ph-NC with ZIF-67 was thermally calcined at 700 degrees C under an Ar atmosphere, which resulted in e-ZIF-67/K-Ph-NC with an etched surface. A comparative electronic and structural analysis followed by a capacitance retention and electrochemical oxygen evolution reaction study revealed the role of Co-nanoparticles as compared to the Mn-phosphate doping in the resulting materials. A symmetric supercapacitor device exhibited a maximum SE value of 22.7 W h kg-1 with a maximum SP of 10 416.7 W kg-1, which is mainly due to the favorable microporous pore architecture in e-ZIF-67/K-Ph-NC as compared to K-Ph-NC and K-Ph-Oxide. This highlights the role of cobalt nanoparticles in e-ZIF-67/K-Ph-NC with an etched outer surface. A promising overpotential of 450 mV at 10 mA cm-2 in the OER by e-ZIF-67/K-Ph-NC can be correlated to the charge transfer resistance across the electrode-electrolyte interface.

Författare

Tapan Dey

Amity University

Nitish Kumar

Indian Inst Technol Jammu

Chalmers, Industri- och materialvetenskap, Material och tillverkning

Rahul Patil

Amity University

Prakash Kumar Pathak

Indian Inst Technol Jammu

Sudip Bhattacharjee

Indian Association for the Cultivation of Science

Praveen Yadav

Raja Ramanna Ctr Adv Technol RRCAT

Asim Bhaumik

Indian Association for the Cultivation of Science

Rahul R. Salunkhe

Indian Inst Technol Jammu

Saikat Dutta

Amity University

Sustainable Energy and Fuels

23984902 (eISSN)

Vol. 9 5 1173-1182

Ämneskategorier (SSIF 2025)

Materialkemi

DOI

10.1039/d4se00979g

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Senast uppdaterat

2025-03-15