Cobalt-doped graphitic carbon nitride: A multifunctional material for humidity sensing, electrochemical water splitting and environmental remediation applications

• Published in: Journal of alloys and compounds 2024-12, Vol.1008, p.176498, Article 176498
• Main Authors: Shanaah, Haneen H., Allangawi, Abdulrahman, Ahmed, Usman, Idrisov, Edvin, Ali, Nasir, Attique, Sanam, Hanif, Muhammad Bilal, Mahmood, Tariq, Iqbal, Javed, Younis, Adnan
• Format: Article
• Language: English
• Subjects: Cobalt-doped graphitic carbon nitride; Electrocatalysts; Humidity sensing; Hydrogen evolution reaction (HER); Oxygen evolution reaction (OER); Photoelectrochemical water splitting
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2024.176498

Graphitic carbon nitride (g-C3N4) has emerged as a promising eco-friendly material for catalysis and sensing applications due to their unique properties. However, limitations like low specific surface area, insufficient light absorption, and poor conductivity hinder their broader usability. Elemental doping has been established as an effective approach to modify the electronic structure and bandgap of g-C3N4 thus significantly expanding its light-responsive range for enhanced charge separation. This work reports on the fabrication of cost-effective and stable g-C3N4 and cobalt-doped g-C3N4 (Co@g-C3N4) via a simple one-step calcination process. The humidity sensing performance of both g-C3N4 and Co@g-C3N4 was evaluated across a broad humidity range (7 % - 94 % RH) at various testing frequencies. The results demonstrated good reversibility with Co@g-C3N4 exhibiting superior performance compared to pristine g-C3N4. Furthermore, the synthesized materials were assessed for their suitability as photoelectrochemical water splitting catalysts for hydrogen production, representing a step towards energy-efficient fuel cells. Notably, Co@g-C3N4 displayed enhanced performance with a lower onset potential (420 mV) and a lower Tafel slope (65.4 mV dec-1) for the hydrogen evolution reaction (HER) compared to undoped counterparts. Additionally, Co@g-C3N4 nanorods exhibited remarkable performance for the oxygen evolution reaction (OER), showcasing a lower onset potential (1.505 V) and a considerably low overpotential (270 mV), surpassing numerous reported electrocatalysts and even rivaling precious-metal-based ones. Finally, enhanced photocatalytic activities for organic dyes degradation were recorded for the mentioned materials. Therefore, g-C3N4 and related materials have great potential for their industrial electrochemcial applications. •Developed cobalt-doped graphitic carbon nitride (Co@g-C3N4) using a one-step hydrothermal process.•Superior humidity sensing performance of (Co@g-C3N4) across a wide range was achieved.•Co@g-C3N4 showed enhanced photoelectrochemical water splitting performance.•Co@g-C3N4 exhibited lower onset potential and Tafel slope for hydrogen evolution reaction (HER).