Recent Advances in Tuning of Carbon-Based Nanostructure Surfaces Toward Electrochemical Nitrogen Reduction Reaction: Inquiry to Insights

The present energy-intensive and feedstock-dependent Haber–Bosch (H–B) process is being replaced with an electrochemical nitrogen reduction reaction (E-NRR) to produce ammonia (NH₃), powered by renewable electricity. The main obstacles to the NRR are the integral inertness of the N₂ molecule and competition from the hydrogen evolution reaction (HER). Although transition metal-based electrocatalysts can overcome the kinetic restriction of N≡N activation via the back-donation method, the d-orbital electrons of transition metal atoms promote the creation of a metal–H bond, which increases the undesired HER. The electrocatalytic NRR activity has increased in recent years owing to carbon-based materials with easily tunable electrical structures. As a result, it is essential to evaluate the latest advances in theoretical and experimental aspects of carbon-based catalysts (CBCs) for NRR. This review focuses on the use of various CBCs and the modifications done to them for their effective use in the E-NRR, providing a comprehensive understanding of the use of CBCs for the E-NRR and aids further research in the field with the aim of making the E-NRR more efficient.