Uttam Kumar Ghorai

The electrochemical nitrate reduction reaction (NO ₃ RR) offers a sustainable route to convert waste NO ₃ ⁻ into valuable ammonia (NH ₃ ) using renewable electricity.

Mo-incorporated Bi ₂ S ₃ enables efficient solar nitrate reduction to ammonia by tuning electronic structure, suppressing H2 evolution and accelerating kinetics. It achives 4.654 mmol g ⁻¹ h ⁻¹ ammonia production with excellent stability under sunlight.

This review provides a “puzzle-cube” framework for magnetoelectrocatalysis by connecting advanced materials, mechanisms, and electrochemical applications towards sustainable chemical transformations.

M(TCNQ) ₂ /CF (M = Mn, Fe, Co) complexes have been synthesised and employed for electrochemical NRR catalysis, where Fe(TCNQ) ₂ /CF, owing to its greater stability due to CFSE during complexation, showed better catalytic activity.

Photocatalytic ammonia (NH ₃ ) production provides a green alternative to the energy‐intensive Haber–Bosch process; however, low efficiency and limited understanding of N ₂ activation hinder progress. Experimental results, supported by density functional theory (DFT), demonstrate that Sn‐doped Bi ₂ MoO ₆ significantly enhances photocatalytic nitrogen reduction reaction (PNRR) by tuning electronic structure and enriched active sites. This work reports at the optimal Sn incorporation, 10% Sn‐BMO with a preferentially exposed (131) facet accompanied by a substantial concentration of oxygen vacancies delivers an NH ₃ production rate of 2.07 mmol g ⁻¹ , which is 10.9 times greater than that of pristine Bi ₂ MoO ₆ under simulated solar irradiation (Xenon lamp). The presence of high amount of oxygen vacancies in the 10% Sn‐BMO promotes N ₂ adsorption and activation, facilitating N≡N bond dissociation through proton coupling. The N ₂ fixation pathway was elucidated by tracking reaction dynamics through infrared spectroscopy. A solar‐to‐NH ₃ efficiency of ∼1.04% in pure water positions this breakthrough as a viable pathway toward decentralized NH ₃ production with improved accessibility and sustainability. Moreover, under natural sunlight in the designed prototype system, 10% Sn‐BMO exhibits an NH ₃ production rate of ∼450 µmol g ⁻¹ . These findings validate efficient laboratory and outdoor solar‐driven NH ₃ production through rational catalyst design for sustainable ammonia synthesis.

Direct electrocatalytic co‐reduction of N ₂ and CO ₂ to urea remains constrained by sluggish kinetics and the absence of frameworks capable of concurrently activating both molecules. Herein, we present the first realization of a metalated porous organic polymer ( M‐POP )‐based electrocatalyst, Cu ₃ Fc‐Pyz‐POP , derived from in situ formed Cu ₃ (pyrazolate) triangular motif and 1,1′‐ferrocenedicarboxaldehyde through a template‐free Schiff base polymerization. The heterometallic Cu–Fe framework hosts atomically dispersed single‐site active centers that cooperatively activate and co‐reduce molecular N ₂ and CO ₂ , thereby promoting selective urea formation under ambient conditions. Operated in a 0.1 M KHCO ₃ electrolyte under ambient conditions, Cu ₃ Fc‐Pyz‐POP delivers an exceptional urea yield rate of 115.23 µgh ⁻¹ mg ⁻¹ and a Faradaic efficiency of 20.68% at –0.6 V vs RHE, surpassing its monometallic analogues. The catalyst exhibits excellent recyclability over 10 cycles and maintains stable performance during 45 h of continuous electrolysis. in situ FT‐IR spectroscopic investigation and DFT computational studies reveal that ferrocene (Fc) moieties facilitate enhanced conductivity with a dramatic decrease of HOMO‐LUMO energy gap and selective C‐N coupling between N ₂ and CO ₂ intermediates. Our finding establishes M‐POPs as promising platforms for ambient urea electrosynthesis, contributing to energy‐efficient fertilizer production and advancing low‐carbon chemistry.

The electrocatalytic nitrate reduction reaction (NO ₃ RR) enables sustainable nitrate remediation and simultaneous ammonia synthesis as an alternative to the energy‐intensive Haber‐Bosch process. Recently, covalent organic frameworks (COFs) have garnered attention as NO ₃ RR platform due to their intrinsic porosity and structural tunability, which enable active‐site engineering. However, current COF‐based systems largely rely on metal active sites, undermining their sustainability and obscuring the catalytic activity of the framework. Here, we introduce a metal‐free COF, that is highly active for NO ₃ RR. The electrocatalyst is a fluorinated ketazine‐linked COF (F‐Ketazine COF), which incorporates electron‐withdrawing fluorine atoms that enhance π–π stacking interactions and promote efficient linkage formation. Synthesized via a rapid solvothermal reaction, the F‐Ketazine COF exhibits superior crystallinity and enhanced electrocatalytic activity compared to its non‐fluorinated analog (n‐Ketazine COF). Under neutral pH conditions, the F‐Ketazine COF achieved a Faradaic efficiency of 59.9% for NH ₃ and an NH ₃ yield rate of 1639.9 µmol h ⁻¹ mg _COF ⁻¹ at −0.9 V versus RHE. To the best of our knowledge, this is the first example of a ketazine‐linked COF applied in electrocatalysis and the first a metal‐free COF for NO ₃ RR. This work demonstrates the potential of fluorinated ketazine linkages in developing sustainable and efficient COF‐based electrocatalysts.

The electrocatalytic nitrate reduction reaction (NO ₃ RR) enables sustainable nitrate remediation and simultaneous ammonia synthesis as an alternative to the energy‐intensive Haber‐Bosch process. Recently, covalent organic frameworks (COFs) have garnered attention as NO ₃ RR platform due to their intrinsic porosity and structural tunability, which enable active‐site engineering. However, current COF‐based systems largely rely on metal active sites, undermining their sustainability and obscuring the catalytic activity of the framework. Here, we introduce a metal‐free COF, that is highly active for NO ₃ RR. The electrocatalyst is a fluorinated ketazine‐linked COF (F‐Ketazine COF), which incorporates electron‐withdrawing fluorine atoms that enhance π–π stacking interactions and promote efficient linkage formation. Synthesized via a rapid solvothermal reaction, the F‐Ketazine COF exhibits superior crystallinity and enhanced electrocatalytic activity compared to its non‐fluorinated analog (n‐Ketazine COF). Under neutral pH conditions, the F‐Ketazine COF achieved a Faradaic efficiency of 59.9% for NH ₃ and an NH ₃ yield rate of 1639.9 µmol h ⁻¹ mg _COF ⁻¹ at −0.9 V versus RHE. To the best of our knowledge, this is the first example of a ketazine‐linked COF applied in electrocatalysis and the first a metal‐free COF for NO ₃ RR. This work demonstrates the potential of fluorinated ketazine linkages in developing sustainable and efficient COF‐based electrocatalysts.

Electrochemical nitrogen reduction reaction (NRR) offers a sustainable route for ammonia synthesis, facilitating reduction of fossil fuels and reducing carbon footprint. This review critically examines emerging 2D materials like doped graphene, MXene, and transition metal‐based engineered to enhance NRR efficiency, activity, and selectivity. Emphasis is placed to integrate insights from density functional theory, machine learning assisted screening, and advanced in situ characterization to elucidate structure activity relationship, and real‐time assessment of reaction intermediates to unveil the mechanistic pathway of NRR. Progress in electrochemical cell design and standardized evaluation protocols is summarized. The potential of commercialization of NRR is evaluated by techno‐economic challenges, integration of renewable energy, and infrastructure adaptability for decentralized green ammonia production. By evaluating these aspects, the review contributes to the progress of sustainable ammonia production, offering insights into potential pathways for a greener future.

The roadmap focusses on the current state of the art of three key reactions for sustainable energy transformation, water electrolysis for hydrogen production, carbon dioxide reduction for electrofuel production, and nitrogen reduction for ammonia production. Each technique is covered in separate chapters as detailed in the outline below. Each chapter is meant to update the reader in a short and concise way about the current state-of the art, the most significant challenges, and the trends and ideas lying ahead as solutions. We foresee a road map paper which will be of high interest for readers involved In current green technologies.