Ashadul Adalder

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.

As a sustainable alternative to the energy-intensive ammonia synthesis through Haber–Bosch method, the electrochemical nitrogen reduction reaction (eNRR) offers a promising sustainable green approach for converting abundant atmospheric N₂ into ammonia. The design and development of transition metal-based composite systems have received significant attraction for eNRR applications due to their abundant active sites, enhanced charge transfer capabilities, and high selectivity. Herein, we report a two-dimensional carbon nitride (C₃N₄)-supported nickel phthalocyanine (NiPc) composite system (NiPc_C₃N₄) that exhibits outstanding performance for the nitrogen reduction reaction (NRR), achieving an ammonia yield rate of 460 ± 14 μg h⁻¹ mg⁻¹ _cat and a faradaic efficiency of 43 ± 1% at −0.3 V vs. RHE under ambient conditions. Our work demonstrates, through density functional theory (DFT) calculations and experimental studies, that NiPc anchored on C₃N₄ significantly facilitates the adsorption and activation of chemically inert nitrogen molecules. The enhanced catalytic activity of the composite system may be attributed to the re-distribution of charges across the NiPc, which adjusts the valence orbital of the Ni center due to the presence of the 2D layer of C₃N₄. This process substantially reduces the energy barrier necessary for the crucial dissociation of inert N₂, hence enhancing N₂ reduction efficiency markedly.

Electrochemical techniques for nitrogen and carbon transformations have recently experienced a spike in attention, coinciding with the growing demand for environmentally friendly and efficient processes. This review investigates the electrochemical conversion of nitrogenous molecules to value‐added products using a metal (M) phthalocyanine (Pc)‐based electrocatalyst. The review is mostly focused on nitrogen reduction to ammonia, nitrate/nitrite reduction to ammonia, nitrogen oxidation to nitric acid, urea formation from dinitrogen (N ₂ )/nitrogenous oxide (NO _x ), and carbon dioxide (CO ₂ ) reduction at the same time, and other similar reactions. This review aims for alternatives to traditional methods that consume significant amounts of energy and emit a lot of greenhouse gases by using cutting‐edge electrocatalyst engineering and a thorough understanding of how they work. A lot of various types of phthalocyanine systems have shown promise as catalysts for electrochemical applications. A better understanding of reaction mechanism and catalyst stability has been achieved through computational modeling and electrochemical characterization (including in situ study). Another focus is to highlight recent advancements, problems, and potential future directions in developing environmentally friendly, scalable, and efficient electrocatalytic systems for the transformation of nitrogen and carbon‐based reactants to generate value‐added products.

The urea‐ammonium‐nitrate (UAN) fertilizers are the optimal supply of nutrients, which promotes healthy plants and reduces the need for frequent applications. Using manganese phthalocyanine (MnPc) supported by amine‐functionalized graphene (AFG) catalyst via a unique electrochemical method that greatly improves the catalytic performance for the UAN synthesis process. During CO ₂ and NO ₃ ⁻ co‐reduction (CO ₂ + 2NO ₃ ⁻ + 18H ⁺ + 16e ⁻ → CO(NH ₂ ) ₂ + 7H ₂ O), the MnPc‐AFG catalyst demonstrated the urea production rate of 397.61 µg h ⁻¹ mg _cat ⁻¹ , as well as a 27.06% Faradaic efficiency (FE) at –1.0 V versus RHE. Simultaneously, the yield rate of ammonia synthesis from NO ₃ ⁻ reduction [NO ₃ ⁻ + 9H ⁺ + 8e ⁻ → NH ₃ + 3H ₂ O] is 433.95 µg h ⁻¹ mg _cat ⁻¹ and exhibiting a 52.13% Faradaic efficiency at –1.0 V versus RHE. The electrolyte still contains unreacted nitrate, which raises the possibility of selective UAN production. In situ Fourier transform infrared spectroscopy (FTIR) confirmed the formation of C─N and N─H bonds during electrolysis. Density functional theory (DFT) analysis provided the overall reaction mechanism and free energy profile for the formation of UAN production. This sustainable development opens up new possibilities for the manufacture of electrochemical UAN fertilizers.

Nitrite (NO ₂ ⁻ ) is a dangerous pollutant that is often found in groundwater sources and endangers human health. In addition to nitrite removal requirements, electrocatalytic nitrite reduction reaction (eNO ₂ RR) holds promise for value‐added ammonia (NH ₃ ) production at room temperature. In this study, a solvothermal technique for the preparation of nickel phthalocyanine (NiPc) is used as a highly active electrocatalyst for the conversion of NO ₂ ⁻ to NH ₃ under ambient conditions. The NiPc catalyst shows a remarkable Faradaic efficiency (FE) of 90.1% at −0.9 V versus RHE with maximum ammonia yield rate of 14667 µg h ⁻¹ mg _cat. ⁻¹ at −1.0 V versus RHE in 0.1 M Na ₂ SO ₄ containing 0.1 M NaNO ₂ solution. Furthermore, the catalyst exhibits exceptional long‐term stability during chronoamperometry tests. These findings boost the future ammonia production from nitrite reduction for sustainable development.

Installation of bis-terpyridine Ru( ii ) complex as a catalyst center into a Zr( iv )-based NDI MOFs through SALE to develop a highly efficient photocatalyst for selective CO ₂ to CO conversion.

Incorporation of Mo and Sn into CdS (Cd_0.60Mo_0.20Sn_0.20S) boost 8-fold photocatalytic NH₃ production with 100% selectivity from N₂ compared to CdS via optimizing band structure, enhancing charge carrier separation, and facilitating N₂ activation.

The orientation of β-CuPc favours the overlap of central Cu with the N of parallel molecules, which is the reason behind high electrical conductivity and selectivity in NH ₃ production via nitrate reduction, which is impossible in other polymorphs.

The current article reports the synthesis of graphitic carbon nitride (GCN), through simple thermal decomposition of urea at a moderate temperature of 550 °C and doping of as-developed material with transition element like nickel. The proper phase formation of the sample was confirmed by x-ray diffraction whereas electron microscopic images analyzed the sample morphologies. The successful doping was verified by x-ray photoelectron spectroscopy whereas thermogravimetric study predicted the stability of the material under elevated temperature. Fourier transformed infrared spectroscopy showed that after Ni doping there is a substantial change in the vibrational energy level of the sample. UV–vis reflectance spectra confirmed the reduction of optical bandgap after metal doping. The samples show promises towards supercapacitor application. Cyclic voltametric study shows that after metal doping the value of specific capacitance became 162 Fg⁻¹ at scan rate 5 mV s⁻¹ and when the same was calculated from galvanostatic charging–discharging characteristics the values came even higher. The energy and power density of both the samples was calculated and all these when compared with different reported results, confirmed the performance of Ni doped GCN is comparable and sometimes even far better along with the advantages of the easy, large scale and high yield synthesis approach.