The electrocatalytic transformation of carbon dioxide into valuable chemical compounds has gained increasing significance, particularly in the production of nitrogen-containing species via C-N bond formation. This review is organized around the “nitrogen source as the main thread, the product as the branch, and the mechanism as the underlying logic”, summarizing and discussing the latest research work on the formation of C-N bonds involving CO2 under electrochemical conditions. Firstly, these works are classified by the N-containing substrates (oxynitrides, dinitrogen gas, and ammonia) and productions (urea, amines, amides, carbamates, and amino acids). Then, various types of electrocatalysts are demonstrated in depth, including experimental and theoretical results. Finally, the conclusion is presented as well as the future perspectives.
The potential of Bixa orellana (annatto) pigments, specifically bixin and norbixin, as sensitizers for dye-sensitized solar cells (DSSCs) was investigated. The pigments were extracted using various solvents (acetone, methanol, ethanol, and hexane), and their optical and photo-electrical properties were investigated using UV-Vis spectroscopy and photoelectrical analysis. Results indicate that acetone extract (a-AP) exhibited the highest power conversion efficiency (PCE) of 0.786%, attributed to its broad absorption spectrum and optimal electronic properties. Quantum chemical calculations revealed that both bixin and norbixin exhibit favourable frontier orbital energies and energy gaps, making them well-suited for efficient electron injection and light absorption. These findings position Bixa orellana pigments as promising, eco-friendly alternatives to conventional synthetic sensitizers, offering a pathway toward more sustainable, locally adaptable, and efficient solar energy harvesting.