The electrocatalytictransformation of carbon dioxide into valuable chemical compounds has gainedincreasing significance, particularly in the production of nitrogen-containingspecies via C-N bond formation. This review is organized around the “nitrogensource as the main thread, the product as the branch, and the mechanism as theunderlying logic”, summarizing and discussing the latest research work on theformation of C-N bonds involving CO₂ under electrochemicalconditions. 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 electrocatalystsare 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-sensitizedsolar cells (DSSCs) was investigated. The pigments were extracted using varioussolvents (acetone, methanol, ethanol, and hexane), and their optical andphoto-electrical properties were investigated using UV-Vis spectroscopy andphotoelectrical analysis. Results indicate that acetone extract (a-AP)exhibited the highest power conversion efficiency (PCE) of 0.786%, attributedto its broad absorption spectrum and optimal electronic properties. Quantumchemical calculations revealed that both bixin and norbixin exhibit favourablefrontier orbital energies and energy gaps, making them well-suited forefficient electron injection and light absorption. These findings position Bixaorellana pigments as promising, eco-friendly alternatives to conventionalsynthetic sensitizers, offering a pathway toward more sustainable, locallyadaptable, and efficient solar energy harvesting.

Silvernanoparticles (AgNPs) were synthesized using a protein/polypeptide-rich aqueousextract from the Eastern lubber grasshopper (Romalea microptera), as anatural reducing and capping agent. The resulting AgNPs exhibited relativelyuniform sizes (10-60 nm) and were characterized by FourierTransform Infrared Spectroscopy (FTIR), Ultraviolet-visible (UV-Vis)spectroscopy, Transmission electron microscopy (TEM), and Scanning Electron Microscopy (SEM). Disk diffusion tests against five bacterialstrains (Methicillin-resistant Staphylococcus aureus (MRSA), Burkholderia cenocepacia, Klebsiellapneumoniae, Pseudomonas aeruginosa, and Escherichia coli) demonstratedthat the insect-extract-induced AgNPs selectively and significantly inhibitedMRSA growth, with an average value of zone of inhibition of 9.16 ± 1.11 mm (n = 4). Statistical analysis confirmed the superiorantibacterial activity of the Eastern lubber grasshopper-derived AgNPs against MRSA comparedto citrate-capped AgNPs and free silver ions. Thesefindings reveal the potential of insect-derivedAgNPs as selective, green-synthesized antibacterial agents with enhancedefficacy and reduced side effects, particularly against antibiotic-resistantpathogens.

Hydrogenis an efficient, clean, and economical energy source, primarily due to itsremarkably high energy density. Electrolytic water is considered an attractiveand feasible method for hydrogen production. The high cost and scarcity oftraditional Pt-based catalysts limit their large-scale application. Transitionmetals (TMs)-based composites, particularly those integrated with carbonnanotubes (CNTs), have emerged as promising alternatives due to their highconductivity, surface area, and ability to enhance the catalytic properties ofTMs. Currently, there is no systematic summary of TMs-based CNTs composites forelectrochemical hydrogen evolution reaction (HER). In this review, the mainsynthesis methods, including the wet chemical method, chemical vapordeposition, and electrochemical techniques, were first summarized. Then, thelatest advancements of TMs/CNTs composites, focusing on their structure,electronic properties and superior HER catalytic performance, weresystematically discussed. The catalytic mechanisms are meticulously examined,with particular emphasis on the pivotal role of CNTs in enhancing chargetransfer and stabilizing metal nanoparticles. Finally, this review addressesthe current challenges and future development directions for HER catalysts.

Carbon dots (CDs) haveattracted considerable interest due to their unique photoluminescence and broadpotential in sensing, bioimaging, and optoelectronics. However, precise controlof their emission properties through molecular design and understanding ofsupramolecular aggregation remain challenging. Here, nitrogen-doped carbon dots(H-CDs) with green fluorescence are synthesized via an ethanol-mediatedsolvothermal method using 1,3-dihydroxynaphthalene as a rigid π-conjugatedcarbon source and 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) as both oxidantand nitrogen donor. The synthesis involves complexmolecular transformations yielding amorphous supramolecular carbon dotsstabilized mainly by noncovalent interactions. Characterization confirmedabundant oxygen- and nitrogen-containing functional groups and an amorphous structuredevoid of crystalline residues. Hierarchical H-type aggregation driven by π-πstacking and hydrogen bonding governs the photophysical behavior of the H-CDs,inducing a concentration-dependent evolution from blue-emitting monomers togreen-emitting supra-CDs, accompanied by particle growth, red-shifts in theemission spectrum, and a pronounced elongation of the fluorescence lifetime. Temperature- and salt-dependent studies reveal thatemission intensity increases with rising temperature and low ionic strength,due to distorted H'-aggregates with weak excitonic coupling and electrostaticscreening of surface charges. These insights deepen the understanding ofstructure-property relationships in carbon dots and offer guidance fortailoring their photophysical properties for advanced optoelectronicapplications.

In this study, we have investigated thestructural evolution of binary La-Ni alloy under different heat treatments bycombing single crystal X-ray diffraction (SXRD) as well as scanning electronmicroscope (SEM) and transmission electron microscopy (TEM). It has been foundthat LaNi and La₇Ni₃ can be successfully synthesizedthrough the arc melting method. Then it was found that LaNi₅ appearsin the binary La-Ni mixture wrapped by a Tantalum sheet, followed byhigh-temperature sintering. Next, some pilot experiments have been carried outon the La-Ni mixture by sealing tube technique with some residual oxygen.Serendipitously, oxidation has not been found while La₃Ni₃Si₂ and La₂NiSi besides LaNi phase show up. Meanwhile, the detailedcrystal structure information and their topological features of theaforementioned phases as well as their high-resolution TEM images, have beenobtained. Furthermore, the orientation relationships of the Si-contaminatedmixed phases have been thoroughly investigated by advanced precession images ofSXRD patterns.