Lignin‐derived carbon quantum dots (L‐CDs) are promising sustainable nanomaterials with exceptional properties and broad applications. This review explores their synthesis, characteristics, and uses, highlighting the valorization of lignin, a renewable biopolymer, in line with green chemistry and bioeconomy principles. Transforming the lignin into L‐CDs leverages its high carbon content and structural properties, aligning with green chemistry and contributing to a sustainable bioeconomy. L‐CDs exhibit fluorescence, biocompatibility, and low toxicity, making them suitable for various applications. Hydrothermal and solvothermal methods are widely used, and the lignin source does not strongly influence L‐CD structure or size. Heteroatom doping, particularly with nitrogen and sulfur, enhances optical properties and functionality. Quantum yield values above 20% associated with higher dopant concentrations. Still, the effect of lignin's botanical origin on L‐CD properties remains unclear and needs further investigation. Despite progress, challenges remain in standardizing synthesis, optimizing production, and deepening structure–property understanding. In conclusion, L‐CDs offer significant potential as sustainable, functional nanomaterials. Future research should address existing gaps to unlock their full potential in advancing bioeconomy‐driven technologies.

Correct identification of species in wood and charcoal commerce is important, and rapid and nondestructive evaluation based on near-infrared techniques can be a good alternative. Four trees from Combretum leprosum, Croton argyrophylloides, Jatropha mutabilis, Luetzelburgia auriculata, Mimosa tenuiflora and Poincianella bracteosa, were cut in a natural forest in the municipality of Coremas, Paraíba state and stem discs with thickness of about 80 mm were taken at 0, 25, 50, 75 and 100% of commercial height. For charcoal production, each sample was wrapped in aluminum foil and carbonized in a muffle furnace, with a final temperature of 450 °C and a heating rate of 1,66 °C min^-1. Spectra were collected directly from sample surface. The best pretreatment was second derivative, while the best classification method was PCA-LDA, and the analysis of full spectra (4000-10000 cm^-1) was indicated. In classification, there was no difference between surfaces where spectra was collected, so in practice, in commercial control for example, the information can be obtained from any surface. For rapid analysis for purposes of control of forest practices or illegal commerce, spectra collected directly from wood and charcoal can be applied to distinguish these six Caatinga species.

The objective of this study was to use colorimetry and visible spectroscopy to discriminate wood species obtained from the Amazon floodplain, in addition to determining the basic density and relating it to the wood colorimetric parameters. The studied material was from a community forest management area in the state of Amazonas, Brazil. For colorimetric and visible spectrum analyses, data were obtained randomly in the transverse anatomical surface. The spectral behavior of the wood samples in the visible region was evaluated. In the statistical analyses, comparisons of colorimetric parameters and visible spectra of wood from floodplain tree species were carried out. Furthermore, the basic density of the wood was determined. The best differentiation of species was achieved mainly by the hue angle. The species Pseudobombax munguba (Mart.) Dugand presented the highest median for the coordinate of the red-green axis, and the medians of the species P. munguba and Hevea spruceana (Benth.) Müll.Arg. obtained higher values of the blue-yellow axis coordinate and saturation. All species evaluated were classified as light and having low-density wood. Thus, it can be concluded that the colorimetric technique has potential to distinguish Amazon floodplain forest species.

The aim of this study was to evaluate the potential of colorimetry to characterize six species (Hymenolobium petraeum, Dipteryx odorata, Ormosia sp., Enterolobium maximum, Hymenaea courbaril e Pseudopiptadenia suaveolens) of the Fabaceae family. Wood samples were collected in extractivist communities in Pará state, Brazil. Colour data were obtained randomly on the three anatomical sections, along with reflectance spectra in the range of 360–740 nm. All analyses were carried out with RStudio. In general, reflectance spectra were similar for all species. However, for the Principal Component Analysis results, P. suaveolens stood out. The colorimetric parameters L*, b* and C*, in radial sections, are more important on colour results of the majority of wood samples. Colorimetry spectroscopy showed potential for characterizing some Fabaceae species. Therefore, the technique can serve as a support tool for better identification of this group, contributing to the reduction of ecological and socio-economic damage.