An integrated approach combining thermal and electrochemical technologies for the valorization of agro-industrial waste. The resulting carbon dots (CDs) show fascinating optical properties, enabling their application as fluorescent chemical probes.

Access to clean and safe water sadly remains an issue in the 21 ^st century. Water reservoirs, whether groundwater or surface water, are routinely contaminated by various harmful Emerging Contaminants (ECs). One of most prevalent pollutants among these pollutants is Bisphenol A, which is classified as an Endocrine Disrupting Compound (EDC). This substance adversely interferes with the endocrine system, primarily by mimicking estrogen, and has been considered a potential contributor to Polycystic Ovary Syndrome (PCOS) with 82.70 % of 1,391 women studied showing a positive correlation between BPA exposure and PCOS. PCOS is currently the most prevalent endocrine disorder affecting women of reproductive age; however, its pathogenesis remains unclear, complicating diagnosis and subsequently patient care. In this review, these topics are thoroughly examined, with particular emphasis on biochar, a new promising method for large‐scale water purification. Biochar, derived from various organic waste materials, has emerged as a cost‐effective substance with remarkable adsorption properties achieving up to 88 % efficiency over four cycles of reuse, similar to that of activated carbon. This review interrogates the suitability of biochar for counteracting the issue of EDC pollutants.

Rationale: The occurrence of N ‐heterocyclic carbenes in imidazolium‐based ionic liquids has long been discussed, but no spectroscopic evidence has been reported yet due to their transient nature. The insertion of an ionizable acid group into the cation scaffold of an ionic liquid which acts as a charge tag allows for the direct detection of free carbenes by mass spectrometry. Methods: Three different Brønsted acidic ionic liquids were synthesized: 1‐methyl‐3‐carboxymethylimidazolium chloride (MAICl), 1‐methyl‐3‐carboxymethylimidazolium acetate (MAIAc) and the corresponding 2‐(3‐methyl‐1 H ‐imidazol‐3‐ium‐1‐yl)acetate zwitterion (MAI − H). The speciation of these compounds was then analysed by electrospray ionization ion‐trap mass spectrometry in the negative ion mode. Results: The C2‐H deprotonation of the imidazolium cation leading to the formation of the corresponding carbene is highly affected by the basic properties of the counter‐anion. In the case of MAICl and MAI − H ionic liquids, no charged species corresponding to the free N ‐heterocyclic carbene was detected. On the contrary, in the presence of a sufficiently basic anion, such as acetate of MAIAc ionic liquid, an intense signal related to the free carbenic species was observed without the addition of an external base. Conclusions: In situ formation of free N ‐heterocyclic carbenes from Brønsted acidic ionic liquids was demonstrated, highlighting the crucial role of anion basicity in promoting the C2‐H proton abstraction from imidazolium cations with a carboxylic side chain.

Photoinduced chemical reactions and the development of new materials represent a current and significant topic. We present a sustainable and eco-friendly approach to the Knoevenagel condensation reaction involving carbonyl and active methylene compounds. Our method utilizes photo-activated carbon dots (CDs) derived from 5-hydroxymethylfurfural (5HMF) within an aqueous medium and does not require acidic, basic, or thermal conditions. This protocol operates effectively with aromatic, aliphatic, and heteroaromatic aldehydes and ketones. The 5HMF-derived-CDs can be reused four times without significant loss of activity. Moreover, this methodology is suitable for scaling up reactions, thereby highlighting its potential for industrial applications.