Tuning mono-divalent cation water composition by the capacitive ion-exchange mechanism.

Soil salinization poses a significant challenge to agricultural activities. To address this, the agricultural industry seeks an irrigation water solution that reduces both ionic conductivity and sodium adsorption rate (SAR), thereby diminishing the risks of soil sodification and fostering sustainable crop production. Capacitive deionization (CDI) is an attractive electrochemical technology to advance this search. Recently, a one-dimensional transient CDI model unveiled a capacitive ion-exchange mechanism presenting the potential to adjust the treated water composition by modifying monovalent and divalent cation concentrations, thereby influencing the SAR index. This behavior would be achieved by using electrodes rich in surface functional groups able to efficiently capture divalent cations during conditioning and releasing them during charging while capturing monovalent ions. Beyond the theoretical modelling, the current experimental research demonstrates, for the first time, the effectiveness of the capacitive ion-exchange mechanism in a CDI pilot plant using real water samples spiked with solutions containing specific mono and divalent ions. Electrosorption experiments and computational modeling, specifically Density-Functional Theory (DFT), were used along with the analysis of the surface functional groups present in the electrodes to describe the capacitive ion-exchange phenomenon and validate the steps involved on it, highlighting the conditioning as a critical step. Various operational and flow modes confirm the versatility of CDI technology, achieving separation factors (RMg/Na) of 5-6 in batch, raising production from 0.5 to 0.8 L m-2 h-1 (batch) to 8.0-8.1 L m-2 h-1 when using single pass although reducing RMg/Na to 2. The reliability of the CDI technology in reducing SAR was also successfully tested with different influent compositions, including magnesium and calcium. Finally, the robustness of the capacitive ion-exchange mechanism was validated by a second CDI laboratory 9-cell stack cycled over 350 cycles. Our results confirm the reported theoretical model and expands the conclusions through the experiments in a pilot plant showing direct implications for employing CDI in agricultural applications.

Eco-Friendly Synthesis of 3D Disordered Carbon Materials for High-Performance Dual Carbon Na-Ion Capacitors.

An eco-friendly and sustainable salt-templating approach was proposed for the production of anode materials with a 3D sponge-like structure for sodium-ion capacitors using gluconic acid as carbon precursor and sodium carbonate as water-removable template. The optimized carbon material combined porous thin walls that provided short diffusional paths, a highly disordered microstructure with dilated interlayer spacing, and a large oxygen content, all of which facilitated Na ion transport and provided plenty of active sites for Na adsorption. This material provided a capacity of 314 mAh g-1 at 0.1 A g-1 and 130 mAh g-1 at 10 A g-1 . When combined with a 3D highly porous carbon cathode (SBET ≈2300 m2 g-1 ) synthesized from the same precursor, the Na-ion capacitor showed high specific energy/power, that is 110 Wh kg-1 at low power and still 71 Wh kg-1 at approximately 26 kW kg-1 , and a good capacity retention of 70 % over 10000 cycles.

Augmented Reality, a Review of a Way to Represent and Manipulate 3D Chemical Structures.

Augmented reality (AR) is a mixed technology that superimposes three-dimensional (3D) digital data onto an image of reality. This technology enables users to represent and manipulate 3D chemical structures. In spite of its potential, the use of these tools in chemistry is still scarce. The aim of this work is to identify the real situation of AR developments and its potential for 3D visualization of molecules. A descriptive analysis of a selection of 143 research publications (extracted from Web of Science between 2018 and 2020) highlights some significant AR examples that had been implemented in chemistry, in both education and research environments. Although the traditional 2D screen visualization is still preferred when teaching chemistry, the application of AR in early education has shown potential to facilitate the understanding and visualization of chemical structures. The increasing connectivity of the AR technology to web platforms and scientific networks should translate into new opportunities for teaching and learning strategies.

Fast and Chemoselective Addition of Highly Polarized Lithium Phosphides Generated in Deep Eutectic Solvents to Aldehydes and Epoxides.

Highly polarized lithium phosphides (LiPR2 ) were synthesized, for the first time, in deep eutectic solvents as sustainable reaction media, at room temperature and in the absence of protecting atmosphere, through direct deprotonation of both aliphatic and aromatic secondary phosphines (HPR2 ) by n-BuLi. The subsequent addition of in-situ generated LiPR2 to aldehydes or epoxides proceeded quickly and chemoselectively, thereby allowing the straightforward access to the corresponding α- or ß-hydroxy phosphine oxides, respectively, under air and at room temperature (bench conditions), which are traditionally considered as textbook-prohibited conditions in the field of polar organometallic chemistry of s-block elements.