RSC Advances

Zhang, Guangyao; Fan, Deqi; Li, Zongze; Li, Yingying; Lu, Yi

doi: 10.1039/d5ra01735apmid: 40385659

Solar-driven interfacial evaporation has emerged as a sustainable solution to address global freshwater scarcity by converting solar energy into thermal energy for efficient water purification. To achieve rapid and energy-efficient steam generation, the development of advanced photothermal materials with optimized light absorption and water activation remains critical. Here, we present a three-dimensional polyvinyl alcohol/chitosan/Nb2C MXene (PCN) hydrogel engineered for high-performance solar evaporation. The composite integrates Nb2C MXene nanosheets into a hydrophilic polymer matrix through hydrogen bonding and electrostatic interactions, forming interconnected microchannels that enable broadband solar absorption (93% across 300–2500 nm) via MXene's plasmonic effects and light-trapping architecture. The synergistic combination of rapid water transport and weakened hydrogen bonding within the hydrated network significantly reduces the evaporation enthalpy to 1426 J g−1. This design achieves an exceptional evaporation rate of 2.72 kg m−2 h−1 and a solar-to-vapor conversion efficiency of 93.2% under 1 sun irradiation, surpassing conventional hydrophilic polymer-based systems. The hydrogel's hierarchical porous structure facilitates effective thermal localization and sustains stable evaporation across varying solar intensities (1–5 sun), demonstrating adaptability for scalable applications. This work provides a rational strategy to design MXene-enhanced hydrogels for practical solar desalination and wastewater purification technologies.

Jiang, Shanshan

doi: 10.1039/d5ra90061apmid: 40385645

Retraction of ‘Palladium complex supported on the surface of magnetic Fe3O4 nanoparticles: an ecofriendly catalyst for carbonylative Suzuki-coupling reactions’ by Shanshan Jiang, RSC Adv., 2023, 13, 34273–34290, https://doi.org/10.1039/D3RA06533B.

Li, Minyu; Zhou, Yifan; Lin, Lingling; Li, Wenmu

doi: 10.1039/d5ra01675dpmid: 40385655

The utilization of harsh chemicals is obligatory during the preparation of biomass-derived carbon materials. ZIF-8 serves as a zinc-based metal–organic framework (MOF), in which the internal zinc ions (Zn2+) are reduced to metallic Zn during high-temperature pyrolysis, which then evaporates and etches the carbon skeleton, significantly increasing the specific surface area and porosity of the material. In the current work, the ZIF-8 and the legume root nodules were used as an activator and biomass precursors to develop a more atom-economical and eco-friendly strategy for the preparation of porous carbon materials. The roles the ZIF-8 and the species of legume root nodules play in the structure and performance of the final carbon materials were well explored and discussed. The specific surface area of our optimal carbon RW@Z8(5) is up to 1459.27 m2 g−1. The catalyst RW@Z8(5) was employed in fuel cells for the oxygen reduction reaction (ORR) and demonstrated a half-wave potential (E1/2) of 0.720 V (vs. RHE) in 0.1 M HClO4, which is only 88 mV lower than that of the Pt/C catalyst. Our results prove the possibility of the metal–organic framework (MOF) activation strategy for the development of biomass-derived porous carbon materials.

Kim, Han Byeol; Han, Dong Kyun; Lee, Jae Kyun; Han, Seo-Jung

doi: 10.1039/d5ra02693hpmid: 40385661

We reported a metal-free electrochemical oxidative C–O homocoupling of 2-naphthols, followed by subsequent alkoxylation under mild conditions. This strategy offered an eco-friendly and cost-effective electrochemical approach using undivided cells. Additionally, the reaction exhibited broad tolerance to various substituted 2-naphthols and diverse alcohols, affording the corresponding naphthalenones in moderate to good yields.

Wang, Jingyi; Gil-Herrera, Luz Karime; Akbulut, Ozge; Dumanli, Ahu Gümrah

doi: 10.1039/d5ra01045dpmid: 40385658

Immobilisation of fluorescent carbon dots (C-dots) in a hydrogel matrix, such as alginates, prevents fluorescence quenching in bioimaging and biosensing applications. However, critical parameters influencing the fluorescence, including the diffusion kinetics of C-dots and their distribution within the hydrogel matrix, remain unexplored. Herein, we investigated two distinct methods for immobilising C-dots within alginate hydrogel beads: (i) adsorption and (ii) premixing the C-dots prior to hydrogel cross-linking. Our batch adsorption experiments and kinetic model fittings revealed rapid, concentration-dependent diffusion from the external solution to the beads, along with their binding to surface active sites. The rate-determining step was the diffusion into interconnecting layers within the matrix, which impacts both diffusion rates and the overall distribution of C-dots within the beads. The fluorescence signal in the hydrogel matrix from the adsorption method exhibited limited penetration depth compared to the premixed method, which showed a more uniform distribution. We demonstrated that C-dots are well-immobilised and interact effectively with the hydrogel matrix, exhibiting stable fluorescence intensities and improved structural integrity. Our findings provide valuable insights into the interaction and diffusion of C-dots in hydrogel systems and will help advance research on the fluorescence properties of C-dots for bioimaging and bio-sensing applications.

Sumayya, ; Butt, Sajid; Irfan, Muhammad; Basit, Muhammad Abdul; Khan, Abdul Faheem; Ansar, Zaka

doi: 10.1039/d5ra00856epmid: 40385643

Indium tin oxide (ITO) has been widely investigated for optoelectronic applications. However, the current study focuses on the thermoelectric aspects of ITO thin films. The thermoelectric transport properties of ITO have been further improved through a facile method of silver (Ag) incorporation into ITO thin films. The Ag incorporation introduces a secondary phase, as inferred from detailed structural characterizations, which leads to the creation of heterogeneous interfaces that help in tuning the thermoelectric properties. These interfaces act as carrier scattering centers which lower the carrier's mobility and result in a simultaneous enhancement of the electrical conductivity and Seebeck coefficient. As a consequence, the power factor reached the highest value of 31.75 μW m−1 K−2 at 625 K, which is about 100% higher than that of the pure ITO. Furthermore, by merely relying on electronic thermal conductivity, a slightly overestimated ZT value of 0.15 has been achieved for the optimized Ag content. The proposed simple and rapid route paves the way to further explore the potential of ITO thin films for thermoelectric applications in smart energy conversion and heating–cooling devices.

Mäkinen, Mario; Laasonen, Kari

doi: 10.1039/d5ra00686dpmid: 40385647

ALD/MLD hybrid thin films can be fabricated by combining atomic and molecular layer deposition (ALD and MLD). Density functional theory (DFT) can be used to determine the reaction paths of the growth reactions of these hybrid thin films. In this study, DFT was utilized to investigate the reaction mechanisms between diethyl zinc and 4-aminophenol using a surface model to examine the reactions responsible for the structure of the zincone thin film. The most feasible reaction path for the film growth was discovered. The effects of reconstructions, steric repulsion and functional group reactivity on the growth rate were also discussed in this study. Additionally, we compared the thin film growth reactions between diethyl zinc and thirteen organic bifunctional precursors using gas-phase calculations. This allowed us to create a trend for the reactivity of the precursors based on their functional groups, which can be used to aid in experimental precursor selection. We also established a connection between the bond strengths of the reacting precursors and the durability of the hybrid thin film in ambient conditions.

Soheili, Saeedeh; Pour, Ali Nakhaei

doi: 10.1039/d5ra02292dpmid: 40385650

Methanol-to-olefins (MTO) conversion is a crucial industrial process for producing valuable light olefins, but developing highly efficient and selective catalysts remains a significant challenge. The incorporation of zirconium has been shown to enhance the catalytic performance of MTO catalysts. In this study, periodic density functional theory (DFT) calculations were employed to investigate the stability and reactivity of zirconium species within the SAPO-18 framework. Results revealed that loading Zr3+ ions into 6-membered rings (6MRs) of the SAPO-18 framework (Zr-ZH) was the most favorable configuration for producing propylene, with a lower activation energy (0.46 eV) than that required for loading Zr4+ ions into 8-membered rings (8MRs) (Zr-ZOH). Analysis of Mulliken charges and partial density of states (DOS) suggested that the incorporation of zirconium into the SAPO-18 framework enhanced the electronic properties of the catalyst, leading to a significant increase in propylene selectivity. In summary, the DFT calculations provided valuable insights into the preferred coordination environments and electronic structures of zirconium species in the SAPO-18 catalyst. These results suggest that optimizing zirconium incorporation can lead to significant improvements in the catalytic performance of MTO processes, particularly with respect to propylene selectivity.

Alqahtani, Saud; Alqahtani, Ali; Alqahtani, Taha; Al Fatease, Adel; Almrasy, Ahmed A.

doi: 10.1039/d5ra01945apmid: 40385648

Diabetes management has increasingly relied on dipeptidyl peptidase-4 inhibitors like linagliptin, creating a need for environmentally sustainable analytical methods to replace conventional chromatographic techniques that often involve complex sample preparation, organic solvent usage, and expensive instrumentation. A sensitive and selective “turn-off” fluorescence quenching method was developed and validated for the determination of linagliptin using eosin Y as the fluorescent probe. The spectral characteristics and sensing mechanisms were investigated using Stern–Volmer analysis, Job's method, and thermodynamic studies, revealing a static quenching process driven by the formation of a non-fluorescent 1 : 1 linagliptin–eosin Y complex with a high Stern–Volmer constant (Ksv = 6.46 × 105 M−1). The influencing factors, including pH, buffer volume, eosin Y concentration, and incubation time, were optimized using a Box–Behnken experimental design. A significant reduced quadratic regression model was established, and the optimal conditions were found to be pH 5.25, buffer volume of 1 mL, eosin Y volume of 1.25 mL, and an incubation time of 5 min based on desirability function analysis that maximizes the quenching efficiency. The developed method demonstrated linearity in the range of 0.1–3.0 μg mL−1 with a correlation coefficient of 0.9999, a limit of detection of 0.03 μg mL−1, and accuracy of 99.59 ± 1.360%, in accordance with ICH guidelines. Selectivity was confirmed by the lack of interference from common pharmaceutical excipients and endogenous plasma components. The eosin Y-based fluorescence quenching method was successfully applied for the determination of linagliptin in pharmaceutical dosage forms and spiked human plasma samples. Statistical comparison of the proposed method with the reported HPLC-UV method revealed comparable analytical performance as evident by non-significant differences in the accuracy and precision profiles as well as interval equivalence testing. Furthermore, a comprehensive assessment of the environmental impact and analytical practicality of the proposed method was conducted, confirming its “green” and “blue” analytical profile. These findings establish the eosin Y-based fluorescence quenching method as a viable and environmentally friendly alternative for the routine analysis of linagliptin in various pharmaceutical and bioanalytical applications shedding light on the potential of spectrofluorometric techniques in green analytical chemistry and bioanalysis.

Yin, Le; Wang, Kai; Jiang, Liping; Xi, Yang; Xu, Ziyi; Song, Zewen; Zhou, Haijun

doi: 10.1039/d5ra00872gpmid: 40385652

In this study, Fe3O4/chitosan/polypyrrole (Fe3O4/CS/PPy) magnetic adsorbents were successfully synthesized using the in situ chemical oxidation polymerization method. These adsorbents were characterized by SEM, FT-IR, TGA, and XPS. The results of batch adsorption experiments showed that the Fe3O4/CS/PPy composite exhibited a maximum adsorption capacity of 193.23 mg g−1 in a 100 mg L−1 Cr(vi) solution at 298 K, with a pH of 2.0. The adsorption behavior of the adsorbent to Cr(vi) was in good agreement with the Langmuir isothermal model and the quasi-second-order kinetic model. Thermodynamic studies indicated that the process of adsorption was spontaneous and endothermic. The mechanism of adsorption may be attributed to electrostatic interactions and chemical reduction. After five cycles, the removal efficiency of the Fe3O4/CS/PPy composite for Cr(vi) has consistently remained at 84.32%. Overall, the Fe3O4/CS/PPy composite exhibits great potential as an adsorbent for effectively removing Cr(vi) from aqueous solutions.