Molecules

Research

18 pages, 4452 KB

Open AccessArticle

An Efficient Phosphorus Adsorbent Prepared from Calcium/Iron-Rich Storm Sewer Sludge: Performance and Mechanism

by Yan Wu, Jinhui Chen, Luyue Zhang, Yi Chen, Haiyan Ye and Qingguo Wang

Molecules 2026, 31(14), 2534; https://doi.org/10.3390/molecules31142534 - 21 Jul 2026

Viewed by 377

Calcium- and iron-rich sludge from urban storm sewer is an ideal source of phosphorus adsorbents. This study used urban storm sewer sludge to prepare phosphorus adsorbents via pyrolysis. Comparing adsorbents prepared under different conditions, the optimal material was produced at 800 °C in [...] Read more.

Calcium- and iron-rich sludge from urban storm sewer is an ideal source of phosphorus adsorbents. This study used urban storm sewer sludge to prepare phosphorus adsorbents via pyrolysis. Comparing adsorbents prepared under different conditions, the optimal material was produced at 800 °C in a nitrogen atmosphere and was named 800N. Analyses were conducted using scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, Brunauer–Emmett–Teller surface area analysis, and X-ray photoelectron spectroscopy. The results showed that 800N is rich in carbon, calcium, and iron. The adsorbent has a pore volume of 0.013 cm³/g and a specific surface area of 3.566 m²/g. Adsorption performance was most effective at a pH of 8, achieving an adsorption capacity (q_e) of 19.32 mg/g and a removal rate of 87.75%. Kinetic and thermodynamic studies revealed that the adsorption of phosphorus by the adsorbent conforms to the pseudo-second-order kinetic model and the Langmuir isotherm model. Based on the characterization results, it can be reasonably inferred that the primary mechanisms involved in phosphorus adsorption by the adsorbent are inner-sphere complexation, ligand exchange, and chemical precipitation. This study offers a novel solution for mitigating phosphorus pollution and promoting the resource utilization of urban storm sewer sludge. Full article

(This article belongs to the Special Issue 5th Anniversary of the "Applied Chemistry" Section)

► Show Figures

Figure 1

18 pages, 8035 KB

Open AccessArticle

Cu-MOF-Derived Nano-Dendritic Self-Supported Electrodes for Efficient Electrochemical Nitrate-to-Ammonia Conversion

by Linfeng Qi, Yu’an Gao, Xiangyan Zhong, Yunxiang Liang, Shijing Yuan and Shaojun Yuan

Molecules 2026, 31(13), 2307; https://doi.org/10.3390/molecules31132307 - 1 Jul 2026

Viewed by 493

Abstract

Electrochemical nitrate reduction reaction (eNO₃RR) has emerged as a promising alternative to the energy-intensive and carbon-intensive Haber–Bosch process for green ammonia synthesis. However, the intrinsic complexity of the eight-electron transfer pathway and inevitable competing side reactions limit the activity and selectivity [...] Read more.

Electrochemical nitrate reduction reaction (eNO₃RR) has emerged as a promising alternative to the energy-intensive and carbon-intensive Haber–Bosch process for green ammonia synthesis. However, the intrinsic complexity of the eight-electron transfer pathway and inevitable competing side reactions limit the activity and selectivity of eNO₃RR. Maximizing the utilization of active sites and ensuring structural stability in electrocatalysts are essential for promoting surface proton-coupled electron transfer and improving Faradaic efficiency. Herein, we present a copper metal–organic framework (Cu-MOF)-derived electrocatalyst synthesized via in situ electrosynthesis on copper foam, using cetyltrimethylammonium bromide (CTAB) as a structure-directing agent, followed by electroreduction to produce a self-supported, nano-dendritic structure. This three-dimensional architecture exposes abundant active sites and facilitates electron transport, enabling efficient nitrate-to-ammonia conversion. The optimized CTAB-assisted electrode achieves an ammonia yield of 14.33 ± 0.61 mg h⁻¹ cm⁻² with a Faradaic efficiency of 90.95 ± 2.28% at −1.7 V versus Ag/AgCl. This study introduces a versatile design strategy for copper-based electrocatalysts that integrates structural stability with high activity, offering a sustainable approach for both ammonia production and nitrate remediation. Full article

(This article belongs to the Special Issue 5th Anniversary of the "Applied Chemistry" Section)

► Show Figures

Figure 1

14 pages, 3365 KB

Open AccessArticle

Construction of Sulfhydryl-Amino UiO-66/PVDF Membranes via Morphology Regulation for the Selective Separation of Artesunate

by Kunyi Li, Ziyang Wang, Lingna Meng and Minjia Meng

Molecules 2026, 31(11), 1885; https://doi.org/10.3390/molecules31111885 - 1 Jun 2026

Viewed by 382

Abstract

Artesunate (ARU), a key derivative of artemisinin (ART), exhibits excellent water solubility and antimalarial activity due to its incorporation of a succinic acid group. However, the synthesis process of ARU often leaves behind ART with a highly similar structure and properties, making traditional [...] Read more.

Artesunate (ARU), a key derivative of artemisinin (ART), exhibits excellent water solubility and antimalarial activity due to its incorporation of a succinic acid group. However, the synthesis process of ARU often leaves behind ART with a highly similar structure and properties, making traditional separation methods ineffective for efficient separation. Developing selective separation technologies holds significant importance. Based on previous studies, in work involving the preparation of bidentate MOFs with different ligands, bidentate MOFs containing thiol/amino groups have been found to exhibit outstanding adsorption capacity and selectivity for ARU molecules. Among these, -NH₂ forms hydrogen bonds with -COOH in ARU, while -SH interacts non-specifically with Aru, significantly enhancing the adsorption effect. This study employed a delayed inversion method to prepare a sulfhydryl-amino UiO-66/PVDF hybrid membrane (UiO-66-SH/NH₂/PVDF) by adjusting the composition of the coagulation bath, which was used for efficient separation of ART/ARU. The effects of ethanol ratio in the coagulation bath on membrane structure and performance were systematically investigated. Results showed that increasing the ethanol ratio delays phase transition, promotes MOF material enrichment on membrane pore surfaces, and forms more abundant pore structures. When the ethanol-to-water volume ratio was 1:1, the UiO-66-SH/NH₂/PVDF membrane exhibited optimal pore structure and highest water flux. Static permeation experiments demonstrated that the membrane achieved effective separation of ARU and ART for 8 h, maintaining stable selective adsorption performance after five cycles. This study reveals the critical role of morphology regulation in separating structural analogs, providing new materials and theoretical foundations for efficient separation of artemisinin-based compounds. Full article

(This article belongs to the Special Issue 5th Anniversary of the "Applied Chemistry" Section)

► Show Figures

Graphical abstract

26 pages, 6250 KB

Open AccessArticle

Electrospun Fibers Encapsulating Triticum vulgare Extract as a Potential Scaffold for the Regeneration of Subepithelial Connective Tissue

by Leydy Tatiana Figueroa-Ariza, Willy Cely-Veloza, Miguelángel Coccaro, Diego Fernando Gualtero, Ronald Andrés Jiménez, Ericsson Coy-Barrera, Ana Delia Pinzón-García, Yamil Lesmes, Leandro Chambrone and Gloria Inés Lafaurie

Molecules 2026, 31(9), 1505; https://doi.org/10.3390/molecules31091505 - 1 May 2026

Viewed by 647

Abstract

Electrospun poly(ε-caprolactone) (PCL) membranes incorporating Triticum vulgare extract (TVE) were developed as biomimetic scaffolds for periodontal regeneration. Using a ternary solvent system, two experimental formulations (µF-P10 and µF-P10T1) were fabricated and compared against a commercial dermal matrix. SEM analysis revealed bimodal fiber distributions [...] Read more.

Electrospun poly(ε-caprolactone) (PCL) membranes incorporating Triticum vulgare extract (TVE) were developed as biomimetic scaffolds for periodontal regeneration. Using a ternary solvent system, two experimental formulations (µF-P10 and µF-P10T1) were fabricated and compared against a commercial dermal matrix. SEM analysis revealed bimodal fiber distributions (0.77–1.74 µm) and a surface porosity of 29.86% for TVE-loaded membranes, significantly higher than that of the commercial control (25.26%). FT-IR confirmed that the PCL chemical integrity was preserved, while mechanical testing showed that extract incorporation reinforced the matrix, increasing the Young’s modulus from 2.90 × 10³ Pa to 3.54 × 10³ Pa. UHPLC–MS identified ferulic acid as the primary bioactive component (90%), with release kinetics following a first-order model (R² = 0.998) over 48 h. Biological assays with human gingival fibroblasts (HGF) confirmed non-cytotoxicity (>70% viability). While both membranes supported healing, the µF-P10 formulation showed superior performance, with 80.2% proliferation and 60.6% wound closure, approaching control levels. These findings demonstrate that PCL-TVE electrospun scaffolds effectively combine favorable morphology and controlled release, offering a promising alternative for subepithelial connective tissue regeneration. Full article

(This article belongs to the Special Issue 5th Anniversary of the "Applied Chemistry" Section)

► Show Figures

Graphical abstract

14 pages, 2296 KB

Open AccessArticle

A Potential Pathway for the Synthesis of Biomass-Based Polyamide Monomer 2,5-Bis(aminomethyl)furan from 2,5-Furandicarboxylic Acid

by Cong Wang, Xin Li, Junqi Zhao, Bin Sun, Enquan Wang, Xuhong Mu and Xiaoxin Zhang

Molecules 2025, 30(22), 4336; https://doi.org/10.3390/molecules30224336 - 8 Nov 2025

Cited by 1 | Viewed by 1138

Abstract

In this study, the transformation of 2,5-furandicarboxylic acid (FDCA) to 2,5-bis(aminomethyl)furan (BAMF) is proposed and investigated for the first time. Using FDCA as the substrate, the process involves two key steps: first, converting FDCA to 2,5-dicyanofuran (DCF) via carboxy-cyanation, followed by the heterogeneous [...] Read more.

In this study, the transformation of 2,5-furandicarboxylic acid (FDCA) to 2,5-bis(aminomethyl)furan (BAMF) is proposed and investigated for the first time. Using FDCA as the substrate, the process involves two key steps: first, converting FDCA to 2,5-dicyanofuran (DCF) via carboxy-cyanation, followed by the heterogeneous catalytic hydrogenation of DCF to produce BAMF. For the carboxy-cyanation, two ammoniation routes were compared, including the molten ammoniated dehydration route and the moderate ammoniated dehydration route. The difference between the ammoniation of bio-based cyclic dicarboxylic acid and that of petroleum-based aliphatic dicarboxylic acid was discovered. A moderate ammoniated dehydration route that is more suitable for bio-based cyclic dicarboxylic acid has been developed. SOCl₂ was found to effectively activate the stable carboxyl group and act as a dehydrating agent, facilitating the dehydration of the intermediate 2,5-furandicarboxamide (FDAM) to DCF with higher efficiency. For the hydrogenation reaction of DCF, Raney Co exhibited excellent catalytic performance, achieving a 94.5% yield of BAMF from DCF. Based on industrial practice, this research represents the first exploration of the pathway from bio-based FDCA to BAMF, which opens a new line for the sustainable production of bio-based diamines. Full article

(This article belongs to the Special Issue 5th Anniversary of the "Applied Chemistry" Section)

► Show Figures

Graphical abstract

16 pages, 2870 KB

Open AccessArticle

Coupling Rare-Earth Complexes with Carbon Dots via Surface Imprinting: A New Strategy for Spectroscopic Cu²⁺ Sensors

by Zuoyi Liu, Bo Hu and Minjia Meng

Molecules 2025, 30(19), 3967; https://doi.org/10.3390/molecules30193967 - 2 Oct 2025

Cited by 1 | Viewed by 956

Abstract

A surface molecularly imprinted ratiometric fluorescent sensor (Eu/CDs@SiO₂@IIPs) was constructed for the selective and visual detection of Cu²⁺. The sensor integrates blue-emitting carbon dots as an internal reference and a custom-designed Eu(III) complex, Eu(MAA)₂(2,9-phen), as both the [...] Read more.

A surface molecularly imprinted ratiometric fluorescent sensor (Eu/CDs@SiO₂@IIPs) was constructed for the selective and visual detection of Cu²⁺. The sensor integrates blue-emitting carbon dots as an internal reference and a custom-designed Eu(III) complex, Eu(MAA)₂(2,9-phen), as both the functional and fluorescent monomer within a surface-imprinted polymer layer, enabling efficient ratiometric fluorescence response. This structural design ensured that all fluorescent monomers were located at the recognition sites, thereby reducing background fluorescence interference and enhancing the accuracy of signal changes. Under optimized conditions, the sensor exhibited a detection limit of 2.79 nM, a wide linear range of 10–100 nM, and a rapid response time of 3.0 min. Moreover, the uncoordinated nitrogen atoms in the phenanthroline ligand improved resistance to interference from competing ions, significantly enhancing selectivity. Practical applicability was validated by spiked recovery tests in deionized and river water, with results showing good agreement with ICP-MS analysis. These findings highlight the potential of Eu/CDs@SiO₂@IIPs as a sensitive, selective, and portable sensing platform for on-site monitoring of Cu²⁺ in complex water environments. Full article

(This article belongs to the Special Issue 5th Anniversary of the "Applied Chemistry" Section)

► Show Figures

Figure 1

9 pages, 584 KB

Open AccessCommunication

Green Synthesis of Trifluoromethanesulfonyl Fluoride as an Eco-Friendly Alternative to SF₆ Gas Insulation and Analysis of Its Acute Inhalation Toxicity

by Shile Wang, Li Dong, Ruichao Peng and Hongding Tang

Molecules 2025, 30(10), 2241; https://doi.org/10.3390/molecules30102241 - 21 May 2025

Cited by 3 | Viewed by 1642

Abstract

This study demonstrates an eco-friendly synthesis of trifluoromethanesulfonyl fluoride (TFSF) as a sustainable SF₆ alternative. Optimized halogen exchange reactions using CF₃SO₂Cl/KF (3:1 ratio) with crown ether catalysis at low temperatures achieved 65% TFSF yield (97.9% purity). Scale-up trials [...] Read more.

This study demonstrates an eco-friendly synthesis of trifluoromethanesulfonyl fluoride (TFSF) as a sustainable SF₆ alternative. Optimized halogen exchange reactions using CF₃SO₂Cl/KF (3:1 ratio) with crown ether catalysis at low temperatures achieved 65% TFSF yield (97.9% purity). Scale-up trials in pressurized reactors showed >50% conversion and >90% selectivity. Acute inhalation tests (OECD standards) on Sprague-Dawley rats revealed transient toxicity at 20,000 ppm (4 h exposure), with survival rates >66% and LC₅₀ exceeding 22,600 ppm—significantly safer than SF₆. These findings confirm TFSF’s technical viability and low toxicity, positioning it as a practical insulating medium to curb SF₆ emissions. The methodology highlights precision halogen exchange control and systematic safety validation, offering actionable solutions for industrial adoption. Full article

(This article belongs to the Special Issue 5th Anniversary of the "Applied Chemistry" Section)

► Show Figures

Figure 1

16 pages, 6706 KB

Open AccessArticle

Enhanced Efficiency and Stability of Perovskite Solar Cells Through Neodymium-Doped Upconversion Nanoparticles with TiO₂ Coating

by Masfer Alkahtani, Bayan Alshehri, Hadeel Alrashood, Latifa Alshehri, Yahya A. Alzahrani, Sultan Alenzi, Ibtisam S. Almalki, Ghazal S. Yafi, Abdulmalik M. Alessa, Faisal S. Alghannam, Abdulaziz Aljuwayr, Nouf K. AL-Saleem, Anwar Alanazi and Masud Almalki

Molecules 2025, 30(10), 2166; https://doi.org/10.3390/molecules30102166 - 14 May 2025

Cited by 6 | Viewed by 2856

Abstract

This study presents an effective strategy to enhance the efficiency and stability of perovskite solar cells (PSCs) by integrating neodymium-doped upconversion nanoparticles (UCNPs) coated with a TiO₂ shell into the mesoporous electron transport layer. The incorporation of neodymium (Nd³⁺) as [...] Read more.

This study presents an effective strategy to enhance the efficiency and stability of perovskite solar cells (PSCs) by integrating neodymium-doped upconversion nanoparticles (UCNPs) coated with a TiO₂ shell into the mesoporous electron transport layer. The incorporation of neodymium (Nd³⁺) as a novel sensitizer shifts the near-infrared (NIR) absorption band away from the water vapor absorption region in the solar spectrum. This modification enables UCNPs to efficiently convert NIR light into ultraviolet (UV) and blue wavelengths, which are readily absorbed by TiO₂, generating additional charge carriers and improving photovoltaic performance. The optimized PSCs, fabricated by blending 30% UCNPs@TiO₂ with commercial TiO₂ paste, achieved a peak power conversion efficiency (PCE) of 21.71%, representing a 20.4% improvement over the control (18.04%). This enhancement included a 0.9% increase in the open-circuit voltage (V_oc), a 6.6% rise in the short-circuit current density (J_sc), and an 11.9% boost in the fill factor (FF). Additionally, the optimized PSCs exhibited remarkable stability, retaining over 90% of their initial PCE after 900 h in humid conditions, compared to only 70% for the control. These improvements result from enhanced light absorption, reduced moisture infiltration, and lower defect-related recombination. This approach provides a promising pathway for developing highly efficient and durable PSCs. Full article

(This article belongs to the Special Issue 5th Anniversary of the "Applied Chemistry" Section)

► Show Figures

Figure 1

Journal Menu

Journal Browser

5th Anniversary of the "Applied Chemistry" Section

Share This Special Issue

Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (8 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI