1. Hydrazone-linked covalent organic framework catalyst via efficient Pd recovery from wastewaterMahira Bashri, Sushil Kumar, Pallab Bhandari, Sasi Stephen, Matthew J. O'Connor, Safa Gaber, Tina Škorjanc, Matjaž Finšgar, Gisha Elizabeth Luckachan, Blaž Belec, 2024, original scientific article Abstract: Global consumption and discharge of palladium (Pd) have raised environmental concerns but also present an opportunity for the sustainable recovery and reuse of this precious metal. Adsorption has proven to be an efficient method for the selective recovery of Pd from industrial wastewater. This study investigated a hydrazone-linked covalent organic framework (Tfpa-Od COF) as a potential material for the high-affinity adsorption of Pd2+ ions from wastewater, achieving a Kd value of 3.62 × 106 mL g–1. The electron-rich backbone of the COF contributes to its excellent selective removal efficiency (up to 100%) and adsorption capacity of 372.59 mg g–1. Furthermore, the Pd-adsorbed COF was evaluated as a sustainable catalyst for the Suzuki–Miyaura coupling reaction, demonstrating good catalytic conversion and recyclability. This work attempts to showcase a protocol for reusing waste palladium generated in water to fabricate heterogeneous catalysts and, thereby, promote the circular economy concept. Keywords: covalent organic frameworks, sustainability, catalysis, palladium adsorption, water purification Published in RUNG: 22.08.2024; Views: 808; Downloads: 6 Full text (4,04 MB) This document has many files! More... |
2. An in situ proton filter covalent organic framework catalyst for highly efficient aqueous electrochemical ammonia productionKayaramkodath C. Ranjeesh, Sukhjot Kaur, Abdul K. Mohammed, Safa Gaber, Divyani Gupta, Khaled Badawy, Mohamed Aslam, Nirpendra Singh, Tina Škorjanc, Matjaž Finšgar, 2024, original scientific article Abstract: The electrocatalytic nitrogen reduction reaction (NRR) driven by renewable electricity provides a green synthesis route for ammonia (NH3) production under ambient conditions but suffers from a low conversion yield and poor Faradaic efficiency (F.E.) because of strong competition from hydrogen evolution reaction (HER) and the poor solubility of N2 in aqueous systems. Herein, an in situ proton filter covalent organic framework catalyst (Ru-Tta-Dfp) is reported with inherent Ruthenium (Ru) sites where the framework controls reactant diffusion by suppressing proton supply and enhancing N2 flux, causing highly selective and efficient catalysis. The smart catalyst design results in a remarkable ammonia production yield rate of 2.03 mg h−1 mgcat−1 with an excellent F.E. of ≈52.9%. The findings are further endorsed with the help of molecular dynamics simulations and control COF systems without in situ proton filter feasibility. The results point to a paradigm shift in engineering high-performance NRR electrocatalysts for more feasible green NH3 production. Keywords: covalent organic frameworks, ammonia, electrochemical synthesis, electrochemistry, nitrogen reduction reaction, ruthenium Published in RUNG: 11.12.2023; Views: 1531; Downloads: 8 Full text (2,77 MB) This document has many files! More... |
3. Crystallizing covalent organic frameworks from metal organic framework through chemical induced-phase engineeringAbdul Khayum Mohammed, Safa Gaber, Jesus Raya, Tina Škorjanc, Nada Elmerhi, Sasi Stephen, Pilar Pena-Sánchez, Felipe Gándara, Steven Hinder, Mark A. Baker, Kyriaki Polychronopoulou, Dinesh Shetty, 2023, original scientific article Abstract: The ordered porous frameworks like MOFs and COFs are generally constructed using the monomers through distinctive metal-coordinated and covalent linkages. Meanwhile, the inter-structural transition between each class of these porous materials is an under-explored research area. However, such altered frameworks are expected to have exciting features compared to their pristine versions. Herein, we have demonstrated a chemical-induction phase-engineering strategy to transform a two dimensional conjugated Cu-based SA-MOF (Cu-Tp) into 2D-COFs (Cu-TpCOFs). The structural phase transition offered in-situ pore size engineering from 1.1 nm to 1.5–2.0 nm. Moreover, the Cu-TpCOFs showed uniform and low percentage-doped (~ 1–1.5%) metal distribution and improved crystallinity, porosity, and stability compared to the parent Cu-Tp MOF. The construction of a framework from another framework with new linkages opens interesting opportunities for phase-engineering. Keywords: metal organic framework, covalent organic framework, phase engineering, chemical transformation, porous materials Published in RUNG: 10.11.2023; Views: 2923; Downloads: 7 Full text (3,64 MB) This document has many files! More... |
4. A rational design of isoindigo-based conjugated microporous n-type semiconductors for high electron mobility and conductivityKayaramkodath C. Ranjeesh, Ayman Rezk, Jose Ignacio Martinez, Safa Gaber, Areej Merhi, Tina Škorjanc, Matjaž Finšgar, Gisha Elizabeth Luckachan, Ali Trabolsi, Bilal R. Kaafarani, 2023, original scientific article Abstract: The development of n-type organic semiconductors has evolved significantly slower in comparison to that of p-type organic semiconductors mainly due to the lack of electron-deficient building blocks with stability and processability. However, to realize a variety of organic optoelectronic devices, high-performance n-type polymer semiconductors are essential. Herein, conjugated microporous polymers (CMPs) comprising isoindigo acceptor units linked to benzene or pyrene donor units (BI and PI) showing n-type semiconducting behavior are reported. In addition, considering the challenges of deposition of a continuous and homogeneous thin film of CMPs for accurate Hall measurements, a plasma-assisted fabrication technique is developed to yield uniform thin films. The fully conjugated 2D networks in PI- and BI-CMP films display high electron mobility of 6.6 and 3.5 cm2 V−1 s−1, respectively. The higher carrier concentration in PI results in high conductivity (5.3 mS cm−1). Both experimental and computational studies are adequately combined to investigate structure–property relations for this intriguing class of materials in the context of organic electronics. Keywords: conjugated microporous polymers, isoindigo, semiconductors, conductivity, electron mobility Published in RUNG: 18.08.2023; Views: 1790; Downloads: 11 Full text (2,08 MB) This document has many files! More... |
5. Salicylaldehydate coordinated two-dimensional-conjugated metal-organic frameworksAbdul Khayum Mohammed, Pilar Pena-Sánchez, Ajmal Pandikassala, Safa Gaber, Ayesha Alkhoori, Tina Škorjanc, Kyriaki Polychronopoulou, Sreekumar Kurungot, Felipe Gándara, Dinesh Shetty, 2023, original scientific article Keywords: metal-organic framework, 2D materials, salicylaldehyde, thin films, mechanochemistry Published in RUNG: 10.02.2023; Views: 2011; Downloads: 3 Link to file This document has many files! More... |