| 1. |
- Abdelhamid, Hani Nasser, 1986-, et al.
(författare)
-
Binder-free Three-dimensional (3D) printing of Cellulose-ZIF8 (CelloZIF-8) for water treatment and carbon dioxide (CO2) adsorption
- 2023
-
Ingår i: Chemical Engineering Journal. - 1385-8947 .- 1873-3212. ; 468
-
Tidskriftsartikel (refereegranskat)abstract
- Metal-organic frameworks (MOFs) have advanced several applications, including energy, biomedical and envi-ronmental remediation. However, most of the reported MOF materials are in powder form limiting their ap-plications. This study reported the processing of MOF via three-dimensional (3D) printing of cellulose-MOFs (denoted as CelloMOFs). The 3D printing procedure involved a one-pot method including three steps: gel for-mation, 3D printing, and in-situ growth of MOF crystals. This procedure offered 3D printing of CelloMOF via a binder-free method with high loading of 67.5 wt%. The 3D-printed porous structures were used as adsorbents for carbon dioxide (CO2), dye, and heavy metal ions. They can be also used as catalysts for the degradation of water pollutants such as organic dyes. The materials can be separated easily without requiring extra procedures such as centrifugation or filtration. The materials offered complete (>99%) removal of organic dyes within 10 min with high selectivity toward anionic dyes e.g, methyl blue (MeB). The materials exhibited CO2 and heavy metal ions adsorption capacities of 0.63 mmol/g (27.7 mg/g) and 8-328 mg/g, respectively, with good recyclability. Our methodology will open new venues for advanced 3D printing of CelloMOF and its applications for water treatment and air purification.
|
|
| 2. |
- Abdelhamid, Hani Nasser, et al.
(författare)
-
CelloZIFPaper : Cellulose-ZIF hybrid paper for heavy metal removal and electrochemical sensing
- 2022
-
Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 446
-
Tidskriftsartikel (refereegranskat)abstract
- The processing of hierarchical porous zeolitic imidazolate frameworks (ZIF-8) into a cellulose paper using sheet former Rapid-Kothen (R.K.) is reported. The procedure is a promising route to overcome a significant bottleneck towards applying metal-organic frameworks (MOFs) in commercial products. ZIF-8 crystals were integrated into cellulose pulp (CP) or TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-oxidized cellulose nanofibrils (TOCNF) following an in-situ or ex-situ process; the materials were denoted as CelloZIFPaper_In Situ and CelloZIFPaper_Ex Situ, respectively. The materials were applied as adsorbents to remove heavy metals from water, with adsorption capacities of 66.2-354.0 mg/g. CelloZIFPaper can also be used as a stand-alone working electrode for the selective sensing of toxic heavy metals, for instance, lead ions (Pb2+), using electrochemical-based methods with a limit of detection (LOD) of 8 mu M. The electrochemical measurements may advance 'Lab-onCelloZIFPaper' technologies for label-free detection of heavy metal ions.
|
|
| 3. |
- Abdelhamid, Hani Nasser, et al.
(författare)
-
Cellulose-zeolitic imidazolate frameworks (CelloZIFs) for multifunctional environmental remediation : Adsorption and catalytic degradation
- 2021
-
Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 426
-
Tidskriftsartikel (refereegranskat)abstract
- The crystal growth of zeolitic imidazolate frameworks (ZIFs) on biopolymers such as cellulose is a promising method for obtaining hybrid materials that combinenatural and synthetic materials. Cellulose derivative viz. 2,2,6,6-tetramethylpiperidine-1-oxylradical (TEMPO)-mediated oxidized nanocellulose (TOCNF) was used to modulate the crystal growth of ZIF-8 (denoted as CelloZIF-8) and ZIF-L (CelloZIF-L). The synthesis procedure occurred in water at room temperature with and without NaOH. The reaction parameters such as the sequence of the chemical's addition and reactant molar ratio were investigated. The phases formed during the crystal growth were monitored. The data analysis ensured the presence of zinc hydroxide nitrate nanosheets modified TOCNF during the crystallization of CelloZIFs. These phases were converted to pure phases ofCelloZIF-8 and CelloZIF-L. The resultant CelloZIFs materials were used for the adsorption ofcarbon dioxide (CO2), metal ions, and dyes. The materials exhibited high selectivity with reasonable efficiency (100%) toward the adsorption of anionic dyes such as methyl blue (MeB). They can also be used as a catalyst for dye degradation via hydrogenation with an efficiency of 100%. CelloZIF crystals can be loaded into a filter paper for simple, fast, and selective adsorption of MeB from a dye mixture. The materials are recyclable for five cycles without significant loss of their performance. The mechanisms of adsorption and catalysis were also investigated.
|
|
| 4. |
- Achour, Abdenour, 1980, et al.
(författare)
-
Evaluation of kraft and hydrolysis lignin hydroconversion over unsupported NiMoS catalyst
- 2023
-
Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 453
-
Tidskriftsartikel (refereegranskat)abstract
- Catalytic hydroconversion of Kraft and hydrolysis lignins was for the first time compared in a batch reactor over an unsupported NiMoS-SBA catalyst. We also report the effect of key reaction parameters on the yields and properties of the products. The results obtained at 20 wt% catalyst loading for hydrolysis lignin showed the highest monomer yield of 76.0 wt%, which consisted of 39 wt% aromatics with the lowest alkylphenolics yield of 10.1 wt%. Identical operating conditions, 400 °C, 80 bar, 5 h at 10 wt% catalyst loading, were used to compare both lignins and the highest monomer yield (64.3 wt%) was found for the hydrolysis lignin, consisting of 16.0 wt% alkylphenolics and 20.1 wt% aromatic compounds. These values are considerably higher than those for Kraft lignin with its 47.0 wt% monomer yield. We suggest that the reason for high yields of monomeric units from hydrolysis lignin is that it is more reactive due to its lower ash and sulfur contents and the chemical structural differences compared to the Kraft lignin. More precisely, the bio-oil from hydrolysis lignin contained higher yields of small molecules, sourced from ring-opening of cellulose in the hydrolysis lignin, which could stabilize the reactive oligomeric groups. These yields were two to seven times higher from kraft and hydrolysis lignin, respectively, compared to those obtained without catalyst. The results showed that the NiMoS-SBA catalyst is a promising catalyst for reductive depolymerization of lignin and in addition that the regenerated catalyst had good stability for multiple reaction cycles.
|
|
| 5. |
- Ahrens, Lutz
(författare)
-
A recent overview of per- and polyfluoroalkyl substances (PFAS) removal by functional framework materials
- 2023
-
Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 452
-
Tidskriftsartikel (refereegranskat)abstract
- Per-and polyfluoroalkyl substances (PFAS) are a class of toxic and bioaccumulative compounds affecting environmental and human health. Conventional wastewater treatment processes are ineffective at remediating these persistent chemicals. While functional framework materials have been shown to remove PFAS via adsorption and catalytic degradation, there is an on-going debate about their practical use in water purification. Inspired by recent research on typical functional framework materials, including zeolites, metal-organic frameworks (MOFs), and covalent organic frameworks (COFs), our review summarizes the principles of their design, properties, and applications with a special emphasis on PFAS removal. The potential of framework material for catalytic degradation of PFAS is constructively discussed, based on limited studies thus far. Finally, the challenges of using framework materials to remove and degrade PFAS in wastewater are presented along with sustainable design prospects to improve the technology. The current review provides new insights in advancing framework materials for PFAS elimination from contaminated waters.
|
|
| 6. |
- Al-Soubaihi, Rola, et al.
(författare)
-
Low-temperature CO oxidation by silver nanoparticles in silica aerogel mesoreactors
- 2023
-
Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 455, s. 140576-
-
Tidskriftsartikel (refereegranskat)abstract
- Low-temperature carbon monoxide (CO) oxidation on silver/silica aerogel (Ag/SiO2 AG) catalyst prepared by one-pot sol-gel synthesis followed by supercritical ethanol drying method is reported. Highly stable and sinterproof catalyst led to easy reactant diffusion to the active sites. The Ag/SiO2 AG catalyst showed enhanced catalytic activity toward low-temperature CO oxidation by preventing agglomeration of silver nanoparticles inside pores and facilitating well-dispersed active sites to enhance the mass heat transfer in the mesopores. Catalyst pretreatment conditions were found to play a crucial role in achieving high CO conversion efficiency at low light-off temperatures. Inverse counter-clockwise CO oxidation hysteresis was found to occur after the first run. The active sites contributing to this enhanced catalytic behavior were confirmed to be Ag0 from XPS, XRD, and TEM analysis. The catalyst exhibited good thermal stability up to 450 degrees C over repeated number of cycles.
|
|
| 7. |
- Arif, Muhammad, et al.
(författare)
-
Unraveling the synergy of interface engineering α-MnO2/Bi2WO6 heterostructures and defective active sites for superdurable photocatalysis: Mechanistic insights into charge separation/transfer
- 2023
-
Ingår i: Chemical Engineering Journal. - : ELSEVIER SCIENCE SA. - 1385-8947 .- 1873-3212. ; 475
-
Tidskriftsartikel (refereegranskat)abstract
- The construction of visible-light-driven hybrid heterostructure photocatalysts is of great significance for environmental remediation, although the utilization of strong visible-light response photocatalysts with high efficiency and stability remains a major challenge. Defect engineering is an excellent way to introduce metal cation vacancies in materials, thereby ensuing in highly enhanced catalytic performance. Inspired by this, we effectively constructed a built-in interface alpha-MnO2/Bi2WO6 heterostructure with abundant intimate interfaces and defective Mn3+/Mn4+ active sites for photocatalytic tetracycline hydrochloride (TC-HCl), hexavalent chromium Cr6+ reduction, and Escherichia coli (E. coli) inactivation. The experimental results, such as the active species test and X-ray photoelectron spectroscopy, indicated that the defective sites Mn3+/Mn4+, surface oxygen vacancies, and Bi(3+x)+ boosted the visible light absorption, and highly enhanced the photoinduced charge separation/transfer. Furthermore, experimental and DFT calculations reveal the high charge density at the built-in interface heterostructure and the Z-scheme charge transfer mechanism during the photocatalytic process. The results further reveal that O-2(-) and O-1(2) are the main reactive active species contributing to the photocatalytic reaction. The exceptional TC-HCl decomposition activity of the alpha-MnO2/Bi2WO6 heterostructure (97.56%, 2.31, and 2.04 times higher than bulk), enhanced reaction kinetics (K-app = 0.041 min(-1), 6.4, and 5.2 times higher than bulk), removal rate of 80.3%, Cr6+ reduction to Cr3+ (98.56%, K-app = 0.0599 min(-1)), and almost 100% bacterial inactivation compared to bulk alpha-MnO2 (42.22%) and Bi2WO6 (47.76%), were mainly due to the enhanced charge separation/transfer at the built-in interface and high charge density. This study opens new horizons for constructing Z-scheme MnO-based interface heterostructures with abundant defect sites for exceptional photocatalytic applications.
|
|
| 8. |
|
|
| 9. |
- Balamurugan, Chandran, et al.
(författare)
-
Large modulation of the chemical and electronic sensitization of TiO2/Ag/NiO nanostructure via in situ hydrothermal-induced heterointerface engineering
- 2022
-
Ingår i: Chemical Engineering Journal. - : ELSEVIER SCIENCE SA. - 1385-8947 .- 1873-3212. ; 430
-
Tidskriftsartikel (refereegranskat)abstract
- Chemical and electronic sensitization in metal oxide gas sensors are severely limited by poor dimension controls of metal oxide nanostructure and their electric/electronic properties. These limitations are overcome using hydrothermal-induced heterointerface engineering approaches. This work demonstrates that forming spherical titanium dioxide nanoparticles on a substrate significantly reduce a surface energy barrier of nucleation and induces novel mesophorous hierarchical TiO2 structure during hydrothermal synthesis, consequently increasing the surface area of the structure by similar to 3 times compared to that of control. In addition, we succeeded in tailoring the energetics of hierarchical TiO2 nanosctructure by decorating with the nickel oxide and silver nanoparticles, which results in a desirable semiconductors/metal heterointerface for fast charge transfer where silver nanoparticles bridge nickel oxide and TiO2 nanostructure, and silver nanoparticles serve as preferential sites for chemisorption and migration of oxygen anions. The resulting heterostructure sensing properties such as sensitivity, limit of detection and selectivity are studied as a function of operating temperature (30-150 degrees C), relative humidity (RH) and various volatile organic analytes concentrations. The TiO2/Ag/NiO heterostructure finally exhibits a high gas response of similar to 2.1 for acetone with a limit of detection of 34 ppb at 30 degrees C (or 21 ppb at 90 degrees C), and retains an excellent selectivity of acetone even at 90 % relative humidity. It exhibited a highly stable and speedy gas response for acetone toward various gases such as formaldehyde, ethanol, hydrogen sulfide, carbon monoxide even operating at 90 degrees C. Our results suggest a potential of constructed TiO2/Ag/NiO heterostructure for superior sensing volatile organic acetone and will also stimulate research on hetero-structured gas sensors with high sensitivity and selectivity.
|
|
| 10. |
- Benavente, Veronica, et al.
(författare)
-
Influence of lipid extraction and processing conditions on hydrothermal conversion of microalgae feedstocks – Effect on hydrochar composition, secondary char formation and phytotoxicity
- 2022
-
Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 428
-
Tidskriftsartikel (refereegranskat)abstract
- This study investigated the effect of lipid extraction of microalgae feedstocks subjected to hydrothermal carbonization (HTC) with regard to the carbonization degree, chemical composition and phytotoxicity of hydrochars produced under different reaction temperatures and residence times. Special attention was given to the formation and composition of secondary char, as this part of the hydrochar may be of particular importance for environmental and technical applications. A microalgae polyculture grown in municipal wastewater was extracted to retrieve lipids, and both unextracted (MA) and extracted microalgae (EMA) were used to produce hydrochars at 180–240 °C for 1–4 h. The composition of the hydrochars was thoroughly characterized by elemental analysis, thermogravimetric analysis and pyrolysis–gas chromatography/mass spectrometry analysis. MA exhibited a greater carbonization degree than EMA and contained higher amounts of secondary char under the same processing conditions. During the carbonization of EMA, more decomposition products remained in the liquid phase and less polymerization occurred than for MA, which explained the lower solid yield of EMA-derived hydrochars in comparison to MA hydrochars. Consequently, although they contained potentially toxic substances (i.e., carboxylic acids, aldehydes and ketones), the EMA-derived hydrochars exhibited a lower phytotoxic potential. This indicates that low-temperature hydrochars containing less than 10% of extractives might be suitable as soil amendments, whereas extractive-rich hydrochars would be more appropriate for other long-term applications, such as adsorbents for contaminant removal, energy storage and composite materials. Detailed characterization of microalgae-derived hydrochars is required to enable the most suitable application areas to be identified for these materials, and thereby make full use of their function as carbon sinks.
|
|
