| 1. |
- Pang, Kanglei, 1993-, et al.
(författare)
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Redirecting configuration of atomically dispersed selenium catalytic sites for efficient hydrazine oxidation
- 2024
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Ingår i: Matter. - 2590-2393 .- 2590-2385. ; 7:2, s. 655-667
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the reconstruction of surface sites is crucial for gaining insights into the true active sites and catalytic mechanisms. While extensive research has been conducted on reconstruction behaviors of atomically dispersed metallic catalytic sites, limited attention has been paid to non-metallic ones despite their potential catalytic activity comparable or even superior to their noble-metal counterpart. Herein, we report a carbonaceous, atomically dispersed non-metallic selenium catalyst that displayed exceptional catalytic activity in the hydrazine oxidation reaction (HzOR) in alkaline media, outperforming the noble-metal Pt catalysts. In situ X-ray absorption spectroscopy (XAS) and Fourier transform infrared spectroscopy revealed that the pristine SeC4 site pre-adsorbs an ∗OH ligand, followed by HzOR occurring on the other side of the OH–SeC4. Theoretical calculations proposed that the pre-adsorbed ∗OH group pulls electrons from the Se site, resulting in a more positively charged Se and a higher polarity of Se–C bonds, thereby enhancing surface reactivity toward HzO/R.
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| 2. |
- Saeedi Garakani, Sadaf, 1993-, et al.
(författare)
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Facile Fabrication of Wood-Derived Porous Fe3C/Nitrogen-Doped Carbon Membrane for Colorimetric Sensing of Ascorbic Acid
- 2023
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Ingår i: Nanomaterials. - 2079-4991. ; 13:20
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Tidskriftsartikel (refereegranskat)abstract
- Fe3C nanoparticles hold promise as catalysts and nanozymes, but their low activity and complex preparation have hindered their use. Herein, this study presents a synthetic alternative toward efficient, durable, and recyclable, Fe3C-nanoparticle-encapsulated nitrogen-doped hierarchically porous carbon membranes (Fe3C/N–C). By employing a simple one-step synthetic method, we utilized wood as a renewable and environmentally friendly carbon precursor, coupled with poly(ionic liquids) as a nitrogen and iron source. This innovative strategy offers sustainable, high-performance catalysts with improved stability and reusability. The Fe3C/N–C exhibits an outstanding peroxidase-like catalytic activity toward the oxidation of 3,3′,5,5′-tetramethylbenzidine in the presence of hydrogen peroxide, which stems from well-dispersed, small Fe3C nanoparticles jointly with the structurally unique micro-/macroporous N–C membrane. Owing to the remarkable catalytic activity for mimicking peroxidase, an efficient and sensitive colorimetric method for detecting ascorbic acid over a broad concentration range with a low limit of detection (~2.64 µM), as well as superior selectivity, and anti-interference capability has been developed. This study offers a widely adaptable and sustainable way to synthesize an Fe3C/N–C membrane as an easy-to-handle, convenient, and recoverable biomimetic enzyme with excellent catalytic performance, providing a convenient and sensitive colorimetric technique for potential applications in medicine, biosensing, and environmental fields.
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| 3. |
- Saeedi Garakani, Sadaf, 1993-, et al.
(författare)
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Poly(ionic liquid)-derived metal-free heteroatom co-doped porous carbons with peroxidase-like activity
- 2024
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Ingår i: Applied Materials Today. - 2352-9407. ; 37
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Tidskriftsartikel (refereegranskat)abstract
- Development of affordable, efficient and metal-free heterogeneous catalytic systems has been a persistent challenge in academia and industry. Heteroatom-doped metal-free carbon materials are increasingly recognized as valuable heterogeneous catalysts, and if well-designed, can present comparable performance to, or even surpass transition metal-containing catalysts. Their physicochemical properties and structural characteristics are tunable in a wide range, plus being free of leakage problems of transition metal species into the environment. Herein, three types of hierarchically porous N/X co-doped carbon materials (X denotes B, P or S) were synthesized via using poly(ionic liquid)s (PILs) as carbon precursors and source of heteroatom dopants. The incorporation of sacrificial pore-inducing templating agents which created abundant edge defects, in combination with a heteroatom co-doping strategy, enhanced the number of active sites and their peroxidase-like catalytic activities. Comparison with only nitrogen single-doped porous carbons as reference demonstrated that co-doping with nitrogen and another heteroatom exhibits higher peroxidase-like activity and affinity towards substrates. Among the three types of heteroatom co-doped porous carbonaceous artificial enzymes, the N/B co-doped carbonaceous catalyst displayed the highest specific activities and Vmax values. These observations suggest a synergistic effect of the co-dopants, here N and B in the enzyme that holds a promising potential to further enhance peroxidase-like activity.
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| 4. |
- Saeedi Garakani, Sadaf, 1993-
(författare)
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Heteroatom-doped porous carbon materials derived from poly(ionic liquid)s and their composites for battery and catalytic applications
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the past decade, there has been significant interest in heteroatom-doped porous carbons, driven by the distinctive and adjustable physical and chemical properties that they exhibit across scales, from the atomic to the macroscopic level. Particularly, attributes such as conductivity, electron density, high specific surface area, hierarchical pore structure, and oxidation resistance offer a wide range of characteristics for diverse applications. The development of multimodal, hierarchical pore sizes, ranging from micropores to macropores, ensures balanced diffusion resistance and a high surface area for active site accommodation. However, their synthesis usually involves multiple steps or complicated processing to incorporate both hierarchically porous structures and heteroatoms in carbon materials.This PhD thesis explores poly(ionic liquid)s (PILs) for preparation of heteroatom-doped porous carbon materials, driven by the growing demand for functional carbons in industry and academia. The aim of this thesis is to develop straightforward synthetic approaches to introduce various heteroatoms and different pore sizes in the carbonous structure and study their diverse functions. Here, we propose and explore fabrication methods based on two precursors. First, PILs were examined as both the carbon and heteroatom source, serving as a sacrificial template for porous carbons. Second, the delicate structure of wood was employed as a carbon source to generate macropores, while being coated with PILs to introduce heteroatoms or iron-based nanoparticles and create additional micropores. Moreover, the application of these carbonaceous materials was studied in two areas, i.e., batteries and artificial enzymes. This research is likely to contribute to a deeper understanding of synthetic methodologies of heteroatom-doped porous carbon materials and their physiochemical properties for various applications.
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| 5. |
- Saeedi Garakani, Sadaf, 1993-, et al.
(författare)
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Poly(ionic liquid)-derived metal-free heteroatom co-doped porous carbons with peroxidase-like activity
-
Ingår i: Applied materials today. - 2352-9407.
-
Tidskriftsartikel (refereegranskat)abstract
- Development of affordable, efficacious and metal-free heterogeneous catalytic systems has been a persistent challenge in academia and industry. Heteroatom-doped metal-free carbon materials are increasingly recognized as valuable heterogeneous catalysts, and if well-designed, can present comparable performance to, or even surpass transition metal-containing catalysts. Their physicochemical properties and structural characteristics are tunable in a wide range, plus being free of leakage of transition metal species into the environment. Herein, three types of hierarchically porous N/X co-doped carbon materials (X denotes B, P or S) were synthesized via using poly(ionic liquid)s (PILs) as carbon precursors and source of heteroatom dopants. The incorporation of sacrificial pore-inducing templating agents which created abundant edge defects, in combination with a heteroatom co-doping strategy enhanced the number of active sites and their peroxidase-like catalytic activities. Comparison with only nitrogen single-doped porous carbons as reference demonstrated that co-doping with nitrogen and another heteroatom exhibits higher peroxidase-like activity and affinity towards substrates. Among the three types of heteroatom co-doped porous carbonaceous artificial enzymes, the N/B co-doped carbonaceous catalyst displayed the highest specific activities and Vmax values. These observations suggest a synergistic effect of the co-dopants, here N and B in the enzyme that holds a promising potential to further enhance peroxidase-like activity.
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| 6. |
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