TY - JOUR A1 - Mei, Shilin A1 - Kochovski, Zdravko A1 - Roa, Rafael A1 - Gu, Sasa A1 - Xu, Xiaohui A1 - Yu, Hongtao A1 - Dzubiella, Joachim A1 - Ballauff, Matthias A1 - Lu, Yan T1 - Enhanced Catalytic Activity of Gold@Polydopamine Nanoreactors with Multi-compartment Structure Under NIR Irradiation JF - Nano-Micro Letters N2 - Photothermal conversion (PTC) nanostructures have great potential for applications in many fields, and therefore, they have attracted tremendous attention. However, the construction of a PTC nanoreactor with multi-compartment structure to achieve the combination of unique chemical properties and structural feature is still challenging due to the synthetic difficulties. Herein, we designed and synthesized a catalytically active, PTC gold (Au)@polydopamine (PDA) nanoreactor driven by infrared irradiation using assembled PS-b-P2VP nanosphere as soft template. The particles exhibit multi-compartment structure which is revealed by 3D electron tomography characterization technique. They feature permeable shells with tunable shell thickness. Full kinetics for the reduction reaction of 4-nitrophenol has been investigated using these particles as nanoreactors and compared with other reported systems. Notably, a remarkable acceleration of the catalytic reaction upon near-infrared irradiation is demonstrated, which reveals for the first time the importance of the synergistic effect of photothermal conversion and complex inner structure to the kinetics of the catalytic reduction. The ease of synthesis and fresh insights into catalysis will promote a new platform for novel nanoreactor studies. KW - Gold@polydopamine KW - 3D tomography KW - Nanoreactor KW - Catalysis KW - Photothermal conversion Y1 - 2019 U6 - https://doi.org/10.1007/s40820-019-0314-9 SN - 2311-6706 SN - 2150-5551 VL - 11 IS - 1 PB - Shanghai JIAO TONG univ press CY - Shanghai ER - TY - JOUR A1 - Xu, Xiao A1 - Angioletti-Uberti, Stefano A1 - Lu, Yan A1 - Dzubiella, Joachim A1 - Ballauff, Matthias T1 - Interaction of Proteins with Polyelectrolytes BT - Comparison of Theory to Experiment JF - Langmuir N2 - We discuss recent investigations of the interaction of polyelectrolytes with proteins. In particular, we review our recent studies on the interaction of simple proteins such as human serum albumin (HSA) and lysozyme with linear polyelectrolytes, charged dendrimers, charged networks, and polyelectrolyte brushes. In all cases discussed here, we combined experimental work with molecular dynamics (MD) simulations and mean-field theories. In particular, isothermal titration calorimetry (ITC) has been employed to obtain the respective binding constants K-b and the Gibbs free energy of binding. MD simulations with explicit counterions but implicit water demonstrate that counterion release is the main driving force for the binding of proteins to strongly charged polyelectrolytes: patches of positive charges located on the surface of the protein become multivalent counterions of the polyelectrolyte, thereby releasing a number of counterions condensed on the polyelectrolyte. The binding Gibbs free energy due to counterion release is predicted to scale with the logarithm of the salt concentration in the system, which is verified by both simulations and experiment. In several cases, namely, for the interaction of proteins with linear polyelectrolytes and highly charged hydrophilic dendrimers, the binding constant could be calculated from simulations to very good approximation. This finding demonstrated that in these cases explicit hydration effects do not contribute to the Gibbs free energy of binding. The Gibbs free energy can also be used to predict the kinetics of protein uptake by microgels for a given system by applying dynamic density functional theory. The entire discussion demonstrates that the direct comparison of theory with experiments can lead to a full understanding of the interaction of proteins with charged polymers. Possible implications for applications, such as drug design, are discussed. Y1 - 2018 U6 - https://doi.org/10.1021/acs.langmuir.8b01802 SN - 0743-7463 VL - 35 IS - 16 SP - 5373 EP - 5391 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Xie, Dongjiu A1 - Xu, Yaolin A1 - Wang, Yonglei A1 - Pan, Xuefeng A1 - Härk, Eneli A1 - Kochovski, Zdravko A1 - Eljarrat, Alberto A1 - Müller, Johannes A1 - Koch, Christoph T. A1 - Yuan, Jiayin A1 - Lu, Yan T1 - Poly(ionic liquid) nanovesicle-templated carbon nanocapsules functionalized with uniform iron nitride nanoparticles as catalytic sulfur host for Li-S batteries JF - ACS nano N2 - Poly(ionic liquid)s (PIL) are common precursors for heteroatom-doped carbon materials. Despite a relatively higher carbonization yield, the PIL-to-carbon conversion process faces challenges in preserving morphological and structural motifs on the nanoscale. Assisted by a thin polydopamine coating route and ion exchange, imidazoliumbased PIL nanovesicles were successfully applied in morphology-maintaining carbonization to prepare carbon composite nanocapsules. Extending this strategy further to their composites, we demonstrate the synthesis of carbon composite nanocapsules functionalized with iron nitride nanoparticles of an ultrafine, uniform size of 3-5 nm (termed "FexN@C "). Due to its unique nanostructure, the sulfur-loaded FexN@C electrode was tested to efficiently mitigate the notorious shuttle effect of lithium polysulfides (LiPSs) in Li-S batteries. The cavity of the carbon nanocapsules was spotted to better the loading content of sulfur. The well-dispersed iron nitride nanoparticles effectively catalyze the conversion of LiPSs to Li2S, owing to their high electronic conductivity and strong binding power to LiPSs. Benefiting from this well-crafted composite nanostructure, the constructed FexN@C/S cathode demonstrated a fairly high discharge capacity of 1085 mAh g(-1) at 0.5 C initially, and a remaining value of 930 mAh g(-1 )after 200 cycles. In addition, it exhibits an excellent rate capability with a high initial discharge capacity of 889.8 mAh g(-1) at 2 C. This facile PIL-to-nanocarbon synthetic approach is applicable for the exquisite design of complex hybrid carbon nanostructures with potential use in electrochemical energy storage and conversion. KW - poly(ionic liquid)s KW - nanovesicles KW - sulfur host KW - iron nitride KW - Li-S KW - batteries Y1 - 2022 U6 - https://doi.org/10.1021/acsnano.2c01992 SN - 1936-0851 SN - 1936-086X VL - 16 IS - 7 SP - 10554 EP - 10565 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Abbasi, Ali A1 - Xu, Yaolin A1 - Khezri, Ramin A1 - Etesami, Mohammad A1 - Lin, C. A1 - Kheawhom, Soorathep A1 - Lu, Yan T1 - Advances in characteristics improvement of polymeric membranes/separators for zinc-air batteries JF - Materials Today Sustainability N2 - Zinc-air batteries (ZABs) are gaining popularity for a wide range of applications due to their high energy density, excellent safety, and environmental friendliness. A membrane/separator is a critical component of ZABs, with substantial implications for battery performance and stability, particularly in the case of a battery in solid state format, which has captured increased attention in recent years. In this review, recent advances as well as insight into the architecture of polymeric membrane/separators for ZABs including porous polymer separators (PPSs), gel polymer electrolytes (GPEs), solid polymer electrolytes (SPEs) and anion exchange membranes (AEMs) are discussed. The paper puts forward strategies to enhance stability, ionic conductivity, ionic selectivity, electrolyte storage capacity and mechanical properties for each type of polymeric membrane. In addition, the remaining major obstacles as well as the most potential avenues for future research are examined in detail. KW - Ionic selectivity KW - Ionic conductivity KW - Gel polymer KW - Ion exchange KW - Porous KW - polymer Y1 - 2022 U6 - https://doi.org/10.1016/j.mtsust.2022.100126 SN - 2589-2347 VL - 18 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Xie, Dongjiu A1 - Mei, Shilin A1 - Xu, Yaolin A1 - Quan, Ting A1 - Haerk, Eneli A1 - Kochovski, Zdravko A1 - Lu, Yan T1 - Efficient sulfur host based on yolk-shell iron oxide/sulfide-carbon nanospindles for lithium-sulfur batteries JF - ChemSusChem : chemistry, sustainability, energy, materials N2 - Numerous nanostructured materials have been reported as efficient sulfur hosts to suppress the problematic "shuttling" of lithium polysulfides (LiPSs) in lithium-sulfur (Li-S) batteries. However, direct comparison of these materials in their efficiency of suppressing LiPSs shuttling is challenging, owing to the structural and morphological differences between individual materials. This study introduces a simple route to synthesize a series of sulfur host materials with the same yolk-shell nanospindle morphology but tunable compositions (Fe3O4, FeS, or FeS2), which allows for a systematic investigation into the specific effect of chemical composition on the electrochemical performances of Li-S batteries. Among them, the S/FeS2-C electrode exhibits the best performance and delivers an initial capacity of 877.6 mAh g(-1) at 0.5 C with a retention ratio of 86.7 % after 350 cycles. This approach can also be extended to the optimization of materials for other functionalities and applications. KW - batteries KW - electrode materials KW - lithium sulfides KW - yolk-shell KW - nanostructures Y1 - 2021 U6 - https://doi.org/10.1002/cssc.202002731 SN - 1864-5631 SN - 1864-564X VL - 14 IS - 5 SP - 1404 EP - 1413 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Mei, Shilin A1 - Xu, Xiaohui A1 - Priestley, Rodney D. A1 - Lu, Yan T1 - Polydopamine-based nanoreactors: synthesis and applications in bioscience and energy materials JF - Chemical science N2 - Polydopamine (PDA)-based nanoreactors have shown exceptional promise as multifunctional materials due to their nanoscale dimensions and sub-microliter volumes for reactions of different systems. Biocompatibility, abundance of active sites, and excellent photothermal conversion have facilitated their extensive use in bioscience and energy storage/conversion. This minireview summarizes recent advances in PDA-based nanoreactors, as applied to the abovementioned fields. We first highlight the design and synthesis of functional PDA-based nanoreactors with structural and compositional diversity. Special emphasis in bioscience has been given to drug/protein delivery, photothermal therapy, and antibacterial properties, while for energy-related applications, the focus is on electrochemical energy storage, catalysis, and solar energy harvesting. In addition, perspectives on pressing challenges and future research opportunities regarding PDA-based nanoreactors are discussed. Y1 - 2020 U6 - https://doi.org/10.1039/d0sc04486e SN - 2041-6520 SN - 2041-6539 VL - 11 IS - 45 SP - 12269 EP - 12281 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Quan, Ting A1 - Haerk, Eneli A1 - Xu, Yaolin A1 - Ahmet, Ibbi A1 - Höhn, Christian A1 - Mei, Shilin A1 - Lu, Yan T1 - Unveiling the formation of solid electrolyte interphase and its temperature dependence in "Water-in-Salt" supercapacitors JF - ACS applied materials & interfaces N2 - "Water-in-salt" (WIS) electrolytes have emerged as an excellent superconcentrated ionic medium for high-power energy storage systems such as supercapacitors due to their extended working potential compared to the conventional dilute aqueous electrolyte. In this work, we have investigated the performance of WIS supercapacitors using hollow carbon nanoplates as electrodes and compared it to that based on the conventional "salt-in-water" electrolytes. Moreover, the potentiostatic electrochemical impedance spectroscopy has been employed to provide an insightful look into the charge transport properties, which also, for the first time, reveals the formation of a solid-electrolyte interphase (SEI and their temperature-dependent impedance for charge transfer and adsorption. Furthermore, the effect of temperature on the electrochemical performance of the WIS supercapacitors in the temperature range from 15 to 60 degrees C has been studied, which presents a gravimetric capacitance of 128 F g(-1) and a volumetric capacitance of 197.12 F cm(-3) at 55 degrees C compared to 87.5 F g(-1) and 134.75 F cm(-3) at 15 degrees C. The in-depth understanding about the formation of SEI layer and the electrochemical performance at different temperatures for WIS supercapacitors will assist the efforts toward designing better aqueous electrolytes for supercapacitors. KW - "water-in-salt" KW - supercapacitor KW - solid electrolyte interphase KW - electrochemical impedance spectroscopy KW - temperature effect Y1 - 2021 U6 - https://doi.org/10.1021/acsami.0c19506 SN - 1944-8244 SN - 1944-8252 VL - 13 IS - 3 SP - 3979 EP - 3990 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Xie, Dongjiu A1 - Jouini, Oumeima A1 - Mei, Shilin A1 - Quan, Ting A1 - Xu, Yaolin A1 - Kochovski, Zdravko A1 - Lu, Yan T1 - Spherical polyelectrolyte brushes templated hollow C@MnO nanospheres as sulfur host materials for Li-S batteries JF - ChemNanoMat : Chemistry of Nanomaterials for Energy, Biology and More N2 - Li-S battery has been considered as the next-generation energy storage device, which still suffers from the shuttle effect of lithium polysulfides (LiPSs). In this work, mesoporous hollow carbon-coated MnO nanospheres (C@MnO) have been designed and synthesized using spherical polyelectrolyte brushes (SPB) as template, KMnO4 as MnO precursor, and polydopamine as carbon source to improve the electrochemical performance of Li-S battery. The hollow C@MnO nanospheres enable the combination of physical confinement and chemical adsorption of the LiPSs. The thin carbon coating layer can provide good electrical conductivity and additional physical confinement to polysulfides. Moreover, the encapsulated MnO inside the carbon shell exhibits strong chemical adsorption to polysulfides. The constructed C@MnO/S cathode shows the discharge capacity of 1026 mAh g(-1) at 0.1 C with 79% capacity retention after 80 cycles. The synthesized hollow C@MnO nanoparticles can work as highly efficient sulfur host materials, providing an effective solution to suppress the shuttle effect in Li-S battery. KW - hollow nanospheres KW - lithium-sulfur battery KW - manganese monoxide KW - sperical KW - polyelectrolyte brushes Y1 - 2022 U6 - https://doi.org/10.1002/cnma.202100455 SN - 2199-692X VL - 8 IS - 4 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Mei, Shilin A1 - Siebert, Andreas A1 - Xu, Yaolin A1 - Quan, Ting A1 - Garcia-Diez, Raul A1 - Bär, Marcus A1 - Härtel, Paul A1 - Abendroth, Thomas A1 - Dörfler, Susanne A1 - Kaskel, Stefan A1 - Lu, Yan T1 - Large-Scale Synthesis of Nanostructured Carbon-Ti4O7 Hollow Particles as Efficient Sulfur Host Materials for Multilayer Lithium-Sulfur Pouch Cells JF - Batteries & supercaps N2 - Applications of advanced cathode materials with well-designed chemical components and/or optimized nanostructures promoting the sulfur redox kinetics and suppressing the shuttle effect of polysulfides are highly valued. However, in the case of actual lithium-sulfur (Li-S) batteries under practical working conditions, one long-term obstacle still exists, which is mainly due to the difficulties in massive synthesis of such nanomaterials with low cost and ease of control on the nanostructure. Herein, we develop a facile synthesis of carbon coated Ti4O7 hollow nanoparticles (Ti4O7) using spherical polymer electrolyte brush as soft template, which is scalable via utilizing a minipilot reactor. The C Ti4O7 hollow nanoparticles provide strong chemical adsorption to polysulfides through the large polar surface and additional physical confinement by rich micro- & mesopores and have successfully been employed as an efficient sulfur host for multilayer pouch cells. Besides, the sluggish kinetics of the sulfur and lithium sulfide redox mechanism can be improved by the highly conductive Ti4O7 via catalyzation of the conversion of polysulfides. Consequently, the C-Ti4O7 based pouch cell endows a high discharge capacity of 1003 mAhg(-1) at 0.05 C, a high-capacity retention of 83.7% after 100 cycles at 0.1 C, and a high Coulombic efficiency of 97.5% at the 100th cycle. This work proposes an effective approach to transfer the synthesis of hollow Ti4O7 nanoparticles from lab- to large-scale production, paving the way to explore a wide range of advanced nanomaterials for multilayer Li-S pouch cells. KW - lithium-sulfur batteries KW - pouch cell KW - spherical polyelectrolyte brushes (SPB) KW - Ti4O7 Y1 - 2022 U6 - https://doi.org/10.1002/batt.202100398 SN - 2566-6223 VL - 5 IS - 6 PB - Wiley-VCH CY - Weinheim ER -