Nature Nanotechnology Research Articles

Perovskite nanocrystal LEDs: Large areas for efficient vivid displays

Large-area perovskite LEDs (PeLEDs) are promising for cost-effective and high-throughput industrial applications. However, growing large-area efficient perovskite light emitters remains a big challenge. In a recent study in Nature Nanotechnology, Lee et al. demonstrated a simple modified bar-coating method for fabricating highly efficient and large-area perovskite nanocrystal-based PeLEDs with external quantum efficiency over 20% for a large pixel area of 900 mm2. Large-area perovskite LEDs (PeLEDs) are promising for cost-effective and high-throughput industrial applications. However, growing large-area efficient perovskite light emitters remains a big challenge. In a recent study in Nature Nanotechnology, Lee et al. demonstrated a simple modified bar-coating method for fabricating highly efficient and large-area perovskite nanocrystal-based PeLEDs with external quantum efficiency over 20% for a large pixel area of 900 mm2.

Passive rapid-cycling atmospheric water generator

Rapid water adsorption-desorption kinetics are the key to realizing exceptional yield in passive atmospheric water harvesting (PAWH). Recently in Nature Nanotechnology, Jia Zhu et al. developed a nanoporous carbon with rapid water adsorption kinetics and excellent photothermal properties to achieve PAWH with high yield. Herein, this facile method can kill two birds with one stone. Rapid water adsorption-desorption kinetics are the key to realizing exceptional yield in passive atmospheric water harvesting (PAWH). Recently in Nature Nanotechnology, Jia Zhu et al. developed a nanoporous carbon with rapid water adsorption kinetics and excellent photothermal properties to achieve PAWH with high yield. Herein, this facile method can kill two birds with one stone.

Epitaxial growth of wafer-scale single-crystal transition metal dichalcogenide monolayers for future electronics

The growth of wafer-scale two-dimensional (2D) single crystals, especially transition metal dichalcogenides (TMDs), is significantly essential for various electronic applications. However, the growth of wafer-scale single-crystal TMD (sc-TMD) monolayers on commercial substrates still remains challenging. Recently, two works published in <i>Nature Nanotechnology</i> have independently reported a substrate-cutting strategy for epitaxial growth of wafer-scale sc-TMD monolayers, which might open up a new route for preparing wafer-scale sc-TMD monolayers on commercially scalable insulating substrates for future electronics.

Cu catalysts detour hydrogen evolution reaction

The use of electrocatalytic reactions in aqueous solution to produce high-value chemicals is severely restricted by the occurrence of the electrochemical reaction of water. In a recent study published in <i>Nature Nanotechnology</i> by Haotian Wang and colleagues, hydrophilic-hydrophobic Cu catalysts, which suppress the undesirable hydrogen evolution reaction, have been discovered to promote conversion of 99% nitrate at an industrial wastewater level into ammonia using an industrial-relevant reduction current of 1 A/cm².

(Invited) Carbon Nanotubes for Plant Genetic Engineering

Plants will benefit from genetic engineering to feed our growing global population in the midst of climate change, to provide our most clinically-relevant drugs, and for our environmental remediation efforts. New generation genome engineering technologies, such as CRISPR/Cas, hold the potential to alter plant genes in a precise and targeted manner. The first step of any plant genetic engineering application is to deliver important biomolecular cargoes into the desired subcellular locations of plant cells. However, the limitations of traditional plant gene delivery methods, i.e. Agrobacterium and gene gun, prevent plant genetic engineering from reaching its full potential.Given the lack of efficient biomolecule delivery vehicles to plants and potential impact of plant biotechnology on food security and sustainability, we developed nanoparticle-based platforms to efficiently deliver small interfering RNA1,2 and plasmid DNA3,4 cargoes into plant cells in a species-independent manner, which eliminates the use of gene gun and addresses the main delivery bottlenecks of plant genetic engineering. We show that pristine single walled carbon nanotubes (SWCNTs) can adsorb small interfering RNA molecules through pi-pi stacking for plant delivery, whereas a covalently modified and positively charged SWCNT platform is more efficient for large double-stranded DNA delivery to mature plant leaf cells.This talk will first briefly summarize the development, characterization and biological verification of each nanoparticle platform for plant delivery applications. Next, I will present our recent results of CRISPR/Cas gene editing in plant leaves using the SWCNT DNA delivery platform5. The talk will be concluded by discussing the several assays performed to demonstrate the effect of nanoparticles on plant health, including an RNA-sequencing analysis of nanoparticle-treated plant leaves6. We believe the SWCNT delivery technologies that are discussed in this talk will have an immense impact on food security and sustainability by enabling the generation of improved plants that can rapidly reach the market in a cost-effective manner. Demirer G.S.*, Zhang H.* et al., DNA Nanostructures Coordinate Gene Silencing in Mature Plants. PNAS (2019). Demirer G.S. et al., Carbon Nanocarriers Deliver siRNA to Intact Plant Cells for Efficient Gene Knockdown. Science Advances (2020). Demirer G.S. et al., High Aspect Ratio Nanomaterials Enable Delivery of Functional Genetic Material Without Transgenic DNA Integration in Mature Plants. Nature Nanotechnology (2019). Demirer G.S. et al., Carbon nanotube–mediated DNA delivery without transgene integration in intact plants. Nature Protocols (2019). Demirer G.S. et al., Nanotechnology to advance CRISPR–Cas genetic engineering of plants. Nature Nanotechnology (2021).González-Grandío E., Demirer, G.S. et al. Carbon nanotube biocompatibility in plants is determined by their surface chemistry. bioRxiv (2021).

CVD Synthesis of Graphene Nanomesh on Ge(001)

Bottom-up synthesis of functional graphene nanostructures on industry-compatible semiconductors such as Si and Ge is the key to unlocking the tremendous potential of graphene in electronic applications. Herein, we demonstrate the growth of graphene nanomesh on Ge using chemical vapor deposition – a technique used widely in the semiconductor industry. Graphene nanomesh is a promsing material in semiconductor electronics because of its ability to simultaneously achieve a large drive current and on/off ratio – one of the key challenges in graphene nanoribbon electronics[1]. However, in order to realize a nanomesh with desired and tunable electrical characteristics – an accurate control over the nanoribbon width, presence of atomically smooth edges, and nanoribbon placement is desired. In the literature, several techniques have been demonstrated to fabricate graphene nanomesh such as top-down lithography[2], bottom-up polymerization[3], and molecule-assisted CVD[4]; yet, a combination of accurate placement, tunable widths and atomically smooth edges has been challenging to achieve. We attempt to overcome this bottleneck by initiating CVD nanoribbon synthesis from deterministically placed arrays of graphene nanoseeds on Ge. We are able to tune the nanoribbon widths by changing the starting seed size and array pitch. The nanoribbons evolved from these nanoseeds fuse into each other when grown long enough – forming a nanomesh. These nanomeshes have atomically smooth edges and exhibit semiconducting characteristics. We also perform extensive simulations to identify the seed-sizes and pitches and demonstrate that this technique allows us to synthesize nanomeshes of desired architecture and electrical characteristics and thus can be used as channel materials in high performance / RF applications as well as BEOL interconnects. References Saraswat et al. ACS Nano, 15,3674-3708 (2021)Bai et al. Nature Nanotechnology, 5, 190–194 (2010)Moreno et al. Science, 360, 199-203 (2018)Kim et al. ACS Applied Materials & Interfaces, 13, 28593-28599 (2021)

(Invited, Digital Presentation) Macroscopically Aligned Carbon Nanotubes for Photonics, Electronics, and Thermoelectrics

The remarkable flexibility, stable chemical structure, and extraordinary thermal, electrical, and optical properties of carbon nanotubes (CNTs) are promising for a variety of applications in flexible and/or high-temperature electronics, optoelectronics, and thermoelectrics, including wearables, refractory photonics, and waste heat harvesting [1]. However, the long-standing goal in the preparation of CNT ensembles is how to maintain the extraordinary properties of individual CNTs on a macroscopic scale. The polydispersity and randomness remain two main challenges.Here, we will discuss different methods for creating macroscopically aligned CNTs, including spontaneous formation of wafer-scale aligned CNT films via controlled vacuum filtration [2-4] and production of ultrahigh-conductivity CNT fibers and films through solution spinning and coating [5,6]. We will then describe the optical [2,7-11], dc and ac electrical [2,12-17], thermal [18], and thermoelectric [19-21] properties of these materials. These results are promising for device applications in various fields such as flexible CNT broadband detectors [22-26], spectrally selective thermal emitters [11], and thermoelectric devices [20,21]. W. Gao et al., “Macroscopically Aligned Carbon Nanotubes for Flexible and High-Temperature Electronics, Optoelectronics, and Thermoelectrics,” Journal of Physics D: Applied Physics 53, 063001 (2020).X. He et al., “Wafer-Scale Monodomain Films of Spontaneously Aligned Single-Walled Carbon Nanotubes,” Nature Nanotechnology 11, 633 (2016).W. Gao and J. Kono, “Science and Applications of Wafer-Scale Crystalline Carbon Nanotube Films Prepared through Controlled Vacuum Filtration,” Royal Society Open Science 6, 181605 (2019).N. Komatsu et al., “Groove-Assisted Global Spontaneous Alignment of Carbon Nanotubes in Vacuum Filtration,” Nano Letters 20, 2332 (2020).N. Behabtu et al., “Strong, Light, Multifunctional Fibers of Carbon Nanotubes with Ultrahigh Conductivity,” Science 339, 182 (2013).L. W. Taylor et al., “Improved Properties, Increased Production, and the Path to Broad Adoption of Carbon Nanotube Fibers,” Carbon 171, 689 (2021).K. Yanagi et al., “Intersubband Plasmons in the Quantum Limit in Gated and Aligned Carbon Nanotubes,” Nature Communications 9, 1121 (2018).W. Gao et al., “Continuous Transition between Weak and Ultrastrong Coupling through Exceptional Points in Carbon Nanotube Microcavity Exciton–Polaritons,” Nature Photonics 12, 362 (2018).M. E. Green et al., “Bright and Ultrafast Photoelectron Emission from Aligned Single-Wall Carbon Nanotubes through Multiphoton Exciton Resonance,” Nano Letters 19, 158 (2019).F. Katsutani et al., “Direct Observation of Cross-Polarized Excitons in Aligned Single-Chirality Single-Wall Carbon Nanotubes,” Physical Review B 99, 035426 (2019).W. Gao et al., “Macroscopically Aligned Carbon Nanotubes as a Refractory Platform for Hyperbolic Thermal Emitters,” ACS Photonics 6, 1602 (2019).X. Wang et al., “High-Ampacity Power Cables of Tightly-Packed and Aligned Carbon Nanotubes,” Advanced Functional Materials 24, 3241 (2014).A. Zubair et al., “Carbon Nanotube Fiber Terahertz Polarizer,” Applied Physics Letters 108, 141107 (2016).D. Tristant et al., “Enlightening the Ultrahigh Electrical Conductivities of Doped Double-Wall Carbon Nanotube Fibers by Raman Spectroscopy and First-Principles Calculations,” Nanoscale 18, 19668 (2016).N. Komatsu et al., “Modulation-Doped Multiple Quantum Wells of Aligned Single-Wall Carbon Nanotubes,” Advanced Functional Materials 27, 1606022 (2017).F. R. G. Bagsican et al., “Terahertz Excitonics in Carbon Nanotubes: Exciton Autoionization and Multiplication,” Nano Letters 20, 3098 (2020).A. Baydin et al., “Giant Terahertz Polarization Rotation in Ultrathin Films of Aligned Carbon Nanotubes,” Optica 8, 760 (2021).S. Yamaguchi et al., “One-Directional Thermal Transport in Densely Aligned Single-Wall Carbon Nanotube Films,” Applied Physics Letters 115, 223104 (2019).K. Fukuhara et al., “Isotropic Seebeck Coefficient of Aligned Single-Wall Carbon Nanotube Films,” Applied Physics Letters 113, 243105 (2018).Y. Ichinose et al., “Solving the Thermoelectric Trade-Off Problem with Metallic Carbon Nanotubes,” Nano Letters 19, 7370 (2019).N. Komatsu et al., “Macroscopic Weavable Fibers of Carbon Nanotubes with Giant Thermoelectric Power Factor,” Nature Communications 12, 4931 (2021).S. Nanot et al., “Broadband, Polarization-Sensitive Photodetector Based on Optically-Thick Films of Macroscopically Long, Dense, and Aligned Carbon Nanotubes,” Scientific Reports 3, 1335 (2013).X. He et al., “Photothermoelectric p-n Junction Photodetector with Intrinsic Broadband Polarimetry Based on Macroscopic Carbon Nanotube Films,” ACS Nano 7, 7271 (2013).X. He et al., “Carbon Nanotube Terahertz Detector,” Nano Letters 14, 3953 (2014).X. He, F. Léonard, and J. Kono, “Uncooled Carbon Nanotube Photodetectors,” Advanced Optical Materials 3, 989 (2015).A. Zubair et al., “Carbon Nanotube Woven Textile Photodetector,” Physical Review Materials 2, 015201 (2018).

(Invited, Digital Presentation) Optoelectronic Processes in Single-Chirality Carbon Nanotube Thin Films

Much understanding exists regarding chirality-dependent properties of single-wall carbon nanotubes (SWCNTs), primarily obtained through single-tube studies. However, macroscopic manifestations of chirality dependence have been limited, especially in electronic transport. Here, recent progress in our optical and electronic transport studies of single-chirality SWCNT thin films will be reviewed. We observed pronounced chirality-dependent electronic localization in temperature and magnetic field dependent conductivity measurements on macroscopic films of single-chirality SWCNTs [1]. We also performed optical absorption measurements in aligned single-chirality (6,5) SWCNT films, and through comparison with detailed theoretical calculations based on the Boltzmann scattering equation, we demonstrated that the background absorption is due to phonon-assisted transitions from the semiconductor vacuum to finite-momentum continuum states of excitons [2]. Furthermore, we conducted terahertz emission and photocurrent studies on films of aligned single-chirality semiconducting SWCNTs and found that excitons autoionize, i.e., spontaneously dissociate into electrons and holes [3]. Some of these studies were enabled by our recent improvement of the controlled vacuum filtration technique [4,5], which allows us to fabricate wafer-scale aligned SWCNTs with extremely anisotropic optical properties [6-9]. W. Gao et al., “Band Structure Dependent Electronic Localization in Macroscopic Films of Single-Chirality Single-Wall Carbon Nanotubes,” Carbon 183, 774 (2021).S. Dal Forno et al., “Origin of the Background Absorption in Carbon Nanotubes: Phonon-Assisted Excitonic Continuum,” Carbon 186, 465 (2021).F. R. G. Bagsican et al., “Terahertz Excitonics in Carbon Nanotubes: Exciton Autoionization and Multiplication,” Nano Letters 20, 3098 (2020).X. He et al., “Wafer-Scale Monodomain Films of Spontaneously Aligned Single-Walled Carbon Nanotubes,” Nature Nanotechnology 11, 633 (2016).W. Gao and J. Kono, “Science and Applications of Wafer-Scale Crystalline Carbon Nanotube Films Prepared through Controlled Vacuum Filtration,” Royal Society Open Science 6, 181605 (2019).F. Katsutani et al., “Direct Observation of Cross-Polarized Excitons in Aligned Single-Chirality Single-Wall Carbon Nanotubes,” Physical Review B 99, 035426 (2019).W. Gao et al., “Macroscopically Aligned Carbon Nanotubes as a Refractory Platform for Hyperbolic Thermal Emitters,” ACS Photonics 6, 1602 (2019).N. Komatsu et al., “Groove-Assisted Global Spontaneous Alignment of Carbon Nanotubes in Vacuum Filtration,” Nano Letters 20, 2332 (2020).A. Baydin et al., “Giant Terahertz Polarization Rotation in Ultrathin Films of Aligned Carbon Nanotubes,” Optica 8, 760 (2021).

Role of Nafion Ionomer in Electrochemical Reduction of CO2 on Au Clusters

More than 80% of the global energy demand is produced by burning fossil fuels, which leads to the emission of environmentally unfriendly greenhouse gases that adversely affect climate and human health. Electrochemical reduction of CO2 into high-value chemicals or fuels can be a promising way to store renewable energy sources such as solar and wind energies into chemical form, along with alleviating the environmental concerns.1 Recently, atomically precise metal clusters have attracted increasing interest in the research field of catalysis due to their unique size-dependent electronic and chemical properties.2 For the robust application and reusability of catalysts, the metal clusters are generally deposited onto a support, and the electrode is prepared by mixing a binder with the active catalyst. The binder remains in the secondary/outer coordination sphere of the supported catalyst; thus, it can interact with the nanoparticles and modulate their chemical and electronic properties resulting in a change in the catalytic activity.3 In this work, we have studied the role of Nafion binder in the electrochemical reduction of CO2 on [Au9(PPh3)8](NO3)3 clusters supported onto a carbon black support. The atomically precise [Au9(PPh3)8](NO3)3 clusters were chemically synthesised, characterised, and deposited on a carbon black support via wet impregnation. The cathode material for the electrochemical CO2 reduction was prepared by spraying Au9/C catalyst along with Nafion ionomer onto a carbon felt. A potentiostatic electrochemical reduction of CO2 at -1.3 V vs. Ag|AgCl was studied in a three-electrode based electrochemical flow cell in 0.2 M KHCO3 electrolyte. The Au9/C electrocatalyst exhibited a gradual increase in the current density and CO Faradaic efficiency over time when studied for potentiostatic (-1.3 V vs. Ag|AgCl) electrochemical CO2RR suggesting activation of the catalyst. Besides, the process of activation was found to be accelerated when the electrode was treated at a higher potential (-1.7 V vs. Ag|AgCl).The physical mixing of Au9 clusters with the Nafion ionomer results in dilution of the solution colours, and a precipitate was obtained within seconds. A concentration-dependent investigation of the physical mixture of Au9 clusters and the Nafion ionomer using UV-Vis absorption and X-ray absorption spectroscopy indicated the formation of chemical bonds between the cluster metallic core and the Nafion ionomer. The X-ray absorption studies on the as-made Au9/C electrode, the electrode after 2 h of electrolysis and the electrode after electrochemical activation at higher potential (-1.7 V vs. Ag|AgCl) suggested that the interaction between the Nafion ionomer and Au9 clusters results in shielding of active sites in the as-made electrode (Figure). The EXAFS fitting of the Au9/C electrode after electrochemical activation show a lower metal ligand coordination number. The results demonstrate that the Nafion-cluster interface restructures itself upon applying an electrochemical potential for a long time or applying a higher potential. This restructuring of the interface allows the reactants to access the active sites resulting in an improvement in the catalytic activity during the electrolysis.An alternative approach for the preparation of cluster-based electrodes was developed to minimise the interactions between the Au9 clusters and the Nafion ionomer by first depositing a layer of carbon black then dropcasting Au9 clusters (Au9 DC electrodes). In addition to that, the effect of the amount of the Nafion ionomer in the catalytic layer and the role of solvent used in the fabrication of the catalytic layer on the electrocatalytic performance were studied.The work shows that the Nafion ionomer, one of the most commonly used binders, has a profound influence on the catalytic behaviour of ultra-small Au clusters. A detailed discussion on the experimental design, and the analysis of electrochemical and X-ray absorption studies will be given in the conference contribution.References Wang, G.; Chen, J.; Ding, Y.; Cai, P.; Yi, L.; Li, Y.; Tu, C.; Hou, Y.; Wen, Z.; Dai, L. Chemical Society Reviews 2021, 50, (8), 4993-5061.Tyo, E. C.; Vajda, S. Nature Nanotechnology 2015, 10, (7), 577-88.Andrews, E.; Katla, S.; Kumar, C.; Patterson, M.; Sprunger, P.; Flake, J. Journal of The Electrochemical Society 2015, 162, (12), F1373-F1378. Figure 1

DNA membrane nanopores with highly tunable shapes and sizes

In a recent <i>Nature Nanotechnology</i> paper, Xing et al. reported <i>de novo</i> design of shape- and size-tunable membrane nanopores by leveraging simple but powerful DNA nanotechnology for single-molecule analysis. This route to artificial membrane nanopores paves the way for transforming protein sensing and advancing synthetic biology for real-world applications.

Membrane catalysts eliminate trace pollutants

The presence of residues in products generated by high-efficiency catalytic reactions is detrimental. In a recent work published in <i>Nature Nanotechnology</i> by Andrea Schäfer and colleagues, membrane catalysts are shown to promote processes while enhancing water purification by degradation of micropollutants via filtration-driven effective collision.

Chiral nanofluidic membrane for detection of circular polarization light

Circularly polarized light is vital for many emerging applications, yet the highly sensitive detection of right- and left-CPL remains challenging. In a recent study in <i>Nature Nanotechnology</i> reported by Kuang and colleagues, chiral nanofluidic membranes assembly by <i>L</i>- and <i>D</i>-phenylalanine-modified plasmonic Au nanoparticles were applied to realize the highly sensitive detection to circular polarization of incident photons based on CPL-induced ion current.

The path to high-rate energy storage goes through narrow channels

In a recent work in <i>Nature Nanotechnology</i>, an international team of scientists offers a strategy for generating rapid ion transport channels in thick but dense films made of 2D flakes of metallic MoS₂ quantum sheets. The narrow channels were sub-1.2 nm in width, but very short (∼6 nm) and allowed fast transport of ions, resulting in high volumetric and areal energy density.

Whiter whites and cooler silk

<h2>Summary</h2> A paper by Bin Zhu, Wei Li, et al. in <i>Nature Nanotechnology</i> reports that white silk, already a cool material that reflects sunlight, can be made even more reflective with the addition of 300 nm Al₂O₃ nanoparticles. The overall solar reflectance is raised from 0.86 to 0.95. Of the observed 900 Wm⁻² noontime solar flux, the solar absorption is 45 Wm⁻². Consequently, the larger thermal infrared radiative cooling effect, inferred to be 73 Wm⁻², causes a net cooling.

Peptide or Protein‐Protected Metal Nanoclusters for Therapeutic Application

Comprehensive SummaryMetal nanoclusters have attracted much attention due to their ultra‐small size and unique properties. The integration of protein or peptide can bring a synergistic effect on the physicochemical and physiological properties of metal clusters. Metal nanoclusters protected by peptides or proteins exhibit excellent biocompatibility and better disease therapeutic effects. We focus on developing new metal nanoclusters and exploring their therapeutic mechanism, including inhibiting enzyme activity, mitochondrial dysfunction, DNA strand break, and block of the signal pathway. What is the most favorite and original chemistry developed in your research group?The most favorite and original work we have done is the development of gold nanoclusters for diagnostic and therapeutic application.How do you get into this specific field? Could you please share some experiences with our readers?I have a great passion for research on bioanalytical imaging and the biomedical effects of nanomaterials, which may contribute to early diagnosis and treatment of diseases. My research is focused on exploring the mechanism of protein or peptide‐protected metal nanoclusters in disease diagnosis and treatment with the expectation of leading to superior therapeutic outcomes.What is the most important personality for scientific research?In my opinion, respect for originality, bold imagination, and innovationare the most important qualities of scientific research.What is your favorite journal(s)?My favorite journal is Nature Nanotechnology, where we can see the top and latest research progress on nanomaterials and learn about the superiority of nanomaterials and their potential for development.What are your hobbies?I love classical culture, poetry, the beauty of the mood. I also like history, and enjoy visiting historical places to appreciate the local customs.If you have anything else to tell our readers, please feel free to do so.I hope that people who have just started independent research work will not rush for quick success, plan your own direction systematically from the long‐term development. Never go flat, but keep "climbing".

Strain creates excellent catalysts for electrolyzers

The development of cost-effective and highly durable oxygen evolution reaction catalysts is one of the major technological hurdles toward the large-scale commercial application of proton exchange membrane water electrolyzers. In a recent report in <i>Nature Nanotechnology</i>, Zhang and Jin et al. present an effective strategy for the fabrication of torsion strained iridium oxide catalysts for building high-performance electrolyzers with significantly reduced usage of iridium.

Molecular Layer Deposition for Stable Lithium Metal Anode: From Composition Design to Mechanism Study

Energy storage systems with higher gravimetric energy density is highly desirable to fulfil the increasing requirement for various applications. One of the most promising direction is the development of next-generation batteries. Lithium (Li) metal is considered as the ‘Holy Grail’ for the anode materials owing to its ultrahigh capacity and low electrochemical potential [1]. Nevertheless, the application of Li metal as anode material has long been hindered due to some great challenges, such as poor cycling stability and short life span. The serious side reaction between metallic Li and organic electrolyte results in the formation of solid electrolyte interphase (SEI). On one hand, the SEI serves as a passivation layer on the surface which partially prevents further side reaction. On the other hands, the undesired dendrite growth cannot be prevented by SEI due to its heterogeneous and unstable properties [2]. Modification on the interphase to tune and stabilize its property has been considered as an approach to improve the cycling performance of Li metal anode. Recent studies on stabilizing SEI for Li metal anode can be divided into two categories, in-situ and ex-situ approach. In-situ approach refers to the design of electrolyte using electrolyte additives or adjusting the concentration of Li salt. Ex-situ approach refers to the construction of surface coating, including metal oxides, phosphates, and polymers on Li prior to electrochemical cycling [3]. An ideal SEI requires high ionic conductivity, good mechanical property, thin thickness, and high chemical stability. Nevertheless, it is still challenging to fulfil all the requirements of an ideal SEI for long-life and stable Li metal anode.Recent studies have demonstrated the application of Atomic layer deposition (ALD) and Molecular layer deposition (MLD) on the interphase modification of batteries. As a coating technique, ALD is can be applied to deposit inorganic materials such as various metal oxides. It shows unique advantages such as low depositing temperature, uniform film morphology and precise control over thickness in nanoscale [4-6]. As a derivative technique to ALD, MLD is widely used to fabricated inorganic-organic hybrid or pure polymer coatings. MLD still possesses the advantages of ALD and provides additional advantages such as tuneable mechanical property and adjustable coating composition. Our group previously reported ALD metal oxide and MLD metalcone as artificial SEI for metallic Li anodes [7-8].In this report, we demonstrate a type of MLD Polyurea (PU) coatings for metallic Li to modify the SEI layer [9-10]. The cycling life and stability has been improved upon the application of MLD PU. The surface chemistry of PU on Li is characterized by TOF-SIMS and XPS to investigate the evolution of SEI and the role of polymer coating. The results showed that MLD coating can effectively suppress the dendrite growth and remain stable under repeated Li plating/stripping. Furthermore, the nitrogen-containing polar groups in PU can effectively regulate the Li-ion flux and lead to a uniform Li deposition. In our following study, aluminium crosslinkers have been introduced into PU to achieve a hybrid nanoscale polymeric protective film with tuneable composition and improved stiffness. Owing to the improvement in the mechanical property, the protected Li can deliver much stable performance for more than 350 h with a higher cycling capacity of 2 mAh cm−2 without a notable increase in overpotential. Moreover, a stable charge/discharge cycling in Li–O2 batteries with the protected Li can be maintained for more than 600 h. Our study on MLD protected Li provides guidance on the rational design of electrode interfaces and opens new opportunities for the fabrication of next‐generation energy storage systems.[1] D. Lin, Y. Cui, et al, Nature Nanotechnology, 2017, 12, 194-206[2] X. Cheng, Q. Zhang, et al, Chemical Reviews, 2017, 117, 10403-10473[3] X. Cheng, Q. Zhang, et al, Adv. Sci., 2016, 3, 1500213[4] Y. Zhao, X. Sun, ACS Energy Lett. 2018, 3, 4, 899–914[5] Y. Zhao, X. Sun, et al, Joule, 2018, 2, 12, 2358-2604[6] Y. Zhao, X. Sun, et al, Chem. Soc. Rev., 2021, 50, 3889-3956[7] Y. Zhao, X. Sun, et al, Small Methods, 2018, 2, 1700417[8] K. R. Adair, X. Sun et al, Angew. Chem. Int. Ed., 2019, 58, 15797.[9] Y. Sun, X. Sun, et al, Adv. Mater., 2019, 31, 1806541[10] Y. Sun, X. Sun, et al, Adv. Energy Mater., 2020, 10, 2001139.

Thin Lithium Metal Foil Technology for Advanced Battery Manufacturing

Lithium metal anode is regarded as the holy grail for the next generation battery materials due to its high theoretical specific capacity which is 10 times higher than that of graphite1. Currently, the most advanced lithium-ion battery cells have energy density of ~300 Wh/kg. Whereas, lithium metal batteries with liquid or semi solid electrolyte from Solidenergy2 and Sion Power3 have demonstrated record specific energy density of over 400 Wh/kg. Solid-state batteries use non-flammable solid electrolytes instead of liquid and, therefore, offer improved safety. The 20 Ah multi-layer all solid-state cells made by Solid Power have achieved 330 Wh/kg.4 However, solid state batteries can exceed the energy density of today's lithium-ion batteries only when the thin lithium metal foil (<20 um thickness) is used as anode enabling a pathway to beyond 400Wh/kg.Industrial scale thin Lithium metal foil is produced by hydraulic extrusion followed by a rolling process. This process usually requires a delicate balance between the pressure and tension created by both extruder and winder, so that the resulting foil is not torn or stretched, retaining all the dimensional characteristics required. This process can be extremely challenging when making lithium metal films with thickness less 20 µm due to the poor mechanical properties of lithium metal.5 Moreover, the cost of making these foils dramatically increases as the thickness decreases. Livent has recently developed Printable Lithium Technology (PLT), which incorporates stabilized lithium metal powder (SLMP®) into a stable printable formulation. This presentation will cover thin lithium foil manufacturing processes and highlight advantages and disadvantages of our approach. The electrochemical performance results will be presented.Figure 1A compares the 50 μm commercially available lithium foil (left) and 20 μm printed lithium foil (right) laminated to copper current collector. Figure 1A shows that a uniform film made from printable lithium formulation is consistent across the application area. Figure 1B and figure 1C are the optical microscope images of 50 μm commercially available lithium foil and 20 μm printed lithium foil, respectively. Figure 1B shows commercial foil made with conventional extrusion and rolling process has rough and scratched surface. Figure 1C shows that printed lithium foil preserves the shape of precursor particles and boundaries are formed creating higher surface area that potentially can mitigate dendrite growth by distributing current over a wider area. Figure 1D and 1E show the SEM and EDS images of the printed Lithium foil after lamination. Figure 1D and 1E show the clear presence of oxygen at the boundaries. Figure 1F shows the microscope image of printed lithium foil before calendering which is a monolayer. Figure 1G compares lithium plating and stripping properties of testing conducted in a symmetric pouch cell format with a current collector coated with 20 um printed lithium foil vs. 50 um commercially available lithium foil. Figure 1G shows that the cell containing the printed lithium foil, with lower thickness, has exceptional cycling stability with negligible potential increases during the first 70 cycles, indicating that the growth of dendritic lithium has been significantly mitigated.Figure Captions: Figure 1A. Image of 50 μm commercially available lithium foil (left) and 20 μm printed lithium foil (right) on a copper current collector. Figure 1B. Microscope (200x) image of the Printed Lithium Foil before lamination. Figure 1C. SEM Image (500x) of the Printed Lithium Foil after lamination. Figure 1D Microscope image of 50 μm commercially available lithium foil. Figure 1E. Microscope image of 20 μm printed lithium foil. Figure 1F. EDS surface mapping of oxygen for the printed foil. FIG. 1G. Lithium plating and stripping properties tested in a pouch cell with a copper current collector coated with 20 μm printable lithium formulation compared to 50 μm commercially available lithium foil. Cycling voltage is between -0.5V and 0.5 V and a current density is 0.5 C for 1h. References D. Lin, Y. Liu, and Y. Cui, Nature Nanotechnology, 12, 194–206 (2017) http://dx.doi.org/10.1038/nnano.2017.16.Q, Hu, Y. Matulevich and Y, Tang, Solidenergy Systems, US Patent No. 16/308,023, June 08th, 2016https://sionpower.com/2021/sion-power-announces-licerion-ev-targeting-electric-vehicles-with-a-large-format-17-ah-400-wh-kg-cell/https://www.greencarcongress.com/2020/12/20201216-solidpower.htmlO. Mashtalir, M. Nguyen, E. Bodoin, L. Swonger, and S. P. O’Brien, ACS Omega, 3, 181–187 (2018).Shu-Hua Wang et al., Nat. Commun.2019,10,4930 Figure 1

Structural Properties of Alkanethiolates and Their Influence on The Stability and Reproducibility of Impedimetric Sensing

The utilization and commercialization of electronic based point of care (PoC) diagnostic devices has been hindered by the lack of repeatability and stability associated with such devices. Consequently, the enzyme-linked immunosorbent assay (ELISA) remains the dominant immunoassay used for the detection of serological diseases despite the numerous drawbacks associated with this platform.1, 2 Most notably, the ELISA relies on trained laboratory personnel to perform the assay in a centralized laboratory, which increases both the cost and time to actionable treatment. An electrochemical impedance biosensor is an example of a label-free biosensing platform that has high sensitivity and can be easily miniaturized and mass produced at a low cost, thus improving the time to actionable treatment.3-7 It has been shown that the repeatability and stability of electronic based biosensors is not associated with the transducing element but rather is dependent on the sensor-molecule interface.8 This interface typically consists of an alkanethiolate-based self-assembled monolayer (SAM) chemisorbed onto a gold (Au) substrate. In the case of Electrochemical Impedance Spectroscopy (EIS) sensing, the SAM forms a barrier to the ionic transport of the selected redox coupling agent. The molecular structure of the alkanethiolate determine the uniformity and density of the SAM, which directly affects its ability to impede the ionic transport of the redox coupling agent. Molecular dynamics studies have shown that shorter, less-ordered alkanethiolates rotate more easily than longer alkylthiolates.9 Their ability to rotate facilitates the gradual coverage of pinholes and defects present on the sensor-molecule interface.9 A separate study has shown that short chain (6C) alkanethiolates leads to significant drift in EIS measurements.10 The drift in charge transfer resistance of the 6C SAM was hypothesized to be associated with the surface reorganization of these thiols. The observed drift in the SAM measurements has been reported to be greater in magnitude than the measured change in charge transfer resistance upon binding of a receptor, thus compromising the reliability of biosensing measurements.10 This work uses a 16C alkanethiolate SAM to show that the stability and reproducibility of EIS measurements is directly dependent on the coverage of pinholes and defects present on the Au substrate as well as the crystallinity of the SAM. Cyclic Voltammetry (CV) and X-ray Photoelectron Spectroscopy (XPS) were used to measure the density and uniformity of the SAM, respectively. We show that stability in EIS measurements of the sensor-molecule interface directly corresponds to stable and reproducible measurements associated with the attachment of the selected receptor and lastly of the target analyte. Thus, through the rational design of a stable sensor-molecule interface we can minimize the drift associated with the SAM, and consequently the receptor interface. Thus, improving both the sensitivity and limit of detection of EIS based sensors.References Yalow, R. S.; Berson, S. A., Immunoassay of endogenous plasma insulin in man. The Journal of clinical investigation, 1960, 39 (7), 1157-1175.Prevention, C. f. D. C. a. Understanding the EIA Test. https://www.cdc.gov/lyme/diagnosistesting/labtest/twostep/eia/index.html Cui, Y., Wei, Q. Q., Park, H. K., and Lieber, C. M., Nanowire nanosensors for highly sensitive and selective detection of biological and chemical species, Science, 2001, 293, 1289-1292.Park, I., Li, Z., Pisano, A. P., and Williams, R. S., Top-down fabricated silicon nanowire sensors for real-time chemical detection, Nanotechnology, 2001, 21, 015501.Patolsky, F., Zheng, G. F., Hayden, O., Lakadamyali, M., Zhuang, X. W., and Lieber, C. M., Electrical detection of single viruses, Proceedings of the National Academy of Sciences of the United States of America, 2004, 101, 14017-14022.Pui, T. S., Agarwal, A., Ye, F., Ton, Z. Q., Huang, Y. X., and Chen, P. Ultra-sensitive detection of adipocytokines with CMOS-compatible silicon nanowire arrays, Nanoscale, 2009, 1, 159-163.Stern, E., Vacic, A., Rajan, N. K., Criscione, J. M., Park, J., Ilic, B. R., Mooney, D. J., Reed, M. A., and Fahmy, T. M. Label-free biomarker detection from whole blood, Nature Nanotechnology, 2010, 5, 138-142.Tarasov, A.; Tsai, M.-Y.; Flynn, E. M.; Joiner, C. A.; Taylor, R. C.; Vogel, E. M., Gold-coated graphene field-effect transistors for quantitative analysis of protein–antibody interactions. 2D Mater. 2015, 2, 044008.Jiang, L., Sangeeth, C. S., Yuan, L., Thompson, D., & Nijhuis, C. A. (2015). One-Nanometer thin Monolayers remove the deleterious effect of substrate defects in Molecular Tunnel Junctions. Nano Letters, 2015 15(10), 6643-6649.Xu, X.; Makaraviciute, A.; Kumar, S.; Wen, C.; Sjödin, M.; Abdurakhmanov, E.U.; Danielson, H.; Nyholm, L.; Zhang Z.; Structural Changes of Mercaptohexanol SelfAssembled Monolayers on Gold and Their Influence on Impedimetric Aptamer Sensors, Analytical Chemistry., 2019 91 (22), 14697-14704

Atomically dispersed metal site in subnanometric clusters catalyze dynamically

Recently in Nature Nanotechnology , Lu and co-workers reported that a linear metal trimer, consisting of a Ni atom bridged by two Cu atoms via hydroxyls, catalyzed the selective hydrogenation of acetylene with exceptionally higher activity and stability than did the monometallic Ni single-atom catalyst. The active Ni atom floated locally upon acetylene adsorption but was fully restored after ethylene desorption, showing a dynamic manner. This work demonstrates that the trimer catalyst is characterized by the highly isolated single site yet is electronically and spatially interacted among the metal atoms, and the work advances the design of atomically dispersed metal catalysts. Recently in Nature Nanotechnology , Lu and co-workers reported that a linear metal trimer, consisting of a Ni atom bridged by two Cu atoms via hydroxyls, catalyzed the selective hydrogenation of acetylene with exceptionally higher activity and stability than did the monometallic Ni single-atom catalyst. The active Ni atom floated locally upon acetylene adsorption but was fully restored after ethylene desorption, showing a dynamic manner. This work demonstrates that the trimer catalyst is characterized by the highly isolated single site but electronically and spatially interacted among the metal atoms and advances the design of atomically dispersed metal catalysts.