bluuebunny/crossref_metadata_2025_split huggingface dataset:
Syntheses of Heteroatom-Substituted and Three-Dimensional Nanocarbon Materials on Surfaces
Authors: Kawai Shigeki 
Published: August 2024

I will present our recent studies on on-surface chemistry with high-resolution scanning probe microscopy operating at low temperature under ultra-high vacuum. We synthesized three-dimensional organometallic compound and graphene nanoribbon by coupling hexabromo substituted-propellane molecules on Au(111) and Ag(111).[1] In the structure, the C-Br bonds distant from the surface remained intact even after the reaction. The radical species were formed by tip-induced debromination and were also stabilized by either tip-manipulated Br atom or fullerene molecule. We also demonstrate systematic tip-induced isomerization via embedding a text of “NIMS” by following binary and ternary ascii cords, in which two chiral dehydroazulene and diradical units were used.[2] Among the three states, the diradical unit showed the spin coupling of 90 meV. For heteroatom substitution, we developed an on-surface reaction, which can synthesize graphene nanoribbon and covalent organic frameworks with silabenzene units by coupling Si atom and Br-substituted molecule.[3] The heavier congeners of cyclic aromatic compounds have been studied as an elusive target product for organic synthesis due to their high reactivity at ambient temperature and difficult isolation. Thus, this result shows the advantage of on-surface synthesis.
Reference
[1] S. Kawai, et al Sci. Adv. 6, eaay8913 (2020).
[2] S. Kawai, et al Nat. Commun. 14, 7741 (2023).
[3] K. Sun et al, Nat. Chem. 15, 136 (2023).
Fabrication of Novel Carbon-based Polymers by On-surface Cycloaromatization of Isopropyl Substituents
Authors: Urgel Jose , Biswas Kalyan , Urbani Maxence , Kinikar Amogh , Pérez Elvira Elena , Barragán Ana , Di Giovannantonio Marco , Soler Diego , Ruffieux Pascal , Fasel Roman , Jelínek Pavel , Torres Tomas , Ecija David 
Published: August 2024

Surface-catalyzed reactions have been employed for the synthesis of carbon nanomaterials featuring precisely defined atomic structures. A recent breakthrough involves the gold surface-catalyzed [3 + 3] cycloaromatization of isopropyl-substituted arenes, allowing for on-surface synthesis of novel carbon-based polymers[1-3]. In this process, the surface plays a crucial role in activating the isopropyl substituents, facilitating the formation of phenylene rings through intermolecular coupling. For instance, such investigations might open new avenues in the field of carbon magnetism, which has gained an increased attention in view of the recent progress made in the synthesis and characterization of open-shell polycyclic aromatic hydrocarbons[2]. Under this scenario, the comprehensive fabrication of magnetic polymers emerges as a highly appealing field of research.
Here, we introduce exemplary approaches toward the bottom-up fabrication of different carbon-based polymers homocoupled via surface-catalyzed [3 + 3] cycloaromatization of isopropyl substituents studied on Au(111) under ultra-high vacuum (UHV) conditions. The chemical structures of the polymers have been clearly elucidated by non-contact atomic force microscopy (nc-AFM). Scanning tunneling spectroscopy (STS), complemented by computational investigations reveals their ground state. Our approach can be a highly relevant step towards the on-surface synthesis of covalently linked 1D organic polymers with prospects in sensing, catalysis and nanoscale spintronic devices.
References:
1 - Kinikar, A. et al. (2022). On-surface polyarylene synthesis by cycloaromatization of isopropyl substituents. Nature Synthesis, 1(4), 289-296.
2 - Biswas, K., et al. (2022). Interplay between π-Conjugation and Exchange Magnetism in One-Dimensional Porphyrinoid Polymers. Journal of the American Chemical Society, 144(28), 12725-12731.
3 - Kinikar, A. et al. (2023). Sterically Selective [3 + 3] Cycloaromatization in the On-Surface Synthesis of Nanographenes. ACS Nanoscience Au.

Figure 1
Anhydride Photolysis on a Semiconductor Surface
Authors: Frezza Federico , Sanchez-Grande Ana , Canola Sofia , Mutombo Pingo , Chen Qifan , Ernst Karl-Heinz , Wäckerlin Christian , Di Giovannantonio Marco , Nachtigallová Dana , Jelínek Pavel 
Published: August 2024

The on-surface synthesis (OSS) method has facilitated the growth of diverse carbon-based nanomaterials, with the goal of integrating them into electronic devices. However, the reliance on metallic substrates in OSS restricts these materials' applications, necessitating strategies for transferring these materials into technological relevant substrates or direct synthesis on non-metallic surfaces, where the low absorption energies and lack of catalytic activity from the substrate complicate this approach. Addressing these limitations, we explore on-surface photochemistry as an alternative to thermally induced reactions, enabling controlled chemical processes at lower temperatures. While prior works have demonstrated light-induced reactions on metallic surfaces, where the hot electrons photogenerated from the metallic surface play a crucial role, synthesizing nanostructures directly on semiconducting or insulating surfaces through a purely intramolecular energy absorption remains challenging.
The photolysis and pyrolysis of anhydrides has proven to be a suitable approach for the formation of arynes, as schematically shown in the Figure. Our study focuses on the selective photodissociation of maleic anhydride-containing precursors on a semiconductor surface (SnSe), unveiling their distinct photochemical behaviors. Specifically, tetraphenylphthalic anhydride (TPPA) undergoes successful photolysis on SnSe, forming tetraphenyl benzyne (TPBY) intermediates, and eventually, tetraphenyl benzene (TPBE) products. Furthermore, TPPA photolysis occurs efficiently also at room temperature, leading to the direct formation of TPBE. Contrastingly, benzo[ghi]perylene-1,2-dicarboxylic anhydride (BPA) possesses an extended pi-conjugated backbone and exhibits no photoactivity upon irradiation on the same semiconductor surface. Our calculations of TPPA and BPA excited states predict different behaviors, demonstrating the relationship between molecular structure, pi-conjugation, and photochemical reactivity, offering insights into the design principles for light-induced reactions on inert surfaces.

Figure 1
On-Surface Synthesis of Open-Shell Nanographenes through the π-Extension of Dibenzo[Hi,St]Ovalene
Authors: Narita Akimitsu 
Published: August 2024

Graphene nanostructures are attracting attentions for their intriguing optical, electronic, and magnetic properties that are critically dependent on their chemical structures. Whereas it is challenging to obtain atomically precise structures by typical top-down fabrication methods, such as lithographic patterning of graphene and unzipping of carbon nanotubes, bottom-up synthesis enables the preparation of molecular nanographenes and graphene nanoribbons (GNRs) with pre-designed structures. In addition to the solution synthesis based on the methods of synthetic organic chemistry, such graphene nanostructures can also be synthesized on metal surfaces under ultrahigh vacuum conditions and directly visualized by atomic resolution scanning probe microscopy (SPM) [1]. Using carefully designed and solution-synthesized molecular precursors, this on-surface synthesis method can provide various nanographenes, including the structures that are highly unstable under ambient conditions. We have previously developed the solution synthesis of dibenzo[hi,st]ovalene (DBOV) with strong red fluorescence [2], and achieved its π-extension to circumpyrene [3]. Following the successful synthesis of rhombus-shaped nanographenes with four zigzag edges, showing a closed-shell or an open-shell depending on the size [4], we functionalized DBOV and circumpyrene with two 2,6-dimethylphenyl groups for their on-surface π-extension to unprecedented zigzag-edged nanographenes. The resulting structures were clearly visualized by scanning tunneling microcopy and their open-shell characters were indicated by theoretical and experimental investigations, revealing large magnetic exchange couplings of up to 190 meV [5]. We have more recently also achieved further π-extension of these open-shell nanographenes on surface and obtained initial results for their polymerization.
[1] Chen, Z.; Narita, A.; Müllen, K.; Adv. Mater.
2020, 32, 2001893.
[2] Paternò, G. M.; Chen, Q.; Wang, X.-Y.; Liu, J.; Motti, S. G.; Petrozza, A.; Feng, X.; Lanzani, G.; Müllen, K.; Narita, A.; Scotognella, F., Angew. Chem. Int. Ed.
2017,
56, 6753–6757.
[3] Chen, Q.; Schollmeyer, D.; Müllen, K.; Narita, A., J. Am. Chem. Soc.
2019, 141, 19994–19999.
[4] Mishra, S.; Yao, X.; Chen, Q.; Eimre, K.; Gröning, O.; Ortiz, R.; Di Giovannantonio, M.; Sancho-García, J. C.; Fernández-Rossier, J.; Pignedoli, C. A.; Müllen, K.; Ruffieux, P.; Narita, A.; Fasel, R.; Nat.
Chem. 2021, 13, 581.
[5] Biswas, K.; Soler, D.; Mishra, S.; Chen, Q.; Yao, X.; Sánchez-Grande, A.; Eimre, K.; Mutombo, P.; Martín-Fuentes, C.; Lauwaet, K.; Gallego, J. M.; Ruffieux, P.; Pignedoli, C. A.; Müllen, K.; Miranda, R.; Urgel, J. I.; Narita, A.; Fasel, R.; Jelínek, P.; Écija, D. J. Am. Chem. Soc. 2023, 145, 2968–2974.
Electrodeposition of WO3 Nanoparticles Onto a Carbon Membrane Surface for the Development of a Hybrid Filtration/Photocatalysis System
Authors: Boldrin Zanoni Maria Valnice , Rojas-Mantilla Hernán Dario , Irikura Kallyni , Souza João Carlos Carlos , Ayala-Durán Saidy Cristina , Lima Gomes Paulo Clairmont Feitosa de , Salazar Ricardo 
Published: August 2024

This study proposes the development of a photoactive filtration membrane using carbon fiber (CF) modified with an n-type semiconductor (WO3) to create a hybrid filtration/photocatalysis system applied in water treatment for simultaneous retention and degradation of the emerging contaminant (Sertraline - SER). The membrane was prepared through chemical electrodeposition in a three-electrode electrochemical cell, utilizing CF as the working electrode, two-dimensionally stable anode counter electrodes (De Nora), and an Ag/AgCl 4.0 mol L-1 KCl reference electrode. The preparation conditions included: 5.0 mmol L-1 of Na2WO4, 0.075% (v/v) H2O2, pH 1.4, with a potential of -0.5 V applied for 1 h, followed by heat treatment at 450 °C.
Characterizations revealed a mesoporous structure, with UV-Vis absorption (300 - 700 nm), a band gap of 3.6 eV, and a BET surface area of 3.1 m2 g-1. Micrographs illustrated the formation of a uniform layer of WO3 on the CF surface, and characteristic peaks of C and WO3 in the monoclinic phase were confirmed. XPS analysis assigned species, including C 1s, O 1s, W (4f, 4f7/2, 4d5/2 4d3/2), with an intense peak at 530 eV related to the metallic bond (W-O).
The optimized experimental conditions: SER 2.0 mg L-1, volume 100 mL, flow rate 180 mL min-1, pH 5.6, UV LED irradiation, complete removal of SER was observed in 30 min when applied to real effluents from a water treatment plant before and after the chlorination step. Additionally, complete degradation was achieved after 90 min of the experiment in simulated effluents in Milli-Q water. The photoactive membrane proved effective under various conditions, achieving 1.41 mg L-1 SER degradation after five reuse cycles and complete SER degradation after 40 min under solar irradiation. Experiments with scavenger agents confirmed the participation of species (HO•, O2
•-, 1O2, h+, and H2O2) in the degradation process. Additionally, six degradation products were identified with mass-charge (m/z) of 176, 189, 191, 273, 293, and 322, generated from hydroxylation, demethylation, and dechlorination reactions.
The photoactive membrane has shown excellent potential for applications in filtration processes, mitigating issues associated with fouling. It facilitates the rapid removal and effective degradation of pollutants while also allowing for its application under various irradiation conditions. This feature simplifies and enables effective management in the treatment of contaminated waters.
(Digital Presentation) Synthesis of Carbon Materials on Aluminum Foil from a Vapor-Gas Environment
Authors: Kuzmina Elena , Barkov Alexey , Mishinkin Vadim , Kolosnitsyn Vladimir 
Published: August 2024

Due to its excellent electrical conductive properties and large specific surface area, one of the allotropic modifications of carbon, carbon nanotubes (CNTs), grown on a metal substrate, have great potential for use in supercapacitor electrodes. After all, growing layers of nanotubes directly on the surface of electrodes. can make it possible to achieve the best adhesion and electrical contact of CNTs with the current collector [1]. The large surface area and exceptional electronic conductivity of CNTs make them prime candidates for high-performance and high-speed electrochemical applications [2].
The aim of the work was to investigate the effect of synthesis conditions on the structure and properties of a carbon layer grown on the surface of aluminum foil.
We used technical aluminum foil with a thickness of 16 microns. Aluminum foil was previously degreased with acetone, kept in an aqueous 1 M NaOH solution for 3 minutes and 30 minutes in a 20% aqueous solution of nickel nitrate at 90 °C. The synthesis of carbon materials on the surface of aluminum foil was carried out by pyrolysis of ethanol vapor in argon at 550 and 600 °C.
Analysis of SEM picture (fig. a) and Raman spectrum (dig. b) allows to conclude that the synthesized carbon materials are nanotubes or nanofibers.
It has been established that pre-treatment of aluminum foil with acetone does not affect the properties and uniformity of distribution of the carbon layer. On aluminum foil, without pretreatment and kept in acetone, after the synthesis of carbon materials from the vapor-gas phase, initial sections of aluminum foil without a carbon layer are observed. Preliminary exposure of aluminum foil in an alkali solution contributed to the uniform distribution of the synthesized carbon; the entire foil was evenly covered with carbon.
When pyrolysis of ethanol vapor is carried out in argon at 550 °C, the carbon layer is heterogeneous (fig. c) and volumetric growths are observed on the foil. When synthesizing carbon materials at 600°C, the carbon layer is dense without bulky formations (fig. d).
This work was performed as part of the Ministry of Science and Higher Education of the Russian Federation
[Government Order Theme No. 121111900148-3].

References

Redkin, A. N., Mitina, A. A., & Yakimov, E. E. (2021). Simple technique of multiwalled carbon nanotubes growth on aluminum foil for supercapacitors. Materials Science and Engineering: B, 272, 115342. DOI:10.1016/j.mseb.2021.115342;

Moyer-Vanderburgh, K., Ma M. C., Park, S.J., Jue, N.L., Buchsbaum, S.F., Wu K.J., Wood, M., Ye, J. Fornasiero, F., Growth and Performance of High-Quality SWCNT Forests on Inconel Foils as Lithium-Ion Battery Anodes: ACS Appl. Mater. Interfaces 2022, 14, 49, 54981–54991. DOI: 10.1021/acsami.2c18396

Figure 1
High-Performance Optimised Porosity Iron Electrode for Hybrid Battery Electrolyzer
Authors: Pal Santosh K. , Mulder Fokko M. 
Published: August 2024

The growing demand for efficient, cost-effective and sustainable energy systems has prompted significant research into the development of advanced electrochemical devices. Hybrid battery electrolyzer, integrating the capabilities of both battery and electrolyzer, is a groundbreaking technology aiming to enhance both energy conversion efficiency and storage capacity. [1] Iron with large earth-abundance, low-cost, robustness, and high capacity is a promising electrode material for such hybrid energy systems. [2-4]
This study focuses on the design, fabrication, and performance evaluation of a novel porous iron electrode tailored for use in a hybrid battery electrolyzer system. The proposed electrode exhibits superior electrocatalytic activity, enhanced mass transport properties, and increased surface area, contributing to improved overall performance. The electrode's porosity and pore structure are tuned to facilitate efficient mass transport and electrolyte penetration, addressing common challenges associated with conventional electrodes. The electrochemical performance of the optimised porosity iron electrode is investigated through comprehensive characterization techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and charge-discharge cycling tests. Results indicate superior electrochemical properties, showcasing enhanced specific capacity, faster charge/discharge kinetics, and prolonged cycle life compared to conventional electrodes. The incorporation of conducting nanocarbon and sintering at optimized temperature of 800 ℃ led to the achievement of a stable and elevated capacity exceeding 500 mAh/g for these advanced iron electrodes. The iron electrodes exhibit outstanding porosity (65 - 70%), along with a pore size of 5-10 µm. This configuration results in exceptional current rate performance, achieving a discharge capacity of 350 mAh/cm2 at a current density of 35 mA/cm2 and 245 mAh/cm2 at 50 mA/cm2. Furthermore, the iron electrodes exhibit superior performance in high-current electrolysis, showcasing an HER potential of -1.25, -1.34, and -1.50 V (vs Hg/HgO) at a current density of 200, 500 and 1000 mA/cm2 respectively.
These findings highlight the potential of optimised porosity iron electrodes as a key component in the development of high-performance and cost-effective hybrid battery electrolyzer systems. The integration of such advanced materials holds promise for unlocking new frontiers in energy storage and green hydrogen technology, contributing to the realization of efficient and sustainable energy systems.
References:

F. M. Mulder, et al., Energy Environ. Sci., 2017, 10, 756.

K. Manohar et al., J. Electrochem. Soc. 2012, 159, A2148.

H. Weinrich, et al., Batteries & Supercaps 2022, 5, e202100415.

Möller-Gulland, et al. submitted.

Figure 1
4D-STEM and Eels Analysis of Complex C-Based Sensor Architectures
Authors: Ogolla Charles Otieno , Hepp Marco , Butz Benjamin 
Published: August 2024

Transforming high-carbon precursors into open-porous carbon foams and coatings via thermal processes is gaining attention as a sustainable method for various applications, including catalysis, energy utilization, and sensing [1]. In this research, we adopt a one-step laser patterning approach to selectively pyrolyze doctor-bladed ink coatings on flexible PET substrates, thereby producing highly porous, intricately designed CO2 sensor structures with a thickness of about 50 µm. Our ink formulation includes glucose as a pore-forming agent and adenine as a nitrogen source to enhance sensing capabilities.
Laser processing in an oxygen-rich setting results in flexible, highly porous sensor heterostructures characterized by distinct areas enriched with nitrogen and oxygen functionalities. The laser intensity’s attenuation with depth leads to the development of a distinctly porous graphitic surface layer (serving as the electrical transducer layer) and a denser nitrogen-enriched lower sensor layer, linked by a narrow transitional region [2].
To understand the formation and functionality of these sensors, we conducted an in-depth TEM analysis of cross-sections of the complete device, prepared through ultramicrotomy cross-sectioning. STEM-EELS elemental distribution maps distinctly show the chemical composition differences between the upper and lower layers of the sensor. Principal component analysis was utilized to separate the complex sensor structures into their constituent crystalline and amorphous carbon and nitrogen-containing phases. 4D-STEM analysis exposed the arrangement of the crystalline graphitic phase and the orientation of graphite basal planes adjacent to the pores of the open-porous sensor. Analyzing these structural parameters is essential for understanding the electrical performance of the sensor, as depicted in Figure 1 [3].

Figure 1: A (top)) SEM micrograph of sensor embedded in epoxy, (bottom) depth-dependent thermal laser intensity attenuation; B (left)) HA ADF-STEM micrograph showing different sensor layers, (middle) STEM-EELS nitrogen distribution map, (right) PCA bond analysis, C) HRTEM images of sensor from transducer (top) and sensor (bottom) layers with SAED image of respective ROIs (inset); D) 4D-STEM analysis depicting misalignment angle between graphitic carbon basal plane normal relative to the pore surface normal
References
[1] M. Hepp, et al. npj Flexible Electronics 6, 1-9 (2022)
[2] H. Wang, et al. Advanced Functional Materials 32, 2207406 (2022)
[3] C. Ophus, et al. Microscopy and Microanalysis 28, 390-403 (2022)

Acknowledgements: We acknowledge use of the DFG-funded Micro-and Nanoanalytics Facility (MNaF) at the University of Siegen (INST 221/131-1).

Figure 1
Developing and Testing Standards to Assess Atmospheric Corrosion of Silver Witness Coupons
Authors: Johnson Alexander , Sanders Christine E. , Santucci Raymond , Policastro Steven A , Hammond Mark H. 
Published: August 2024

Silver witness coupons are used to assess the corrosivity and chemistry of an ambient environment. The formation of silver corrosion products such as silver chloride is highly dependent on local conditions. However, the mechanisms that are responsible for these corrosion products are not well-understood, and there is a lack of standards used to compare and assess the quality of observations.
The goal of this study is to synthesize silver corrosion film standards with known thickness and morphology. Compounds of interest include silver chloride, silver oxide, silver sulfide, silver sulfite, and silver sulfate. These compounds were generated electrochemically by oxidizing the silver in the presence of the anion of interest (chloride, sulfite, or sulfate), chemically by submerging the silver in a solution containing the anion, and chemically by dipping the silver in molten silver salts. The surface chemistry of these films was then analyzed using galvanostatic reduction, x-ray diffraction, x-ray photon spectroscopy, Raman spectroscopy, and energy dispersion spectroscopy. The films generated from each method were compared against each other to determine the optimal film thickness and morphology. In the future, these results will be compared against the surface chemistry of silver films formed by testing in laboratory chambers or by exposure in field environments.

Figure 1