Surface Chemistry Research Articles

Modulating Electrochemical Energy Storage and Multi-Spectra Defense of MXenes by Interfacial Dual-Filler Engineering.

MXenes have attracted growing interest in electrochemical energy storage owing to their high electronic conductivity and editable surface chemistry. Besides, rendering MXenes with spectrum defense properties further broadens their versatile applications. However, the development of MXenes suffers from weak van der Waal interaction-driven self-restacking that leads to random alignment and inferior interface microenvironments. Herein, a nacre-inspired MXene film is tailored by dual-filling of 2-ureido-4[1H]-pyrimidinone (UPy)-modified polyvinyl alcohol (PVA-UPy) and carbon nanotubes (CNTs). The dual-nanofillers engineering endows the nanocomposite film with a highly ordered structure (a Herman's order value of 0.838), a high mechanical strength (139.5MPa), and continuous conductive pathways of both the ab plane and c-axis. As a proof-of-concept, the tailored nanocomposite film achieves a considerable capacitance of 508.2 F cm-3 and long-term cycling stability without performance degradation for 10000 cycles. It is efficient for spectra defense in radar and infrared bands, displaying a high electromagnetic shielding capacity (19186dB cm2 g-1) and a super-low infrared (IR) emissivity (0.16), with negligible performance decay after saving in the air for 1 year, responsible for the applications in specific and complex conditions. This interfacial dual-filler engineering concept showcases effective nanotechnology toward sustainable energy applications with a long lifetime and safety.

Upcycling rice husk ash and coal-fired fly ash as si/al sources into hierarchical ZSM-5 for efficient mercury capture from industrial flue gas

Limiting gaseous Hg0 emission is pressing due to the high toxicity in the ecosystem. Zeolites can be regarded as a promising alternative to carbon-based Hg0 adsorbents. However, the mass transfer limitations of conventional singe-sized zeolites constrain the industrial application of zeolites. This study explores the synthesis of hierarchical ZSM-5 zeolites using rice husk ash (RHA) and coal-fired fly ash (FA) as sustainable sources of silicon and aluminum, aimed at enhancing Hg0 removal from industrial flue gases. By adopting a one-step hydrothermal method, we introduced hierarchical porosity into the ZSM-5 framework, enhancing mass transfer and adsorption efficiencies. Iron (III) chloride (FeCl3) was utilized as an active species for modifying the hierarchical ZSM-5, significantly boosting its Hg0 adsorption capabilities. Fe/6RF-hZ demonstrating more than 92% mercury removal efficiency in 60 min under mixed flue gas condition. The structural and chemical attributes of the synthesized ZSM-5 were detailedly characterized, revealing notable differences in surface chemistry and porosity that correlate with varying calcination temperatures of RHA. TEA analysis reveals that hierarchical ZSM-5 zeolites outperform traditional sorbents in demercuration (DeHg) applications, with exceptional DeHg efficiency, energy efficiency (12 kWh), synthesis cost (860 $/ton), and carbon content (non-carbon). This study not only sheds light on the upcycling of solid wastes in synthesizing novel adsorbents but also contributes to the broader application of zeolitic materials in environmental remediation.

Influence of Surface Chemistry on Metal Deposition Outcomes in Copper Selenide-Based Nanoheterostructure Synthesis.

The use of nanoparticle surface chemistry to direct metal deposition has been well-studied in the modification of metal nanoparticle substrates but is not yet well-established for metal chalcogenide particle substrates, although integration of these particles into nanoheterostructures is of high interest. In this report, we investigate the effect of Cu2-xSe surface chemistry on the morphology of metal deposition on these plasmonic semiconductor nanoparticles. Specifically, we functionalize Cu2-xSe nanoparticles with a suite of 12 different ligands and investigate how different aspects of the ligand structure do or do not impact the morphology and extent of subsequent metal deposition on the Cu2-xSe surface. Surprisingly, our results indicate that the morphology of the resulting metal deposits and the extent of metal deposition onto the existing Cu2-xSe particle substrate are indistinguishable for the majority of ligands tested. An exception to these findings is observed for particles functionalized by quaternary alkylammonium bromides, which exhibit statistically distinct metal deposition patterns compared to all other ligands tested. We hypothesize that this unique behavior is due to a cooperative binding mechanism of the quaternary alkylammonium bromides to the surface of copper selenide. Taken together, these results yield both new strategies for controlling postsynthetic modification of copper selenide nanoparticles and also reveal limitations of surface chemistry-based approaches for this system.

CSA-doped PANI-CNT nano composites for Ku band microwave shielding applications

The major concern in high-frequency communication is electromagnetic interference. To address this, there are several material composites developed. This article focuses on a cost-effective development method for synthesizing CSA-doped PANI-CNT nanocomposites for microwave shielding applications. The nanocomposite is prepared using chemical polymerization. The chemical structure, surface characteristics and atomic structure of the material are characterized using FTIR, XRD, SEM, and TEM, respectively. The EMI shielding characteristics of the synthesized material are investigated as a function of weight percentage of CNT in PANI. The efficacy of the developed material is studied using the waveguide method. The analysis reveals good improvement in the shielding at the X and Ku-band frequencies.

Mesoporous Silica-Based Membranes in Transdermal Drug Delivery: The Role of Drug Loss in the Skin

Compared to other forms of drug administration, the use of Transdermal Drug Delivery Systems (TDDSs) offers significant advantages, including uniform drug release profiles that contribute to lower side effects and higher tolerability, avoidance of direct exposure to the gastrointestinal tract, better patient compliance due to their non-invasive means of application and others. Mesoporous silica membranes are of particular interest in this regard, due to their chemical stability and their tunable porous system, with adjustable pore sizes, pore volumes and surface chemistries. While this allows for fine-tuning and, thus, the development of optimized TDDSs with high loading capacities and the desired release profile of a given drug, its systemic availability also relies on skin penetration. In this paper, using a TDDS based on mesoporous silica membranes in Franz cell experiments on porcine skin, we demonstrate surprisingly substantial drug loss during skin penetration. Drug passage through porcine skin was found to be dependent on the age and pre-treatment of the skin. pH and temperature were major determinants of drug recovery rates as well, indicating drug loss in the skin by enzymatic metabolization. Regarding the TDDS, higher loading obtained by SO3H surface modification of the mesoporous silica membranes reduced drug loss. Still, high loss rates in the skin were determined for different drugs, including anastrozole, xylazine and imiquimod. We conclude that, beyond the fine-tuned drug release profiles from the mesoporous silica membrane TDDS, remarkably high drug loss in the skin is a major issue for achieving desired skin penetration and, thus, the systemic availability of drugs. This also poses critical requirements for defining an optimal TDDS based on mesoporous silica membranes.

Thoughts on the past, present and future of UHV surface chemistry and the birth of Single-Atom Alloys

Throughout its relatively short lifetime, ultra-high vacuum (UHV) surface chemistry has progressed quickly. In the 1960′s, pioneers like Ertl and Somorjai started the field using single crystals and gained significant insight into catalytic processes by relating surface structure to reactivity. The more recent proliferation of scanning probes has significantly increased the power of the single crystal approach by enabling the atomic-scale structure of active sites to be correlated with their reactivity. In this perspective we briefly discuss how the field developed, identify some challenges, and highlight Single-Atom Alloys (SAAs), a new class of heterogeneous catalyst that was developed from a fundamental surface science approach. However, despite recent successes, funding for fundamental surface science has declined. Academic hires in the discipline are also declining in part due to the start-up costs. We make the case that fundamental UHV surface chemistry is still too young a field to be in recession.

Mechanism of the Terahertz Wave-MXene Interaction and Surface/Interface Chemistry of MXene for Terahertz Absorption and Shielding.

ConspectusOver the past two decades, terahertz (THz) technology has undergone rapid development, driven by advancements and the growing demand for THz applications across various scientific and technological domains. As the cornerstone of THz technology, strong THz-matter interactions, especially realized as high THz intrinsic absorption in nanometer-thick materials, play a highly important role in various applications including but not limited to THz absorption/shielding, detection, etc. The rigorous electromagnetic theory has posited a maximum intrinsic absorption of 50% for electromagnetic waves by thin films, and the succinct impedance matching condition has also been formulated to guide the design of highly intrinsically absorbing materials. However, these theories face challenges when applied to the THz spectrum with an ultrabroad bandwidth. Existing thin films typically achieve a maximum intrinsic absorption within a narrow frequency range, significantly limiting the performance of THz absorbers and detectors. To date, both theoretical frameworks and experimental solutions are lacking in overcoming the challenge of achieving broadband maximum intrinsic absorption in the THz regime.In this Account, we describe how two-dimensional (2D) transition-metal carbide and/or nitride (MXene) films with nanometer thickness can realize the maximum intrinsic absorption in the ultrabroad THz band, which successfully addresses the forementioned longstanding issue. Surprisingly, traditional DC impedance matching theory fails to explain this phenomenon, while we instead propose a novel theory of AC impedance matching to provide a satisfactory explanation. By delving into the microscopic transport behavior of free electrons in MXene, we discover that intraflake transport dominates terahertz conductivity under THz wave excitation, while interflake transport primarily dictates DC conductivity. This not only elucidates the significant disparities between DC and AC impedance in MXenes but also underscores the suitability of AC impedance matching for achieving broadband THz absorption limits. Furthermore, we identify a high electron concentration and short relaxation time as crucial factors for achieving broadband maximum absorption in the THz regime. Although approaching the THz intrinsic absorbing limits, it still faces hurdles to the use of MXene in practical applications. First, diverse and uncontrollable terminations exist on the surface of MXene stemming from the synthesis process, which largely influence the electron structure and THz absorbing property of MXene. Second, MXene suffers from poor stability in the presence of oxygen and water. To address the above issues, we have undertaken distinctive works to precisely control the terminations and suppress the oxidation of MXene even at high temperature through surface and interface chemistry, such as low-temperature Lewis basic halide treatment and building a Ti3C2Tx/extracted bentonite (EB) interface. For practical application consideration, we proposed a copolymer-polyacrylic latex (PAL)-based MXene waterborne paint (MWP) with a strong intermolecular polar interaction between MWP and the substrate provided by the cyano group in PAL. This not only has strong THz EMI shielding/absorption efficiency but also can easily adhere to various substrates that are commonly used in the THz band. These studies may have significant implications for future applications of MXene nanofilms in THz optoelectronic devices.

Eco-conscious upcycling of sugarcane bagasse into flexible polyurethane foam for mechanical & acoustic relevance.

This study explores the use of sugarcane bagasse (SCB), a byproduct of sugarcane processing, as a bio-filler in the production of flexible polyurethane foam (FPU), focusing on its benefits for both the environment and the economy. By varying the inclusion of SCB waste from 1 to 6 wt%, the research aims to enhance the FPU's mechanical and acoustic characteristics. Techniques such as Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscopy (FESEM) were utilized to analyze the chemical structure and surface characteristics of both SCB and the FPU/SCB composites. Additionally, tests on gel fraction, density, and mechanical properties were conducted. The results indicate that adding 4 wt% SCB to FPU considerably improved the foam's properties. This modification resulted in a 148.63% increase in apparent density, a 228.47% rise in compressive strength, and a 116.24% boost in tensile strength. Furthermore, sound absorption across various frequency ranges was enhanced compared to the control foam. Additionally, the findings show that SCB effectively shifts sound absorption characteristics to lower frequencies. Specifically, at a low frequency of 500 Hz, the sound absorption coefficient increased to 0.4 with a foam thickness of 20 mm. This demonstrates that SCB can significantly improve FPU's performance, making it an attractive option for applications requiring noise mitigation, such as in the automotive and construction industries, thereby offering a sustainable solution to waste management and materials innovation.

Smart zwitterionic coatings with precise pH-responsive antibacterial functions for bone implants to combat bacterial infections.

Hydrophilic antifouling coatings based on zwitterionic polymers have been widely applied for the surface modification of bone implants to combat biofilm formation and reduce the likelihood of implant-related infections. However, their long-term effectiveness is significantly limited by the lack of effective and precise antibacterial activity. Here, a pH-responsive smart zwitterionic antibacterial coating (PSB/GS coating) was designed and robustly fabricated onto titanium-base bone implants by using a facile two-step method. First, dopamine (DA) and a poly(sulfobetaine methacrylate-co-dopamine methacrylamide) (PSBDA) copolymer were deposited on implants via mussel-inspired surface chemistry, resulting in a hydrophilic base coating with abundant catechol residues. Next, an amino-rich antibiotic, gentamicin sulfate (GS), was covalently linked to the coating through the formation of acid-sensitive Schiff base bonds between the amine groups of GS and the catechol residues present in both the zwitterionic polymer and the DA component. During the initial implantation period, the hydrophilic zwitterionic polymers demonstrated the desired anti-fouling properties that could effectively reduce protein and bacterial adhesion by over 90%. With time, the bacterial proliferation led to a decrease in the microenvironment pH value, resulting in the hydrolysis of the acid-sensitive Schiff base bonds, thereby releasing GS on demand and effectively enhancing the anti-biofilm properties of coatings. Benefiting from this synergistic antifouling and smart antibacterial activities, the PSB/GS coating exerted an excellent anti-infective activity in both in vivo preoperative and postoperative infection rat models. This proposed facile yet effective coating strategy is expected to provide a promising solution to combat bone implant-related infections.

Facile chemical surface modification of boron nitride platelets and improved thermal and mechanical properties of their polymer compounds for 2.5D/3D packaging applications

Thermally conductive yet electrically insulative epoxy composites are sought after as encapsulation materials to tackle the heat dissipation challenges in modern electronics. In this work, we developed a novel one-step and facile solvothermal reflux method using a high-boiling-point solvent to surface-modify hexagonal boron nitride (h-BN) with glycine. By refluxing glycine at high temperature, amino functional groups are grafted onto the BN surface, which can enhance the affinity of fillers for epoxy and reduce the interfacial thermal resistance of the filler/epoxy composites. We investigated the mechanism of glycine-grafted layer formation, optimizing reactant mass ratios for enhanced interfacial thermal transport. The resulting BN@G11/epoxy composites exhibit a remarkable thermal conductivity of 1.04 W/mK at 30 wt% modified-BN loading, representing a 477.8 % increase over neat epoxy and 57.5 % higher than h-BN/epoxy composites at equivalent BN filler loading. Additionally, these composites demonstrate improved thermomechanical properties, confirming the strengthened BN/epoxy interface bonding using modified BN fillers. Compared to other surface treatment methods, this solvothermal reflux approach stands out for its scalability and cost-effectiveness. This scalable and eco-friendly innovation presents a competitive strategy for designing polymer-based composites for thermal management, catering to the demands of future 2.5D/3D semiconductor packaging.

Red and Green Laser Powder Bed Fusion of Pure Copper in Combination with Chemical Post-Processing for RF Cavity Fabrication

Linear particle accelerators (Linacs) are primarily composed of radio frequency cavities (cavities). Compared to traditional manufacturing, Laser Powder Bed Fusion (L-PBF) holds the potential to fabricate cavities in a single piece, enhancing Linac performance and significantly reducing investment costs. However, the question of whether red or green laser PBF yields superior results for pure copper remains a subject of ongoing debate. Eight 4.2 GHz single-cell cavities (SCs) were manufactured from pure copper using both red and green PBF (SCs R and SCs G). Subsequently, the surface roughness of the SCs was reduced through a chemical post-processing method (Hirtisation) and annealed at 460 °C to maximize their quality factor (Q0). The geometric accuracy of the printed SCs was evaluated using optical methods and resonant frequency (fR) measurements. Surface conductivity was determined by measuring the quality factor (Q0) of the SCs. Laser scanning microscopy was utilized for surface roughness characterization. The impact of annealing was quantified using Energy-Dispersive X-ray Spectroscopy and Electron Backscatter Diffraction to evaluate chemical surface properties and grain size. Both the SCs R and SCs G achieved the necessary geometric accuracy and thus fR precision. The SCs R achieved a 95% Q0 after a material removal of 40 µm. The SCs G achieved an approximately 80% Q0 after maximum material removal of 160 µm. Annealing increased the Q0 by an average of about 5%. The additive manufacturing process is at least equivalent to conventional manufacturing for producing cavities in the low-gradient range. The presented cavities justify the first high-gradient tests.

Gas sensing properties of two dimensional tin oxides: A DFT study

This study delves into the surface science of 2D SnO, SnO2, and Sn2O3 materials, exploring their potential applications in sensing technologies. Our research focuses on the surface engineering of these materials, including gas sensing capabilities, interactions with potential substrates, thermal expansion, and optical and anodic properties. Our adsorption calculations demonstrate the promising gas sensing abilities of SnO2 and Sn2O3, particularly in detecting ammonia (NH3) and nitrogen dioxide (NO2), respectively, which could be crucial in environmental monitoring and sensing technologies. Additionally, the adsorption of DNA molecules suggests the potential for DNA identification using physisorption methods. The study also investigates the suitability of lithium niobate (LiNbO3) as a substrate for the growth of Sn2O3, highlighting its potential for surface engineering applications. The optical properties of the three monolayers reveal a commonality in exhibiting a primary absorption peak in the ultraviolet range, which could be beneficial for gas sensing applications. This research contributes to the understanding of surface science of 2D materials, with implications for the development of advanced sensing technologies.

Synthesis of green ceramic adsorbent for the treatment of tire factory effluent containing lead, zinc, aluminum, cobalt, iron and manganese ions

In this study, a novel nano-composite ceramic adsorbent was synthesized and characterized for the removal of heavy metal ions from industrial wastewater. The adsorbent was prepared using low-cost materials including clay and human hair, and hydroxyapatite nanoparticles derived from bovine bones. The synthesis method, material properties, and adsorption performance were thoroughly investigated wed XRD, FT-IR, FE-SEM and, BET. The adsorption process was optimized using Design Expert software, resulting in optimal conditions of pH 6.5, adsorbent mass of 22.5 g, temperature of 44.5 °C, initial concentration of 281 mgL−1, and retention time of 192 min. Thermodynamic parameters indicated that the adsorption process was spontaneous, endothermic, and followed the Freundlich isotherm model. The adsorption mechanism involved ion exchange, physical and chemical surface adsorption, facilitated by the unique surface properties of the nano-composite adsorbent. Moreover, the adsorbent exhibited high regeneration efficiency, with up to 73 cycles of reuse without a decrease in removal efficiency.

Toward Quantifying the Chemical Sensitivity of Nuclear Spin Surface Relaxivity in Mesoporous Media.

Low-field nuclear magnetic resonance (NMR) relaxation is a promising non-invasive technique for characterizing solid-liquid interactions within functional porous materials. However, the ability of the solid-liquid interface to enhance adsorbate relaxation rates, known as the surface relaxivity, in the case of different solvents and reagents involved in various chemical processes has yet to be evaluated in a quantitative manner. In this study, we systematically explore the surface relaxation characteristics of 10 liquid adsorbates (cyclohexane, acetone, water, and 7 alcohols, including ethylene glycol) confined within mesoporous silicas with pore sizes between 6 and 50 nm using low-field (12.7 MHz) two-dimensional 1H T1-T2 relaxation measurements. Functional-group-specific relaxation phenomena associated with the alkyl and hydroxyl groups of the confined alcohols are clearly distinguished; we report the dependence of both longitudinal (T1) and transverse (T2) relaxation rates of these 1H-bearing moieties on pore surface-to-volume ratio, facilitating the quantification and assignment of surface relaxivity values to specific functional groups within the same adsorbate molecule for the first time. We further demonstrate that alkyl group transverse surface relaxivities correlate strongly with the alkyl/hydroxyl ratio of the adsorbates assessed, providing evidence for a simple, quantitative relationship between surface relaxivity and interfacial chemistry. Overall, our observations highlight potential pitfalls in the application of NMR relaxation for the evaluation of pore size distributions using hydroxylated probe molecules, and provide motivation for the exploration of nuclear spin relaxation measurements as a route to adsorbate identity within functional porous materials.

Surface termination effects on Raman spectra of Ti3C2Tx MXenes: an in situ UHV analysis.

Ti3C2Tx MXenes have typically a mixed surface termination of oxygen, hydroxyl and fluorine groups (Tx). In this work, we investigate the influence of the surface termination on the vibrational properties of Ti3C2Tx by performing thermal desorption and in situ Raman spectroscopy in ultra-high-vacuum (UHV). Significant changes in the Raman spectra occur after annealing above 600 °C, correlated with the desorption of approximately 80% of the fluorine termination, as confirmed by mass spectrometry and X-ray photoemission spectra. In particular, the intense Raman mode at 203 cm-1, usually attributed to a Ti-C-layer stretching vibration, is strongly damped upon fluorine desorption, while the broad spectral features between 220 and 680 cm-1, usually attributed to surface group vibrations, are not changing significantly. We show that the Raman spectra and the change induced by fluorine desorption are well represented by the phonon density of states instead of zone-center phonon modes. Disorder-induced Raman scattering strongly contributes to the Raman spectra. Moreover, due to the metallic nature of MXenes, charge density fluctuation scattering contributes as well. We show that the two scattering mechanisms, deformation potential and charge density fluctuation, may lead to opposite interpretations concerning the symmetry of the fluorine-related mode at 203 cm-1. This study provides new insights into the interpretation of the Raman spectra of MXenes, especially regarding the relation between surface chemistry and vibrational spectroscopy.

The ESO SupJup Survey II. The 12C/13C isotope ratios of three young brown dwarfs with CRIRES+

Young brown dwarfs exhibit atmospheric characteristics similar to those of super-Jupiters, providing a unique opportunity to study planetary atmospheres. Atmospheric retrievals of high-resolution spectra reveal detailed properties of these objects, with elemental and isotopic ratios offering insights into their formation history. The ESO SupJup Survey, utilising CRIRES$^+$ on the Very Large Telescope, aims to assess the role of as a formation tracer. We present observations of three young brown dwarfs: 2MASS J12003792-7845082, TWA 28, and 2MASS J08561384-1342242. Our goal is to constrain their chemical compositions, thermal profiles, surface gravities, spin rotations, and Cratio. We conducted atmospheric retrievals of CRIRES$^+$ K-band spectra, coupling the radiative transfer code petitRADTRANS with the Bayesian inference algorithm MultiNest The retrievals provide a detailed characterisation of the atmospheres of the three objects. We report the volume mixing ratios of the main molecular and atomic species: HF, Na, Ca, and Ti, including the novel detection of hydrogen fluoride (HF) in the atmosphere of a brown dwarf. We determine values of $ and $79^ $ in the atmospheres of TWA 28 and J0856, respectively, with strong significance ($>3 We also report tentative evidence ($ of in J1200, at $. Additionally, we detect at moderate significance in J0856 (3.3sigma ) and TWA 28 (2.1sigma ). The retrieved thermal profiles are consistent with hot atmospheres ($2300-2600$ K) with low surface gravities and slow spins, as expected for young objects. The measured carbon isotope ratios are consistent among the three objects and show no significant deviation from that of the local interstellar medium, suggesting a fragmentation-based formation mechanism similar to star formation. The tentative detection of in two objects of our sample highlights the potential of high-resolution spectroscopy to probe additional isotope ratios, such as O in the atmospheres of brown dwarfs and super-Jupiters.

Unveiling enhanced sound absorption in coconut wood through hemicellulose and lignin modification.

Coconut wood (Cocos nucifera L.) is lightweight and has variable quality, making it a potential candidate for manufacturing sound absorption boards. However, its sound absorption coefficient needs enhancement to optimize its effectiveness in this application. This study aims to enhance its sound absorption properties using eco-friendly hydrogen peroxide and acetic acid treatments. This treatment modified the carbohydrate polymers (hemicellulose and cellulose) and lignin structures in the wood cell wall. The novelty of this approach lies in using these chemicals to improve acoustic performance significantly. Coconut wood samples were treated with a 1:1 acetic acid and hydrogen peroxide mixture for 20, 40, 60, and 80min. Characterization techniques such as FTIR, XPS, and XRD, and 3D optical profilometry analyzed changes in chemical functionalities, crystallinity, and surface roughness. Sound absorption coefficients were measured using the impedance tube method. Results showed a significant improvement in sound absorption for all treated samples, especially at 60min. The treatment also enhanced surface roughness, air permeability, porosity, and pore sizes, contributing to better sound absorption. This proposed treatment method addresses environmental consciousness and enhances the sustainable use and utilization of coconut wood.

Modulating the coordination environment and metal choice in carbon buckypapers supported metal phthalocyanines for enhanced electrocatalytic carbon dioxide reduction

In the search of versatile electrocatalysts for the electrochemical reduction of carbon dioxide (CO2RR), different transition metal phthalocyanines (MPc, where M=Fe, Co, Ni and Cu) have been immobilized by an easy and scalable wet impregnation on carbon nanotubes (CNTs) in the form of buckypaper (BP). Both the nature of the metal and the surface chemistry of the carbon support were found to play a pivotal role in determining their CO2RR efficiency and selectivity. We disclose here a potentiodynamic strategy for the controlled surface modification of BP with N- and P-containing polymeric species as a simple heterogenization strategy for molecular catalysts, enabling to easily tune their electrocatalytic performance. Syngas (mixture of H2 and CO) was obtained as the main product from CO2RR using FePc, CoPc and NiPc as electrocatalysts on functionalized (BPf) or non-modified BP. In contrast, CuPc was found to mainly catalyze the hydrogen evolution reaction (HER), with small amounts of formate as the only CO2RR product. It is possible to modulate the H2/CO ratio in the final product through the appropriate selection of the metal in MPc, the modification of the coordination environment by the controlled functionalization of the carbon support and the adjustment of the operating conditions. In particular, H2/CO ratios in a range between 0.17 and 1.28 have been obtained with good stability during electrolysis. Among all the MPc studied, CoPc surfaced as the most promising candidate for the reduction of CO2 to CO and H2 production, a finding substantiated by computational studies highlighting the positive impact of phosphate ligands on CoPc. This strategy outlines the starting line of a potential route toward the controlled generation of CO2RR-related products.

Chemical and UV Durability of Hydrophobic and Icephobic Surface Layers on Femtosecond Laser Structured Stainless Steel

Femtosecond laser processing significantly alters the surface structure and chemical composition, impacting its wetting properties. Post-treatments such as immersion in a hydrocarbon liquid (petrol) or storage in a vacuum can significantly reduce ice adhesion, making the surfaces interesting for anti-ice applications. This study investigates their durability against acetone, ethylene glycol, and UV radiation. The laser-structured surfaces were immersed in the respective liquids for up to 48 h. The results indicate limited durability of the superhydrophobic and icephobic layers when submerged in acetone and ethylene glycol, with more favorable results for petrol treatment than vacuum treatment. Similar results were obtained after 100 h of UV exposure, showing a decrease in superhydrophobic properties and an increase in ice adhesion. However, repeated vacuum treatments conducted after the chemical durability tests revealed the potential for partial recovery of the hydrophobic and icephobic properties. XPS analysis was performed throughout the experiments to evaluate changes in surface chemistry resulting from the post-laser treatments and the durability tests.

Solution Synthesis of NdTe3 Magnetic Nanosheets.

Neodymium tritelluride is a layered van der Waals material, with correlated electronic properties including high electronic mobility, charge density waves, and antiferromagnetism. We developed a solution synthesis method to form free-standing nanosheets of NdTe3, with nanosheet lateral dimensions of 200-400 nm. The morphology of the nanosheet was influenced by the neodymium precursor. When Nd[(N(SiMe3)2]3 was used as the metal source the nanosheet thickness average was 12 ± 2.5 nm, alternatively the combination of NdCl3 and Li(N(SiMe3)2) led to thicker nanosheets, approximately 19 ± 2.4 nm. We believe that the difference in thickness and changes in surface chemistry point to the role of chloride in accelerating nanocrystal growth for the synthesis with NdCl3 (and Li(N(SiMe3)2). Both types of nanosheets exhibit charge density wave (CDW) distortions as measured using electron diffraction and investigated using variable temperature Raman scattering. Interestingly, the magnetic studies suggest a distinct change in properties between 12 and 19 nm thickness in antiferromagnetic NdTe3.