ChemNanoMat最新文献

We analyze the adsorption of the proteinogenic amino acids (AAs) glutamine, glutamic acid, lysine, tyrosine, proline, and valine onto bare iron oxide nanoparticles (approx. 10 nm). Aiming to identify the governing principles of low molecular weight coronae, which remain underinvestigated, our study covers broad concentration ranges up to the solubility limit of the AAs. Isothermal experiments reveal that the highly soluble AAs valine, proline, and lysine form extensive multilayers on the nanoparticle surface, and infrared measurements indicate intermolecular interactions, particularly with valine and lysine, for higher AA contents. Conversely, the low solubility of tyrosine and glutamic acid restricts their adsorption capacity, despite their higher partitioning on the solid surface. Parameters derived from fitting a classic saturation model seem to align with well-documented physicochemical properties such as the hydrophobicity and the complexity indices – a promising first step towards formulating design principles. Scaling these parameters by the AA solubility reveals a clear correlation with the adsorption behavior. In adsorption experiments with AA model mixtures, sequential incubation increases the adsorption capacity for valine and proline, whereas simultaneous incubation with these AAs reduces tyrosine's capacity. Future studies should seek to elucidate adsorption patterns to advance our understanding of corona growth and evolution mechanisms.

Nontoxic Sn-based perovskite solar cells (PSCs) represent a promising alternative to Pb-based PSCs, given their similar electronic properties and an ideal bandgap, accompanied by the highest theoretical efficiency (>33%). However, the performance of Sn-based PSCs lags significantly behind their Pb-based counterparts. This disparity arises from the susceptibility of Sn²⁺ to easy oxidation to Sn⁴⁺, an energy level mismatch, and fast crystilization. It is widely acknowledged that the oxidation of Sn²⁺ to Sn⁴⁺ results in severe P-type doping, leading to increased recombination, which is a primary factor contributing to the lower device performance. In this perspective article, we summarized the utilization of metallic Sn in Sn-based PSCs to facilitate the reduction of Sn⁴⁺ back to Sn²⁺. This approach is preferred due to its effectiveness, simplicity in process, and the absence of introducing additional impurities. Moreover, metallic Sn can serve as a source for synthesizing SnI₂ and act as hole transport material through transformation from Sn to SnO_x. We hope this article serve as a valuable reference for the ongoing development of Sn-based materials in PSCs technology.

The development of bifunctional electrocatalysts coupled with HER and OER activities in the same electrolyte to achieve overall water decomposition is more attractive and challenging for practical applications. Here, we prepared a CoFe-LDH catalyst via a hydrothermal method, and grew highly dispersed Pt−CoFe@CC bifunctional catalyst on a carbon cloth via the ethylene glycol thermal reduction method. The low content of Pt was limited to CoFe-LDH to balance the catalytic performance and cost, to achieve effective water decomposition. Surprisingly, the overall decomposition of water can be achieved with a voltage of only 1.6 V and good stability for up to 20 hours. This work provides a design idea and method for combining HER and OER bifunctional electrocatalysts.

Herein, we report the utilization of biochar derived from rice straw (RSB) as an effective support matrix for Pd nanoparticles and its application as an electrocatalyst for ethanol electro-oxidation (EEO) in an alkaline medium. Rice straw, a common agricultural byproduct, was pyrolyzed at 600 °C, 700 °C, and 800 °C under N₂ atmosphere. Pd was loaded onto the RSB via borohydride reduction of Pd²⁺, with a nominal loading of 20 % Pd. Spectroscopic and morphological characterization revealed the formation of dispersed Pd nanoparticles on the RSB surface. Pyrolysis temperature was observed to influence both the porosity of the resulting RSB and the dispersion and degree of exposure of Pd nanoparticles deposited on the surface. Electrochemical characterization revealed that Pd/RSB could be a potential EEO electrocatalyst for direct ethanol fuel cell applications. Pd/RSB-700 exhibited better performance in terms of EEO forward mass activity (j_f) and forward and backward mass activity (j_f/j_b) ratio relative to Pd/RSB-600 and Pd/RSB-800. Moreover, Pd/RSB was shown to be superior to commercial Pd on carbon black in terms of electrochemical stability. This study opens the potential of rice straw biochar as a sustainable and environmentally friendly carbon-based support matrix for Pd-based EEO electrocatalysts.

Gecko-like structures have been prepared by soft-template electropolymerization in micellar solution. Various monomers were designed from a triphenylamine core but only one monomer gives such structures even if the monomer is not perfectly planar. Extremely long and densely packed-microtubes are obtained at constant potential. However, the surfaces are not both highly hydrophobic and with strong water adhesion as gecko foot but are superhydrophilic. These differences can be explained by a higher surface energy or difference in arrangement structures for our surfaces. More information can be found in the Research Article by Thierry Darmanin and co-workers.

Stimuli-responsive color/fluorescence dual-switchable materials have garnered significant attention in displays, sensors, and anti-counterfeiting. However, current material systems are hampered by the single stimulus-response and unregulated fluorescence. Viologen derivatives featuring fluorophore as N-substituent and halogen anions as counteranions not only exhibit responsiveness to both electric and light stimuli but also enable adjustable emission. In this work, we explored the influence of halogen anions on the color/fluorescence dual-switching behaviors of 1,10-phenanthroline-based viologen derivatives. The energy level gaps for phen-Vio[2Cl⁻] (2.93 eV), phen-Vio[2Br⁻] (2.67 eV), and phen-Vio[2I⁻] (2.34 eV) decreased with the decrease of electron affinity of halogen anions (Cl⁻>Br⁻>I⁻), which leads to a sequential improvement in their electrochromic/electrofluorochromic and photochromic/photofluorochromic properties. This work has important guidance for the design and development of smart materials and their optoelectronic devices.

Manganese dioxide (MnO₂) nanoparticles are increasingly recognized for their potential in biomedical applications, particularly in the realm of hypoxic cancer therapy, due to their unique physicochemical characteristics. This investigation introduces a novel, template-free synthesis strategy. The reducing groups inherent in bovine serum albumin (BSA) facilitate a redox reaction with potassium permanganate (KMnO₄), while the abundance of functional groups in BSA is instrumental in the formation of MnO₂. The transmission electron microscopy (TEM) analysis has characterized the synthesized MnO₂ nanoparticles, termed BM NPs, as spherical particles with a mean diameter of 210 nm and zeta potential of −40.1 mV measured by dynamic light scattering (DLS). The Fourier transform infrared (FT-IR) spectrum of BM NPs exhibits the characteristic peak of MnO₂ at 1113 cm⁻¹ and 620 cm⁻¹_. Furthermore, the elemental composition of BM NPs has been ascertained through energy-dispersive X-ray (EDX) elemental mapping analysis. Though concentration of BM NPs up to 200 μg/mL, the survival rate of 4T1 cells remained approximately 75 %. Given that BM NPs at a concentration of 100 μg/mL significantly alleviate cellular hypoxia, the high oxygen-generating capacity of these nanoparticles is proved, suggesting their suitability as a drug delivery system, especially in the context of hypoxic tumor microenvironments.

p-Nitrophenol (PNP), a highly toxic water pollutant, poses significant risks to human health and the environment. For detecting PNP, a colorimetric method utilizing a nanozyme that mimics laccase activity presents a viable approach. In this study, PV₁₄@MIL-88A, a robust nanozyme with superior laccase-mimic capabilities, was synthesized by incorporating Na₇H₂[PV₁₄O₄₂] (PV₁₄) into MIL-88A, a metal-organic framework (MOF). This nanozyme demonstrates optimal laccase-mimicking activity, enabling effective PNP detection via colorimetry and digital image colorimetry using smartphones. Theoretical analyses suggest that the outstanding laccase-mimic activity of PV₁₄@MIL-88A is derived from the optimized d-band center in PV₁₄. Upon calcination with dicyandiamide (DCDA), PV₁₄@MIL-88A transforms into Fe₂O₃/VO₂@NCNF. In the presence of NaBH₄, Fe₂O₃/VO₂@NCNF facilitates the conversion of PNP to p-aminophenol (PAP), an essential precursor in paracetamol synthesis. The interaction between Fe₂O₃ and VO₂ in Fe₂O₃/VO₂@NCNF enhances adsorption and subsequent reduction of PNP. The saturation magnetization of Fe₂O₃/VO₂@NCNF reaches 25 emu g⁻¹, which supports efficient magnetic separation in the reduction process. This study not only advances an effective method for PNP detection but also facilitates its transformation from a hazardous pollutant into a valuable chemical precursor.

The oral rifampicin (RIF) dosage forms possess various side effects and limited efficacy for tuberculosis treatment. Thus, this work developed the nano-in-microparticles containing RIF (trojan nRIF) as a novel pulmonary delivery system. The RIF-loaded nanoparticles (nRIF) were prepared by self-assembly polyelectrolyte complexation between lecithin and chitosan, whereas the trojan nRIF were formulated by spray-drying method of nRIF and mannitol/maltodextrin. The nRIF had a spherical shape with sizes of 86–126 nm, zeta potentials of 24–39 mV, entrapment efficiencies of 44–80 %, and drug loading capacities of 13–42 %. The RIF release from nRIF occurred in two stages, the initially rapid release stage and the controlled release stage upto 96 h, followed the Higuchi model. The trojan nRIF possessed the mass median aerodynamic diameter of 3.7–4.6 μm, fine particle fraction of 34–40 %, and alveolar fraction of 17–21 %. Compared to mannitol, maltodextrin was a superior carrier for nRIF, which yielded better aerodynamic properties and RIF was mainly stayed in the amorphous form. Moreover, using the scanning electron microscopy, the nano-in-microparticles were clearly observed with hollow structure. Finally, the trojan nRIF could preserve the physical properties of the encapsulated nRIF. In summary, the trojan nRIF could become a potential inhalation anti-tuberculosis product.