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We present a highly efficient single‐atom catalyst (SACs) tailored for nitroarene reduction using NaBH4 under ambient conditions. Employing an unique approach, we harnessed NaCl under high temperature to create host materials enriched with negatively charged nitrogenous and oxygenated functional groups, capable of anchoring and stabilizing Ni ions within the aromatic structure. The nickel single sites were prepared by a straightforward cation exchange method. STEM‐HAADF imaging confirmed the presence of nickel single‐atoms, while XPS, FTIR, and Raman spectra validated nickel coordination within the catalyst. Remarkably, the CN−Ni catalyst exhibited exceptional catalytic performance under ambient conditions, achieving a high catalytic activity with NaBH4 (TOF 2246± ${\pm }$ 452 h−1 and 107± ${\pm }$ 47 mmol g−1 min−1). It also demonstrated remarkable conversion exceeding 90 % and outstanding selectivity. Equally impressive was its ability to maintain full catalytic activity over multiple reaction cycles, highlighting its robustness. This work is a significant leap in SACs design, offering a versatile and highly effective preparation method for SACs based on N‐doped carbon with far‐reaching implications in industrial reduction reactions. [ABSTRACT FROM AUTHOR]

A new screen-printed electrode (SPE) modified with carbon black and ternary oxide (SiO2/TiO2/Nb2O5), denominated SPE/CB/SiTiNb and was developed for the direct detection of triclosan in tap water and mouthwash samples. The morphological characterization and electrochemical behavior of the sensors were performed by scanning electron microscopy, energy dispersive spectroscopy, and cyclic voltammetry. Differential pulse voltammetry was used to evaluate the proposed sensor in Britton–Robinson buffer 0.1 mol L−1 and showed a limit detection of 1.23 nmol L−1 in a linear range from 0.025 to 57.01 µmol L−1. Studies with possible interferents were performed demonstrating a significant selectivity of the sensor to the triclosan oxidation reaction. The sensor was applied in tap water and mouthwash real sample analyses, whose recoveries ranged from 93.4 to 98.8%, demonstrating that the sensor shows promise in the detection of triclosan in different matrices allied to high sensitivity, selectivity, low-cost, portability, disposability, and low sample volume, without pre-treatment, per analysis. [ABSTRACT FROM AUTHOR]

Over the last decade, the CO2 reduction reaction (CO2RR) has been increasingly exploited for the synthesis of high‐value raw materials in gaseous or liquid form, although no examples of CO2 fixation in nanoparticle systems have been demonstrated. Herein, CO2 fixation into solid nanomaterials by laser synthesis and processing of gold colloids in water, traditionally considered a green approach leading to ligand‐free nanoparticles without the formation of by‐products, is reported. If carbon monoxide‐rich gold nanoparticles are observable even after synthesis in deionized water, the presence of CO2 derivatives in alkaline water environment leads to C2 and C3 coupling with the production of carboxylic acids as a typical CO2RR fingerprint. While laser processing of preformed gold colloids is selective for C2 coupling, both C2 and C3 coupling to lactic acid are observed during pulsed laser ablation of a gold target. In the latter case, it is demonstrated that it is possible to synthesize photoluminescent organometallic nanocomposites in the blue spectral region with a quantum yield of about 20% under adequate experimental conditions. In this research, new pathways are offered to be explored in energetics, photonics, catalysis, and synthesis at the nanoscale. [ABSTRACT FROM AUTHOR]

Although several studies assess the biological effects of micro and titanium dioxide nanoparticles (TiO2 NPs), the literature shows controversial results regarding their effect on bone cell behavior. Studies on the effects of nanoparticles on mammalian cells on two-dimensional (2D) cell cultures display several disadvantages, such as changes in cell morphology, function, and metabolism and fewer cell–cell contacts. This highlights the need to explore the effects of TiO2 NPs in more complex 3D environments, to better mimic the bone microenvironment. This study aims to compare the differentiation and mineralized matrix production of human osteoblasts SAOS-2 in a monolayer or 3D models after exposure to different concentrations of TiO2 NPs. Nanoparticles were characterized, and their internalization and effects on the SAOS-2 monolayer and 3D spheroid cells were evaluated with morphological analysis. The mineralization of human osteoblasts upon exposure to TiO2 NPs was evaluated by alizarin red staining, demonstrating a dose-dependent increase in mineralized matrix in human primary osteoblasts and SAOS-2 both in the monolayer and 3D models. Furthermore, our results reveal that, after high exposure to TiO2 NPs, the dose-dependent increase in the bone mineralized matrix in the 3D cells model is higher than in the 2D culture, showing a promising model to test the effect on bone osteointegration. [ABSTRACT FROM AUTHOR]

The study aimed to develop an electrochemical sensor based on glassy carbon, mixed oxide (SiO2/TiO2/Sb2O5), and carbon black. The material was synthesized, characterized, and used to determine thiamethoxam in raw honey and water. The morphologic structure and electrochemical performance of the sensor was characterized by scanning electron microscopy and cyclic voltammetry. Differential pulse voltammetry with a concentration of 0.1 mol L−1 of Britton-Robinson buffer at pH 7.0 allowed the generation of a method to determine thiamethoxam in a linear range of 0.25 to 100.5 μmol L−1 and with a limit of detection of 0.012 μmol L−1. The system efficiently quantified traces of thiamethoxam in raw honey and tap water samples. The modified sensor did not present interferences of K+, Na+, Ca2+, Mg2+, glyphosate, imidacloprid, and carbendazim. In addition, the device showed good recovery values for thiamethoxam when applied directly to honey and water samples without any treatment, presenting an electrochemical sensor to monitor real-time hazardous substances in environmental and food matrices. [ABSTRACT FROM AUTHOR]

In the last decade, transition metal dichalcogenides (TMDs) have been intensively synthesized/studied thus linking their morphological aspect to their physical properties, and consequently leading to the understanding of the possible benefits of defects in such materials. Nevertheless, for future applications, quantifying and identifying defects in TMDs is still a milestone to reach in order to better employ these materials in optoelectronic devices. Raman Spectroscopy has been successfully employed in graphene to quantify punctual or line defects. In this paper, we bombarded monolayer MoSe2 with He ions and found out the existence of three defect activated Raman bands around 250–300 cm−1. Density functional theory calculations were employed to obtain the electronic and phonon dispersion bands, making it possible to infer that these bands arise from inter-valley Raman double resonance processes. Interestingly, the same punctual defect model, that allows one to predict the defect concentration at which graphene starts to become amorphous, also works for TMDs. Hence, this work opens the door to the macroscopic quantification of defects in TMDs, which is essential for technological applications. [ABSTRACT FROM AUTHOR]