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A novel Fe2Mo3O8/MoO2@MoS2 nanocomposite is synthesized for extremely sensitive detection of NH3 in the breath of kidney disease patients at room temperature. Compared to MoS2, α‐Fe2O3/MoS2, and MoO2@MoS2, it shows the optimal gas‐sensing performance by optimizing the formation of Fe2Mo3O8 at 900 °C. The annealed Fe2Mo3O8/MoO2@MoS2 nanocomposite (Fe2Mo3O8/MoO2@MoS2‐900 °C) sensor demonstrates a remarkably high selectivity of NH3 with a response of 875% to 30 ppm NH3 and an ultralow detection limit of 3.7 ppb. This sensor demonstrates excellent linearity, repeatability, and long‐term stability. Furthermore, it effectively differentiates between patients at varying stages of kidney disease through quantitative NH3 measurements. The sensing mechanism is elucidated through the analysis of alterations in X‐ray photoelectron spectroscopy (XPS) signals, which is supported by density functional theory (DFT) calculations illustrating the NH3 adsorption and oxidation pathways and their effects on charge transfer, resulting in the conductivity change as the sensing signal. The excellent performance is mainly attributed to the heterojunction among MoS2, MoO2, and Fe2Mo3O8 and the exceptional adsorption and catalytic activity of Fe2Mo3O8/MoO2@MoS2‐900 °C for NH3. This research presents a promising new material optimized for detecting NH3 in exhaled breath and a new strategy for the early diagnosis and management of kidney disease. [ABSTRACT FROM AUTHOR]

A new NO2 nanohybrid of a gas sensor (CTAB-MoS2/rGO) was constructed for sensitive room-temperature detection of NO2 by 3D molybdenum disulfide (MoS2) and reduced graphene oxide (rGO), assisted with hexadecyl trimethyl ammonium bromide (CTAB). In comparison with MoS2 and MoS2/rGO, the BET and SEM characterization results depicted the three-dimensional structure of the CTAB-MoS2/rGO nanohybrid, which possessed a larger specific surface area to provide more active reaction sites to boost its gas-sensing performance. Observations of the gas-sensing properties indicated that the CTAB-MoS2/rGO sensor performed a high response of 45.5% for 17.5 ppm NO2, a remarkable selectivity of NO2, an ultra-low detection limit of 26.55 ppb and long-term stability for a 30-day measurement. In addition, the response obtained for the CTAB-MoS2/rGO sensor was about two to four times that obtained for the MoS2/rGO sensor and the MoS2 sensor toward 8 ppm NO2, which correlated with the heterojunction between MoS2 and rGO, and the improvement in surface area and conductivity correlated with the introduction of CTAB and rGO. The excellent performance of the CTAB-MoS2/rGO sensor further suggested the advantage of CTAB in assisting a reliable detection of trace NO2 and an alternative method for highly efficiently detecting NO2 in the environment. [ABSTRACT FROM AUTHOR]

Nickel-iron layered double hydroxides (NiFe LDHs) are considered as promising substitutes for precious metals in oxygen evolution reaction (OER). However, most of the reported NiFe LDHs suffer from poor long-term stability because of the Fe loss during OER resulting in severe inactivation. Herein, a dynamically stable chelating interface through in situ transformation of asymmetric aldehyde-ligand (THB, 1,3,5-Tris(3'-hydroxy-4'-formylphenyl)-benzene) modified NiFe LDHs to anchor Fe and significantly enhance the OER stability is reported. The fabricated asymmetric aldehyde-containing ligand THB is capable of stimulating much more interfacial charge transfer from NiFe LDHs to the oxygen group of THB and accelerating the formation of highly valent active Fe species leading to the strong combination between Fe and ligand and the reduced activation energy barrier of the intermediate, respectively. The optimized aldehyde-ligand-chelated NiFe LDHs (NiFe LDH/THB) shows enhanced OER performance featuring an overpotential of 224 mV at 100 mA cm -2 and robust stability for over 3860 h at 100 mA cm -2 in a water splitting device maintaining a cell voltage of only 1.68 V, which paves a new avenue to improve the water electrolysis performance of non-noble metal catalysts., (© 2024 Wiley‐VCH GmbH.)

Crystal calls: the remarkable crystal modulation ability of quercetin (QUE) in highly oriented hydroxyapatite (HAp) array crystallization is reported. Organized HAp crystals were obtained by hydrothermal exchange of α-tricalcium phosphate (α-TCP) precursor in solution with a progressive increase in QUE concentration. Experimental results revealed that QUE would be a potentially effective crystal modulation assistant., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)