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A green corrosion inhibitor was prepared from the bio‐based platform compound 5‐hydroxymethylfurfural through a green synthetic route, which avoid the use of toxic reagent. The inhibition performance and mechanism of this compound for the corrosion of mild steel in 0.1 M HCl was investigated by using the weight loss experiments, polarization measurements, EIS measurements and quantum chemical calculations. The corrosion inhibition efficiency by weight loss measurement (ηWLM%) of this inhibitor can reach up to 90.3 % at 303 K with 1.2 mM concentration. Moreover, the electrochemical experiments revealed that this corrosion inhibitor acts as a mixed‐type inhibitor. Thermodynamic studies gave the values of the standard Gibbs free energy ΔGads0 ${{\rm \Delta }{G}_{ads}^{0}}$ , fall within the range of −20 kJ/mol to −40 kJ/mol, suggested the adsorption of this compound is a spontaneous process involving both physisorption and chemisorption. In addition, quantum chemical calculations were conducted to further validate the formation of an effective absorption layer by this inhibitor on metal surfaces, which showed that the electron density iso‐surfaces of HOMO was mainly distributed on chloride ions, while LUMO tended to be distributed on furan rings and aldehyde groups. Besides, the other quantum chemical parameters of this inhibitor were also calculated to explore the molecular activity, such as, the molecular volume (ν, 333.105 Å), global hardness (η, 4.706 eV), global softness (σ, 0.2125 eV), electronegativity (χ, 4.93 eV), dipolemoment (μ, 13.1429 D) and vertical ionization energy (VIE, 7.2646 eV). [ABSTRACT FROM AUTHOR]

Amorphous Si3N4 and SiBN monoliths without sintering additives are successfully prepared by high‐pressure–low‐temperature (HPLT) sintering using the single‐source‐precursor‐derived amorphous Si3N4 and SiBN powders as raw materials. The microstructural evolution and crystallization behavior of the as‐prepared samples are investigated using scanning electron and transmission electron microscopy and X‐ray powder diffraction, respectively. The results show that the incorporation of boron in the Si–N network enhances the crystallization temperature up to 1200 °C. The Vickers' hardness of the HPLT‐sintered Si3N4 sample amounts ≈11.6 GPa whether prepared at 1000 or 1200 °C, while the maximum hardness of the SiBN sample is up to 16.3 GPa. The fracture toughness of amorphous Si3N4 and SiBN5 samples is almost identical (around 2.5 MPa m1/2) whether prepared at 1000 or 1200 °C, and SiBN2 and SiBN5 samples show an improved fracture toughness. In addition, the oxidation resistance of the as‐prepared samples is investigated at temperatures up to 1000 °C. A comparison between amorphous Si3N4 and SiBN monoliths demonstrates a positive effect of the presence of boron on their oxidation resistance. [ABSTRACT FROM AUTHOR]

The temperature-dependent magnetic susceptibility combined with first-principle calculations was conducted to unravel the magnetic structure and the magnetic interaction of the laminar structure of manganese diboride (MnB2). MnB2 showed weak ferromagnetic, antiferromagnetic, and paramagnetic behavior with increased temperature. Its weak ferromagnetic property below 135.6 K Curie temperature (TC) originated from the spin canting antiferromagnetic magnetic structure. The exotic kink of temperature-dependent magnetic susceptibility at 330 K Néel temperature (TN) correlated with the transition from antiferromagnetic to paramagnetic structure. First-principle calculation show that the antiferromagnetic ordering show lower energy, and suggest a canting anti-ferromagnetic ordering for its ferromagnetic behavior. The peculiar magnetic behavior of MnB2 may be due to the insertion of the honeycomb boron layers into the host matrix of manganese atoms. The honeycomb boron layers played a key role in the exchange between two manganese layers. This study resolved the longstanding puzzle of the magnetic structure of MnB2 and provided a typical laminar magnetic structure prototype. [ABSTRACT FROM AUTHOR]

The oxygen evolution reaction (OER) is an important half-reaction in rechargeable metal–air batteries and water splitting devices, and it suffers from slow kinetics due to the multiple step proton-electron coupled process. Therefore, the major challenge for the OER is to develop durable and low-cost electrocatalysts with high catalytic performance. Herein, a ternary metal CoNiFe subacetate nano prism (CoNiFe NP) was synthesized by a one-step hydrothermal method, with the aim of accelerating the water dissociation and improving the reaction rate using the synergy of the ternary metal. The results show that the electrocatalytic performance of the ternary metal CoNiFe layered double hydroxide is significantly improved compared with the binary metal and single metal catalysts. In particular, the overpotential of the prepared CoNiFe NP for the OER at 10 mA cm−2 is as low as 292 mV, and the Tafel slope is 75.6 mV dec−1. This work provides a new platform for the design of medium-entropy electrocatalysts using the interaction of polymetallic components. [ABSTRACT FROM AUTHOR]

Selection of the friction electrode materials is crucial to the performance of a triboelectric nanogenerator (TENG). In the present study, a metal–organic coordination complex containing organosulfonate counteranions with electron‐donating ability was synthesized through the coordination‐driven self‐assembly approach under mild reaction conditions and was chosen as a positive electrode material to construct a triboelectric nanogenerator, exhibiting high‐output performance with a peak value of short circuit current density of 98.6 μA and an output voltage of 1180 V. As a practical application, it was shown to light up 1488 commercial green LEDs and power an anticorrosion system device to protect metals from corrosion. [ABSTRACT FROM AUTHOR]

Hematite (α-Fe2O3) is a red material with a band gap of about 2.0 eV, which indicates that it can absorb more solar light. It is a promising photocatalyst applied in many fields. In this paper, α-Fe2O3 single crystal hollow hexagonal bipyramids were synthesized by a simple one-pot hydrothermal method. The morphology and structure of the prepared α-Fe2O3 hollow hexagonal bipyramids were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The hollow single crystals show a good light absorption and performance in photodegradation of methylene blue (MB). Due to the strategy of depositing ultra-thin layers of Al2O3 by atomic layer deposition (ALD), the photoelectrochemical (PEC) performance of α-Fe2O3 under the simulated solar light irradiation is also improved. [ABSTRACT FROM AUTHOR]

A simple method to improve the photoelectrochemical performance of TiO2 nanotube arrays (NTs) by simple air plasma post-treatment is reported. The air plasma treated sample shows higher photocurrent density and incident photo current efficiency with high stability, about 3–4 times that of the pristine TiO2 NTs even after six months. [ABSTRACT FROM AUTHOR]

A new photoanode polypyrrole nanowire/TiO 2 nanotube (PPy NW/TiO 2 NT) nanocomposite material with a coaxial heterojunction structure is constructed by electrodeposting p-type polypyrrole nanowire into n-type TiO 2 nanotubes. Photo-induced open circuit potential, photocurrent density, electrochemical impedance spectroscopy, and Tafel curves are measured under visible light to evaluate the photocathodic protection effect and anticorrosion properties of the nanocomposite. The results indicate that the synergistic effect between the photogenerated cathodic protection and the favorable corrosion resistance of the nanocomposite makes PPy NW/TiO 2 NTs nanocomposite a promising material for protecting Ti substrate and the coupled 304 stainless steel from corrosion. [ABSTRACT FROM AUTHOR]

Designing materials with high triboelectric is an efficient way of improving output performance of triboelectric nanogenerators (TENGs). Herein, we synthesized a series of covalent organic frameworks (COFs) with similar skeletons but various functional groups ranging between electron-donating and electron-withdrawing. These COFs form an ideal platform for clarifying the contribution of each group to TENG performance because the pore wall is perturbed in a predesigned manner. Kelvin probe force microscopy and computational data suggest that surface potentials and electron affinities of COFs can be improved by introducing electron-donating or withdrawing groups, with the highest values observed for fluorinated COF. The TENG with fluorinated COF delivered an output voltage and current of 420 V and 64 μA, respectively, which are comparable to other reported materials. This strategy can be used to efficiently screen suitable frameworks as TENG materials with excellent output performance., (© 2022 Wiley-VCH GmbH.)

Covalent organic frameworks (COFs) enable precise integration of various organic building blocks into porous skeletons through topology predesign. Here, we report the first example of COFs by integrating electron withdrawing bromine group onto the skeletons for triboelectric nanogenerators (TENG). The resulting framework exhibits high surface area and good crystallinity. Thus, the bromine functionalized COF has more regular aligned π columns and arrays over the skeleton than bare COFs, which in turn significantly enhances charge transport ability. As a result, bromine functionalized COFs showed higher electrical output performance at 5 Hz with a peak value of short circuit current density of 43.6 μA and output voltage of 416 V, which is 2 and 1.3 times higher than those of bare COFs (21.6 μA and 318 V), respectively. These results demonstrated that this strategy for engineering electron withdrawing groups on the skeleton could open a new aspect of COFs for developing TENG devices., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Selection of the friction electrode materials is crucial to the performance of a triboelectric nanogenerator (TENG). In the present study, a metal-organic coordination complex containing organosulfonate counteranions with electron-donating ability was synthesized through the coordination-driven self-assembly approach under mild reaction conditions and was chosen as a positive electrode material to construct a triboelectric nanogenerator, exhibiting high-output performance with a peak value of short circuit current density of 98.6 μA and an output voltage of 1180 V. As a practical application, it was shown to light up 1488 commercial green LEDs and power an anticorrosion system device to protect metals from corrosion., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)