The effects of aluminum content on microstructure, ductility and formability of advanced high strength low alloy TRIP (Transformation-Induced Plasticity)-aided ferrous sheet steels with annealed martensite matrix (or TRIP-aided annealed martensitic steel) were investigated in order to realize hot-dip galvanization. Aluminum addition of 0.5-1.0 mass% (and simultaneous silicon removal of the same amount) to a 0.2C-1.5Si-1.5Mn-0.04Al (mass%) steel refined the matrix structure and retained austenite needles and increased carbon concentration of retained austenite. It also brought on an excellent total elongation, stretchflangeability and bendability, although the tensile strength decreased. Optimum austempering temperature for the total elongation increased to 450-475ЊC, due to the increased carbon concentration of retained austenite. On the other hand, optimum austempering temperatures for the stretch-flangeability and bendability were maintained at 350-400ЊC, mainly due to uniform fine lath matrix and retained austenite needles. If only large total elongation is required for the TRIP-aided steel, it is expected that hot-dip galvanizing immediately after continuous intercritical annealing can be realized.

The toxicity of the Pb element limits the large-scale application of inorganic cesium–lead halide (CsPbX3, with X = Cl, Br, and I) perovskite nanocrystals (NCs). Pb-free cesium–tin halide (CsSnX3) NCs have emerged as a viable alternative because of its excellent photoelectric conversion efficiency. However, the applications are hampered by its poor stability and low photoluminescence quantum yield (PLQY). In this study, extraordinarily stable CsSnCl3 NCs were prepared by exploiting bone gelatin as surface capping agents, which retain 95% of the photoluminescence intensity in water for 55 h. Additionally, after bone gelatin encapsulation, the PLQY of CsSnCl3 NCs was found to increase from 2.17% to 3.13% for the uncapped counterparts because of an improved radiative recombination rate. With such remarkable optical properties of the bone gelatin–CsSnCl3 NCs, metal ions like Fe3+ in aqueous solutions can be readily detected and monitored, signifying the potential application of such stable bone gelatin–CsSnCl3 NCs in the development of fluorescence sensors and detectors.

Nanocarbon materials as metal-free catalysts for the oxidative coupling of primary amines to imines suffer from high catalyst loading, low reaction rate and high oxygen demand. Doping heteroatom in nanocarbons...

The rational design of an asymmetric supercapacitor (ASC) with an expanded operating voltage window has been recognized as a promising strategy to maximize the energy density of the device. Nevertheless, it remains challenging to have electrode materials that feature good electrical conductivity and high specific capacitance. Herein, a 3D layered Ti3C2T X @NiO-reduced graphene oxide (RGO) heterostructured hydrogel was successfully synthesized by uniform deposition of NiO nanoflowers onto Ti3C2T X nanosheets, and the heterostructure was assembled into a 3D porous hydrogel through a hydrothermal GO-gelation process at low temperatures. The resultant Ti3C2T X @NiO-RGO heterostructured hydrogel exhibited an ultrahigh specific capacitance of 979 F g–1 at 0.5 A g–1, in comparison to that of Ti3C2T X @NiO (623 F g–1) and Ti3C2T X (112 F g–1). Separately, a defective RGO (DRGO) hydrogel was found to exhibit a drastic increase in specific capacitance, compared to untreated RGO (261 vs 178 F g–1 at 0.5 A g–1), owing to abundant mesopores. These two materials were then used as free-standing anode and cathode to construct an ASC, which displayed a large operating voltage (1.8 V), a high energy density (79.02 Wh kg–1 at 450 W kg–1 and 45.68 Wh kg–1 at 9000 W kg–1), and remarkable cycling stability (retention of 95.6% of the capacitance after 10,000 cycles at 10 A g–1). This work highlights the unique potential of Ti3C2T X -based heterostructured hydrogels as viable electrode materials for ASCs.

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Metal oxides have been attracting extensive interest in the design and engineering of effective electrocatalysts owing to their unique electronic structure and natural abundance. However, the limited electrical conductivity and sluggish electron-transfer kinetics have hampered their widespread applications. These issues can be mitigated by structural engineering with the incorporation of select precious metal species. Herein, iron oxide nanostructures decorated with platinum species are prepared by the facile thermal annealing of a MIL-101 precursor along with the addition of a controlled amount of PtCl4 and exhibit apparent electrocatalytic activity toward the hydrogen evolution reaction in 0.5 M H2SO4. The best sample needs only an ultralow overpotential of −15 mV to reach the current density of 10 mA cm–2, along with a low Tafel slope of 25.4 mV dec–1, a performance markedly better than that of commercial 20 wt % Pt/C. This is ascribed to the synergistic interactions between the Pt and Fe2O3 scaffold that impact the material’s electrical conductivity and electron-transfer kinetics and the Cl residuals that regulate the adsorption free energy of H, as confirmed in computational studies based on density functional theory. Results from this study highlight the unique potential of metal oxide-based nanocomposites as high-performance, low-cost electrocatalysts for electrochemical energy technologies where the performance can be further regulated by anion residuals.

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Electrocatalytic synthesis of hydrogen peroxide (H 2 O 2 ) via two-electron reduction of oxygen has emerged as an effective strategy to replace the traditional anthraquinone oxidation route. Herein, copper/carbon nanocomposites are prepared by pyrolytic treatment of a metal organic framework precursor, which consists of copper oxide (CuO x ) nanoparticles dispersed within a carbon matrix, as evidenced by results from transmission electron microscopy and X-ray photoelectron spectroscopy measurements. Deliberate electrochemical activation enriches the Cu 2 O species on the nanocomposite surface and markedly enhances the performance of electrocatalytic oxygen reduction to H 2 O 2 with the selectivity increased to 68% from ca. 45% (at +0.1 V) for the as-produced counterparts. This can be exploited for the effective electrochemical degradation of methylene blue. This is accounted for by the weakened interaction with peroxide intermediates on Cu 2 O, as confirmed by results from first-principles calculations. Results from this study underline the significance of structural engineering based on electrochemical activation for the enhanced selectivity of oxygen reduction reaction for H 2 O 2 production.