Quantum dot light emitting diodes (QLEDs) are increasingly attractive owing to their compatibility with the inkjet printing process and potential application in low-cost large-area full-color pixelated display. The strategy for controlling the morphology of the quantum dot layer is definitely critical for realizing all-solution processed QLEDs with high performance, which certainly requires in-depth thinking regarding the design of ink composition and their optimization in the printing process. Herein, by carefully controlling the quantum dot ink composition and physicochemical properties, we demonstrate that the viscosity, contact angle, and the three-phase contact line moving would affect the final morphology of the quantum dot film formed by inkjet printing. We achieved coffee ring-free and low-roughness quantum dot film, and all-solution processed QLEDs with normal structure were fabricated for the first time. The devices have a low turn-on voltage of 2.0 V, a luminance of 12100 cd/m at the voltage of 12 V, and a maximum current efficiency of 4.44 cd/A at the luminance of 1974 cd/m, which is the best result to date for inkjet-printed red QLEDs. The results will pave the way for future application of inkjet printing in solution processed pixelated QLED display.

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. b s t r a c tThe novelty of this work is the formation and deposition of SiO 2 , as opposed to deposition using commercially available SiO 2 powder suspension in the solution, to form ceramic coating on polypropylene (PP) separators for lithium-ion battery. The formation of SiO 2 nanoparticles with uniform particle size is accomplished through direct hydrolysis of tetraethyl orthosilicate (TEOS), while the deposition of the formed SiO 2 on PP separators was conducted in the same solution containing polyvinylidene fluoridehexafluoropropylene (PVDF-HFP) as binders and acetone as the solvent. The effects of the ceramic coating on the surface morphology, tensile strength, contact angles, electrolyte uptake, thermal shrinkage of the PP separators and the cell performances such as battery rate capability and Coulombic efficiency were investigated. The coated separators show significant reduction in thermal shrinkage and improvement in tensile strength, contact angles, electrolyte uptake and battery performance as compared to the plain PP separator. Crown

There has been a surge of interest in interfacial ozone chemistry for its application in indoor air quality and public health. Squalene, one of the most abundant ozone reactive constituents in an indoor environment, has received increasing attention lately, and a number of studies have been devoted to its heterogeneous interaction with ozone in actual and simulated settings. At present, there is still a large discrepancy in the measurement of the reactive uptake coefficient of ozone onto a squalene surface, and knowledge about this system remains incomplete. In this work, we investigated the ozone initiated heterogeneous oxidation of squalene using attenuated total reflection infrared spectroscopy (ATR-IR). We measured pseudo-first-order rate constants and uptake coefficients based on time dependent absorbance changes in C═C (1668 cm(-1)) and C═O (1730 cm(-1)) vibration bands. The uptake coefficients are (1.7 ± 0.2) × 10(-4) from the C═C band and (5.1 ± 0.7) × 10(-4) from the C═O band. The latter is likely an upper limit of reaction probability for ozone uptake onto squalene. Studies of temperature (5-32 °C) and relative humidity (0 and 80% RH) dependence revealed that indoor temperatures and RHs did not affect reaction kinetics. The insignificant RH effect is probably due to the weak interaction between water and squalene molecules. We quantitatively characterized the hydrophilicity and redox activity of squalene before and after exposure to ozone for the first time, and observed considerable enhancements in both hydrophilicity and redox activity during reaction. This may imply that ozone initiated heterogeneous oxidation could pose a higher public health risk in an indoor environment, and it may help explain some of the adverse health effects associated with elevated indoor pollutants.

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Nanoparticles of single-phase lepidocrocite (γ-FeOOH) and goethite (α-FeOOH) have been synthesized by forced hydrolysis of ferric nitrate with no other additives, and the particles have been characterized by XRD, FT-IR and TEM. At low Fe(NO(3))(3) concentrations the hydrolysis product is predominantly γ-FeOOH, while at high concentrations it is α-FeOOH. These particles are nanometers in size and fall within narrow particle size distributions. The dependence of the oxyhydoxide phase on ferric nitrate concentration is attributed to two thermodynamic factors, the enthalpy of formation and the surface enthalpy of hydration at the oxide-water interface (which is a function of surface area). Two potential mechanisms for the phase-specific growth are proposed that explain the solution concentration dependence of the phase formed. Three other common nanoscale particles (α-Fe(2)O(3), Fe(3)O(4) and γ-Fe(2)O(3)) have also been prepared by relatively simple thermal/chemical treatment of the γ-FeOOH nanoparticles.

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In view of high catalytic activity and oxygen vacancy concentration, Ruddlesden−Popper (R-P) structure oxide has been widely used as the electrode material for solid oxide fuel cells (SOFCs). Herein, three R-P structure oxides, Pr 2−x Sr x Ni 0.2 Mn 0.8 O 4 (x = 1, 1.2, and 1.5), are used as the semiconductor materials of single-component cells. The materials for the oxygen side are hybrid oxides consisting of R-P structure oxide and perovskite oxide. The hydrogen side was exposed to the reduction atmosphere before the test, and the perovskite structure disappeared and the lattice parameters of the R-P structure changed, resulting in the formation of a new R-P structure and MnO 2 or NiMn alloy. In addition, Pr 0.5 Sr 1.5 Ni 0.2 Mn 0.8 O 4 and reduced Pr 0.5 Sr 1.5 Ni 0.2 Mn 0.8 O 4 exhibit the most content of oxygen vacancy. For a single-component fuel cell (SCFC), the cell performance increased with the decrease in Pr content. The SCFC composed of Pr 0.5 Sr 1.5 Ni 0.2 Mn 0.8 O 4 shows the highest maximum power densities (P max ), which reached 206.6 mW cm −2 at 700 °C. It is because the reduced Pr 0.5 Sr 1.5 Ni 0.2 Mn 0.8 O 4 has the highest catalytic activity for hydrogen oxidation reaction (HOR). Furthermore, the P max at 700 °C can reach a value of 198.1 mW cm −2 in SOFC mode, and in the case of SOEC mode, the current density at 700 °C is as high as −390.8 mA cm −2 with an applied electrolysis voltage of 1.3 V for the reversible single-component cell (RSCC) with Pr 0.5 Sr 1.5 Ni 0.2 Mn 0.8 O 4 as the semiconducting electrocatalyst.

Silicon photocathodes coated with drop-casted {Mo 3 S 4 }-based polyoxothiometalate assemblies are demonstrated to be effective for sunlight-driven hydrogen evolution reaction (HER) in acid conditions. These photocathodes are catalytically more efficient than that coated with the parent thiomolybdate incorporating an organic ligand, as supported by a higher onset potential and a lower overvoltage at 10 mA cm –2 . At pH 7.3, the trend is inversed and the beneficial effect of the polyoxometalate for the HER is not observed. Moreover, the polyoxothiometalate-modified photocathode is found to be also more stable under acid conditions and can be operated at the light-limited catalytic current for more than 40 h. Furthermore, X-ray photoelectron spectroscopy and atomic force microscopy measurements indicate that the cathodic polarization of both photocathodes leads to the release of a large amount of the deposited material into the electrolyte solution concomitantly with the formation of mixed valence species {Mo(IV) 3– x Mo(III) x O 4– n S n } (4– x )+ resulting from the replacement of S 2– sulfido ligands in the cluster by oxo O 2– groups; these combined effects are shown to be beneficial for the photoelectrocatalysis.