We report here an electrodeposition route for the preparation of oriented and well-defined ZnO nanostructures by kinetically controlling the growth rates of various facets of the deposit by appropriate capping agents. We demonstrated that adsorption of Cl(-) takes places preferentially onto the (0001) planes to hinder the crystal growth along the c-axis, and results in the formation of platelet-like crystals. It is also shown that the morphology evolved from hexagonal tapers to hexagonal rods and rhombohedral rods by changing the compositions of the capping agents. Furthermore, strong UV emissions at 380 approximately 390 nm and negligible green bands at around 500 nm were observed, indicating that these ZnO electrodeposits are highly crystallized and of excellent optical quality.

The power conversion efficiency (PCE) of CH3NH3PbX3 (X = I, Br, Cl) perovskite solar cells has been developed rapidly from 6.5 to 18% within 3 years. However, the anomalous hysteresis found in I-V measurements can cause an inaccurate estimation of the efficiency. We attribute the phenomena to the ferroelectric effect and build a model based on the ferroelectric diode to explain it. The ferroelectric effect of CH3NH3PbI3-xClx is strongly suggested by characterization methods and the E-P (electrical field-polarization) loop. The hysteresis in I-V curves is found to greatly depend on the scan range as well as the velocity, which is well explained by the ferroelectric diode model. We also find that the current signals show exponential decay in ∼10 s under prolonged stepwise measurements, and the anomalous hysteresis disappears using these stabilized current values. The experimental results accord well with the model based on ferroelectric properties and prove that prolonged stepwise measurement is an effective way to evaluate the real efficiency of perovskite solar cells. Most importantly, this work provides a meaningful perspective that the ferroelectric effect (if it really exists) should be paid special attention in the optimization of perovskite solar cells.

Highly ordered TiO 2 single-crystalline nanowire arrays have been fabricated within the pores of anodic aluminum oxide (AAO) template by a cathodically induced sol−gel method. Raman spectra confirmed that the nanowires are composed of pure anatase TiO 2 . TEM investigations indicated that these nanowires have a uniform tetragonal single-crystal structure. Finally, a possible growth mechanism of the TiO 2 nanowires is discussed.

Splitting of alcohols into hydrogen and corresponding carbonyl compounds has potential applications in hydrogen production and chemical industry. Herein, we report that a heterogeneous photocatalyst (Ni-modified CdS nanoparticles) could efficiently split alcohols into hydrogen and corresponding aldehydes or ketones in a stoichiometric manner under visible light irradiation. Optimized apparent quantum yields of 38%, 46%, and 48% were obtained at 447 nm for dehydrogenation of methanol, ethanol, and 2-propanol, respectively. In the case of dehydrogenation of 2-propanol, a turnover number of greater than 44 000 was achieved. To our knowledge, these are unprecedented values for photocatalytic splitting of liquid alcohols under visible light to date. Besides, the current catalyst system functions well with other aliphatic and aromatic alcohols, affording the corresponding carbonyl compounds with good to excellent conversion and outstanding selectivity. Moreover, mechanistic investigations suggest that an interface between Ni nanocrystal and CdS plays a key role in the reaction mechanism of the photocatalytic splitting of alcohol.

Tetragonal faceted-nanorods of single-crystalline anatase TiO(2) with a large percentage of higher-energy {100} facets have been synthesized by hydrothermal transformation of alkali titanate nanotubes in basic solution.

In this paper, we develop a simple and general method for the fabrication of yolk/shell structures through a one-step encapsulation of particles by SiO(2) shells in aqueous mixtures of lauryl sulfonate betaine (LSB) and sodium dodecyl benzenesulfonate (SDBS). Various yolk/shell structures with different particle cores, such as SiO(2)@SiO(2), Au@SiO(2), and Fe(2)O(3)@SiO(2), have been successfully prepared.

Understanding interfacial loss and the ways to improving interfacial property is critical to fabricate highly efficient and reproducible perovskite solar cells (PSCs). In SnO2‐based PSCs, nonradiative recombination sites at the SnO2–perovskite interface lead to a large potential loss and performance variation in the resulting photovoltaic devices. Here, a novel SnO2‐in‐polymer matrix (i.e., polyethylene glycol) is devised as the electron transporting layer to improve the film quality of the SnO2 electron transporting layer. The SnO2‐in‐polymer matrix is fabricated through spin‐coating a polymer‐incorporated SnO2 colloidal ink. The polymer is uniformly dispersed in SnO2 colloidal ink and promotes the nanoparticle disaggregation in the ink. Owing to polymer incorporation, the compactness and wetting property of SnO2 layer is significantly ameliorated. Finally, photovoltaic devices based on Cs0.05FA0.81MA0.14PbI2.55Br0.45 perovskite sandwiched between SnO2 and Spiro‐OMeTAD layer are fabricated. Compared with the averaging power conversion efficiency of 16.2% with 1.2% deviation for control devices, the optimized devices exhibit an improved averaging efficiency of 19.5% with 0.25% deviation. The conception of polymer incorporation in the electron transporting layer paves a way to further increase the performance of planar perovskite solar cells.

Yolk/shell particles possess a unique structure that is composed of hollow shells that encapsulate other particles but with an interstitial space between them. These structures are different from core/shell particles in that the core particles are freely movable in the shell. Yolk/shell particles combine the properties of each component, and can find potential applications in catalysis, lithium ion batteries, and biosensors. In this Research News article, a soft-template-assisted method for the preparation of yolk/silica shell particles is presented. The demonstrated method is simple and general, and can produce hollow silica spheres incorporated with different particles independent of their diameters, geometry, and composition. Furthermore, yolk/mesoporous silica shell particles and multishelled particles are also prepared through optimization of the experimental conditions. Finally, potential applications of these particles are discussed.