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Abstract: Novel Zn x Cd1−x S nanoflake dendrites were synthesized by an original hydrothermal process at 95°C for 1h. Highly ordered embranchments were found on the trunks of the dendrites and each of the embranchments consisted of numbers of uniform regular hexagon nanoflakes. The nanoflake dendrites were oriented along the [0001] direction. With a fixed composition of reactants, Cd/Zn ratio of the product Zn x Cd1−x S was close to the composition in the recipe and gradually decreased from trunks to embranchments and then to nanoflakes. By adjusting the initial Zn/Cd ratio of the reactants, gradual changes in morphology of the final products were observed. The variation of Cd/Zn ratio in different parts of the nanoflake dendrite and morphology transformation of the final product Zn x Cd1−x S were governed by a competition between the trunk-like and the flake-like growth mode. [Copyright &y& Elsevier]

Abstract: Cadmium sulphide (CdS) 1D nanocrystals were prepared using a simple poly(vinyl-alcohol) (PVA)-assisted solvothermal method which employed ethylenediamine (en) as solvent. The obtained nanorods were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), ultraviolet–visible (UV–vis) absorption, and photoluminescence (PL) spectra. XRD results show that the nanorods are hexagonal phase. The TEM results indicate that the synthesized CdS nanorods with PVA-assisted showed larger aspect ratio and uniform faces compared with the sample prepared in the absence of PVA. The results of the photoluminescence and UV–vis spectroscopy measurements reveal that the as-prepared CdS nanorods show a quantum confinement effect. It is also found that the dosage of PVA is a vital factor in the morphology and optical properties of CdS nanorods. Moreover, when the best dosage of 3g PVA/70ml en was used, CdS nanorods with regular morphology and longer length were obtained. The probable mechanism for PVA-assisted solvothermal synthesis of CdS nanorods was also discussed. [Copyright &y& Elsevier]

Porous carbons have recently drawn extensive attention in energy conversion and storage devices. Boosting energy densities of carbon family is still a challenge due to their limited surface area and accessible active sites. In this work, porous carbons with hierarchically structures were prepared from natural Juncus effuses (CJE) and homogeneous MnO 2 layer was successfully incorporated on their surfaces without changing their original porous structure. The CJE/MnO 2 composite showed large specific capacitance (283 F/g at 1 A/g), which was on account of high specific surface area (1283 m2/g) and abundant active sites for pseudocapacitance, particularly, resulted from the introduction of MnO 2. Significantly, the assembled symmetric supercapacitor from CJE/MnO 2 in Na 2 SO 4 aqueous electrolyte delivered high energy/power densities (19.13 Wh/kg at 225 W/kg and 13.73 Wh/kg at 8984 W/kg) and good cyclic performance (86.2% capacitance retention over 5000 cycles at 10.0 A/g). These results demonstrate the CJE/MnO 2 composite can be a potential candidate for supercapacitors. • The surfaces of porous carbons from Juncus effuses are functioned. • Oxygen-containing functional groups facilitate the formation of MnO 2 layer. • Prepared CJE/MnO 2 composites show high specific surface area and capacitance. • The supercapacitor from CJE/MnO 2 delivers excellent energy-power output. [ABSTRACT FROM AUTHOR]

Piezoelectric polarization is a promising approach to promoting the separation and transfer of charge carriers of photocatalysts by modulating energy band structure. A binary piezoelectric integrated piezo-photocatalytic heterojunction o-KNbO 3 /MoS 2 (o-KN/MS) is fabricated through few-layered MoS 2 nanosheets growth on the ferroelectric orthorhombic KNbO 3 (o-KNbO 3). Under simultaneous light irradiation and ultrasonication, the optimal o-KN/MS exhibits a higher piezo-photocatalytic rhodamine B degradation rate (0.16979 min−1) than individual photocatalysis (0.00981 min−1) or individual piezocatalysis (0.09419 min−1). The piezo-photocatalytic degradation rates of RhB (0.16979 min−1), Cr (VI) (0.00877 min−1), and MB (0.01017 min−1) of o-KN/MS are 2.6, 7.9, and 4.2 times as large as that of single piezoelectric hybrid piezo-photocatalyst c-KNbO 3 /MoS 2 , respectively, where c-KNbO 3 in c-KN/MS refers to non-piezoelectric paraelectric cubic KNbO 3 (c-KNbO 3). At the same condition, the current density for o-KN/MS reaches 54.96 μA/cm2, which is 2.9 folds as high as that of c-KN/MS. These results demonstrate that the altering piezoelectric polarization from the binary piezoelectric materials promotes continuous carrier separation within o-KNbO 3 and MoS 2 but also on the heterojunction interface, which provides a strategy for designing integrated piezo-photocatalyst to achieve efficient pollutant degradation and enhance electrochemical performance. [Display omitted] • A bi-piezoelectric o-KNbO 3 /MoS 2 contains few-layered MoS 2 and o-KNbO 3 nanosheets. • The bi-piezoelectric polarization accelerates charge separation and transfer. • The piezo-photocatalysis yields efficient RhB, Cr (VI) and MB degradation. • The charge migration mechanism of bi-piezoelectric synergistic effect is revealed. [ABSTRACT FROM AUTHOR]

TiO 2 -nanosheet (TNS) was firstly fabricated using a one-pot hydrothermal route followed with photo depositing various dosages of Pt nanoparticles over its surface. The hydrogen production performance of these as-prepared samples was assessed in triehanolamine (TEOA) aqueous solutions under visible-light irradiation. The results showed the optimal ratio of Pt: TNS was 0.5 wt %, with apparent quantum efficiency (QE) climbing 15.44%. And on this basis, it was used to H 2 production simultaneous photodegradation with individual or both kinds of dyes (namely, methyl orange (MO), eosine Y (EY), methyl blue (MB) and rhedamine B (RhB)), respectively. As the figures indicated, although the rate of hydrogen production saw a steady increase in the single dye in the solution, it was outmatched by any two kinds of dyes group, which played significant positive synergism effects. In particular, when MB/EY group was added intoTEOA solution, the QE reached a peaking of 25.42% dramatically. In addition, real textile industrial wastewater was applied in this system, and the QE was 20.45%, which was 1.32 fold that of clean water. The crucial factor in improving the photocatalytic activity was that appropriate amount of functional 0D-2D Schottky barrier heterostructures were constructed. Such a novel architecture provided a large and intimate contact interface for fast interfacial photo-charges separation. The effective charge transfer from TNS to Pt was demonstrated by the significant enhancement of photocurrent responses in 0D-2D Pt-TNS composite. This work created new opportunities for designing and constructing highly efficient photocatalysts by interfacial engineering. [ABSTRACT FROM AUTHOR]