Interfacial Modification of Mesoporous TiO2 Films with PbI2-Ethanolamine-Dimethyl Sulfoxide Solution for CsPbIBr2 Perovskite Solar Cells

As one of the most frequently-used electron-transporting materials, the mesoporous titanium dioxide (m-TiO2) film used in mesoporous structured perovskite solar cells (PSCs) can be employed for the scaffold of the perovskite film and as a pathway for electron transport, and the contact area between the perovskite and m-TiO2 directly determines the comprehensive performance of the PSCs. Because of the substandard interface combining quality between the all-inorganic perovskite CsPbIBr2 and m-TiO2, the development of the mesoporous structured CsPbIBr2 PSCs synthesized by the one-step method is severely limited. Here, we used a solution containing PbI2, monoethanolamine (EA) and dimethyl sulfoxide (DMSO) (PED) as the interfacial modifier to enhance the contact area and modify the m-TiO2/CsPbIBr2 contact characteristics. Comparatively, the performance of the solar device based on the PED-modified m-TiO2 layer has improved considerably, and its power conversion efficiency is up to 6.39%

Low-Temperature Processed Brookite Interfacial Modification for Perovskite Solar Cells with Improved Performance

The scaffold layer plays an important role in transporting electrons and preventing carrier recombination in mesoporous perovskite solar cells (PSCs), so the engineering of the interface between the scaffold layer and the light absorption layer has attracted widespread concern. In this work, vertically grown TiO2 nanorods (NRs) as scaffold layers are fabricated and further treated with TiCl4 aqueous solution. It can be found that a thin brookite TiO2 nanoparticle (NP) layer is formed by the chemical bath deposition (CBD) method on the surface of every rutile NR with a low annealing temperature (150 °C), which is beneficial for the infiltration and growth of perovskite. The PSC based on the TiO2 NR/brookite NP structure shows the best power conversion of 15.2%, which is 56.37% higher than that of the PSC based on bare NRs (9.72%). This complex structure presents an improved pore filling fraction and better carrier transport capability with less trap-assisted carrier recombination. In addition, low-annealing-temperature-formed brookite NPs possess a more suitable edge potential for electrons to transport from the perovskite layer to the electron collection layer when compared with high-annealing-temperature-formed anatase NPs. The brookite phase TiO2 fabricated at a low temperature presents great potential for flexible PSCs

Au/CdS Core-Shell Sensitized Actinomorphic Flower-Like ZnO Nanorods for Enhanced Photocatalytic Water Splitting Performance

Herein, a novel actinomorphic flower-like ZnO/Au/CdS nanorods ternary composite photocatalyst is prepared to extend the light-responsive range, reduce the photogenerated charge carriers recombination, and ultimately improve the water splitting performance. Flower-like ZnO nanorods are synthesized by a chemical bath method and the CdS nanoparticles are sensitized by successive ionic layer adsorption and reaction method. Then the Au nanoparticles as co-catalysts are introduced by the photodeposition method to modify the interface of ZnO/CdS for reducing the photogenerated electron recombination rate and further improving the performance of water splitting. Detailed characterizations and measurements are employed to analyse the crystallinity, morphology, composition, and optical properties of the flower-like ZnO/Au/CdS nanorods samples. As a result, the flower-like ZnO/Au/CdS nanorod samples present significantly enhanced water splitting performance with a high gas evolution rate of 502.2 μmol/g/h, which is about 22.5 and 1.5 times higher than that of the pure ZnO sample and ZnO/CdS sample. The results demonstrate that the flower-like ZnO/Au/CdS nanorods ternary composite materials have great application potential in photocatalytic water splitting for the hydrogen evolution field

First identification and multilocus genotyping of Giardia duodenalis in pet chipmunks (Eutamias asiaticus) in Sichuan Province, southwestern China

Abstract Background Giardia duodenalis is a flagellated parasite that causes diarrhea in humans and other animals. Although G. duodenalis is found in companion animals worldwide, information regarding the prevalence and genetic characteristics of G. duodenalis in pet chipmunks in China is limited. The present study therefore aimed to investigate the prevalence and genotypes of G. duodenalis in pet chipmunks in Sichuan province, southwestern China, as well as to assess zoonotic potential of revealed assemblages. Results A total of 279 fecal samples were collected from pet chipmunks in seven pet shops and one breeding facility in Sichuan province, southwestern China. The prevalence of G. duodenalis was 8.6% (24/279), as determined by nested PCR detection of the beta giardin (bg) gene. Giardia duodenalis assemblages and subtypes were determined using multilocus genotyping of the bg, triosephosphate isomerase (tpi), and glutamate dehydrogenase (gdh) loci. Two assemblages were identified: potentially zoonotic assemblage A (54.2%, 13/24) and rodent-specific assemblage G (45.8%, 11/24). A total of 24, 17 and 17 sequences of the bg, gdh and tpi loci, respectively, were successfully obtained, which formed four, four and three subtypes, respectively. Moreover, four assemblage A (MLGs A1-A4) and three assemblage G (MLGs G1-G3) multilocus genotypes were identified. Conclusions To our knowledge, this is the first study that investigated G. duodenalis in pet chipmunks in China. Detection of assemblage A in pet chipmunks and in previous studies in humans suggests a possible role of chipmunks as a reservoir for human giardiasis in Sichuan Province, China

Photoelectrochemical Performance of Multiple Semiconductors (CdS/CdSe/ZnS) Cosensitized TiO₂ Photoelectrodes

The morphology of TiO₂ nanotubes with nanowires directly formed on top (designed as TiO₂ NTWs) would be a promising nanostructure in fabricating photoelectrochemical solar cells for its advantages in charge separation, electronic transport, and light harvesting. In this study, a TiO₂ NTWs array film was prepared by a simple anodization method. The formation of CdS, CdSe, and ZnS quantum dots (QDs) sensitized TiO₂ NTWs photoelectrode was carried out by successive ionic layer adsorption. The as-prepared materials were characterized by scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray diffraction. Our results indicate that the nanocrystals have effectively covered both inner and outer surfaces of TiO₂ NTWs array. The interfacial structure of QDs/TiO₂ was also investigated for the first time in our experiment, and the growth interface when annealed to 300 °C was verified. Under AM 1.5G illumination, we found the photoelectrodes have an optimum short-circuit photocurrent density of 4.30 mA/cm² and corresponding energy conversation efficiency of 2.408%, which is 28 times higher than that of a bare TiO₂ NTWs array. The excellent photoelectrochemical properties of our photoanodes suggest that the TiO₂ NTWs array films (2.6–2.8 μm) cosensitized by CdS, CdSe, and ZnS nanoclusters have potential applications in solar cells