Machine Learning-Assisted Sensor Based on CsPbBr@ZnO Nanocrystals for Identifying Methanol in Mixed Environments.

Methanol is a respiratory biomarker for pulmonary diseases, including COVID-19, and is a common chemical that may harm people if they are accidentally exposed to it. It is significant to effectively identify methanol in complex environments, yet few sensors can do so. In this work, the strategy of coating perovskites with metal oxides is proposed to synthesize core-shell CsPbBr@ZnO nanocrystals.

A p-p Homojunction-Enhanced Hole Transfer in Inverted Planar Perovskite Solar Cells.

Perovskite solar cells (PSCs) have triggered a research trend in solar energy devices in view of their high power conversion efficiency and ease of fabrication. However, more delicate strategies are still required to suppress carrier recombination at charge transfer interfaces, which is the necessary path to high-efficiency solar cells. Here, a p-p homojunction was constructed on basis of NiO film to enhance hole transfer in an inverted planar perovskite solar cell.

Hybridized Mechanical and Solar Energy-Driven Self-Powered Hydrogen Production.

Photoelectrochemical hydrogen generation is a promising approach to address the environmental pollution and energy crisis. In this work, we present a hybridized mechanical and solar energy-driven self-powered hydrogen production system. A rotatory disc-shaped triboelectric nanogenerator was employed to harvest mechanical energy from water and functions as a sufficient external power source.

A facile sol-gel synthesis of low-fusing titanium opaque porcelain using borate-silicate system and its bioactivity.

The titanium opaque porcelain was synthesized through sol-gel using borate-silicate system. The porcelain was characterized by DSC-TG, X-ray diffraction, N adsorption-desorption isotherms and scanning electron microscope tests. The results of DSC showed that the nitrates could be decomposed completely when the bioglass xerogel precursor was heat-treated at 760 ℃.

Surface engineering of perovskite films for efficient solar cells.

It is critical to prepare smooth and dense perovskite films for the fabrication of high efficiency perovskite solar cells. However, solution casting process often results in films with pinhole formation and incomplete surface coverage. Herein, we demonstrate a fast and efficient vacuum deposition method to optimize the surface morphology of solution-based perovskite films.

Low-Temperature Soft-Cover Deposition of Uniform Large-Scale Perovskite Films for High-Performance Solar Cells.

Large-scale high-quality perovskite thin films are crucial to produce high-performance perovskite solar cells. However, for perovskite films fabricated by solvent-rich processes, film uniformity can be prevented by convection during thermal evaporation of the solvent. Here, a scalable low-temperature soft-cover deposition (LT-SCD) method is presented, where the thermal convection-induced defects in perovskite films are eliminated through a strategy of surface tension relaxation.

Cost-Performance Analysis of Perovskite Solar Modules.

Perovskite solar cells (PSCs) are promising candidates for the next generation of solar cells because they are easy to fabricate and have high power conversion efficiencies. However, there has been no detailed analysis of the cost of PSC modules. We selected two representative examples of PSCs and performed a cost analysis of their productions: one was a moderate-efficiency module produced from cheap materials, and the other was a high-efficiency module produced from expensive materials.

CNTs-Modified NbOF Hybrid Nanocrystal towards Faster Carrier Migration, Lower Bandgap and Higher Photocatalytic Activity.

Novel semiconductor photocatalysts have been the research focus and received much attention in recent years. The key issues for novel semiconductor photocatalysts are to effectively harvest solar energy and enhance the separation efficiency of the electron-hole pairs. In this work, novel NbOF/CNTs hybrid nanocomposites with enhanced photocatalytic activity have been successfully synthesized by a facile hydrothermal plus etching technique.

Improving the photovoltaic performance of perovskite solar cells with acetate.

In an all-solid-state perovskite solar cell, methylammonium lead halide film is in charge of generating photo-excited electrons, thus its quality can directly influence the final photovoltaic performance of the solar cell. This paper accentuates a very simple chemical approach to improving the quality of a perovskite film with a suitable amount of acetic acid. With introduction of acetate ions, a homogeneous, continual and hole-free perovskite film comprised of high-crystallinity grains is obtained.

ZnO based heterojunctions and their application in environmental photocatalysis.

As an alternative to TiO2 photocatalysts, ZnO exhibits a large potential for photocatalytic (PC) applications in environmental treatments, such as degradation of wastewater, sterilization of drinking water, and air cleaning. However, the efficiency achieved with ZnO to date is far from that expected for commercialization, due to rapid charge recombination, photo-corrosion as well as poor utilization of solar energy. Fortunately, in recent years, a great number of breakthroughs have been achieved in PC performance (including activity and stability) of micro-/nano- structured ZnO by forming heterojunctions (HJs) with metal nanoparticles (NPs), carbon nanostructures and other semiconductors.

Direct Synthesis of Few-Layer F-Doped Graphene Foam and Its Lithium/Potassium Storage Properties.

Heteroatom-doped graphene is considered a potential electrode materials for lithium-ion batteries (LIBs). However, potassium-ion batteries (PIBs) systems are possible alternatives due to the comparatively higher abundance. Here, a practical solid-state method is described for the preparation of few-layer F-doped graphene foam (FFGF) with thickness of about 4 nm and high surface area (874 m(2)g(-1)).

One-pot hydrothermal synthesis of Nitrogen-doped graphene as high-performance anode materials for lithium ion batteries.

Nitrogen-doped (N-doped) graphene has been prepared by a simple one-step hydrothermal approach using hexamethylenetetramine (HMTA) as single carbon and nitrogen source. In this hydrothermal process, HMTA pyrolyzes at high temperature and the N-doped graphene subsequently self-assembles on the surface of MgO particles (formed by the Mg powder reacting with H2O) during which graphene synthesis and nitrogen doping are simultaneously achieved. The as-synthesized graphene with incorporation of nitrogen groups possesses unique structure including thin layer thickness, high surface area, mesopores and vacancies.

Surface modifications and Nano-composite coatings to improve the bonding strength of titanium-porcelain.

Surface modifications of Ti and nano-composite coatings were employed to simultaneously improve the surface roughness, corrosion resistance and chemical bonding between porclain-Ti. The specimens were studied by field-emission scanning electron microscopy, surface roughness, differential scanning calorimetry, Fourier transform infrared spectroscopy, corrosion resistance and bonding strength tests. The SEM results showed that hybrid structures with micro-stripes, nano-pores and nano-protuberances were prepared by surface modification of Ti, which significantly enhanced the surface roughness and corrosion resistance of Ti.

One-Pot Hydrothermal Synthesis of FeMoO₄ Nanocubes as an Anode Material for Lithium-Ion Batteries with Excellent Electrochemical Performance.

Metal molybdates nanostructures hold great promise as high-performance electrode materials for next-generation lithium-ion batteries. In this work, the facial design and synthesis of monodisperse FeMoO4 nanocubes with the edge lengths of about 100 nm have been successfully prepared and present as a novel anode material for highly efficient and reversible lithium storage. Well-defined single-crystalline FeMoO4 with high uniformity are first obtained as nanosheets and then self-aggregated into nanocubes.

[Study on the occurrence status of formamide in kaolinite-formamide intercalation system and the microstructure of its compounds by FTIR and XRD].

The objectives of this study are to investigate the possible occurrence status of formamide in the intercalation system, the founction of water and the molecular configurations and orientations of formamide inserted into the interlayer of kaolinite, by washing the products with acetone to eliminate the interferences due to the outersurface absorbed formamide molecules in FTIR spectrometry. The results show that the intercalated, absorbed and free formamide probably exist in the intercalation system. Free formamide is easily to be eliminated selectively by drying, whereas the absorbed formamide is removed only by washing with the proper eluting reagent.

Electrochemical and electronic properties of LiCoO2 cathode investigated by galvanostatic cycling and EIS.

The processes of extraction and insertion of lithium ions in LiCoO(2) cathode are investigated by galvanostatic cycling and electrochemical impedance spectroscopy (EIS) at different potentials during the first charge/discharge cycle and at different temperatures after 10 charge/discharge cycles. The spectra exhibit three semicircles and a slightly inclined line that appear successively as the frequency decreases. An appropriate equivalent circuit is proposed to fit the experimental EIS data.

[FTIR and XRD analysis studies of intercalation of kaolinite with benzamide].

Benzamide was intercalated into kaolinite by replacing DMSO pre-intercalated. Pure kaolinite-benzamide intercalation compounds were obtained by washing resulting products with acetone. The analysis of XRD shows that the basal spacing of kaolinite-benzamide intercalation compounds increased to 1.