Stability Strategies and Applications of Iodide Perovskites.

Iodide perovskites have demonstrated their unprecedented high efficiency and commercialization potential, and their superior optoelectronic properties, such as high absorption coefficient, high carrier mobility, and narrow direct bandgap, have attracted much attention, especially in solar cells, photodetectors, and light-emitting diodes (LEDs). However, whether it is organic iodide perovskite, organic-inorganic hybrid iodide perovskite or all-inorganic iodide perovskite the stability of these iodide perovskites is still poor and the contamination is high. In recent years, scholars have studied more iodide perovskites to improve their stability as well as optoelectronic properties from various angles. This paper systematically reviews the strategies (component engineering, additive engineering, dimensionality reduction engineering, and phase mixing engineering) used to improve the stability of iodide perovskites and their applications in recent years.

Synthesis of F-doped materials and applications in catalysis and rechargeable batteries.

Elemental doping is one of the most essential techniques for material modification. It is well known that fluorine is considered to be a highly efficient and inexpensive dopant in the field of materials. Fluorine is one of the most reactive elements with the highest electronegativity (χ = 3.98). Compared to cationic doping, anionic doping is another valuable method for improving the properties of materials. Many materials have physicochemical limitations that affect their practical application in the field of catalysis and rechargeable ion batteries. Many researchers have demonstrated that F-doping can significantly improve the performance of materials for practical applications. This paper reviews the applications of various F-doped materials in photocatalysis, electrocatalysis, lithium-ion batteries, and sodium-ion batteries, as well as briefly introducing their preparation methods and mechanisms to provide researchers with more ideas and options for material modification.

Copper nanodot-embedded nitrogen and fluorine co-doped porous carbon nanofibers as advanced electrocatalysts for rechargeable zinc-air batteries.

Porous carbon-based electrocatalysts for cathodes in zinc-air batteries (ZABs) are limited by their low catalytic activity and poor electronic conductivity, making it difficult for them to be quickly commercialized. To solve these problems of ZABs, copper nanodot-embedded N, F co-doped porous carbon nanofibers (CuNDs@NFPCNFs) are prepared to enhance the electronic conductivity and catalytic activity in this study. The CuNDs@NFPCNFs exhibit excellent oxygen reduction reaction (ORR) performance based on experimental and density functional theory (DFT) simulation results. The copper nanodots (CuNDs) and N, F co-doped carbon nanofibers (NFPCNFs) synergistically enhance the electrocatalytic activity. The CuNDs in the NFPCNFs also enhance the electronic conductivity to facilitate electron transfer during the ORR. The open porous structure of the NFPCNFs promotes the fast diffusion of dissolved oxygen and the formation of abundant gas-liquid-solid interfaces, leading to enhanced ORR activity. Finally, the CuNDs@NFPCNFs show excellent ORR performance, maintaining 92.5% of the catalytic activity after a long-term ORR test of 20000 s. The CuNDs@NFPCNFs also demonstrate super stable charge-discharge cycling for over 400 h, a high specific capacity of 771.3 mAh g-1 and an excellent power density of 204.9 mW cm-2 as a cathode electrode in ZABs. This work is expected to provide reference and guidance for research on the mechanism of action of metal nanodot-enhanced carbon materials for ORR electrocatalyst design.

Dual-modality and Noninvasive Diagnostic of MNP-PEG-Mn Nanoprobe for Renal Fibrosis Based on Photoacoustic and Magnetic Resonance Imaging.

To date, imaging-guided multimodality therapy is important to improve the accuracy of the diagnosis of renal fibrosis, and nanoplatforms for imaging-guided multimodality diagnosis are gaining more and more attention. There are many limitations and deficiencies in clinical use for early-stage diagnosis of renal fibrosis, and multimodal imaging can contribute more thoroughly and provide in-detail information for effective clinical diagnosis. Melanin is an endogenous biomaterial, and we developed an ultrasmall particle size melanin nanoprobe (MNP-PEG-Mn) based on photoacoustic (PA) and magnetic resonance (MR) dual-modal imaging. MNP-PEG-Mn nanoprobe, with the average diameter about 2.7 nm, can be passively targeted for accumulation in the kidney, and it has excellent free radical scavenging and antioxidant abilities without further exacerbating renal fibrosis. Using the normal group signal as a control, the dual-modal imaging results showed that the MR imaging (MAI) and PA imaging (PAI) signals reached the strongest at 6 h when MNP-PEG-Mn entered the 7 day renal fibrosis group via the left vein of the tail end of the mice; however, the strength of the dual-modal imaging signal and the gradient of signal change were significantly weaker in the 28 day renal fibrosis group than in the 7 day renal fibrosis group and normal group. The phenomenon preliminarily indicates that as a PAI/MRI dual-modality contrast medium candidate, MNP-PEG-Mn has outstanding ability in clinical application potential.

Melanin theranostic nanoplatform as an efficient drug delivery system for imaging-guided renal fibrosis therapy.

As renal fibrosis nanotherapeutics, the endogenous biomaterial melanin not only has natural biocompatibility and biodegradability but also has inherent photoacoustic imaging ability and certain anti-inflammatory effects. These properties determine that melanin can not only as a carrier of medication but also track the biodistribution and renal uptake of drugs in vivo by photoacoustic imaging in real-time. Curcumin is a natural compound with biological activity, which has excellent ROS scavenging ability and good anti-inflammatory property. These materials appear more advantages in the development of nanoscale diagnostic and therapeutic platforms for future clinical translation. Herein, this study developed curcumin-loaded melanin nanoparticles (MNP-PEG-CUR NPs) as an efficient medication delivery system for photoacoustic imaging guidance renal fibrosis treatment. The nanoparticles are about 10 nm in size, exhibit good renal clearance efficiency, excellent photoacoustic imaging ability, and good in vitro and in vivo biocompatibility. These preliminary results indicated that MNP-PEG-CUR have clinically applicable potential as a therapeutic nanoplatform for renal fibrosis.

TiO2 Gas Sensors Combining Experimental and DFT Calculations: A Review.

Gas sensors play an irreplaceable role in industry and life. Different types of gas sensors, including metal-oxide sensors, are developed for different scenarios. Titanium dioxide is widely used in dyes, photocatalysis, and other fields by virtue of its nontoxic and nonhazardous properties, and excellent performance. Additionally, researchers are continuously exploring applications in other fields, such as gas sensors and batteries. The preparation methods include deposition, magnetron sputtering, and electrostatic spinning. As researchers continue to study sensors with the help of modern computers, microcosm simulations have been implemented, opening up new possibilities for research. The combination of simulation and calculation will help us to better grasp the reaction mechanisms, improve the design of gas sensor materials, and better respond to different gas environments. In this paper, the experimental and computational aspects of TiO2 are reviewed, and the future research directions are described.

Cobalt-doping of molybdenum phosphide nanofibers for trapping-diffusion-conversion of lithium polysulfides towards high-rate and long-life lithium-sulfur batteries.

Rational design of separators is especially critical to solve the "shuttle effect" of lithium polysulfides (LiPSs) and the sluggish redox kinetics in lithium-sulfur batteries (LSBs). Here, the multi-functional nanocomposite involving Co-doped molybdenum phosphide (Co-MoP) nanofibers and porous carbon nanofibers (PCNFs) is designed and prepared through electro-blow spinning and phosphating process, which possesses multiple adsorption and catalytic sites and is acted as the functional material for LSBs separators. In this multifunctional nanocomposite, the prepared Co-MoP nanofibers can provide internal adsorption and catalytic sites for LiPSs conversion. And the interconnected nitrogen-doped PCNFs can be elaborated an efficient LiPSs mediator and accommodate the huge volume changes in the reaction process for LSBs. Benefiting from the multiple adsorptive and catalytic sites of the developed functional materials, the assembled LSBs with a Co-MoP/PCNFs modified separator display outstanding electrochemical performances, including an admirable capacity retention of 770.4 mAh g-1 after 400 cycles at 1.0 C, only 0.08 % capacity decay per cycle at 2.0 C, rate performance up to 5 C, and also decent areal capacity even under a high sulfur loading of 4.9 mg cm-2. The work provides a facile pathway towards multifunctional separators in LSBs, and it may also help deepen preparation method of MoP through the electrostatic blowing/electrospinning technology in other related energy storage fields.

Synthesis of MoS2-based nanostructures and their applications in rechargeable ion batteries, catalysts and gas sensors: a review.

Molybdenum disulfide (MoS2) is a two-dimensional (2D) layered material with a graphene-like structure that has attracted attention because of its large specific surface area and abundant active sites. In addition, the compounding of MoS2 with other materials can enhance the performance in applications such as batteries, catalysts, and optoelectronic devices, etc. MoS2 is prepared by various methods, among which chemical deposition and hydrothermal methods are widely used. In this review, we focus on summarizing the applications of MoS2 and MoS2 composite nanomaterials in rechargeable ion batteries, catalysts for water splitting and gas sensors, and briefly outline the preparation methods.

Melanin-gelatin nanoparticles with both EPR effect and renal clearance for PA/MRI dual-modal imaging of tumors.

As cancer nanotherapeutics, the ideal multifunctional nanoparticles not only have the processing ability to accumulate effectively in tumors, but also can be excreted rapidly from the body via renal clearance after effective treatment. Melanin is an endogenous biological material, and gelatin has natural biocompatibility and biodegradability. Such materials are more promising in the development of diagnostic and therapeutic nanoplatform for future clinical translation. In this study, we have developed a kind of size-shrinkable PA/MRI theranostic agent based on gelatin fabricated ultrasmall melanin nanoparticles (MNPs-GNP). The MNPs-GNP nanoparticles, with a size of about 100 nm, presented good dispersibility, broadband light absorbance, negligible cellular cytotoxicity, preferable tumor accumulation by EPR-based passive targeting. The dual-modal imaging results showed that the nanoparticles have excellent photoacoustic (PA) imaging and nuclear magnetic resonance (MRI) imaging after tumor-bearing mice were intravenously injected with MNPs-GNP. Additionally, gelatin is the substrate of matrix metalloproteinase-2 (MMP-2), following with the degradation of gelatin nanoparticles by MMP-2, the large-size MNPs-GNP turns to be small-size melanin, which could mainly be excreted via renal clearance avoiding potential toxicity to body tissues. These preliminary results indicated that MNPs-GNP can overcome the dilemma between EPR and renal clearance, which has clinical application potentiality as a PA/MRI dual-modal candidate agent for cancer theranostics.

Functional Component Isolated from Phaseolus vulgaris Lectin Exerts In Vitro and In Vivo Anti-Tumor Activity Through Potentiation of Apoptosis and Immunomodulation.

Phytohemagglutinin (PHA), the lectin purified from red kidney bean (Phaseolus vulgaris), is a well-known mitogen for human lymphocyte. Because it has obvious anti-proliferative and anti-tumor activity, PHA may serve as a potential antineoplastic drug in future cancer therapeutics. However, the literature is also replete with data on detrimental effects of PHA including oral toxicity, hemagglutinating activity, and immunogenicity. There is a critical need to evaluate the functional as well as the toxic components of PHAs to assist the rational designs of treatment with it. In this report, we performed SDS-PAGE to identify components of PHA-L, the tetrameric isomer of PHA with four identical L-type subunits, and then characterized biological function or toxicity of the major protein bands through in vitro experiments. It was found that the protein appearing as a 130 kD band in SDS-PAGE gel run under the condition of removal of ß-mercaptoethanol from the sample buffer together with omission of a heating step could inhibit tumor cell growth and stimulate lymphocyte proliferation, while most of the 35 kD proteins are likely non-functional impurity proteins and 15 kD protein may be related to hemolytic effect. Importantly, the 130 kD functional protein exhibits promising in vivo anti-tumor activity in B16-F10 melanoma C57 BL/6 mouse models, which may be achieved through potentiation of apoptosis and immunomodulation. Altogether, our results suggest that PHA-L prepared from crude extracts of red kidney bean by standard strategies is a mixture of many ingredients, and a 130 kD protein of PHA-L was purified and identified as the major functional component. Our study may pave the way for PHA-L as a potential anticancer drug.