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Randall Guy posted an update 6 months ago
Among the three-dimensional (3D) organic-inorganic hybrid perovskites (OIHPs), mixed formamidinium and methylammonium cation lead iodide is one of the most promising for solar cell application. After optimizing the use of a methylammonium chloride (MACl) additive for the preparation of compact, high-quality, and large crystal grain layers made of a pure α-phase perovskite with the FA0.94MA0.06PbI3 composition, the treatment of the perovskite surface by a 2-phenylethylammonium iodide (PEAI) solution has been performed. check details This treatment, without any thermal annealing, leads notably to the spontaneous formation of a crystallized (PEA)2PbI4 two-dimensional (2D) perovskite nanolayer at the film surface due to partial organic cation dissolution. This buffer layer is shown to favor a fast transfer of the holes toward the hole transporting layer (HTL) and to reduce the recombinations at and near the perovskite/HTL interface in perovskite solar cells (PSCs). It is shown to boost their maximum power conversion efficiency (PCE) from 20.37 to 22.18%, while the hysteresis becomes negligible. A comprehensive study of the electrical response of the device has been performed. The electrical impedance spectroscopy (EIS) measurements have been fitted with ad hoc equivalent electrical circuits. The electrical responses due to interface stabilization, the intrinsic dielectric relaxation of the perovskite, and the charge depletion and charge recombinations have been distinguished. The low-frequency capacitance is analyzed as a charge recombination capacitance. The perovskite surface buffer layer is notably shown to suppress charge recombinations from the boosting of the high- and low-frequency recombination resistances as well as from the marked decrease of the low-frequency recombination capacitance. The prepared devices are proven to be especially resistant to electrical stresses, light irradiation, and moisture.Solar-driven water splitting is considered as a futuristic sustainable way to generate hydrogen and chemical storage of solar energy. Further, considering the technological competence, silicon is one of the potential materials for developing large-scale and cost-effective photocathodes (PCs), but it lacks efficacy and stability. Here, we show that chlorophyll(a)/carbon quantum dots (Chl/CQDs) bio-nanocomposite (b-NC)-decorated Si-nanowires (SiNWs) as PC can surpass the reported efficiency for photoelectrochemical (PEC) hydrogen generation along with stability. The optimized heterojunction (Chl/CQDs_SiNW) significantly enhances broad-band solar absorption and protects Si surface from corrosion. Further, the appropriate band alignment enforces efficient photogenerated charge separation and possesses directional exciton transport property via the Förster resonance energy transfer (FRET) mechanism. This synergic effect demonstrates an ∼18 times increase in photocurrent density (26.36 mA/cm2) compared to pristine SiNW PC at 1.07 V vs reversible hydrogen electrode (RHE). The efficiency reaches ∼7.86%, which is comparably the highest reported for hybrid Si-based photocathodes. Hydrogen evaluation rate was measured to be ∼113 μmol/h at 0.8 V vs RHE under 1 sun illumination. With Si-process line compatibility, this new finding opens a new direction toward the development of Si-based efficient and stable PCs at a large scale for commercial applications.The overuse of antibiotics has led to the emergence of multidrug-resistant pathogens. There is an urgent need to develop alternative therapeutic strategies to reduce mortality and morbidity related to drug-resistant bacterial infections. Self-synthesized tetrahedral framework nucleic acids (tFNAs) are used as the drug loading platform to deliver ampicillin to combat methicillin-resistant Staphylococcus aureus (MRSA) infection. The results of average dimension, zeta potential, transmission electron microscopy, and ultraviolet spectrophotometry showed that tFNAs-ampicillin combined with a sufficient encapsulation rate and good stability. tFNAs-ampicillin had a better affinity to MRSA than free ampicillin because it had a better uptake by MRSA cells. Additionally, tFNAs-ampicillin had a better antibacterial effect and lower levels of resistance development than free ampicillin. The downregulation of genes related to bacterial cell wall synthesis (murA and murZ) and upregulation of a gene related to antibiotic sensibility (PBP2) were responsible for the enhanced killing effect of tFNAs-ampicillin against MRSA.Multifunctional gold (Au)-based nanomaterials with high atomic number (symbol Z) and strong absorbance in the second near-infrared window (NIR-II) property are emerging as promising candidates for tumor thermo-radiotherapy. The main limitations of applying Au-based nanomaterials to biomedical studies include the absence of active tumor-targeting ability, penetrating efficiency, and stability. In this study, we present a novel type of tumor cell-derived stellate plasmonic exosomes (TDSP-Exos) for penetrative targeted tumor NIR-II thermo-radiotherapy and photoacoustic imaging. The TDSP-Exos are abundantly and easily produced by the incubation of tumor cells with gold nanostars, based on which gold nanostars promote the exocytosis of exosomes from tumor cells. Compared with bare gold nanostars, the TDSP-Exos exhibit pronounced accumulation in deep tumor tissues and perform well in both PA imaging and NIR-II thermo-radiotherapy against the tumor. Moreover, the TDSP-Exos improve tumor hypoxia to enhanced radiotherapy by NIR-II photothermal therapy. This work indicates that the tumor cell-derived exosomes have the potential to function as a universal carrier of photothermal agents for targeted tumor NIR-II thermo-radiotherapy.Aluminum (Al) foil serving as the most widely used cathode current collector for lithium-ion batteries (LIBs) is still not flawless to fulfill the increasing demand of rechargeable energy storage systems. The limited contact area and weak adhesion to cathode material as well as local corrosion during long-term operations could deteriorate the performance of LIBs with a higher working voltage. Herein, a reduced graphene oxide (RGO)-modified Al foil (RGO/Al) is developed via electrospraying to increase interfacial adhesion and inhibit anodic corrosion as a functional current collector. Valid corrosion resistance to electrolyte and strengthened adhesion of electrode particles to current collectors are beneficial to improve the interfacial reaction dynamics. The RGO/Al-based LiNi0.5Mn1.5O4 cells (LNMO-RGO/Al) exhibit better electrochemical performances in terms of long-term cycling discharge capacity retention (90% after 840 cycles at 1 C), rate capability (101.8 mAh g-1 at 5 C), and interfacial resistance, prominently superior to bare Al-based cells (LNMO-Al).