Next Nanotechnology最新文献

Perovskite solar cells (PSC) have emerged as highly efficient photovoltaic devices, boasting remarkable power conversion efficiencies (PCE) exceeding 25.5%. However, the incorporation of perovskite films raises environmental concerns due to associated toxicity, and PSC deteriorates over time due to material breakdown accelerated by heat, moisture, and undesired chemical reactions at interfaces. For example, employing titanium dioxide TiO₂ as the electron transport layer (ETL) and the organic semiconductor Spiro-OMeTAD as the hole transport layer (HTL) can lead to instability in the device. The broad bandgap of TiO₂ leads to charge carrier recombination in ETL, undermining device performance, along with the high cost and complex synthesis of Spiro-OMeTAD. Researchers have investigated several methods to tackle these challenges, including altering the interfacial structure and employing adaptable materials between the charge-gathering electrode and perovskite active layers. Due to their extensive bandgap and notable electron mobility, perovskite oxides are highly attractive; however, these materials encounter difficulties such as clustering, which can cause short circuits and leakage current. They also suffer from inefficient charge separation, surface hydrophilicity, and inadequate absorption of visible light. Furthermore, the addition of graphene particles to both compact and mesoporous TiO₂ layers, which act as electron-selective layers, aims to lower series resistance and boost electron extraction efficiency, achieving a peak PCE of 26.3%. These materials have garnered attention for their outstanding optoelectronic properties, superior stability, and non-toxic characteristics. This review extensively delves into the integration of graphene-based materials as interfacial layers and how that will affect the performance of PSC in terms of stability and efficiency.

Solar-driven steam generation technology is an environmentally friendly, cost-effective means of sewage treatment and seawater desalination. A significant challenge in the development of this technology is improving the evaporation performance of evaporation devices. Herein, we report an innovative three-dimensional (3D) solar evaporator constructed with MXene-TiO_X nanocomposite as the photothermal layer and polyvinyl alcohol hydrogel as the water-transport medium. An inverted cone-concave structure of 30° on the photothermal layer can absorb more sunlight through diffuse light reflection. The 3D solar evaporator demonstrates a notable evaporation rate of 2.09 kg m⁻² h⁻¹ , surpassing the efficacy of alternative evaporative systems. In the seawater desalination experiment, the condensed water had salinity levels that were considerably lower than the established threshold for drinking water. The ion rejection ratios for the four primary ions demonstrate a high level of efficacy, with values approaching 99.91%. In addition, the 3D solar evaporator exhibits robust performance in the context of wastewater treatment. This study provides significant contributions to the understanding of the efficiency of solar evaporators based on structural design principles, offering approaches to mitigate the challenges posed by limited freshwater availability.

The present study focuses on the hydrothermal synthesis of nickel sulfide (NiS) stabilized on carbon nanospheres (CNSs) with varying concentrations of CNSs. The samples were annealed to study the effect on their structural, chemical, and optical properties. Various characterizations were performed to confirm the presence of NiS nanocomposites, to study the annealing effects, and to examine how the increased amount of carbon nanospheres affects the sample properties. X-ray diffraction (XRD) patterns revealed the formation of multiple-phase C/NiS₂/NiSO₄·6(H₂O) nanocomposites, which were observed to be forming CNSs/NiS nanocomposites after annealing, indicating the removal of sulfate impurity. Significant variations in the bandgap and absorption spectra were observed due to the varying concentration of CNSs from 0.3 g to 0.7 g. Morphological study through field emission scanning electron microscope (FESEM) showed the formation of nanosheets of NiS₂/NiSO₄·6(H₂O) over carbon nanospheres, which was reduced to NiS after annealing. Transmission electron microscope (TEM) images of annealed samples showed the formation of CNSs/NiS nanocomposites. Electrochemical studies conducted through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) showed diffusion-controlled behavior in all samples, rendering samples ideal for solar cell applications with the value of Warburg impedance 116.4 Ohm(s)^1/2 for CNS1. Overall, the characterization results provide valuable insights into the properties and behavior of the synthesized nanocomposites.

This study addresses the synthesis, characterization, and evaluation of L-Cysteine (L-Cys) molecules anchored on superparamagnetic iron oxide nanoparticles (SPIONs), mainly magnetite (Fe₃O₄), for potential drug delivery applications. Fe₃O₄ nanoparticles are obtained via co-precipitation and functionalized with L-Cys to improve biocompatibility and antioxidant activity. To optimize the functionalization process, the dimerization of cysteine to cystine is investigated by varying the reaction time and mass proportions. The samples are characterized by powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) and Raman spectroscopies, transmission electron microscopy (TEM), and magnetic curves. These results confirm that L-Cys molecules are anchored on the nanoparticle surface through their carboxylate groups, with free SH groups present in the dispersed nanoparticles. However, in the solid state, L-Cys dimerization leads to a cystine crystal structure, resulting in no free SH groups. The nanoparticles have a magnetite structure with an average crystallite size of (8.7±0.8) nm and superparamagnetic behavior. In vitro biological assays show the antioxidant effect of L-Cysteine on the surface of the nanoparticles.

Due to the positive link between the application of nanoparticles (NPs) and the improved nutritional status/value of the plants exposed to them, nanomaterials have recently attracted rising interest in the field of agriculture. Numerous NPs, including carbon-based NPs, silica NPs, etc., have been discovered to positively affect plants by raising their ratio of nutrient uptake and nutrient utilization efficiency, amongst other things. All of these qualities have opened the door for potential improvements in plant development, vigor, growth, etc. when these NPs are used primarily as Nano fertilizers. In light of all of this, it is also possible to draw the conclusion that nanotechnology holds great promise for playing a significant role in the international situation of growing demand for the production of food as well as supply in the years to come. In order to give researchers working in this field a thorough understanding, an effort has been made to compile all the encouraging developments about the application of various NPs on plants, together with their likely mode of action, in this review.

High pressure study is crucial in chemical, physical and materials sciences for understanding phase transitions, new phase evolution and in designing pressure sensors. Utilizing the high potential of pyrochlore as luminescent sensors and its structural diversity, Lu₂Sn₂O₇:5.0%Eu³⁺ (LSOE) nanoparticles (NPs) have been synthesized using a hydrothermal method and characterized at ambient condition using x-ray diffraction (XRD), Raman spectroscopy and field emission scanning electron microscopy (FESEM). The reduced intensity of hypersensitive electric dipole transitions (⁵D₀→⁷F₂), reduction in average luminescence lifetime, and increase in symmetry around Eu³⁺ has also being observed in the LSOE NPs induced by the applied high pressure. The same is reflected in color tuning from red to orange to yellow on switching pressure from low to medium to high. Lifetime spectroscopy suggests that high pressure causes site-swapping of europium ion from Lu³⁺ to Sn⁴⁺, which triggers change in local symmetry around Eu³⁺. This work will pave a newer way of designing high pressure induced color tunable phosphor, high pressure sensor and need-based site engineering in pyrochlore compounds and their nanomaterials for high pressure applications.

Micro light-emitting diodes (μLEDs) with unparalleled photoelectric characteristics are essential components for developing metaverse-related technologies. Immersive displays require reducing the LED size to the micro- or sub-microscale while retaining optimal optoelectronic capabilities. μLEDs, fabricated through the quantum dots colour conversion layer (QDs-CCL) process, offer a cost-effective solution for achieving displays with full-colour and ultrahigh quality. However, the sidewall defects significantly affect the optical and electrical properties of μLEDs with reduced chip size. Furthermore, QDs suffer from low excitation radiation and inferior operational stability induced by their intrinsic properties. Atomic layer deposition (ALD) is a promising chemical surface treatment technique with self-limiting properties that can enhance full-colour μLED devices. In this review, we explore recent studies on ALD techniques for full-colour μLED device fabrication. We discuss in detail the significant contribution of ALD in repairing sidewall defects in RGB tricolour μLED chips. Moreover, we explore applications of ALD in the protection of QDs and preparation of high-resolution CCLs. Finally, we discuss future prospects of ALD in developing high-resolution, full-colour displays.

The energy crisis and complex environmental issues stemming from fossil fuel consumption have propelled the development and utilization of renewable energy sources, with electrochemical water splitting (EWS) being an effective way and ideal method for producing clean and renewable energy (hydrogen). Up to now, the majority of EWS-related reactions have been studied mainly under acidic and alkaline conditions, which have achieved relatively excellent catalytic activities and efficiencies, albeit with certain safety risks, accompanied by corrosion, contamination, and the generation of waste liquids, in addition to the demand for acid- and alkali-resistant electrocatalytic materials as well as costly anion/cation-exchange membranes. To overcome these shortcomings, the development of advanced catalysts for neutral EWS becomes an attractive and more sustainable option. Unfortunately, there are relatively few theoretical discussions and practical applications of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) as well as other anodic oxidation reactions under neutral conditions. Single/dual-atom electrocatalysts (S/DACs), characterized by maximum metal utilization efficiency, homogeneous active sites, and remarkable synergistic effect, exhibit great potential for EWS-related reactions under neutral conditions. Therefore, we provide a brief mechanistic discussion of neutral HER/OER, focusing on the synthesis, modulation strategies, characterization techniques and current representative applications in EWS-related reactions under neutral conditions, as well as the challenges and prospects of S/DACs. This review may provide some insights to facilitate the practical application of efficient hydrogen production under neutral conditions.

This study investigates integrating pixelated colloidal quantum dot (QD) layers into LCDs to enhance color conversion and pixel-level enrichment for future display technologies. We developed miniature prototypes with pixel-sized QD color-converter layers seamlessly integrated into the backlight unit (BLU). The prototypes, featuring red- and green-emitting QD pixels with a single blue LED on glass substrates, underwent rigorous environmental tests such as Thermal Shock Test (TST), Thermal Cycle Test (TCT), High Temperature High Humidity Test (HHT), and Low Temperature Test (LTT). The assessment covered the uniformity of light, spectral radiance, and CIE color coordinates, revealing insights into the performance of the QD layers through the analysis of pre- and post-environmental tests. Despite a decrease in luminance, the QD layers exhibited resilience against rapid temperature variations, enduring thermal shock, and thermal cycle tests without cracking. However, high-temperature and high-humidity conditions revealed susceptibility. Low-temperature stress tests demonstrated stable color gamut coordinates with no discernible shifts. This research fills a notable gap in the existing literature by conducting comprehensive environmental tests on pixel-sized QD utilization in display technologies, providing valuable insights to enhance the stability, durability, and reliability of QD displays.

Micro light-emitting diodes (micro-LEDs) are considered crucial for the next-generation display technology. However, the high cost of large-scale transfer technology and the lack of maturity in full-color technology have hindered the availability of mature products. The perovskite quantum dot (PQD) material offers a promising solution for achieving full-color capabilities in micro-LED displays. This review article aims to provide an overview on the latest progresses on PQD full-color technology for micro-LEDs. The review covers a variety of patterning techniques, including photolithography, inkjet printing, microfluidic processing, and laser processing, as well as the research on intrinsic stability of PQDs. Finally, the current drawbacks and solutions of PQD color conversion micro-LEDs are discussed, and the future research prospects in this field are anticipated.