MXenes, a large family of two-dimensional transition metal carbides and nitrides, have been attracting great interest since the discovery of Ti3C2Tx in 2011. The unique combination of metallic ...conductivity and hydrophilicity in Ti3C2Tx resulted in outstanding performances in electrochemical applications. The surface of MXene is highly chemically active after selective chemical etching of their precursor phases and always forms surface terminations such as hydroxyl, oxygen, or fluorine. Those surface functional groups not only affect their hydrophilic behavior and electrochemical properties such as ion adsorption and diffusion, but also affect their electronic structure, conductivity, work function, and hence their electronic properties. In this review, the emerging electronic and photonic applications of MXenes (henceforth referred to as MXetronics) are discussed. This is a fast-emerging field of MXene research with huge potential.
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•2D Ti3C2Tx MXene has shown promising performance in electrochemical energy storage applications based on its metallic conductivity and hydrophilic surface nature.•The rich surface chemistry, tunable interlayer spacing and work function of MXenes feature them as promising candidate materials in nanoelectronic devices, beyond energy storage applications.•The recent progress in electronic and photonic applications of MXenes (MXetronics) is summarized, and remaining challenges are discussed.
MXenes are an interesting class of 2D materials consisting of transition metal carbides and nitrides, which are currently a subject of extensive studies. Although there have been theoretical ...calculations estimating the thermoelectric properties of MXenes, no experimental measurements have been reported so far. In this report, three compositions of Mo-based MXenes (Mo2CT x , Mo2TiC2T x , and Mo2Ti2C3T x ) have been synthesized and processed into free-standing binder-free papers by vacuum-assisted filtration, and their electrical and thermoelectric properties are measured. Upon heating to 800 K, these MXene papers exhibit high conductivity and n-type Seebeck coefficient. The thermoelectric power reaches 3.09 × 10–4 W m–1 K–2 at 803 K for the Mo2TiC2T x MXene. While the thermoelectric properties of MXenes do not reach that of the best materials, they exceed their parent ternary and quaternary layered carbides. Mo2TiC2T x shows the highest electrical conductivity in combination with the largest Seebeck coefficient of the three 2D materials studied.
As a thriving member of the 2D nanomaterials family, MXenes, i.e., transition metal carbides, nitrides, and carbonitrides, exhibit outstanding electrochemical, electronic, optical, and mechanical ...properties. They have been exploited in many applications including energy storage, electronics, optoelectronics, biomedicine, sensors, and catalysis. Compared to other 2D materials, MXenes possess a unique set of properties such as high metallic conductivity, excellent dispersion quality, negative surface charge, and hydrophilicity, making them particularly suitable as inks for printing applications. Printing and pre/post‐patterned coating methods represent a whole range of simple, economically efficient, versatile, and eco‐friendly manufacturing techniques for devices based on MXenes. Moreover, printing can allow for complex 3D architectures and multifunctionality that are highly required in various applications. By means of printing and patterned coating, the performance and application range of MXenes can be dramatically increased through careful patterning in three dimensions; thus, printing/coating is not only a device fabrication tool but also an enabling tool for new applications as well as for industrialization.
Recent progress in the deposition/patterning of MXenes through printing and coating methods is summarized, including issues that are related to the formulation of MXene inks (e.g., dispersion, stability, and tuning of physical–chemical and morphological properties), relevant printing/coating methods, and their applications in energy storage, electronics/optoelectronics, sensing, and actuation.
Water scarcity is a particularly severe challenge in arid and desert climates. While a substantial amount of water is present in the form of vapour in the atmosphere, harvesting this water by ...state-of-the-art dewing technology can be extremely energy intensive and impractical, particularly when the relative humidity (RH) is low (i.e., below ~40% RH). In contrast, atmospheric water generators that utilise sorbents enable capture of vapour at low RH conditions and can be driven by the abundant source of solar-thermal energy with higher efficiency. Here, we demonstrate an air-cooled sorbent-based atmospheric water harvesting device using the metal-organic framework (MOF)-801 Zr
O
(OH)
(fumarate)
operating in an exceptionally arid climate (10-40% RH) and sub-zero dew points (Tempe, Arizona, USA) with a thermal efficiency (solar input to water conversion) of ~14%. We predict that this device delivered over 0.25 L of water per kg of MOF for a single daily cycle.
A titanium carbide (Ti3C2Tx) MXene is employed as an efficient solid support to host a nitrogen (N) and sulfur (S) coordinated ruthenium single atom (RuSA) catalyst, which displays superior activity ...toward the hydrogen evolution reaction (HER). X‐ray absorption fine structure spectroscopy and aberration corrected scanning transmission electron microscopy reveal the atomic dispersion of Ru on the Ti3C2Tx MXene support and the successful coordination of RuSA with the N and S species on the Ti3C2Tx MXene. The resultant RuSA‐N‐S‐Ti3C2Tx catalyst exhibits a low overpotential of 76 mV to achieve the current density of 10 mA cm−2. Furthermore, it is shown that integrating the RuSA‐N‐S‐Ti3C2Tx catalyst on n+np+‐Si photocathode enables photoelectrochemical hydrogen production with exceptionally high photocurrent density of 37.6 mA cm−2 that is higher than the reported precious Pt and other noble metals catalysts coupled to Si photocathodes. Density functional theory calculations suggest that RuSA coordinated with N and S sites on the Ti3C2Tx MXene support is the origin of this enhanced HER activity. This work would extend the possibility of using the MXene family as a solid support for the rational design of various single atom catalysts.
Ti3C2Tx MXene is demonstrated as a 2D solid support to host a ruthenium single atom (RuSA) catalyst for water splitting. The resultant RuSA‐N‐S‐Ti3C2Tx catalyst coupled with n+np+‐Si photocathode enables photoelectrochemical H2 production with exceptionally high photocurrent density of 37.6 mA cm−2 under AM 1.5G illumination.
•Energy demand and CO2 emissions from space cooling have been increasing remarkably.•Semiclathrate hydrate proposed as a sustainable PCM for cold energy storage and transport.•A comprehensive review ...on thermophysical, kinetic and rheological properties.•State-of-the-art cooling applications proposed based on semiclathrate hydrate technologies.
The energy demand for space cooling has more than tripled for the past thirty years and was responsible for emissions of about 1 Gt CO2 annually. The ever-increasing energy demand for cooling has posed a demanding question on improving the energy efficiency of cooling processes. On the other hand, with the growing global demand on LNG, cold energy released from LNG terminals has been growing to a historical high at 6.6 × 1014 kJ in 2017. Thus, there is a strong need to search for a suitable phase change material (PCM) best utilizing the cold energy released from the production sectors for storage and transport to the needed sectors. Among all the PCMs, semiclathrate hydrates (SCHs) with a suitable phase change temperature (5–27 °C) and high latent heat (190–220 kJ/kg) stand out as one promising candidate (a) to store and transport the cold energy and (b) to improve the energy efficiency of the cooling processes synergistically. In this review, we focus on reviewing SCHs as a cold energy storage and transport PCM covering both its fundamental properties (thermophysical properties, kinetics of formation and dissociation, rheological and transport properties, and safety and economic aspects) and its novel applications in several cooling processes. Prospects and challenges are also delineated on commercializing SCHs as a key technology enabler for the cold energy industry. There is strong confidence that possible disruptive SCH-based cooling technologies could be developed in the near future for energy efficiency improvement and environmental sustainability.
Abstract
Organic-inorganic hybrid perovskite solar cells (PSCs) have been extensively studied because of their outstanding performance: a power conversion efficiency exceeding 22% has been achieved. ...The most commonly used PSCs consist of CH
3
NH
3
PbI
3
(MAPbI
3
) with a hole-selective contact, such as 2,2′,7,7′-tetrakis(
N
,
N
-di-
p
-methoxyphenylamine)-9,9-spiro-bifluorene (spiro-OMeTAD), for collecting holes. From the perspective of long-term operation of solar cells, the cell performance and constituent layers (MAPbI
3
, spiro-OMeTAD, etc.) may be influenced by external conditions like temperature, light, etc. Herein, we report the effects of temperature on spiro-OMeTAD and the interface between MAPbI
3
and spiro-OMeTAD in a solar cell. It was confirmed that, at high temperatures (85 °C), I
−
and CH
3
NH
3
+
(MA
+
) diffused into the spiro-OMeTAD layer in the form of CH
3
NH
3
I (MAI). The diffused I
−
ions prevented oxidation of spiro-OMeTAD, thereby degrading the electrical properties of spiro-OMeTAD. Since ion diffusion can occur during outdoor operation, the structural design of PSCs must be considered to achieve long-term stability.
This study aimed to assess the effect of antibiotics on the clinical outcomes of patients with solid cancers undergoing treatment with immune checkpoint inhibitors (ICIs).
The medical records of 234 ...patients treated with ICIs for any type of solid cancer between February 2012 and May 2018 at the Seoul St. Mary's Hospital were retrospectively reviewed. The data of patients who received antibiotics within 60 days before the initiation of ICI treatment were analyzed. The patients' responses to ICI treatment and their survival were evaluated.
Non-small-cell lung carcinoma was the most common type of cancer. About half of the patients were treated with nivolumab (51.9%), and cephalosporin (35.2%) was the most commonly used class of antibiotics. The total objective response rate was 21%. Antibiotics use was associated with a decreased objective response (odds ratio 0.466, 95% confidence interval CI 0.225-0.968, p = 0.040). The antibiotics group exhibited shorter progression-free survival (PFS) and overall survival (OS) than the no antibiotics group (median PFS: 2 months vs. 4 months, p < 0.001; median OS: 5 months vs. 17 months, p < 0.001). In the multivariate analysis, antibiotics use was a significant predictor of patient survival (PFS: hazard ratio HR 1.715, 95% CI 1.264-2.326, p = 0.001; OS: HR 1.785, 95% CI 1.265-2.519, p = 0.001).
The use of antibiotics may affect the clinical outcomes of patients with solid cancers treated with ICIs. Careful prescription of antibiotics is warranted in candidates who are scheduled for ICI treatment.
Not applicable (retrospective study).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Intratumoral heterogeneity hampers the success of marker-based anticancer treatment because the targeted therapy may eliminate a specific subpopulation of tumor cells while leaving others unharmed. ...Accordingly, a rational strategy minimizing survival of the drug-resistant subpopulation is essential to achieve long-term therapeutic efficacy.
Using single-cell RNA sequencing (RNA-seq), we examine the intratumoral heterogeneity of a pair of primary renal cell carcinoma and its lung metastasis. Activation of drug target pathways demonstrates considerable variability between the primary and metastatic sites, as well as among individual cancer cells within each site. Based on the prediction of multiple drug target pathway activation, we derive a combinatorial regimen co-targeting two mutually exclusive pathways for the metastatic cancer cells. This combinatorial strategy shows significant increase in the treatment efficacy over monotherapy in the experimental validation using patient-derived xenograft platforms in vitro and in vivo.
Our findings demonstrate the investigational application of single-cell RNA-seq in the design of an anticancer regimen. The approach may overcome intratumoral heterogeneity which hampers the success of precision medicine.
Methylammonium lead halide (MAPbX3) perovskites exhibit exceptional carrier transport properties. But their commercial deployment as solar absorbers is currently limited by their intrinsic ...instability in the presence of humidity and their lead content. Guided by our theoretical predictions, we explored the potential of methylammonium bismuth iodide (MBI) as a solar absorber through detailed materials characterization. We synthesized phase‐pure MBI by solution and vapor processing. In contrast to MAPbX3, MBI is air stable, forming a surface layer that does not increase the recombination rate. We found that MBI luminesces at room temperature, with the vapor‐processed films exhibiting superior photoluminescence (PL) decay times that are promising for photovoltaic applications. The thermodynamic, electronic, and structural features of MBI that are amenable to these properties are also present in other hybrid ternary bismuth halide compounds. Through MBI, we demonstrate a lead‐free and stable alternative to MAPbX3 that has a similar electronic structure and nanosecond lifetimes.
Call me MA‐Bi‐I! A lead‐free alternative to hybrid lead perovskites is explored for solar cells: methylammonium bismuth iodide (see figure). This material exhibits higher air stability than hybrid lead perovskites, while demonstrating optoelectronic properties promising for solar absorbers.
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