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Ionic liquids (ILs) and deep eutectic solvents (DESs) have tremendous potential for reactive capture and conversion (RCC) of CO2 due to their wide electrochemical stability window, low volatility, and high CO2 solubility. There is environmental and economic interest in the direct utilization of the captured CO2 using electrified and modular processes that forgo the thermal- or pressure-swing regeneration steps to concentrate CO2, eliminating the need to compress, transport, or store the gas. The conventional electrochemical conversion of CO2 with aqueous electrolytes presents limited CO2 solubility and high energy requirement to achieve industrially relevant products. Additionally, aqueous systems have competitive hydrogen evolution. In the past decade, there has been significant progress toward the design of ILs and DESs, and their composites to separate CO2 from dilute streams. In parallel, but not necessarily in synergy, there have been studies focused on a few select ILs and DESs for electrochemical reduction of CO2, often diluting them with aqueous or non-aqueous solvents. The resulting electrode–electrolyte interfaces present a complex speciation for RCC. In this review, we describe how the ILs and DESs are tuned for RCC and specifically address the CO2 chemisorption and electroreduction mechanisms. Critical bulk and interfacial properties of ILs and DESs are discussed in the context of RCC, and the potential of these electrolytes are presented through a techno-economic evaluation. [ABSTRACT FROM AUTHOR]

Platinum is known as the best catalyst for the hydrogen evolution reaction (HER) but the scarcity and high cost of Pt limit its widespread applicability. Herein, the role of the underlying substrate on the HER activity of dispersed Pt atoms is uncovered. A direct current magnetron sputtering technique is utilized to deposit transition metal (TM) thin films of W, Ti, and Ta as underlying substrates for extremely low loading of Pt (<1.5 at%). The electrocatalytic performance of as‐synthesized samples for the HER is examined in both alkali and acidic media. The results show that despite the low loading of Pt, the Pt/TM catalysts produce hydrogen at a rate comparable to that of pristine bulk Pt. Pt/TM catalysts also display good stability with less than 5% decay in performance after 10 h of continuous HER operation. Based on the computational study, the excellent performance is attributed to the modified electronic properties of the Pt atoms, offering ideal binding energy for HER due to interaction with the underlying substrates. This work provides a robust and industry‐friendly route toward designing efficient catalytic systems for important electrochemical reactions such as HER and others. [ABSTRACT FROM AUTHOR]

A new magneto‐thermo‐electric cooling device (MTECD) comprising a central magnetocaloric (MC) material (e.g., Gd) sandwiched by two thermoelectric (TE) materials (e.g., MnP) is proposed. The presence of the TE materials in the MTECD guides the heat flow direction and enhances heat pulsation. In this case, the usage of a ferromagnetic TE material that combines large TE with small MC properties within a similar temperature region can enhance the magnetic flux density and heat exchange efficiency. Herein, it is shown that MnP nanorod‐structured films with desired magnetic, MC, and TE properties are very promising for use in MTECDs. The films are grown on Si substrates at 300, 400, and 500 °C using molecular beam epitaxy. The 400 °C sample shows a desired TE and MC combination. A large power factor of 24.06 μW m−1 K−2 is achieved at room temperature. In this temperature region, the film exhibits a small MC effect (−ΔSM ≈0.64 J kg−1 K and ΔTad ≈0.3 K at μ0H = 2 T) but ferromagnetism that gives rise to the enhanced MC effect of the central MC material. These properties can enable the MTECD to operate at high frequency. [ABSTRACT FROM AUTHOR]

Detection and analysis of volatile organic compounds' (VOCs) biomarkers lead to improvement in healthcare diagnosis and other applications such as chemical threat detection and food quality control. Here, we report on tri-molybdenum phosphide (Mo3P) and multiwalled carbon nanotube (MWCNT) junction-based vapor quantum resistive sensors (vQRSs), which exhibit more than one order of magnitude higher sensitivity and superior selectivity for biomarkers in comparison to pristine MWCNT junctions based vQRSs. Transmission electron microscope/scanning tunneling electron microscope with energy dispersive x-ray spectroscopy, x-ray diffraction, and x-ray photoelectron spectroscopy studies reveal the crystallinity and the presence of Mo and P elements in the network. The presence of Mo3P clearly enhanced the performance of vQRS as evidenced in sensitivity and selectivity studies. The vQRSs are stable over extended periods of time and are reproducible, making them a potential candidate for sensing related applications. [ABSTRACT FROM AUTHOR]

The magnetocaloric and thermomagnetic properties of Ni50Mn35(In1-xCrx)15 and (Mn1-xCrx) NiGe1.05 systems for 0⩽x⩽0.105 and 0⩽x⩽0.1, respectively, have been studied by x-ray diffraction, differential scanning calorimetry, and magnetization measurements. Partial substitution of Cr for Mn in (Mn1-xCrx)NiGe1.05 results in a first order magnetostructural transition from a hexagonal paramagnetic to an orthorhombic paramagnetic phase near TM~380K (for x=0.07). Partial substitution of Cr for In in Ni50Mn35(In1-xCrx)15 shifts the magnetostructural transition to a higher temperature (T=TM~450 K) for x=0.1. Large magnetic entropy changes of ΔS=-12 (J/(kgK)) and ΔS=-11 (J/(kgK)), both for a magnetic field change of 5 T, were observed in the vicinity of TM for (Mn1-xCrx)NiGe1.05 and Ni50Mn35(In1-xCrx)15, respectively. [ABSTRACT FROM AUTHOR]

Few-layered films of WS2, synthesized by chemical vapor deposition on quartz, are successfully used as light sensors. The film samples are structurally characterized by Raman spectroscopy, atomic force microscopy, scanning electron microscopy, and high-resolution transmission electron microscopy. The produced samples consist of few layered sheets possessing up to 10 layers. UV-visible absorbance spectra reveals absorption peaks at energies of 1.95 and 2.33 eV, consistent with the A and B excitons characteristic of WS2. Current-voltage ( I- V) and photoresponse measurements carried out at room temperature are performed by connecting the WS2 layered material with Au/Ti contacts. The photocurrent measurements are carried out using five different laser lines ranging between 457 and 647 nm. The results indicate that the electrical response strongly depends on the photon energy from the excitation lasers. In addition, it is found that the photocurrent varies non-linearly with the incident power, and the generated photocurrent in the WS2 samples varies as a squared root of the incident power. The excellent response of few-layered WS2 to detect different photon wavelengths, over a wide range of intensities, makes it a strong candidate for constructing novel optoelectronic devices. [ABSTRACT FROM AUTHOR]

Wereport on the low-temperature electrical transport propertiesof large area boron and nitrogen codoped graphene layers (BNC). Thetemperature dependence of resistivity (5 K < T< 400 K) of BNC layers show semiconducting nature and displaya band gap which increases with B and N content, in sharp contrastto large area graphene layers, which shows metallic behavior. Ourinvestigations show that the amount of B dominates the semiconductingnature of the BNC layers. This experimental observations agree withthe density functional theory (DFT) calculations performed on BNCstructures similar in composition to the experimentally measured samples.In addition, the temperature dependence of the electrical conductivityof these samples displays two regimes: at higher temperatures, thedoped samples display an Arrhenius-like temperature dependence thusindicating a well-defined band gap. At the lowest temperatures, thetemperature dependence of the conductivity deviates from activatedbehavior and displays a conduction mechanism consistent with Mott’stwo-dimensional (2D) variable range hopping (2D-VRH). The abilityto tune the electronic properties of thin layers of BNC by simplyvarying the concentration of B and N will provide a tremendous boostfor obtaining materials with tunable electronic properties relevantto applications in solid state electronics. [ABSTRACT FROM AUTHOR]

2-Dimensional structures with swift optical response have several technological advantages, for example they could be used as components of ultrafast light modulators, photo-detectors, and optical switches. Here we report on the fast photo switching behavior of thin films of liquid phase exfoliated MoS2, when excited with a continuous laser of λ = 658 nm (E = 1.88 eV), over a broad range of laser power. Transient photo-conductivity measurements, using an optical pump and THz probe (OPTP), reveal that photo carrier decay follows a bi-exponential time dependence, with decay times of the order of picoseconds, indicating that the photo carrier recombination occurs via trap states. The nature of variation of photocurrent with temperature confirms that the trap states are continuously distributed within the mobility gap in these thin film of MoS2, and play a vital role in influencing the overall photo response. Our findings provide a fundamental understanding of the photo-physics associated with optically active 2D materials and are crucial for developing advanced optoelectronic devices. [ABSTRACT FROM AUTHOR]

M. Terrones and co‐workers design a photodetector consisting of a few‐layered WS2 film on quartz with Au/Ti contacts. On page 5511, different laser wavelengths are applied perpendicularly to the film. The few‐layered films of WS2 are synthesized by chemical vapor deposition and the photodevices exhibit very fast responses (on the order of 5 ms). The excellent response of few‐layered WS2 to detect different photon wavelengths over a wide range of intensities makes it a strong candidate for constructing novel optoelectronic devices. [ABSTRACT FROM AUTHOR]

Technoeconomic analysis (TEA) studies are vital for formulating guidelines that drive the commercialization of electrochemical CO 2 reduction (eCO 2 R) technologies. In this review, we first discuss the progress in the field of eCO 2 R processes by providing current state-of-the-art metrices (e.g., faradic efficiency, current density) based on the recent heterogeneous catalysts' discovery, electrolytes, electrolyzers configuration, and electrolysis process designs. Next, we assessed the TEA studies for a wide range of eCO 2 R final products, different modes of eCO 2 R systems/processes, and discussed their relative competitiveness with relevant commercial products. Finally, we discuss challenges and future directions essential for eCO 2 R commercialization by linking suggestions from TEA studies. We believe that this review will catalyze innovation in formulating advanced eCO 2 R strategies to meet the TEA benchmarks for the conversion of CO 2 into valuable chemicals at the industrial scale., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)