Harnessing mixed-phase MoS for efficient room-temperature ammonia sensing.

Molybdenum disulfide (MoS), a notable two-dimensional (2D) material, has attracted considerable interest for its potential applications in gas sensing, despite its typically insulating characteristics, which have limited its practical use. In this study, we present the use of mixed phase MoS (1T@2H-MoS) to overcome sensing limitations of MoS material by enhancing its conductivity and demonstrating its high-performance characteristics for sensing ammonia (NH) at room temperature (20 °C). The 1T@2H-MoS was synthesized a hydrothermal process, and the coexistence of two different phases (the 1T and 2H phases) was confirmed by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Raman spectroscopy.

Pt-Decorated ZnO Nanorods for Light-Assisted Ethanol Sensing and Analysis of the Sensing Mechanism under Light Irradiation.

ZnO nanorods have attracted much attention owing to their outstanding properties for chemical gas sensors. Although they show greater sensing properties than conventional nanoparticulate ZnO, high operation temperature (>250-350 °C) is required for them to work even if precious metals are deposited on them to sensitize their sensing properties. Light irradiation is one solution for overcoming the high operation temperature and the gas selectivity because it assists the oxidation activity on the surface that affects the sensor response.

Superselective Hydrogen Separation through a Mixed Conducting Graphene Oxide Membrane.

A cost-effective H separation method is required for the purification of gaseous mixtures containing H. Thus, in this study, we investigate the H separation properties of Ce ion-doped partially reduced graphene oxide (prGO) membranes. Pt/C-catalyst-coated, dense, micrometer-thick membranes are fabricated by stacking Ce-prGO nanosheets, followed by thermal annealing.

Ambient Air-Synthesized CsPbBr Nanocrystals Coupled with TiO Film as an Efficient Hybrid Photoanode for Photoelectrochemical Methanol-to-Formaldehyde Conversion.

Due to its exceptional optoelectronic properties in the visible spectrum, cesium lead bromide (CsPbBr) perovskite has attracted considerable attention in solar-driven organic transformations via photoelectrochemical (PEC) cells. However, the performance of the devices is adversely affected by electron-hole recombination occurring between a transparent conductive substrate, such as fluorine-doped tin dioxide (FTO), and a perovskite layer. Herein, to mitigate this issue, a compact layer of titanium dioxide (TiO) was employed as both an electron transport layer and a hole blocking layer to diminish charge recombination while facilitating electron transfer in such perovskite material.

Investigation on luminescence photoswitching stability in diarylethene-perovskite quantum dot hybrids.

Perovskite quantum dots (pQDs) have gathered a lot of attention because of their outstanding optoelectronic properties. Photoswitchable pQDs have the potential for application in single particle optical memories and bio-imaging. Hybrids of photochromic diarylethenes (DAE) and pQDs show a luminescence photoswitching property, however, the cycle stability in such systems is low because of photoinduced electron transfer (PET) from pQDs to DAE.

A photoelectrochemical capacitor using polyoxometalates coupled with semiconductor nanocrystals as the photosensitizer.

Solar energy storage technology ensures a sustainable and reliable energy supply. Herein, we show that electrons generated in semiconductor nanocrystals (NCs) of CsPbBr by visible light excitation can be stored in polyoxometalates (POMs) of WO, and extracted as an electric current using a photoelectrochemical cell.

Graphene Oxide Membrane Reactor for Electrochemical Deuteration Reactions.

The deuteration of organic molecules is considerably important in organic and medicinal chemistry. An electrochemical membrane reactor using proton-conducting graphene oxide (GO) nanosheets was developed to synthesize valuable deuterium-labeled products via an efficient hydrogen-to-deuterium (H/D) exchange under mild conditions at ambient temperature and atmospheric pressure. Deuterons (D) formed by the anodic oxidation of heavy water (DO) at the Pt/C anode permeate through the GO membrane to the Pt/C cathode, where organic molecules with functional groups (C≡C and C═O) are deuterated with adsorbed atomic D species.

Selective Detection of CO Using Proton-Conducting Graphene Oxide Membranes with Pt-Doped SnO Electrocatalysts: Mechanistic Study by Operando DRIFTS.

To reduce the risk of carbon monoxide (CO) poisoning, there is a strong need for small, compact gas sensors to detect and monitor CO at ppm concentrations. In this study, we focused on detecting CO with electrochemical sensors based on proton-conducting graphene oxide (GO) nanosheets at room temperature. We found that a Ce-doped GO nanosheet membrane fitted with the sensing electrode composed of Pt (10 wt %)-doped SnO nanocrystals exhibits an excellent sensor response to CO at 25 °C.

Bandgap Engineering of Melon using Highly Reduced Graphene Oxide for Enhanced Photoelectrochemical Hydrogen Evolution.

The uncondensed form of polymeric carbon nitrides (PCN), generally known as melon, is a stacked 2D structure of poly(aminoimino)heptazine. Melon is used as a photocatalyst in solar energy conversion applications, but suffers from poor photoconversion efficiency due to weak optical absorption in the visible spectrum, high activation energy, and inefficient separation of photoexcited charge carriers. Experimental and theoretical studies are reported to engineer the bandgap of melon with highly reduced graphene oxide (HRG).

Energy Application of Graphene Based Membrane: Hydrogen Separation.

Hydrogen gas (H ) is a viable energy carrier that has the potential to replace the traditional fossil fuels and contribute to achieving zero net emissions, making it an attractive option for a hydrogen-based society. However, current H purification technologies are often limited by high energy consumption, and as a result, there is a growing demand for alternative techniques that offer higher H purity and energy efficiency. Membrane separation has emerged as a promising approach for obtaining high-purity H gas with low energy consumption.

Single Crystallization of CsPbBr Perovskite from Supersaturated Organic Solutions Optimized Through Solubility Studies.

We demonstrate the fabrication of millimeter-sized single crystals of 0D-CsPbBr grown in a supersaturated solution consisting of organic solvents without HBr (aq). One of the precursors, CsBr, was dissolved in ethylene glycol (EG) mixed with dimethyl sulfoxide, which is a good solvent for the other precursor, PbBr. At a solvent ratio of 20 vol % EG, the solubility of cesium bromide decreased and the title compound, CsPbBr, was selectively formed, whereas, with an EG ratio of 80 vol %, 3D-CsPbBr was formed.

Fast and selective production of quercetin and saccharides from rutin using microwave-assisted hydrothermal treatment in the presence of graphene oxide.

Rutin is a flavonoid glycoside, well-known for its antioxidant, anticarcinogenic, and cardioprotective properties. However, it exhibits lower bio absorptivity and bioactivity than its aglycon form, quercetin. Although liquid acid catalysts are conventionally utilized to obtain quercetin via rutin hydrolysis, the neutralization procedure is a major disadvantage owing to the added cost.

Light-Stimulated Luminescence Control of Lead Halide-Based Perovskite Nanocrystals Coupled with Photochromic Molecules via Electron and Energy Transfer.

Photoswitchable nanomaterials are key materials in the development of advanced imaging techniques, such as super-resolution fluorescence microscopy. The combination of perovskite CsPbBr nanocrystals (NCs) with bright photoluminescence (PL) emission and diarylethenes (DAEs) with structural changes in response to ultraviolet (UV) and visible light is a promising candidate system. Herein, CsPbBr NCs are coupled with photochromic DAE molecules to control the PL emission from the NCs by light stimulation.

Study on Sensing Mechanism of Volatile Organic Compounds Using Pt-Loaded ZnO Nanocrystals.

Understanding the surface chemistry of target gases on sensing materials is essential for designing high-performance gas sensors. Here, we report the effect of Pt-loading on the sensing of volatile organic compounds (VOCs) with ZnO gas sensors, demonstrated by diffuse reflection infrared Fourier transform (DRIFT) spectroscopy. Pt-loaded ZnO nanocrystals (NCs) of 13~22 nm are synthesized using the hot soap method.

Electrochemical Detection of Ethanol in Air Using Graphene Oxide Nanosheets Combined with Au-WO.

Detection, monitoring, and analysis of ethanol are important in various fields such as health care, food industries, and safety control. In this study, we report that a solid electrolyte gas sensor based on a proton-conducting membrane is promising for detecting ethanol in air. We focused on graphene oxide (GO) as a new solid electrolyte because it shows a high proton conductivity at room temperature.

Facile and Green Fabrication of Microwave-Assisted Reduced Graphene Oxide/Titanium Dioxide Nanocomposites as Photocatalysts for Rhodamine 6G Degradation.

Organic pollutants, such as synthetic dyes, are treated to prevent them from contaminating natural water sources. One of the treatment methods is advanced oxidation process using a photocatalyst material as the active agent. However, many photocatalysts are hindered by their production cost and efficiency.

Synergizing Sulfonated Hydrothermal Carbon and Microwave Irradiation for Intensified Esterification Reaction.

The synergy of sulfonated hydrothermal carbon and microwave (MW) irradiation was applied for the esterification of oleic acid with methanol (MeOH) to produce biodiesel. The effects of temperature, reaction time, ratio of oleic acid to methanol, and catalyst loading were investigated at a fixed MW power of 400 W. The addition of hexane, serving as a co-solvent and separator, was also investigated.

Biogasoline production from linoleic acid via catalytic cracking over nickel and copper-doped ZSM-5 catalysts.

Catalytic cracking of vegetable oil mainly processed over zeolites, and among all the zeolites particularly HZMS-5 has been investigated on wide range for renewable and clean gasoline production from various plant oils. Despite the fact that HZSM-5 offers a higher conversion degree and boost aromatics yield, the isomerate yield reduces due to high cracking activity and shape selectivity of HZSM-5. Hence, to overcome these problems, in this study the transition metals, such as nickel and copper doped over HZSM-5 were tested for its efficiencies to improve the isoparaffin compounds.

WO-Based Gas Sensors: Identifying Inherent Qualities and Understanding the Sensing Mechanism.

Semiconducting metal oxide-based gas sensors are an attractive option for a wide array of applications. In particular, sensors based on WO are promising for applications varying from indoor air quality to breath analysis. There is a great breadth of literature which examines how the sensing characteristics of WO can be tuned via changes in, for example, morphology or surface additives.

Role of alkan-1-ol solvents in the synthesis of yellow luminescent carbon quantum dots (CQDs): van der Waals force-caused aggregation and agglomeration.

Carbon quantum dots (CQDs; luminescent carbon nanoparticles, size < 10 nm) have attracted much attention with respect to their eco-friendliness and multi-functionality. The solvent-dependent photoluminescence of CQDs has been well investigated to optimize the synthesis process and homogeneous dispersion. Although some alkan-1-ol solvents, such as ethanol, have been well utilized empirically as good solvents when synthesizing highly photoluminescent CQDs, the role of alkan-1-ol solvents, particularly long-chain alkan-1-ols (, 1-nonanol, 1-decanol), has not yet been clarified.

Carbocatalysed hydrolytic cleaving of the glycosidic bond in fucoidan under microwave irradiation.

Biomass valorization involves breaking down naturally occurring long chain polysaccharides into their constituent monomers. The polysaccharide chain consists of monomers adjoined C (carbon)-O (oxygen) glycosidic linkages that are typically cleaved hydrolytic scission. In this study, we aimed to recover fucose from the polysaccharide fucoidan, which can be extracted from seaweed biomass.

Reversible ON/OFF switching of photoluminescence from CsPbX quantum dots coated with silica using photochromic diarylethene.

Highly luminescent silica-coated CsPbX3 quantum dots (QDs) with good photostability were synthesized and coupled with photochromic diarylethene to modulate the QDs' photoluminescence (PL). Upon successive UV and visible light irradiation, the PL emission from the silica-coated CsPbX3 QDs was repeatedly quenched and restored, demonstrating the promising feasibility of the QD/diarylethene-based photoswitches.

Synthesis of Cu₂O/CuO Nanocrystals and Their Application to H₂S Sensing.

Semiconducting metal oxide nanocrystals are an important class of materials that have versatile applications because of their useful properties and high stability. Here, we developed a simple route to synthesize nanocrystals (NCs) of copper oxides such as Cu₂O and CuO using a hot-soap method, and applied them to H₂S sensing. Cu₂O NCs were synthesized by simply heating a copper precursor in oleylamine in the presence of diol at 160 °C under an Ar flow.