Recent Advances in Engineering of 2D Layered Metal Chalcogenides for Resistive-Type Gas Sensor.

2D nanomaterials have triggered widespread attention in sensing applications. Especially for 2D layered metal chalcogenides (LMCs), the unique semiconducting properties and high surface area endow them with great potential for gas sensors. The assembly of 2D LMCs with guest species is an effective functionalization method to produce the synergistic effects of hybridization for greatly enhancing the gas-sensing properties.

Enhanced oxygen anions generation on BiS/SbS heterostructure by visible light for trace HS detection at room temperature.

Bismuth sulfide (BiS) possesses unique properties that make it a promising material for effective hydrogen sulfide (HS) detection at room temperature. However, when exposed to light, the oxygen anions (O) adsorbed on the surface of BiS can react with photoinduced holes, ultimately reducing the ability to respond to HS. In this study, BiS/SbS heterostructures were synthesized, producing photoinduced oxygen anions (O) under visible light conditions, resulting in enhanced HS sensing capability.

Femtosecond Laser-Driven Phase Engineering of WS for Nano-Periodic Phase Patterning and Sub-ppm Ammonia Gas Sensing.

Laser-driven phase transition of 2D transition metal dichalcogenides has attracted much attention due to its high flexibility and rapidity. However, there are some limitations during the laser irradiation process, especially the unsatisfied surface ablation, the inability of nanoscale phase patterning, and the unexploited physical properties of new phase. In this work, the well-controlled femtosecond (fs) laser-driven transformation from the metallic 2M-WS to the semiconducting 2H-WS is reported, which is confirmed to be a single-crystal to single-crystal transition without layer thinning or obvious ablation.

Synergy of S-vacancy and heterostructure in BiOCl/BiS boosting room-temperature NO sensing.

The special physicochemical properties of BiS nanomaterial endow it to be exceptional NO sensing properties. However, sensors based on pure BiS cannot detect trace NO at room temperature effectively due to the scanty active sites and poor charge transfer efficiency. Herein, vacancy defect and heterostructure engineering are rationally integrated to explore BiOCl/BiS heterostructure with rich S vacancies to enhance NO sensing performance.

Targeting tumor energy metabolism via simultaneous inhibition of mitochondrial respiration and glycolysis using biodegradable hydroxyapatite nanorods.

Tumor cells obtain energy supply from the unique metabolic pathways of mitochondrial respiration and glycolysis, which can be used interchangeably to produce adenosine triphosphate (ATP) for survival. To simultaneously block the two metabolic pathways and sharply cut off ATP supply, a multifunctional "nanoenabled energy interrupter" (called as HNHA-GC) was prepared by attaching glucose oxidase (GOx), hyaluronic acid (HA), and 10-hydroxycamptothecin (CPT) on the surface of degradable hydroxyapatite (NHA) nanorods. After targeted delivery of HNHA-GC to the tumor site by HA, the tumor-selective acid degradation of HNHA-GC as well as the subsequent deliveries of Ca, drug CPT, and GOx take place.

Boosting room-temperature NO detection via in-situ interfacial engineering on AgS/SnS heterostructures.

The effective detection of hazardous gases has become extremely necessary for the ecological environment and public health. Interfacial engineering plays an indispensable role in the development of innovative materials with exceptional properties, thus triggering a new revolution in the realization of high-performance gas sensing. Herein, the rational designed AgS/SnS heterostructures were synthesized via a facile in-situ cation-exchange method.

Construction of Z-scheme heterojunction by coupling BiSnO and BiOBr with abundant oxygen vacancies: Enhanced photodegradation performance and mechanism insight.

Promoting charge migration and enhancing redox ability of photogenerated carriers are important for the development of highly efficient semiconductor-based photocatalyst. Here, BiOBr/BiSnO heterojunction with oxygen vacancies (OVs) was constructed by homogeneously depositing BiSnO nanoparticles on the Vo-BiOBr surface. The experimental results manifested that Vo-BiOBr/BiSnO displayed better performance for rhodamine B, ciprofloxacin, and tetracycline degradation than counterparts without OVs.

Increased Active Sites and Charge Transfer in the SnS/TiO Heterostructure for Visible-Light-Assisted NO Sensing.

Tin disulfide (SnS) has been extensively researched as a promising sensing material due to its large electronegativity, suitable band gap, earth abundance, and nontoxicity. However, the poor conductivity and slow response/recovery speed at room temperature greatly hinder its application in high-performance practical gas sensors. Herein, to promote the study of SnS-based gas sensors, a hierarchical SnS/TiO heterostructure was synthesized and used as a sensing material to detect NO with the help of light illumination.

Synergically engineering defect and interlayer in SnS for enhanced room-temperature NO sensing.

Defect and interlayer engineering are considered as two promising strategies to alter the electronic structures of sensing materials for improved gas sensing properties. Herein, ethylene glycol intercalated Al-doped SnS (EG-Al-SnS) featuring Al doping, sulfur (S) vacancies, and an expanded interlayer spacing was prepared and developed as an active NO sensing material. Compared to the pristine SnS with failure in detecting NO at room temperature, the developed EG-Al-SnS exhibited a better conductivity, which was beneficial for realizing the room-temperature NO sensing.

Boosted charge transfer in dual Z-scheme BiVO@ZnInS/BiSnO heterojunctions: Towards superior photocatalytic properties for organic pollutant degradation.

A core-shell structured dual Z-scheme ternary photocatalyst BiVO@ZnInS/BiSnO was fabricated via hydrothermal and heat-circumfluence strategy. With ZnInS serving as a bridge to connect BiVO and BiSnO, the developed ternary catalyst displayed boosted charge transfer and spatial separation capabilities. The effect of mass ratios of BiVO@ZnInS and BiSnO on photodegradation efficiency under visible light irradiation was explored.

Engineering SnO nanorods/ethylenediamine-modified graphene heterojunctions with selective adsorption and electronic structure modulation for ultrasensitive room-temperature NO detection.

Ever-increasing concerns over air quality and the newly emerged internet of things (IoT) for future environmental monitoring are stimulating the development of ultrasensitive room-temperature gas sensors, especially for nitrogen dioxide (NO), one of the most harmful air pollution species released round-the-clock from power plants and vehicle exhausts. Herein, tin dioxide nanorods/ethylenediamine-modified reduced graphene oxide (SnO/EDA-rGO) heterojunctions with selective adsorption and electronic structure modulation were engineered for highly sensitive and selective detection of NO at room temperature. The modified EDA groups not only enable selective adsorption to significantly enrich NO molecules around the interface but also realize a favorable modulation of SnO/EDA-rGO electronic structure by increasing the Fermi level of rGO, through which the sensing performance of NO is synergistically enhanced.

2D/2D heterojunction of g-CN/SnS: room-temperature sensing material for ultrasensitive and rapid-recoverable NO detection.

Heterojunction engineering plays an indispensable role in improving gas-sensing performance. However, rational heterojunction engineering to achieve room-temperature NO sensing with both high response and rapid recovery is still a challenge. Herein, a 2D/2D heterojunction of g-CN/SnS is designed to improve the sensing performance of SnS and used for ultrasensitive and rapid-recoverable NO detection at room temperature.

SnS/SnS p-n heterojunctions with an accumulation layer for ultrasensitive room-temperature NO detection.

The unique features of SnS make it a sensitive material ideal for preparing high-performance nitrogen dioxide (NO) gas sensors. However, sensors based on pristine tin disulfide (SnS) fail to work at room temperature (RT) owing to their poor intrinsic conductivity and weak adsorptivity toward the target gas, thereby impeding their wide application. Herein, an ultrasensitive and fully recoverable room-temperature NO gas sensor based on SnS/SnS p-n heterojunctions with an accumulation layer was fabricated.

Hierarchical SnS/SnO nanoheterojunctions with increased active-sites and charge transfer for ultrasensitive NO detection.

SnS2 nanosheets with unique properties are excellent candidate materials for fabricating high-performance NO2 gas sensors. However, serious restacking and aggregation during sensor fabrication have greatly impacted the sensing response. In this study, flower-like hierarchical SnS2 was prepared by a simple microwave method and partially thermally oxidized to form hierarchical SnS2/SnO2 nanocomposites to further improve the sensing performance at low operating temperature.

Selective deposition of organic molecules onto DPPC templates--a molecular dynamics study.

The site-selective deposition of organic molecules onto template structures to create ordered micro/nanoscale arrangements has drawn more and more attention because of the broad possibility, for example, application in organic electronic devices. Here we present a molecular dynamics study toward the selective deposition of organic molecules 3(5)-(9-anthryl) pyrazole (ANP), perylene and sexiphenyl (6P) onto template structures made of the phospholipid L-α-dipalmitoyl-phosphatidylcholine (DPPC) in alternating liquid expanded (LE) and liquid condensed (LC) states. The simulation results indicate, first of all, that the molecules immerge into both LE and LC phases instead of staying on top of them.

Fabrication of split-ring resonators by tilted nanoimprint lithography.

An efficient fabrication technique for large area periodic metallic split-ring arrays has been demonstrated by the combination of tilted nanoimprint lithography and nanotransfer imprinting. The feature size of the split-rings can be adjusted by varying the key geometry parameters of the original imprinting mold. Due to the flexible nature of PDMS molds, these arrays can be patterned on curved surfaces.

Tuning the intensity of metal-enhanced fluorescence by engineering silver nanoparticle arrays.

It is demonstrated that silver nanoparticle (SNP) arrays fabricated by combining nanoimprint lithography and electrochemical deposition methods can be used as substrates for metal-enhanced fluorescence, which is widely used in optics, sensitive detection, and bioimaging. The method presented here is simple and efficient at controlling the nanoparticle density and interparticle distance within one array. Furthermore, it is found that the fluorescence intensity can be tuned by engineering the feature size of the SNP arrays.

Creating bicolor patterns via selective photobleaching with a single dye species.

Bicolor fluorescent pattern in thin polymer film is fabricated via a photobleaching process. Dye molecules exhibit monomer emission when they are dispersed inside the polymer and aggregate emission when they are on the surface of the polymer. Thus, a mixed emission of monomer and aggregate can be obtained by evaporating a single dye species on the polymer film.

Fabrication of multicolor patterns with a single dye species on a polymer surface.

Multicolored patterns can be fabricated by evaporating a single dye species on a prepatterned polymer substrate. The ratios of dye to polymer are different on protrusion and recess areas of the prepatterned surface, which can result in different aggregates and emissions. The polymer substrate was prepatterned using nanoimprint lithography (NIL) without any further process.

Site-selective patterning of organic luminescent molecules via gas phase deposition.

In this paper, we present a bottom-up approach to pattern organic luminescent molecules with a feature size down to sub-100 nm over wafer-sized areas. This method is based on the selective gas deposition of organic molecules on self-organized patterned structures, which consist of an organic monolayer with two different phases rather than different materials. The site selectivity is controllable by deposition rate and the pattern features.