Molybdenum

A University of Birmingham research team has developed a novel vibration-based technique for producing graphene and other 2D materials that achieves production rates over six times higher than current methods while functioning at concentrations up to 1000 mg mL⁻¹. The work demonstrates a sustainable approach that operates at room temperature without requiring toxic solvents.

The researchers employed a resonant acoustic mixing system that vibrates dispersions at frequencies of 60 Hz and accelerations up to 100g, delivering energy density two orders of magnitude lower than shear exfoliation. Using electron microscopy combined with multiphase computational models, the team revealed that vibrational motion causes graphite particles to fold at the edges, followed by particle fracture and sheet peeling. In the liquid phase, mechanical forces exceed the interlayer binding energy between layers, facilitating molecular-scale sheet delamination into atomically thin graphene.

Researchers from China's Jiangnan University and Dalian University of Technology have designed MoS₂/rGO nanoflowers as cathodes for aluminum-ion batteries (AIBs).

Aluminum-ion batteries (AIBs) show promise thanks to their high aluminum reserves, high theoretical specific capacity, and high safety. However, their actual capacity is far lower than the real capacity due to the limitation of cathode. The team's new strategy utilizes reduced graphene oxide-intercalated MoS₂ nanoflowers for AIB cathodes, via a hydrothermal method. This approach promoted the transition of MoS₂ crystal phase from 2H to 1 T, and the expansion of interlayer spacing from 0.62 nm to 1.03 nm, overcoming the shortcomings of slow electrochemical reaction kinetics and low capacity caused by the outstanding semiconductor properties of 2H MoS₂ and the compact interlayers. 

It is a known fact that animals require the integration of cues collected from multiple sensory organs to enhance the overall perceptual experience and thereby facilitate better decision-making in most aspects of life. However, despite the importance of multisensory integration in animals, the field of artificial intelligence (AI) and neuromorphic computing has primarily focused on processing unisensory information. This lack of emphasis on multisensory integration can be attributed to the absence of a miniaturized hardware platform capable of co-locating multiple sensing modalities and enabling in-sensor and near-sensor processing. 

a) A simplified abstraction of visual and chemical stimuli from male butterflies and visuo-chemical integration pathway in female butterflies. b) Butterfly-inspired neuromorphic hardware comprising of monolayer MoS₂ memtransistor-based visual afferent neuron, graphene-based chemoreceptor neuron, and MoS₂ memtransistor-based neuro-mimetic mating circuits. Image credit: Advanced Materials

In their recent study, researchers at Penn State University addressed this limitation by utilizing the chemo-sensing properties of graphene and the photo-sensing capability of monolayer molybdenum disulfide (MoS₂) to create a multisensory platform for visuochemical integration. 

Researchers at Penn State University recently developed an electronic “tongue” and an electronic “gustatory cortex” based on graphene ans MoS₂. The artificial tastebuds comprise tiny, graphene-based electronic sensors called chemitransistors that can detect gas or chemical molecules. The other part of the circuit uses memtransistors, which is a transistor that remembers past signals, made with molybdenum disulfide. This allowed the researchers to design an “electronic gustatory cortex” that connect a physiology-drive “hunger neuron,” psychology-driven “appetite neuron” and a “feeding circuit.”   

For instance, when detecting salt, or sodium chloride, the device senses sodium ions, explained Subir Ghosh, a doctoral student in engineering science and mechanics and co-author of the study. “This means the device can ‘taste’ salt,” Ghosh said. 

Researchers from the University of the Bundeswehr Munich & SENS Research Center and KTH Royal Institute of Technology recently demonstrated the noncontact and resist-free patterning of platinum diselenide (PtSe₂), molybdenum disulfide (MoS₂), and graphene layers with nanoscale precision at high processing speed while preserving the integrity of the surrounding material. 

The team used a commercial, off-the-shelf two-photon 3D printer to directly write patterns in the 2D materials with features down to 100 nm at a maximum writing speed of 50 mm/s. 

Researchers from the Indian Institute of Science have developed ultramicro-electrochemical capacitors with two-dimensional (2D) molybdenum disulphide (MoS₂) and graphene-based electrodes. The development has great potential for wearables and implantable electronics as well as for sensors and miniature “smart” technology. 

The miniature energy storage device uses graphene Flakes and MoS₂ alternately in each electrode - the cathode and anode. Gel was used as the electrolyte, which makes it possible to integrate micro-supercapacitors into chips. This would be difficult if not impossible with a water-soluble electrolyte. The capacitor showed a capacitance of 1.8 mF/cm² for a single-layer structure (graphene-MoS₂). The multilayer electrode structure, consisting of multiple alternating layers of graphene and molybdenum disulfide, gained 30 times greater capacitance, or 54 μF/cm^2.

An international team of researchers, including ones from Aalto University, Shanghai Jiao Tong University, Zhejiang University, Sichuan University,  Oregon State University, Yonsei University and the University of Cambridge, have designed a miniaturized spectrometer made of a ‘sandwich’ of different ingredients, including graphene, molybdenum disulfide, and tungsten diselenide. 

The spectrometer reportedly breaks all current resolution records, and does so in a much smaller package, thanks to computational programs and artificial intelligence. The new miniaturized devices could be used in a broad range of sectors, from checking the quality of food to analyzing starlight or detecting faint clues of life in outer space.

An international research group, including teams from CHOSE at the University of Rome Tor Vergata, Hellenic Mediterranean University in Greece and others, has developed a large-area perovskite solar panel with graphene-doped electron transporting layers (ETLs) and functionalized molybdenum disulfide (fMoS₂) buffer layers inserted between the perovskite layer and the hole transporting layer (HTL).

The team reported that with increasing temperatures, the module exhibited a smaller drop in open-circuit voltage than commercially available crystalline silicon panels.

Researchers from China's Tsinghua University and East China Normal University have created a transistor with the smallest gate length ever reported. This milestone was made possible by using graphene and molybdenum disulfide and stacking them into a staircase-like structure with two steps.

The structure of the side-wall transistor: Silicon dioxide base (dark blue), aluminum covered in aluminum oxide (brown ), the thin, light blue strip is graphene, the yellow and black strip is molybdenum disulfide, and underneath it, the hafnium dioxide.

On the higher step, there is the source, and on top of the lower step, there is the drain. Both are made of a titanium palladium alloy separated by the surface of the stairs, which is made of a single sheet of a molybdenum disulfide (MoS2), itself resting on a layer of hafnium dioxide that acts as an electrical insulator.

A Penn State-led international research team (led by Professor Huanyu Larry Cheng at Penn State) recently published two studies that could boost research and development of future motion detection, tactile sensing and health monitoring devices.

There are various substances that can be converted into carbon to create graphene through laser radiation, in a process called laser-induced graphene (LIG). The resulting product can have specific properties determined by the original material. The team set out to test this process and has reached interesting conclusions.