The rechargeable aluminum-ion battery (AIB) is a promising candidate for next-generation high-performance batteries, but its cathode materials require more development to improve their capacity and cycling life. We have demonstrated the growth of MoSe 2 three-dimensional helical nanorod arrays on a polyimide substrate by the deposition of Mo helical nanorod arrays followed by a low-temperature plasma-assisted selenization process to form novel cathodes for AIBs. The binder-free 3D MoSe 2 -based AIB shows a high specific capacity of 753 mAh g −1 at a current density of 0.3 A g −1 and can maintain a high specific capacity of 138 mAh g −1 at a current density of 5 A g −1 with 10 000 cycles. Ex situ Raman, XPS, and TEM characterization results of the electrodes under different states confirm the reversible alloying conversion and intercalation hybrid mechanism during the discharge and charge cycles. All possible chemical reactions were proposed by the electrochemical curves and characterization. Further exploratory works on interdigital flexible AIBs and stretchable AIBs were demonstrated, exhibiting a steady output capacity under different bending and stretching states. This method provides a controllable strategy for selenide nanostructure-based AIBs for use in future applications of energy-storage devices in flexible and wearable electronics.

Aluminum–sulfur batteries (ASBs) have attracted substantial interest due to their high theoretical specific energy density, low cost, and environmental friendliness, while the traditional sulfur cathode and ionic liquid have very fast capacity decay, limiting cycling performance because of the sluggishly electrochemical reaction and side reactions with the electrolyte. Herein, we demonstrate, for the first time, excellent rechargeable aluminum–selenium batteries (ASeBs) using a new deep eutectic solvent, thiourea-AlCl3, as an electrolyte and Se nanowires grown directly on a flexible carbon cloth substrate (Se NWs@CC) by a low-temperature selenization process as a cathode. Selenium (Se) is a chemical analogue of sulfur with higher electronic conductivity and lower ionization potential that can improve the battery kinetics on the sluggishly electrochemical reaction and the reduction of the polarization where the thiourea-AlCl3 electrolyte can stabilize the side reaction during the reversible conversion reaction of Al–Se alloying processes during the charge–discharge process, yielding a high specific capacity of 260 mAh g–1 at 50 mA g–1 and a long cycling life of 100 times with a high Coulombic efficiency of nearly 93% at 100 mA g–1. The working mechanism based on the reversible conversion reaction of the Al–Se alloying processes, confirmed by the ex situ Raman, XRD, and XPS measurements, was proposed. This work provides new insights into the development of rechargeable aluminum–chalcogenide (S, Se, and Te) batteries.

has attracted much attention and been extensively studied as the transistor [7] or photodetector devices. [8,9] However, the absorption of the incident light may be limited from the reduced atomic thickness of the MoS 2 . Meanwhile, plasmonic materials, especially the noble metals (e.g., platinum and gold), have been reported to facilitate the strong light-matter interaction and carrier transportation at the intimate interface of semiconductor-metal nanodomains. [10,11] Previous works have revealed the enhanced electromagnetic field and the light confinement effect by combining plasmonic metal nanostructures and 2D-based photodetectors, leading to the improvement of the light absorption under the visible spectral region. [12][13][14][15] Also, by applying metal particles with diverse morphologies such as nanoparticles, [16][17][18][19] nanotubes/ nanowires, [20,21] nanodiscs, [22][23][24] core-shell particles [25,26] and creating nanoarray patterns, [27][28][29] the resonance wavelength can be tunable. To achieve the better performance of photodetector on the MoS 2 layered material, we aim to combine highly absorptive CuInS 2 (CIS) nanoparticles with noble metal nanoparticles as the photosensitizer to enhance the intrinsic absorptivity of noble metal nanocrystals. The interests of noble nanocrystals such as platinum and gold are featured for their distinctive properties of the carrier transportation and the storage when combined with semiconductor materials. [30,31] The accompanying noble metal NPs induce an A facile approach for the synthesis of Au-and Pt-decorated CuInS 2 nanocrystals (CIS NCs) as sensitizer materials on the top of MoS 2 bilayers is demonstrated. A single surfactant (oleylamine) is used to prepare such heterostructured noble metal decorated CIS NCs from the pristine CIS. Such a feasible way to synthesize heterostructured noble metal decorated CIS NCs from the single surfactant can stimulate the development of the functionalized heterostructured NCs in large scale for practical applications such as solar cells and photodetectors. Photodetectors based on MoS 2 bilayers with the synthesized nanocrystals display enhanced photocurrent, almost 20-40 times higher responsivity and the On/Off ratio is enlarged one order of magnitude compared with the pristine MoS 2 bilayers-based photodetectors. Remarkably, by using Pt-or Au-decorated CIS NCs, the photocurrent enhancement of MoS 2 photodetectors can be tuned between blue (405 nm) to green (532 nm). The strategy described here acts as a perspective to significantly improve the performance of MoS 2 -based photodetectors with the controllable absorption wavelengths in the visible light range, showing the feasibility of the possible color detection.

Recently, extracting hot electrons from plasmonic nanostructures and utilizing them to enhance the optical quantum yield of two-dimensional transition-metal dichalcogenides (TMDs) have been topics of interest in the field of optoelectronic device applications, such as solar cells, light-emitting diodes, photodetectors, and so on. The coupling of plasmonic nanostructures with nanolayers of TMDs depends on the optical properties of the plasmonic materials, including radiation pattern, resonance strength, and hot electron injection efficiency. Herein, we demonstrate the augmented photodetection of a large-scale, transfer-free bilayer MoS2 by decorating this TMD with four different morphology-controlled plasmonic nanoparticles. This approach allows engineering the band gap of the bilayer MoS2 due to localized strain that stems up from plasmonic nanoparticles. In particular, the plasmonic strain blue shifts the band gap of bilayer MoS2 with 32 times enhanced photoresponse demonstrating immense hot electron injection. Besides, we observed the varied photoresponse of MoS2 bilayer hybridized with different morphology-controlled plasmonic nanostructures. Although hot electron injection was a substantial factor for photocurrent enhancement in hybrid plasmonic semiconductor devices, our investigations further show that other key factors such as highly directional plasmonic modes, high-aspect-ratio plasmonic nanostructures, and plasmonic strain-induced beneficial band structure modifications were crucial parameters for effective coupling of plasmons with excitons. As a result, our study sheds light on designing highly tailorable plasmonic nanoparticle-integrated transition-metal dichalcogenide-based optoelectronic devices.

High quality PtSe2 can be fabricated under 600 °C and has excellent NO2 sensitivity, which can reach sub ppb level.