Rich-grain-boundary Ni-Co-Se nanowire arrays for fast charge storage in alkaline electrolyte

In this work, the one-dimensional (1D) Ni-Co-Se nanowire arrays with rich grain-boundaries were prepared through the solvothermal method and gas-phase selenizaiton. The results showed that the structure and crystallization of the Ni-Co-Se nanowire arrays could be modulated through the optimization of selenizaiton time. The optimal Ni-Co-Se electrode sample displayed an area specific capacitance of 242.6μAh cm-2at 30 mA cm-2with a current retention rate of 68.34%. The assembled Ni-Co-Se/Active carbon (AC) electrode-based asymmetric supercapacitor (ASC) showed the area specific capacitances of 329.2μAh cm-2and 225.8μAh cm-2at 3 mA cm-2and 30 mA cm-2, respectively. A 73.33% retention rate of capacitance was observed after 8000 charge/discharge cycles. Besides, the further fabricated all-solid ASC delivered the power densities of 342.94 W kg-1and 3441.33 W kg-1at the energy densities of 37.62 Wh kg-1and 25.81 Wh kg-1, respectively. Those results suggested the potentials of the obtained Ni-Co-Se nanowire arrays as electrode material for the high-performance pseudocapacitors.

Modulating Electronic Structure of PtCo-Ptrich Nanowires with Ru atoms for Boosted Hydrogen Evolution Catalysis

Rational design and development of highly efficient hydrogen evolution reaction (HER) electrocatalysts is of great significance for the development of green water electrolysis hydrogen production technology. Ru-engineered 1D PtCo-Ptrich nanowires (Ru-Ptrich Co NWs) are fabricated by a facile electrodeposition method. The rich Pt surface on 1D Pt3 Co contributes to the fully exposed active sites and enhanced intrinsic catalytic activity (co-engineered by Ru and Co atoms) for HER. The incorporation of Ru atoms can not only accelerate the water dissociation in alkaline condition to provide sufficient H* but also modulate the electronic structure of Pt to achieve optimized H* adsorption energy. As a result, Ru-Ptrich Co NWs have exhibited ultralow HER overpotentials (η) of 8 and 112 mV to achieve current densities of 10 and 100 mA cm-2 in 1 m KOH, respectively, which far exceed those of commercial Pt/C catalyst (η10  = 29 mV, η100  = 206 mV). Density functional theory (DFT) calculations further demonstrate that the incorporated Ru atoms possess strong water adsorption capacity (-0.52 vs -0.12 eV for Pt), facilitating water dissociation. The Pt atoms in the outermost Pt-rich skin of Ru-Ptrich Co NWs achieve optimized H* adsorption free energy (ΔGH* ) of -0.08 eV, boosting hydrogen generation.

Laser-assisted micropyramid patterned PDMS encapsulation of 1D tellurium nanowires on cellulose paper for highly sensitive strain sensor and its photodetection studies

This work demonstrates the fabrication of tellurium-nanowires (Te-NWs)/paper based device encapsulated using laser assisted mircopyramid patterned polydimethylsiloxane (PDMS) films. Although there are multiple reports published on 1D Te, most of them are limited to establishing its properties and studying its behavior as a sensor and research on the utilization of Te-NWs for physical sensors remain unexplored. Further, reports on p-type photodetectors also remain scarce. The fabricated Te-NWs/paper with micropyramid structured PDMS films encapsulation was used as a strain sensor, and it exhibited considerable improvement (∼60%) in sensitivity compared to smooth PDMS films. The gauge factor of the developed strain sensor was found to be ∼15.3. In addition, fabricated Te-NWs/paper device with contacts was used as a photodetector and it showed photoresponsivity of ∼22.5 mA W^-1and ∼14.5 mA W^-1in visible and NIR regions, respectively. Furthermore, the device exhibited long-term mechanical stability under harsh deformations. Fabricated 1D Te-NWs/paper device was utilized as a strain sensor to monitor the angular movements in the human body and successfully monitored various human motions, including wrist bending, finger knuckle, elbow joint, and knee joint. The successful demonstration of Te-NWs based physical sensors and utilization in broadband photodetectors opens avenues of research for tellurium based flexible and wearable devices.

Engineering Spiny PtFePd@PtFe/Pt Core@Multishell Nanowires with Enhanced Performance for Alcohol Electrooxidation

Engineering robust electrocatalysts is always a key point in direct alcohol fuel cells. Catalysts with a one-dimension (1D) structure are well studied and considered as promising candidates among various catalysts in the past decades; however, the precise regulation on the surface structure of 1D nanomaterials is still a worthy subject. By creatively introducing a trimetallic nanoalloy, core@multishell structure, and 1D nanowire (NW) morphology, we have constructed a kind of novel spiny PtFePd@PtFe/Pt core@multishell 1D NW catalysts with PtFePd as the core and PtFe/Pt as the multishell on the basis of improving catalytic property. The composition-optimized Pt₅FePd₂ 1D NWs display remarkable catalytic properties for ethanol oxidation reaction and methanol oxidation reaction, in which mass activities are 4.965 and 4.038 A mg^-1, 4.6 and 5.0 and 4.0 and 9.2-fold higher than Pt/C and Pd/C catalysts. Furthermore, the obtained Pt₅FePd₂ NWs can also retain favorable stability after durability tests. The unique core@multishell structure, spiny 1D NWs with many steps and kinks, and interior electronic and synergistic effect all contribute to the advanced catalytic performance. The present work has rationally designed the novel 1D PtFePd@PtFe/Pt core@multishell NW catalysts and offered a meaningful guideline for the designing of high-performance electrocatalysts.

Investigation of Self-Assembly and Charge-Transport Property of One-dimensional PDI₈-CN₂ Nanowires by Solvent-Vapor Annealing

One-dimensional (1D) nanowires have attracted great interest, while air-stable n-type 1D nanowires still remain scarce. Herein, we present solvent-vapor annealing (SVA) made nanowires based on perylene tetracarboxylic diimide (PDI) derivative. It was found that the spin-coated thin films reorganized into nanowires distributed all over the substrate, as a result of the following solvent-vapor annealing effect. Cooperating with the atomic force microscopy and fluorescence microscopy characterization, the PDI₈-CN₂ molecules were supposed to conduct a long-range and entire transport to form the 1D nanowires through the SVA process, which may guarantee its potential morphology tailoring ability. In addition, the nanowire-based transistors displayed air stable electron mobility reaching to 0.15 cm² V-1 s-1, attributing to effective in situ reassembly. Owing to the broader application of organic small-molecule nanowires, this work opens up an attractive approach for exploring new high-performance micro- and nanoelectronics.