Stabilizing Polyoxometalate for Enhanced OER Performance Using a Porous Manganese Oxide Support.

The oxygen evolution reaction (OER) is a critical challenge in electrocatalytic water splitting, hindered by high energy demands and slow kinetics. Polyoxometalates (POMs), recognized for their unique redox capabilities, structural archetypes, and molecular precision, are promising candidates for the oxygen evolution reaction (OER). Yet, their application is hindered by high water solubility, causing rapid degradation and efficiency loss under harsh OER conditions.

Potassium hydroxide treatment of layered WSe with enhanced electronic performances.

2D WSe-based electronic devices have received much research interest. However, it is still a challenge to achieve high electronic performance in WSe-based devices. In this work, we report greatly enhanced performances of different thickness WSe ambipolar transistors and demonstrate homogeneous WSe inverter devices, which are obtained by using a semiconductor processing-compatible layer removal technique chemical removal of the surface top WO layer formed by O plasma treatment.

Synthesis and Electrocatalytic Applications of Layer-Structured Metal Chalcogenides Composites.

Featured with the attractive properties such as large surface area, unique atomic layer thickness, excellent electronic conductivity, and superior catalytic activity, layered metal chalcogenides (LMCs) have received considerable research attention in electrocatalytic applications. In this review, the approaches developed to synthesize LMCs-based electrocatalysts are summarized. Recent progress in LMCs-based composites for electrochemical energy conversion applications including oxygen reduction reaction, carbon dioxide reduction reaction, oxygen evolution reaction, hydrogen evolution reaction, overall water splitting, and nitrogen reduction reaction is reviewed, and the potential opportunities and practical obstacles for the development of LMCs-based composites as high-performing active substances for electrocatalytic applications are also discussed.

Liquid-phase catalyst pre-seeding for controlled growth of layered MoS films over a large area chemical vapor deposition.

We introduce an innovative method that facilitates precise control of high-quality molybdenum disulfide (MoS) growth, extending up to three layers, on a large scale. This scalable growth is realized by employing solution-based catalysts and precursors in conjunction with chemical vapor deposition (CVD). The catalyst not only diminishes the precursor's activation energy and melting temperature but also augments the overall reaction rate.

Transferring 2D TMDs through water-soluble sodium salt catalytic layer.

This study reports a clean and damage-free transfer method that enables the ultrafast transfer of two-dimensional (2D) transition metal dichalcogenides (TMDs) onto desired substrates with a remarkably high yield. We employ a water-soluble sodium salt as both a transfer sacrificial layer for facile transfer and a catalytic layer for the growth of high-quality large-area MoSusing liquid-phase chemical vapor deposition via a catalyzed kinetic growth. We show that the pristine structural and electrical properties of the grown MoScan be reliably preserved by avoiding detrimental effects during the prolonged harsh-environment transfer process.

High-Performance Flexible Energy Storage Devices Based on Graphene Decorated with Flower-Shaped MoS Heterostructures.

MoS, owing to its advantages of having a sheet-like structure, high electrical conductivity, and benign environmental nature, has emerged as a candidate of choice for electrodes of next-generation supercapacitors. Its widespread use is offset, however, by its low energy density and poor durability. In this study, to overcome these limitations, flower-shaped MoS/graphene heterostructures have been deployed as electrode materials on flexible substrates.

Interfacial Microenvironment Modulation Enhancing Catalytic Kinetics of Binary Metal Sulfides Heterostructures for Advanced Water Splitting Electrocatalysts.

Interfacial microenvironment modulation has been proven to be a promising route to fabricate highly efficient catalysts. In this work, the lattice defect-rich NiS /MoS nanoflakes (NMS NFs) electrocatalysts are successfully synthesized by a simple strategy. Benefiting from the abundant lattice defects and modulated interfacial microenvironment between NiS and MoS , the prepared NMS NFs show superior catalytic activity for water splitting.

Flexible Supercapacitor-Type Rectifier-free Self-Charging Power Unit Based on a Multifunctional Polyvinylidene Fluoride-ZnO-rGO Piezoelectric Matrix.

The development of an effective mechanical to electrical energy conversion device and its functional integration with an energy storage device for self-powered portable gadgets are cutting-edge research fields. However, the generated power and the mechanical stability of these integrated devices are still not efficient to power up portable electronics. We fabricated a rectifier-free piezoelectric nanogenerator (NG) integrated with a supercapacitor (SC).

Synthesis and Enhanced Photocatalytic Activity of Porous SrTiO₃/TiO₂ Composites.

Porous photocatalysts have attracted significant attention for their large specific surface area, numerous surface catalytic active sites, and high photocatalytic activity. In this study, porous SrTiO₃/TiO₂ composites were successfully fabricated through a hydrothermal approach utilizing porous TiO₂ as a substrate. The as-synthesized SrTiO₃/TiO₂ composites were then characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy, Brunauer-Emmett-Teller (BET), and ultraviolet-visible spectroscopy (UV-Vis) analysis.

Ultrahigh Output Piezoelectric and Triboelectric Hybrid Nanogenerators Based on ZnO Nanoflakes/Polydimethylsiloxane Composite Films.

We demonstrated a hybrid nanogenerator (NG) exploiting both piezoelectric and triboelectric effects induced from ZnO nanoflakes (NFs)/polydimethylsiloxane (PDMS) composite films through a facile, cost-effective fabrication method. This hybrid NG exhibited not only high piezoelectric output current owing to the enhanced surface piezoelectricity of the ZnO NFs but also high triboelectric output voltage owing to the pronounced triboelectrification of Au-PDMS contact, producing a peak-to-peak output voltage of ∼470 V, a current density of ∼60 μA·cm, and an average power density of ∼28.2 mW·cm.

Poly(dimethylsiloxane)/ZnO Nanoflakes/Three-Dimensional Graphene Heterostructures for High-Performance Flexible Energy Harvesters with Simultaneous Piezoelectric and Triboelectric Generation.

Herein, we report the successful synthesis of poly(dimethylsiloxane)/ZnO nanoflakes/three-dimensional graphene (PDMS/ZnO NFs/3D Gr) heterostructures using Ni foams as the template substrate via a facile route, while adapting a rational material design for a high-performance energy-harvester application. The PDMS/ZnO NFs/3D Gr heterostructure-based hybrid energy harvester simultaneously exploits the piezoelectric effect and triboelectrification and shows peak-to-peak output voltages up to 122 V and peak-to-peak current densities up to 51 μA cm, resulting in an ultrahigh power density of 6.22 mW cm.

Large-Area High-Quality AB-Stacked Bilayer Graphene on h-BN/Pt Foil by Chemical Vapor Deposition.

Large-area, high-quality bilayer graphene (BLG) has attracted great interest because of its immense potential for many viable applications. However, its growth is still greatly limited owing to its small size and low carrier mobility. In this article, we report the successful growth of large-area, high-quality AB-stacked BLG on hexagonal boron nitride (h-BN)/Pt foil by chemical vapor deposition (CVD).

Growth of Graphene/h-BN Heterostructures on Recyclable Pt Foils by One-Batch Chemical Vapor Deposition.

High-quality large-area graphene/h-BN vertical heterostructures are promising building blocks for many viable applications such as energy harvesting/conversion, electronics and optoelectronics. Here, we successfully grew high-quality large-area graphene/h-BN vertical heterostructures on Pt foils by one-batch low-pressure chemical vapor deposition (LPCVD). We obtained the high quality of about 200-µm-wide graphene/h-BN film having uniform layer thickness.

PMMA-Etching-Free Transfer of Wafer-scale Chemical Vapor Deposition Two-dimensional Atomic Crystal by a Water Soluble Polyvinyl Alcohol Polymer Method.

We have explored a facile technique to transfer large area 2-Dimensional (2D) materials grown by chemical vapor deposition method onto various substrates by adding a water-soluble Polyvinyl Alcohol (PVA) layer between the polymethyl-methacrylate (PMMA) and the 2D material film. This technique not only allows the effective transfer to an arbitrary target substrate with a high degree of freedom, but also avoids PMMA etching thereby maintaining the high quality of the transferred 2D materials with minimum contamination. We applied this method to transfer various 2D materials grown on different rigid substrates of general interest, such as graphene on copper foil, h-BN on platinum and MoS2 on SiO2/Si.