Antioxidant Triggered Metallic 1T’ Phase Transformations of Chemically Exfoliated Tungsten Disulfide (WS₂) Nanosheets

Abstract

Developing facile methods for inducing phase transformation between metallic and semiconducting 2D transition metal dichalcogenide (TMDC) materials is crucial toward leveraging their use in cutting‐edge energy devices. Herein, 2H‐to‐1T’ phase transformations in chemically exfoliated Tungsten Disulfide (WS2) nanosheet films, triggered by antioxidants toward highly conductive 2D TMDC electrode materials, are introduced. It is found that antioxidants cause residual LiOx compounds to reduce to Li metal, subsequently inducing 1T’ phase transformations in layered WS2 nanosheets, resulting in significantly enhanced conductivity across the overall films. Both thermoelectric devices and supercapacitors are fabricated utilizing the highly conductive 1T’ phase WS2 nanosheet films as a working electrode, allowing for outstanding performance due to the increased conductivity of the WS2 nanosheet films. The method constitutes a facile approach toward the use of chemically exfoliated 1T’ TMDC nanosheets for highly efficient energy device applications.

Hydrothermal synthesis and controlled growth of group-VIB W metal compound nanostructures from tungsten oxide to tungsten disulphide

“…WO 3 is fully sulfided with sufficient S source, and excess NH 4+ ions intercalate between the S-W-S interlayer to generate 1T-WS 2 nanosheets. 8 However, the diffraction peak of WS 2(8:1) -240 °C was not found at 9.3°, which may be due to a phase transition by the interaction of cations with S. 53 Although the content of WS 15 The result indicated that the sample was pure WO 3 nanorods. In WS x O y(5:1) -180 °C, there were two new feature peaks located at 352 cm −1 and 418 cm −1 , reflecting the inplane E 1 2g and out-of-plane A 1g vibration peaks of WS 2 , respectively.…”

“…WO 3 is fully sulfided with sufficient S source, and excess NH 4+ ions intercalate between the S–W–S interlayer to generate 1T-WS 2 nanosheets. 8 However, the diffraction peak of WS 2(8:1) -240 °C was not found at 9.3°, which may be due to a phase transition by the interaction of cations with S. 53 Although the content of WS 2 spans directly from 0% to 100% as the S source increases, the process of vulcanization still occurred. The formation process of WS 2(10:1) -240 °C nanoflowers is described in detail (Fig.…”

Self-Healing Guar Gum-Based Nanocomposite Hydrogel Promotes Infected Wound Healing through Photothermal Antibacterial Therapy

“…Photothermal therapy (PTT) is an innovative antibacterial strategy that utilizes photothermal agents (PTAs) to convert laser energy into thermal energy . PTT can disrupt bacterial membranes, denature proteins, and lead to irreversible bacterial destruction. , PTT offers several advantages over traditional antibiotic therapy, including broad-spectrum antibacterial activity, remote controllability, targeting selectivity, rapid effectiveness, and less side effects. , Various materials with photothermal properties, such as noble-metal-based nanomaterials, carbon-based nanomaterials, semiconducting polymers, and photosensitive organic dyes, have been explored for PTT applications. − Noteworthily, some PTAs have limited photothermal capacity, high cost, and potential cytotoxicity . Therefore, the choice of PTAs could be essential for antibacterial and wound healing efficiency and biosafety.…”

Re Modulation of Metallic Ultrathin 2M-WS2 for Highly Efficient Hydrogen Evolution in Both Acidic and Alkaline Media

“…The metastable 2M-phase WS 2 with metallic nature exhibits enhanced catalytic activity, ,,, which is a promising TMD-based electrocatalyst for HER. However, it is metastable and is easily transformed into the thermodynamically more stable 2H phase with poor activity. − To address these issues, several effective strategies have been implemented to improve its stability, such as surface adsorption of functional groups − and cation insertion for electronic regulation. ,− However, these strategies cannot solve the phase degradation issue intrinsically, especially after exfoliation with an enhanced specific surface area.…”

“…32,36−39 The Jahn−Teller distortion of octahedral coordination in 1T-phase WS 2 will further cause the phase transition to form a triangular cluster stacking 1T″′ structure and a zigzag chain-like 1T′ structure (2M phase). 40−43 The metastable 2M-phase WS 2 with metallic nature exhibits enhanced catalytic activity, 40,42,44,45 which is a promising TMD-based electrocatalyst for HER. However, it is metastable and is easily transformed into the thermodynamically more stable 2H phase with poor activity.…”