Hydrophilic 1T-WS2 Nanosheet Arrays toward Conductive Textiles for High-Efficient and Continuous Hydroelectric Generation and Storage.

Flexible hydroelectric generators (HEGs) are promising self-powered devices that spontaneously derive electrical power from moisture. However, achieving the desired compatibility between a continuous operating voltage and superior current density remains a significant challenge. Herein, a textile-based van der Waals heterostructure is rationally designed between conductive 1T phase tungsten disulfide@carbonized silk (1T-WS2 @CSilk) and carbon black@cotton (CB@Cotton) fabrics with an asymmetric distribution of oxygen-containing functional groups, which enhances the proton concentration gradients toward high-performance wearable HEGs. The vertically staggered 1T-WS2 nanosheet arrays on the CSilk fabric provide abundant hydrophilic nanochannels for rapid carrier transport. Furthermore, the moisture-induced primary battery formed between the active aluminum (Al) electrode and the conductive textiles introduces the desired electric field to facilitate charge separation and compensate for the decreased streaming potential. These devices exhibit a power density of 21.6 µW cm-2 , an open-circuit voltage (Voc ) of 0.65 V sustained for over 10 000 s, and a current density of 0.17 mA cm-2 . This performance makes them capable of supplying power to commercial electronics and human respiratory monitoring. This study presents a promising strategy for the refined design of wearable electronics.

Vertical Phase-Engineering MoS2 Nanosheet-Enhanced Textiles for Efficient Moisture-Based Energy Generation.

Flexible moisture-electric generators (MEGs) capture chemical energy from atmospheric moisture for sustainable electricity, gaining attention in wearable electronics. However, challenges persist in the large-scale integration and miniaturization of MEGs for long-term, high-power output. Herein, a vertical heterogeneous phase-engineering MoS2 nanosheet structure based silk and cotton were rationally designed and successfully applied to construct wearable MEGs for moisture-energy conversion. The prepared METs exhibit ∼0.8 V open-circuit voltage, ∼0.27 mA/cm2 current density for >10 h, and >36.12 µW/cm2 peak output power density, 3 orders higher than current standards. And the large-scale device realizes a current output of 0.145 A. An internal phase gradient between the 2H semiconductor MoS2 in carbonized silks and 1T metallic MoS2 in cotton fibers enables a phase-engineering-based heterogeneous electric double layer functioning as an equivalent parallel circuit, leading to enhanced high-power output. Owing to their facile customization for seamless adaptation to the human body, we envision exciting possibilities for these wearable METs as integrated self-power sources, enabling real-time monitoring of physiological parameters in wearable electronics.

MXene-Decorated Smart Textiles with the Desired Mid-Infrared Emissivity for Passive Personal Thermal Management.

Multifunctional and long-term stable wearable heating systems have attracted extensive attention from experts, yet smart textiles that only rely on harvesting the body's heat without additional energy still face huge challenges in practical applications. Herein, we rationally prepared the monolayer MXene Ti3C2Tx nanosheets via an in situ hydrofluoric acid generation method, which was further employed to construct a wearable heating system of MXene @ polyester polyurethane blend fabrics (MP textile) for the passive personal thermal management through a simple spraying process. Owing to the unique two-dimensional (2D) structure, the MP textile presents the desired mid-infrared emissivity, which could efficiently suppress the thermal radiation loss from the human body. Notably, the MP textile with an MXene concentration of 28 mg/mL exhibits a low mid-infrared emissivity of 19.53% at 7-14 µm. Significantly, these prepared MP textiles demonstrate an enhanced temperature of more than 6.83 °C compared with those of favorably traditional fabrics, involving the black polyester fabric, pristine polyester polyurethane blend fabric (PU/PET), and cotton, suggesting a charming indoor passive radiative heating performance. The temperature of real human skin covered by MP textile is 2.68 °C higher than that covered by cotton fabric. Impressively, these prepared MP textiles simultaneously possess attractive breathability, moisture permeability, mechanical strength, and washability, which provide new insight into human body temperature regulation and physical health.

Organic Charge-Transfer Cocrystals toward Large-Area Nanofiber Membrane for Photothermal Conversion and Imaging.

Organic photothermal materials integrating a high-efficiency light-heat conversion effect and high flexibility have generated immense interest in fundamental research and practical applications. Nevertheless, their practical applications still remain a challenge, owing to the complicated design, tedious synthesis, and limited programmable substrates. Herein, an organic charge-transfer cocrystal with a narrow energy gap of 0.33 eV and a high photothermal conversion efficiency (PCE) of 69.3% was rationally designed and synthesized via a facile self-assembly process, which was introduced into polyurethane for forming a large-area photothermal nanofiber membrane via electrospinning technology. Femtosecond transient absorption spectroscopy elucidates that the excellent PCE is attributed to the nonradiation transition process, including internal conversion and charge dissociation processes. Furthermore, the temperature of the as-prepared photothermal nanofiber membrane could quickly rise to 52 °C under laser irradiation with a power density of 0.183 W/cm2, suggesting a high PCE of 53.7%. This work successfully achieves the fabrication of a large-area photothermal membrane and the development of photothermal imaging.

Smart Textiles Based on MoS2 Hollow Nanospheres for Personal Thermal Management.

Two-dimensional transition metal dichalcogenides are of particular interest in high-performance photothermal conversion, yet there remains a huge challenge in their practical application in smart textiles for healthcare, energy, and personal protection. Herein, we controllably prepared MoS2 hollow nanospheres with a high photothermal conversion efficiency of 36% via a microemulsion-hydrothermal method, which was further applied to construct photothermal fibers for personal thermal management after a hot-blast dip-drying process. Because of the prominent photothermal effect, the temperature of the photothermal fibers sharply increases from the room temperature value of 25.0 to 55.5 °C in 60 s under near-infrared illumination with a power density of 500 W/cm2. Furthermore, the photothermal fiber pad demonstrated an obvious temperature enhancement of 38.0 °C from a skin temperature of 22.0 °C after it was irradiated by natural sunlight for 60 s. Significantly, the antibacterial elimination rates of the photothermal fibers for Escherichia coli and Staphylococcus aureus are ∼99.9 and ∼99.8%, respectively. This strategy affords an avenue toward the practical application of photothermal materials in smart fibers for personal thermoregulation.