Excellent Photothermal Performance Research Articles

Low-cost ZIF-67-modified fabrics with effective photothermal disinfection for antimicrobial personal protective equipment production

Aerosol-based transmission contributes to infection by various pathogens. Consequently, it is urgent to design antimicrobial personal protective equipment (PPE) and address the potential biological contamination of discarded PPE. We report a novel ZIF-67-modified PP fabric for photothermal disinfection; our work provides a fast, one-step, and low-cost preparation approach for incorporating zeolitic imidazolate framework (ZIF) nanoparticles (NPs) onto polypropylene (PP) fabric. First, we prepared ZIF-67-water NPs and ZIF-67-methanol NPs using relevant solvents and characterized them by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and field-emission scanning electron microscopy. We then used only ultrasonication to prepare ZIF-67-modified fabrics by incorporating ZIF-67 NPs onto PP fabric with a 0.5－1.5 mg/cm2 loading rate (18.5－40.5 wt%). The ZIF-67-modified fabrics were subjected to the same characterization, and then they were evaluated for photothermal performance, hydrophobicity and antimicrobial ability. The fabric of ZIF-67-water@PP-1.5 was selected to repurpose an antimicrobial mask. We demonstrated that the ZIF-67-modified fabrics have excellent photothermal performance with near-infrared (NIR) radiation and exhibit increased hydrophobicity, which is determined by the loading rate of ZIF-67 NPs. The surface temperature reached and maintained peak levels (70 °C and 90 °C) with NIR radiation, whilst the highest contact angle was over 140°. The photothermal behaviour could kill over 99.9% of gram-negative and gram-positive drug-resistant bacteria, whilst the haemolytic behaviour was less than 5%. The repurposed mask retained controllable photothermal properties. The application of these fabrics not only addresses the demand for affordable antimicrobial PPE but also contributes to reducing potential biochemical threats in discarded PPE.

Environmental-friendly biomass-based Janus ink/urushiol modified cotton fabric for efficient solar-driven interfacial evaporation

Much attention has been paid to the interfacial solar-thermal conversion method for water resource purification. According to the hydrophilicity of ink carbon particles and the amphiphilicity of urushiol molecules (the main compound of Chinese lacquer), a novel environmentally friendly biomass Janus ink/urushiol modified cotton fabric was successfully prepared and exhibited one hydrophilic side and one hydrophobic side through simple immersion and spraying treatments. The Janus fabric displayed excellent water transport behavior, mechanical stability, thermal conductivity, and photothermal conversion performance. Under one stimulated solar radiation, the temperature of the Janus fabric increased to 85 °C in 2 min. Additionally, a photothermal vapor device prepared using a polyethylene ring and the Janus fabric demonstrated a high conversion efficiency of 94.3% with an impressive evaporation rate of 1.64 kg m−2h−1, which was 3.35 times the rate of water evaporation in the absence of the modified fabric. The Janus fabric showed satisfactory resistance to ultraviolet radiation and pH values. After 8 cycles (every 10 h) of exposure to outdoor sunlight, the modified fabric showed a slightly decreased evaporation rate, which could be restored to the previous level by re-spraying ink on the modified fabric. In the concentrated salt solutions, the solar-driven evaporator displayed excellent salt rejection capacity. During the desalination of high-concentration saline water, the Janus fabric showed acceptable diurnal correspondence. After desalination, the water quality reached the required standards for drinking water. In particular, the B3+ content droppingto 0.33 mg L−1(below the thresholdof 0.5 mg L−1). The solar steam generator also showed remarkable purifying capabilities for wastewater containing heavy metals and organic dyes. The Janus ink/urushiol fabric, prepared in an easy way, has a wide range of applications in seawater desalination and sewage treatment, which can be applied for mitigation of freshwater crises and environmental remediation.

Transparent Liquid-like Slippery Coating with Excellent Photothermal Performance and Durability for Anti-/De-Icing Applications

Transparent Liquid-like Slippery Coating with Excellent Photothermal Performance and Durability for Anti-/De-Icing Applications

Superhydrophobic, flexible and high thermal stable ANFs/CNTs film for controllable light driven actuators

Superhydrophobic and light-responsive actuators (SLRAs) can be driven to move on water surface remotely and in a non-contact manner, and have shown promising applications in soft robotics, environmental protection, etc. It remains a big challenge to develop high performance SLRAs with excellent thermal stability, fast light responsivity and controllable motion. Here, we propose a layer-by-layer vacuum filtration method to prepare flexible, freestanding and superhydrophobic composite films composed of alternately deposited oleylamine modified acid carbon nanotubes (O-ACNTs) and aramid nanofibers (ANFs). The composite film has excellent thermal stability with the maximum weight loss rate temperature as high as 520 ℃. The closely packed structure and strong interlayer interaction ensure the surface stability and durability of the composite film. The composite film possesses excellent photothermal conversion performance, and can maintain the structure integrity without deformation when its surface temperature reaches 208 °C. When used as a self-propelled actuator, the SLRA film can response to the light quickly and move on the water surface, and the motion speed and direction can be controlled by adjusting the irradiation intensity and position. The outstanding thermal stability guarantees the stability and reliability of the self-propelled motions. The present study opens a new avenue to design high performance SLRAs.

A novel multifunctional magnetically recyclable BiOBr/ZnFe2O4-GO S-scheme ternary heterojunction: Photothermal synergistic catalysis under Vis/NIR light and NIR-driven photothermal detection of tetracycline

The threat of tetracycline (TC) to human health has become a significant issue that cannot be disregarded. Herein, in order to achieve effective degradation and high-sensitivity detection of TC, BiOBr/ZnFe2O4-GO (BOB/ZFO-GO) S-scheme heterojunction nanocomposites (NCs) have been prepared using hydrothermal method. GO with high light absorption capacity accelerated the electron transfer between BiOBr and ZnFe2O4 nanocrystals and extended the light absorption region of BOB/ZFO NCs. The optimal GO addition of BOB/ZFO-GO NCs could degrade TC solution of 10 mg/L in 80 min and have a high reaction rate constant (k) of 0.072 min−1 under visible/NIR light. According to calculations, the non-metal photocatalyst (BOB/ZFO-GO(2)) with the best degradation performance had a photothermal conversion efficiency of up to 23%. Meanwhile, BOB/ZFO-GO NCs could be recycled by magnetic field. The excellent photocatalytic and photothermal performance could be maintained even after several cycles. In addition, a photothermal detection sensor based on a photothermal material/specific recognition element/tetracycline sandwich-type structure was constructed for the trace detection of TC concentration with a detection limit as low as 10-4 ng/mL. This research provides a unique idea for the multi-functionalization of photocatalysts and has a wide range of potential applications for the identification and treatment of organic wastewater.

A droplet friction/solar-thermal hybrid power generation device for energy harvesting in both rainy and sunny weathers

Photovoltaic device is highly dependent on the weather, which is completely ineffective on rainy days. Therefore, it is very significant to design an all-weather power generation system that can utilize a variety of natural energy. This work develops a water droplet friction power generation (WDFG)/solar-thermal power generation (STG) hybrid system. The WDFG consists of two metal electrodes and a candle soot/polymer composite film, which also can be regarded as a capacitor. Thus, the capacitor coupled power generation (C-WDFG) device can achieve a sustainable and stable direct-current (DC) output under continuous dripping without external conversion circuits. A single device can produce an open-circuit voltage of ca.0.52 V and a short-circuit current of ca.0.06 mA, which can be further scaled up through series or parallel connection to drive commercial electronics. Moreover, we demonstrate that the C-WDFG is highly compatible with the thermoelectric device. The excellent photothermal performance of soot/polymer composite film can efficiently convert solar into heat, which is then converted to electricity by the thermoelectric device. Therefore, this C-WDFG/STG hybrid system can work in both rainy and sunny days.

Photothermal catalytic oxidation of toluene by perovskite oxide/biochar nanocomposite: Effect of biomass incorporation

The utilization of waste biomass for the development of full-spectrum response photothermal catalysts shows significant potential in catalytic oxidation of volatile organic compounds (VOCs). Herein, perovskite oxide LaCoO3/biomass-derived biochar nanocomposite was synthesized by the sol–gel method using wasted pomegranate peel as complex agent. The introduction of biomass resulted in improved dispersion of LaCoO3 particles and enhanced the adsorption of toluene attributed to the large specific surface area and rich functional groups of biochar. Furthermore, the biochar exhibited strong broadband absorption and efficient photo-thermal conversion under light illumination, which not only activated the lattice oxygen on the surface to react with toluene, but also increased the transmission rate of photogenerated charge carriers. The defects of LaCoO3 caused by carbon doping facilitated the circulation of oxygen species, leading to the generation of more reactive oxygen species. When the mass ratio of LaCoO3 to biomass was 1:0.6, the LaCoO3/biochar composite exhibited excellent photothermal catalytic performance with a T90 value of 270 °C (temperature at 90 % degradation) and displaying high stability. Moreover, In-situ DRIFTS analysis revealed that both adsorbed oxygen and lattice oxygen participated in the reaction with toluene, promoting the ring-opening reaction of toluene and subsequent conversion of intermediates.

Hydroxyl functionalized MWCNT nanofluids with excellent photothermal conversion performance in direct absorption solar collectors

Developing novel nanofluids with good stability, excellent photothermal conversion performance, and appropriate thermophysical properties is of great importance in promoting the practical utilization of nanofluids in solar collectors. In this work, hydroxyl multi-walled carbon nanotube (MWCNT-OH) nanofluids are proposed, which can achieve a high photothermal conversion of 88.2 % at a concentration of 20 ppm under 1-sun irradiation. Both the sedimentation experiment and spectrophotometer analysis prove that the prepared MWCNT-OH nanofluids have excellent stability. The influence of hydroxyl functionalization, MWCNT-OH concentrations, and temperature on the thermophysical and optical properties is analyzed. Moreover, the comparison between MWCNT-based nanofluids with different functionalization reported in the literature and our work is carried out, the results show that MWCNT-OH nanofluids in our work outperform MWCNT-based nanofluids with other types of functionalization reported in the literature. This work may promote the use of MWCNT-OH nanofluids as working fluids in solar collectors.

Hydrophobic organogel sorbent and its coated porous substrates for efficient oil/water emulsion separation and effective spilled oil remediation

Frequent offshore oil leakage accidents and large quantities of oily-wastewater produced in industry and daily life bring huge challenges to global water purification. The adaptability and stability of organogels as adsorbent materials have shown wide application prospects in the field of oil-water separation. Herein, the organogels displayed stable hydrophobic/lipophilic properties with high absorption ability (1200 wt./wt%), efficient sorption of multiple emulsions (>99.0%), and good reusability. More importantly, the organogels were successfully assembled with 2D/3D substrates to achieve excellent sorption capacity (102.5 g/g) and recycling performance (50 cycles). The gel-carbon black assembled on MS (GCB-MS) sorbent with excellent photothermal conversion performance, and can rapidly heat the surface to 70.4 °C under 1.0 sunlight radiation (1.0 kW/m2) and achieved an ultra-high sorption capacity of about 103 g/g for viscous crude oil. Meanwhile, the GCB-MS was combined with a pump to build continuous oil spill cleaning equipment to achieve a super-fast cleanup rate of 6.83 g/min. The developed hydrophobic organogels had been expanded unprecedentedly to realize the comprehensive treatment of oily-wastewater in complex environments, including layered oils, emulsions, and viscous crude oil spill, which provided an effective path for the comprehensive treatment of oily wastewater in complex environments.

Efficient antibiotic wastewater treatment via interfacial water evaporation based soot-coated conjugated microporous polymer hollow microspheres

Solar-driven interfacial evaporation (SDIE) technology holds the promise of purification and removal of organic pollutants from water samples. In this work, an efficient SDIE composed of multifunctional self-floating photothermal materials based on candle soot-coated conjugated microporous polymer hollow spheres (CS-CMPsHM) for treatment of tetracycline (TC) wastewater is reported. By depositing candle soot nanoparticles, CS-CMPsHM achieved excellent interfacial evaporation performance by extending the light absorption. Additionally, the π-π interaction between CMP's unique conjugated network and TC molecules and the well-developed porosity facilitates the capture of target contaminants. The synthesized CS-CMPsHM evaporator demonstrated remarkable properties, i.e., excellent photothermal performance (with superior photothermal conversion efficiency up to 94 % and evaporation rate of 1.55 kg m−2h−1 under one sun irradiation), extremely low wet thermal conductivity (0.075 W m-1K−1), reusability, superior salt resistance, stability, adsorption of pollutants and renewable performance. Furthermore, CS-CMPsHM remains its excellent purification performance from real water samples (the Yellow River) measured by a three-dimensional fluorescence spectrometer. The results of biological toxicity show that the purified water recovered by the SDIE method effectively reduced the phytotoxicity of TC. With its straightforward and scalable manufacturing process, our CS-CMPsHM demonstrates promising potential as advanced photothermal materials for the treatment of various pollutants using SDIE.

Integrated photothermal agents with fluorescence intensity ratio/lifetime dual-mode temperature sensing

Non-invasive photo-thermal therapy (PTT) has been proposed as a powerful method for cancer treatment, in which accurate temperature monitoring is necessary to prevent ineffective therapy or damage to normal cells during the process of PTT. This promotes the design and development of photothermal agents (PTAs) with real-time temperature control and excellent photothermal conversion. Here, the designed dual-function photothermal agents YVO4: Nd3+, Yb3+@IR-780 were obtained, while the temperature detection behavior based on the fluorescence intensity ratio (FIR) of Nd3+ (4F3/2 → 4I11/2) to Yb3+ (2F5/2 → 2F7/2) and the temperature-dependent Yb3+ lifetime were investigated in detail. The advantages of fluorescence lifetime thermometry in the biological field were confirmed by the internal temperature detection of pork tissue through comparison with fluorescence intensity ratio technology. The photo-thermal conversion efficiency of samples YVO4: Nd3+, Yb3+@IR-780 reached about 34.3% and its potential application was also evaluated by the sterilization of E. coli and S. aureus, which shows that IR-780 coated nano-materials have excellent photo-thermal conversion performance. Results illuminated that the present photothermal agents with temperature self-monitoring had a bright future in the process of photothermal therapy.

A humidity/thermal dual response 3D-fabric with porous poly(N-isopropyl acrylamide) hydrogel towards efficient atmospheric water harvesting

Atmospheric water harvesting is a promising approach for obtaining freshwater resources, but achieving high levels of light absorption, hygroscopic capacity, and desorption efficiency simultaneously remains a challenge. In this study, we developed an innovative atmospheric water harvester that incorporates a poly(N-isopropylacrylamide) hydrogel and a polydopamine/polypyrrole-modified 3D raised-fabric. The interlacing structure and polydopamine/polypyrrole synergistically enhance the harvester's photothermal conversion capability, while the hydrogel-modified raised-fabric with its increased pore structure and high specific surface area ensures effective contact between the internal adsorbent and external moisture, thereby improving moisture capture and storage capacity. Our results indicate that the hydrogel-modified 3D raised-fabric has excellent photothermal conversion performance, as evidenced by its rapid temperature rise to 75.9 °C under 1 sun light intensity, which effectively promotes water evaporation and harvesting. Furthermore, the 3D raised-fabric exhibits exceptional water absorption (3.1 g g−1, RH 90%) and water desorption (1.75 kg m-2h−1, 1 sun) properties. Overall, the 3D raised-fabric with its integrated photothermal, hygroscopic, and hydrophobic properties can effectively collect water under low humidity conditions, making it a promising solution for water scarcity issues.

Hierarchical metal-organic framework-functionalized PVDF tree-like nanofiber membrane for high-efficient photothermal membrane distillation

The development of membrane with strong sunlight absorption and high energy efficiency is the key to improve the water production efficiency in photothermal membrane distillation (PMD). In this paper, a hierarchical Cu-based metal–organic framework-functionalized polyvinylidene fluoride (PVDF) tree-like nanofiber membrane (Cu-CAT@TLNM-TLNMs) was developed for high-efficient PMD. The Cu-CAT@TLNM-TLNM was prepared by in-situ growth of Cu-CAT on the surface of PVDF tree-like nanofiber membrane (TLNM) as photothermal layer and PVDF TLNM as support layer, which exhibited excellent photothermal conversion performance, high energy utilization and high permeate flux. The PVDF TLNM with high specific surface area provided more active sites for the growth of Cu-CAT, thus forming a uniform Cu-CAT nanoarray. The spinous structure of the Cu-CAT photothermal layer can increase the length of the light-matter interaction and improve light absorption. In addition, the tree-like structure of the support layer with high porosity and small pore size can improve the permeate flux and long-term stability. Under the illumination of 1 kW·m−2, the surface temperature of the Cu-CAT@TLNM-TLNMs reached about 80 °C within 50 s, with a permeate flux of 1.37 kg·m−2·h−1, a salt rejection of >99.99 %, and a photothermal conversion efficiency of 76 %. More importantly, the permeate flux of the Cu-CAT@TLNM-TLNMs was still stable at 0.79 kg·m−2·h−1 with a salt rejection of >99.99 % after 84 h of continuous operation. This photothermal nanofiber composite membrane can be applied to solve the problem of freshwater shortage in areas where freshwater and fuel resources are scarce and solar energy is abundant.

Bio-derived 1T-MoS2/C-based aerogel by synergistic solar evaporation and tetracyclines removal for efficient freshwater generation

Tetracycline, a broad-spectrum antibiotic, has been widely used in disease treatment and other fields. However, due to the unreasonable use, tetracycline residue remains in water which eventually endangers human health. The green environmental protection, low-cost, and renewability biomass aerogel are highly attractive for the purification of tetracycline wastewater. Here, the flower-like 1T-MoS2 with S vacancies was uniformly grown on the supporting poplar catkin fibers-based biomass carbon matrix, which was constructed 3D porous aerogel by ice template method. The adsorption kinetics and adsorption isotherms model of MoS2/C-based aerogel for tetracycline in wastewater was investigated, revealing a maximum adsorption capacity of 124.4 mg g−1. More notably, the MoS2/C-based aerogel displayed excellent photothermal performance, which could synergistically raise the local temperature. The solar evaporation induced transpiration was able to accelerate the adsorption of tetracycline, owing to the endothermic behavior of tetracycline adsorption process. The MoS2/C-based aerogel attained an excellent water evaporation rate of 2.54 kg m−2 h−1 under one sun illumination, which is 11 times that of pure water. The solar purification prototype-based on MoS2/C-based aerogel could effectively remove tetracycline and generate freshwater. The freshwater production was about 33.6 kg m−2, and the tetracyclines were completed removed in the generation of condensed water on sunny days. The unique bifunctional capability of the MoS2/C-based aerogel paved a new strategy for tetracycline wastewater treatment and alleviated the dilemma of global water.

AuPt-Loaded Cu-Doped Polydopamine Nanocomposites with Multienzyme-Mimic Activities for Dual-Modal Imaging-Guided and Cuproptosis-Enhanced Photothermal/Nanocatalytic Therapy.

Nanocatalytic therapy (NCT) has made great achievements in tumor treatments due to its remarkable enzyme-like activities and high specificity. Nevertheless, the limited types of nanozymes and undesirable tumor microenvironments (TME) greatly weaken the therapeutic efficiency. Developing a combination therapy integrating NCT and other strategies is of great significance for optimal treatment outcomes. Herein, a AuPt-loaded Cu-doped polydopamine nanocomposite (AuPt@Cu-PDA) with multiple enzyme-like activities was rationally designed, which integrated photothermal therapy (PTT) and NCT. The peroxidase (POD)-like activity of AuPt@Cu-PDA can catalyze hydrogen peroxide (H2O2) into ·OH, and the catalase (CAT)-mimic activity can decompose H2O2 into O2 to alleviate hypoxia of TME, and O2 can be further converted into toxic ·O2- by its oxidase (OXD)-mimic activity. In addition, Cu2+ in AuPt@Cu-PDA can effectively consume GSH overexpressed in tumor cells. The boosting of reactive oxygen species (ROS) and glutathione (GSH) depletion can lead to severe oxidative stress, which can be enhanced by its excellent photothermal performance. Most importantly, the accumulation of Cu2+ can disrupt copper homeostasis, promote the aggregation of lipoylated dihydrolipoamide S-acetyltransferase (DLAT), disrupt the mitochondrial tricarboxylic acid (TCA) cycle, and finally result in cuproptosis. Collectively, photothermal and photoacoustic imaging (PTI/PAI)-guided cuproptosis-enhanced NCT/PTT can be achieved. This work may expand the application of nanozymes in synergistic therapy and provide new insights into cuproptosis-related therapeutic strategies.

Cu-hemin multilayer nanosheets with integration of peroxidase and photothermal properties for efficient synergistic sterilization

The increasing drug resistance of bacteria due to the inappropriate use of various antibiotics has become an ongoing public health problem around the world. In this work, a novel Cu-hemin nanosheet with multilayer structure was synthesized by a simple green method. Integrating the peroxidase properties of hemin with the excellent photothermal conversion performance of IR780, the as-prepared Cu-hemin@IR780 can not only effectively catalyze hydrogen peroxide to produce reactive oxygen species (ROS), but also has a highly efficient and stable photothermal effect for sterilization. The antibacterial efficiency against MRSA can reach up to 98.96% by using chemodynamic therapy (CDT) and photothermal therapy (PTT) for synergistic sterilization.

Thermal and electrical conductive 2D CuO evaporator for all-day steam generation

Solar energy-driven water evaporation is an effective way to obtain clean water through seawater desalination. Due to the day and night cycle, all-day steam generation is an urgent project. Here, 2D evaporators with effective heat management were designed and constructed by facile folding, in which superhydrophilic CuO coatings with honeycomb-like pores were in situ deposited on brass plates via electroplating and heat oxidation. In the daytime, the 2D evaporator has excellent photothermal performance due to the appropriate pore structure, light absorption, and water supply. The evaporation rate reaches 1.4 kg m−2 h−1, and the energy conversion efficiency of 93.5% under 1 sun in 3.5% artificial seawater for ten cycles. Except forsolar-driven water evaporation, some heat converts into electricity due to the temperature difference between the two surfaces of the high thermal conductive 2D evaporator. At night, steam is generated through the flexible photoelectric transition. The evaporation rate is 5.8 kg m−2 h−1 at an input voltage of 6 V. The stable evaporation performance of this evaporation system and the advantages of all-day steam generation show considerable prospects. It may be widely used in pure water production in the future.

Waterproof, Light Responsive, and Highly Sensitive Fabric Strain Sensor for Flexible Electronics.

Corrosion resistant, durable, and lightweight flexible strain sensor with multiple functionalities is an urgent demand for modern flexible wearable devices. However, currently developed wearable devices are still limited by poor environmental adaptability and functional singleness. In this work, a conductive fabric with multifunctionality in addition to sensing was successfully prepared by assembling zero dimensional silver nanoparticles (AgNPs) and one-dimensional carbon nanotubes (CNTs) layer by layer on the surface of the elastic polypropylene nonwoven fabric (named PACS fabric). Polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene (SEBS) added as binder materials favored strong interaction between conductive fillers and the fabric. Benefiting from the synergistic interaction among the conductive fillers with different dimensions and the fabric, the strain sensor based on the conductive fabric showed high sensitivity (GF up to 8064), wide detection range (0-200%), and excellent stability and durability (more than 10000 stretch-release cycles). Besides, the prepared conductive fabric showed superhydrophobicity (water contact angle = 154°) with excellent durability. This ensured the performance stability of the fabric sensor in harsh environments. At the same time, the fabric also showed excellent photothermal conversion performance (90 °C at a power density of 0.2 W/cm2 within 20 s). The PACS fabric strain sensor proved excellent performance and environmental adaptability, revealing great potential to be applied in human motion monitoring, self-cleaning, biomedicine, and other fields.

Versatile MXene composite probe-mediated homogeneous electrochemiluminescence biosensor with integrated signal transduction and near-infrared modulation strategy for concanavalin A detection.

Based on the highly specific interaction between concanavalin A (Con A) and glucose (Glu), a competitive electrochemiluminescence (ECL) biosensor was constructed for ultrasensitive detection of Con A. Nanocomposites with excellent electrocatalytic and photothermal properties were obtained by covalently bonding zinc oxide quantum dots (ZnO QDs) to vanadium carbide MXene (V2C MXene) surfaces. The modification of ZnO QDs hinders the aggregation of V2C MXene and increases the catalytic activity of oxygen reduction reaction, thus amplifying the luminol cathodic emission. In addition, the excellent photothermal performance of the V2C MXene-ZnO QDs can convert light energy into heat energy under the irradiation of 808 nm near infrared laser, thus increasing the temperature of the reaction system and accelerating the electron transfer process to realize the synergistic amplified homogeneous ECL system. This innovative work not only enriches the fundamental research on multifunctional MXene nanomaterials for biosensing, but also provides an effective strategy for ECL signal amplification.

In-situ twisted spiral fiber with tree-ring like structure for joule heating, photothermal and humidity sensing

Smart fibers are increasingly becoming an optimal material for producing the next generation of flexible wearable electronics. However, balancing practical functionality and comfort remains a major challenge at this stage. Herein, we have prepared a bacterial cellulose (BC)/MXene-30% composite fiber using an in-situ twisting method, as this fiber possessed excellent conductivity (4050 S/m) and mechanical strength (108 Mpa). In addition, this BC/MXene spiral fiber has excellent joule heating and photothermal performance, which can be rapidly heated up to 70 °C within 25 s under a low voltage of only 9 V. They also have a stable and repeatable light-induced heating capability under 250 W infrared light. This new fiber material has a simple preparation process and versatile functional characteristics, which broadens its application in the fields of intelligent hyperthermia, respiratory monitoring, water level warnings and so on. The BC/MXene spiral fiber exhibited in this work is expected to provide a powerful database and theoretical reference for the next generation of flexible wearable electronic products.