Facile Vacuum Filtration Method Research Articles

Enhanced heterogeneous Electro-Fenton catalysis using CNT/MoS2/FeCo-LDH cathode membranes for efficient phenol removal from wastewater

Herein, we innovatively crafted a novel CNT/MoS2/FeCo-LDH cathode membrane using a facile vacuum filtration method. Benefiting from the unique heterostructure between FeCo-LDH and MoS2, the prepared CNT/MoS2/FeCo-LDH cathode membranes catalyzed the production of high-concentration H2O2 (7.59 mg/L) at a low current density of 1.50 mA/cm2. The peak degradation efficiency of phenol (98.80%) was reached in only 60 min. Under optimized operating conditions, the phenol removal rate of the CNT/MoS2/FeCo-LDH cathode membrane remained above 80.00% within a wide pH range (3.0–9.0), demonstrating excellent adaptability. The synergistic incorporation of Mo, Fe, and Co ions facilitated additional chemical reaction pathways for Fenton-like reactions, thereby significantly enhancing hydrogen peroxide production. Notably, our approach exhibited moderate total organic carbon degradation efficiency, even for the actual pretreatment of coking wastewater, presenting a promising strategy for addressing recalcitrant industrial wastewater.

Asymmetric sandwiched nanofibrillated cellulose composites prepared by one-pot vacuum filtration for ultrahigh electromagnetic interference shielding

High-efficiency electromagnetic interference (EMI) shielding composite films (EMI shielding effectiveness (SE) value > 100 dB) with a small thickness are imminently desired for eliminating the serious electromagnetic wave pollution. Herein, asymmetric sandwiched silver-coated four-needle zinc oxide whisker/nanofibrillated cellulose/Ti3C2Tx (F-ZnO&Ag/NFC/Ti3C2Tx) composite films consisting of the loose F-ZnO&Ag sedimentary layer and compact upper Ti3C2Tx layer were successful fabricated by a facile one-pot vacuum filtration method in combination with gravity-induced delamination. Arising from the favorable electrical conductivity and unique asymmetric sandwich structure, electromagnetic waves can be trapped and dissipated in the F-ZnO&Ag skeletons and strongly multiply reflected between top Ti3C2Tx layer and bottom F-ZnO&Ag layers. Thereby, F-ZnO&Ag/NFC/Ti3C2Tx-30.4 exhibits the ultrahigh averaged EMI SET of 103.9 dB (the maximal value of 123.8 dB) at a low thickness of merely 209 μm, which is far superior to that of almost all the reported NFC composites at the similar thickness to date. In the real EMI shielding application test, composite films are confirmed to block signal transmission and switch off the toy car system. Such simple and high-efficiency asymmetric sandwich structure design makes a great progress towards preparing and adjusting thin EMI shielding composite films for the promising application prospects in advanced electronics and communication technology.

Bioinspired multiscale cellulose/lignin-silver composite films with robust mechanical, antioxidant and antibacterial properties for ultraviolet shielding

Constructing a high-performance ultraviolet shielding film is an effective way for addressing the growing problem of ultraviolet radiation. However, it is still a great challenge to achieve a combination of multifunctional, excellent mechanical properties and low cost. Here, inspired by the multiscale structure of biomaterials and features of lignin, a multifunctional composite film (CNF/CMF/Lig-Ag) is constructed via a facile vacuum-filtration method by introducing micron-sized cellulose fibers (CMF) and lignin-silver nanoparticles (Lig-Ag NPs) into the cellulose nanofibers (CNF) film network. In this composite film, the microfibers interweave with nanofibers to form a multiscale three-dimensional network, which ensures satisfactory mechanical properties of the composite film. Meanwhile, the Lig-Ag NPs are employed as a multifunctional filler to enhance the composite film's antioxidant, antibacterial and ultraviolet shielding abilities. As a result, the prepared CNF/CMF/Lig-Ag composite film demonstrates excellent mechanical properties (with tensile strength of 133.8 MPa and fracture strain of 7.4 %), good biocompatibility, high thermal stability, potent antioxidant and antibacterial properties. More importantly, such composite film achieves a high ultraviolet shielding rate of 98.2 % for ultraviolet radiation A (UVA) and 99.4 % for ultraviolet radiation B (UVB), respectively. Therefore, the prepared CNF/CMF/Lig-Ag composite film shows great potential in application of ultraviolet protection.

MXene/aramid nanofiber films enables highly efficient photothermal conversion for solar-driven water evaporation

Efficient utilization of solar energy is a resultful strategy to solve the problem of shortage of traditional fossil energy. Solar-driven water evaporation is considered as an effective, low-cost, renewable, and environment-friendly technology for clean water production. Herein, a novel MXene/ANF composite film was fabricated by facile vacuum filtration method. Benefiting from the excellent photothermal conversion property of MXene and the flexibility and stability of ANF, the MXene/ANF composite film exhibits high-efficient photothermal conversion and water evaporation ability. The as-prepared MXene/ANF composite film can reach as high as 98.0 °C at the laser power density of 1 kW/m2 and 54.0 °C under the solar power density of 1 kW/m2. Meanwhile, the water evaporation of MXene/ANF composite film can reach 1.432 kg/m2 under the solar power density of 1 kW/m2. Therefore, the MXene/ANF composite films possess a good prospect to be applied as a solar-driven water evaporation device to solve the problem of shortage of traditional fossil energy and inadequate freshwater supply.

Multifunctional CoFe2O4@MXene-AgNWs/Cellulose Nanofiber Composite Films with Asymmetric Layered Architecture for High-Efficiency Electromagnetic Interference Shielding and Remarkable Thermal Management Capability.

Developing high-efficiency electromagnetic interference (EMI) shielding composite films with outstanding flexibility and excellent thermal management capability is vital but challenging for modern integrated electronic devices. Herein, a facile two-step vacuum filtration method was used to fabricate ultrathin, flexible, and multifunctional cellulose nanofiber (CNF)-based composite films with an asymmetric layered architecture. The asymmetric layered structure is composed of a low-conductivity CoFe2O4@MXene/CNF layer and a highly conductive silver nanowires (AgNWs)/CNF layer. Benefiting from the rational placement of the impedance matching layer and shielding layer, as well as the synergistic effect of electric and magnetic losses, the resultant composite film exhibits an extremely high EMI shielding effectiveness (SE) of 73.3 dB and an average EMI SE of 70.9 dB with low reflected efficiency of 4.9 dB at only 0.1 mm thickness. Sufficiently reliable EMI SE (over 95% reservation) is attained even after suffering from continuous physical deformations and long-term chemical attacks. Moreover, the prepared films exhibit extraordinary flexibility, strong mechanical properties, and satisfactory thermal management capability. This work offers a viable strategy for exploiting high performance EMI shielding films with attractive thermal management capacity, and the resultant films present extensive application potential in aerospace, artificial intelligence, advanced electronics, stealth technology, and the national defense industry, even under harsh environments.

Flexible microfibrillated cellulose/carbon nanotube multilayered composite films with electromagnetic interference shielding and thermal conductivity

Ultrathin, lightweight, and flexible materials with outstanding electromagnetic interference (EMI) and thermal conductivity (TC) performances simultaneously are urgently needed to effectively minimize the EMI issue and dissipate the accumulative heat. Herein, we prepared sustainable microfibrillated cellulose (MFC) reinforced carbon nanotubes (CNT) composite films (MFC/CNT) with an alternating multilayered structure by the facile vacuum filtration method. The effects of different structures on the mechanical, EMI shielding, and TC properties of composite films were comprehensively compared. All the mechanical, EMI shielding, and TC properties of the alternating multilayered MFC@CNT films were higher than those of homogeneous blend film. The tensile strength and fracture strain of the optimal film (M4C3, alternating structure with 4 layers of MFC and 3 layers of CNT) were 33.31 MPa and 5.86%, respectively. The corresponding EMI shielding efficiency (EMI SE) and specific EMI SE (SSE/t) values reached 26.67 dB and 9944 dB cm2/g at a thickness of 36 μm. Simultaneously, the optimal film also had a high anisotropic TC, the cross-plane and in-plane TC were 0.24 and 8.50 W/mK, respectively. This work provides guidance for fabricating high-performance CNT-based composite materials through structural design.

Superhydrophobic, biocompatible and durable nanofiber composite with an asymmetric structure for anisotropic strain sensing and body motion detection

Anisotropic strain sensors show multi-directional sensing that can be used to monitor complex human motions. Aligned electrically conductive nanofiber membranes have been candidates for anisotropic strain sensors. Challenges remain for developing nanofiber composite strain sensors with a large workable strain range, corrosion resistance, excellent durability and biocompatibility. Here, we propose a facile vacuum filtration method to prepare an asymmetric nanofiber composite for the anisotropic strain sensing. The carbon nanofibers (CNF)/polydimethylsiloxane (PDMS) are deposited onto an aligned thermoplastic polyurethane (TPU) nanofiber membrane surface, forming a two layered structure. The PDMS ensures strong interfacial adhesion between the TPU nanofibers and the CNF layer, which endows the nanofiber composite with excellent surface stability and durability. The superhydrophobic CNF/PDMS constructs the conductive network, while the aligned nanofiber layer provides the anisotropic mechanical deformation. The nanofiber composite is cytotoxicity-free and exhibits excellent biocompatibility and biosafety. The asymmetric nanofiber composite shows anisotropy in the mechanical property and sensing behavior. The nanofiber composite demonstrates a large working strain range and outstanding sensing durability, and can be used for monitoring the multidirectional body joint motions even under corrosive conditions. Furthermore, the conductive CNF/PDMS exhibits excellent photothermal conversion performance and a negative temperature coefficient (NTC) behavior, and is hence suitable for isotropic temperature sensing. The asymmetric structure opens a new avenue for multifunctional and anisotropic strain sensing.

Thermoelectric characteristics of flexible reduced graphene oxide/silver selenide nanowire composites prepared by a facile vacuum filtration process

The reduced graphene oxide/silver selenide nanowire (rGO/Ag2Se NW) composite powders were fabricated via a wet chemical approach, and then flexible rGO/Ag2Se NW composite film was prepared by a facile vacuum filtration method combined with cold-pressing treatment. A highest power factor of 228.88 μW·m−1·K−2 was obtained at 331 K for the cold-pressed rGO/Ag2Se NW composite film with 0.01 wt% rGO. The rGO/Ag2Se NW composite film revealed superior flexibility as the power factor retained 94.62% after bending for 500 times with a bending radius of 4 mm, which might be due to the interwoven network structures of Ag2Se NWs and pliability of rGO as well as nylon membrane. These results demonstrated that the GO/Ag2Se NW composite film has a potential for preparation of flexible thermoelectric devices.

Aramid nanofiber-based porous membrane for suppressing dendrite growth of metal-ion batteries with enhanced electrochemistry performance

Huge volume changes, uncontrolled side-reactions with electrolytes and irregular dendrite induced short-circuits have impeded practical application in rechargeable batteries based on metallic electrodes including lithium (Li), sodium (Na) and aluminum (Al). Separator with superior mechanical strength represent attractive alternatives to inhibit metal-dendrite growth while preventing capacity fading by stabilizing the solid electrolyte interphase (SEI). However, the challenge of simultaneous retaining high thermal resistance and good electrolyte wettability still have been not overcome in commonly used separators. Here we show that these key properties can be acquired in a porous membrane fabricated from Kevlar microfiber-derived aramid nanofibers (ANFs) prepared in a facile and scalable vacuum filtration method. The obtained ANFs membrane (ANFM), which yields mechanically strong that are markedly effective in inhibit dendrite growth as well as provides good electrolyte wettability to ensure excellent electrochemistry performance. Benefitting from these merits, ANFM guarantee stable cycling of Li-ion or Na-ion rechargeable batteries paired with conventional intercalating cathodes (LiCoO4 and Na2Ti3O7) even at a high operated temperature (150 ℃ for Li-ion battery). Replacing polyolefins-based separator with an ANFM appear to offer a major step towards dendrite-free Li /Na batteries and potentially other metal-ion batteries.

Enhanced tensile and electrochemical performance of MXene/CNT hierarchical film

Nowadays, it is highly desirable to achieve high strength, flexibility and electrochemical performance for supercapacitor electrodes simultaneously. Herein, few-layer MXene flakes are assembled into free-standing films by facile vacuum-filtration method, in which hydrophilic-functionalized carbon nanotubes (CNTs) are further incorporated. The morphology of MXene/CNT composite films evolves from compact to ‘CNT in MXene’ to laminar to ‘MXene in CNT’ and finally to separate structures when increasing the CNT weight percentage. Among them, the laminar structure in which thin MXene and CNT layers are stacked alternately is demonstrated to be the best. The laminar MXene/CNT film possesses much higher strength, elongation and specific capacitance than MXene film due to the engineered porosity, good interaction between MXene flakes and CNTs, and proper CNTs’ distribution. As a result, high specific capacitance of 423.4 F g−1 at 1 A g−1 and capacitance retention of nearly 60% at 10 A g−1 are accomplished. Moreover, the composite film is flexible and withstands bending up to 180°, indicating that the proposed laminar MXene/CNT composite film is a superb candidate for flexible supercapacitors.

Large area deposition of Janus MoS2x Se2(x−1) on paper as a multifunctional electromechanical sensor for versatile physiological signal monitoring

The recent advancements in smart materials, processing techniques, and sensing technology have pervasive to the development of the modern era of flexible electronic systems. Flexible pressure and strain sensors with multi-functional sensing capabilities have gained significant interest as they have potential applications in human motion detection, physiological signal monitoring, flexible robotics, electronic skin, and smart displays. Hence this puts forward a higher requirement to develop highly sensitive, low cost and high-performance electromechanical sensors. Herein, we demonstrate the fabrication of solution-processed MoSSe/paper-based flexible Pressure and strain sensor with PDMS encapsulation using facile hydrothermal and vacuum filtration method with merits of low cost, large-area deposition, high scalability, and superior sensing performance. The fabricated device exhibited a very high sensitivity of 108.09 kPa−1 and a gauge factor of 27.57 with good reproducibility, stability, and resilience for 1200 bending cycles which indicates the robustness of the device. The enhanced sensing efficiency can be accounted for the excellent piezoelectric property and the pressure, strain-induced bandgap modulation observed in Janus MoSSe which arises due to the loss of symmetry in the crystal lattice. The sensors were utilized for real-time applications for the detection of various human physiological signals by integrating them into body parts, breath sensing, handwriting recognition, unknown shape detection, and pressure mapping. This successful demonstration of high performance, low cost, and large area deposited paper-based pressure and strain sensors, opens up new opportunities for far-reaching applications in health care, security, smart systems, and robotics.

Spent coffee ground-based interfacial solar steam generation

In this work, for the first time, spent coffee grounds (SCGs) were utilized for photothermal conversion. SCG-coated filter paper was obtained by a facile vacuum filtration method, then a floatable interfacial solar steam generation (ISSG) device was fabricated by wrapping expandable polyethylene (EPE) foam with the SCG-coated filter paper. The photothermal property and solar-driven evaporation performance of the ISSG device were investigated. Experimental results showed that there were graphitic π electrons in SCG and it exhibited light adsorption above 50% within the wavelength of 200–720 nm. The surface temperature of the ISSG device can finally achieve 63.2 °C under 0.25 sun irradiation, and the solar steam yield was enhanced by 0.56 times with the assistance of the floating ISSG device on bulk water surface. This study can provide a feasible technical support for the effective utilization of SCG and water treatment via low-cost ISSG process.

Super-adsorptive and photo-regenerable carbon nanotube based membrane for highly efficient water purification

Carbon nanotube (CNT) based adsorbents have attracted extensive research interest for aqueous pollutants removal. However, such adsorbents face the problems of limited adsorption capacities and costly regeneration. Here, we report a highly adsorptive photo-regenerable CNT based multifunctional membrane with excellent self-cleaning properties via the facile vacuum filtration method, followed by FeOOH in-situ anchoring and silver-amino reaction. Various dyes (Rhodamine B, methylene blue, eosin Y and acid orange 7) and emerging contaminants (bisphenol A, amoxicillin and p-nitrophenol) were tested with the CNT based membrane. Our membrane exhibited superior adsorption performance to dyes among CNT based adsorbents reported in literature. In particular, the CNT based composite membrane displayed even better adsorption performance to cationic dyes. The adsorption capacities of the membrane for Rhodamine B and methylene blue were up to 181 and 247 mg/g, respectively. The membrane also had excellent self-cleaning and photo-regenerable properties after severe organic fouling. Our multifunctional CNT based membrane combined the features of adsorption, membrane separation, and catalytic degradation into one system, showing great promise for dye polluted wastewater purification. This study also offers a new strategy to engineer robust adsorptive, self-cleaning and regenerable membranes for wastewater treatment.

An environment friendly free-standing cellulose membrane derived for catalytic reduction of 4-nitrophenol: A sustainable approach

Catalytic active and high flux free standing cellulose membrane is developed through mussel inspired polydopamine (PDA) chemistry using facile vacuum filtration method. Herein, quasi-spherical silver nanoparticles (AgNPs) illuminated nanocelluose (NC) fiber (AgNPs@NC) based membrane was fabricated by in-situ reduction of silver salt over the surface of nanometer thick PDA coated synthesized NC. The permeation behavior of the membranes was studied using pure water under gravimetric condition. The catalytic activity was evaluated by assessing the reduction of 4-nitrophenol (4-NP) as a water contaminant. The conversion efficiency of the 4-NP by the stacking membranes under gravimetric condition showed above 95 %. The catalytic activity was also studied toward reduction of 4-NP in a batch reactor and complete conversion could be accomplished within 8 min having turn over frequency (TOF) 2.25 × 10−3 molecules per gram per min. High water flux of the fabricated membrane was possibly due to the hydrophilicity of the PDA coated NC and hydrophobic pushing of AgNPs. Excellent catalytic activity of the synthesized AgNPs@NC membrane can be described by the synergistic effect of PDA coated NC and AgNPs. Beside this, higher number of catalytic reusability proved excellent bonding ability of adhesive like PDA between NC and AgNPs. In future, the fabricated AgNPs@NC membrane would be a potential candidate as catalytic converter for industrial applications.

Mxene (Ti3C2Tx)/cellulose nanofiber/porous carbon film as free-standing electrode for ultrathin and flexible supercapacitors

Traditional porous carbon (PC)-based supercapacitors (SCs) are generally stiff and heavy owing to their rigid components and bulky additives, such as binders, conducting materials, and current collectors. Herein, a porous (574.5 m2 g−1), conductive (83.1 S cm−1), and flexible MXene (Ti3C2Tx)/cellulose nanofiber (CNF)/PC hybrid film is prepared by strong interfacial interactions among its components via a facile vacuum-filtration method. Three-dimensional PC provides abundant micropores for charge storage and considerable amount of meso/macropores for fast diffusion of ions. Two-dimensional Ti3C2Tx offers a significantly high conductivity of 2.6 × 103 S cm−1 and a good film-forming ability. A one-dimensional CNF ensures high mechanical properties with a tensile strength of 38.6 MPa for the hybrid film by binding the adjacent Ti3C2Tx flakes and PC. Additionally, the presence of CNF and PC increases the interlayer distance between Ti3C2Tx flakes, thereby providing more ion-accessible surface areas on Ti3C2Tx and creating open gaps for fast ion transport. Benefiting from these electrochemically attractive properties, this film is further employed as a free-standing electrode to fabricate a high-performance quasi-solid-state SC, which demonstrates an ultrathin thickness of 0.2 mm, a high flexibility, a significantly high areal capacitance of 143 mF cm−2 at 0.1 mA cm−2, and a large areal energy density of 2.4 μWh cm−2 at 17.5 μW cm−2, with a high retention of ~50% even after increasing the power density by ~100 fold. This work will pave the way for developing free-standing MXene-based hybrid films that simultaneously possess excellent conductivity, good mechanical properties, and large charge storage capacity for flexible and high-performance SCs.

Flexible cellulose nanofiber/Bi2Te3 composite film for wearable thermoelectric devices

Cellulose nanofiber (CNF) is obtained from cellulose resources (e.g., natural cellulose, bacterial cellulose, etc.) and is considered to be a low-cost, green and inexhaustible material. The impressive optical, mechanical, and thermal properties of this material have aroused great interest in fabricating of flexible electronic devices based on CNF. Hereby, the CNF/Bi2Te3 thermoelectric composite films are fabricated using a facile vacuum filtration method. Subsequently, n-type and p-type films composed of this composite materials are used as legs to assemble thermoelectric generator (TEG) prototype. Besides, these composite films exhibit excellent mechanical flexibility and the electrical conductivity of the CNF/Bi2Te3 film only decreases by 8% after 1000 bending cycles. And the contact angle of the polytetrafluoroethylene (PTFE) solution and alkylketene dimmer (AKD) emulsion co-treated film is as high as 150.7°, which has superhydrophobic properties. The TEG prototype consists of five p-n legs. At a temperature gradient of 60 K, the output voltage of the TEG prototype is 22.34 mV and the output power is 561 nW. This work not only proves the great potential of CNF application in flexible thermoelectric (TE) materials, but also promotes robust development of cellulose-based electronics.

Cellulose-based Ni-decorated graphene magnetic film for electromagnetic interference shielding

Flexible and ultrathin electromagnetic interference (EMI) shielding films are urgently required to manage increasingly serious radiation pollution. In this work, the EMI shielding performance and flexibility of conductive polymer films were addressed by assembling magnetic graphene-based hybrid and cellulose nanofiber (CNF). Briefly, magnetic graphene hybrid anchored by Ni nanoparticles (TRGO@Ni) was synthesized by in situ thermal reduction. Then, highly flexible and ultrathin CNF/TRGO@Ni film with “brick-mortar” layered structure was assembled via a facile vacuum filtration method. As expected, CNF/TRGO@Ni film with 50 wt% filler loading exhibits an enhanced electrical conductivity (262.7 S/m) and EMI shielding effectiveness (32.2 dB) comparing to CNF/TRGO film. Moreover, the excellent mechanical flexibility of CNF/TRGO@Ni film results in that the electrical conductivity and EMI SE only declines by 7.5% after bending 1000 cycles. The EMI shielding mechanism is attributed to the combination of enhancing impedance mismatch, multireflection in “brick-mortar” lamellar structure and endowing synergetic loss by graphene and Ni nanoparticles.

Free‐Standing Single‐Walled Carbon Nanotube/SnSe Nanosheet/Poly(3,4‐Ethylenedioxythiophene):Poly(4‐Styrenesulfonate) Nanocomposite Films for Flexible Thermoelectric Power Generators

Flexible single‐walled carbon nanotube (SWCNT)/SnSe nanosheet (NS)/poly(3,4‐ethylenedioxythiophene):poly(4‐styrenesulfonate) (PEDOT:PSS) nanocomposite films are first successfully prepared by a facile vacuum filtration method on nylon membrane. An optimized power factor of 109.9 μWm−1 K−2 for the as‐prepared free‐standing nanocomposite film with 60 wt% SWCNTs is obtained at the temperature of 380 K, and the electrical conductivity only decreases by 1% after 1000 bending cycles (the bending radius is ≈4.3 mm), indicating excellent flexibility. A flexible thermoelectric generator consisting of 8‐unit free‐standing composite film strips (25 mm × 4 mm for each strip) is assembled on a polyimide substrate, which can generate an open‐circuit voltage of 20.6 mV and a maximum output power of 1.16 μW at a temperature gradient of 74.4 K. This work offers quite an effective strategy for preparation of high‐performance flexible free‐standing thermoelectric composite films, and the as‐prepared films can avoid excess heat loss induced by the substrate‐adherent layer of thin films, when compared with the traditional thermoelectric composite films prepared on different kinds of substrates, e.g., glass substrate. Therefore, the composite films have a great potential to be used for the flexible thermoelectric devices.

Ultra-black and self-cleaning all carbon nanotube hybrid films for efficient water desalination and purification

All-carbon nanotube (CNT) hybrid films are fabricated through a facile vacuum filtration method by using hydrophilic single-walled carbon nanotube (SWCNT) films as filters and multi-walled carbon nanotube (MWCNT) powder dispersed in ethanol as liquor. The hydrophilic SWCNT film provides penetration channels for water, while the superhydrophobic MWCNTs have self-cleaning, self-spreading, and broadband absorption ability. The hybrid film exhibits ultra-high solar absorbance (∼99%), low thermal conductivity, and excellent light-to-heat conversion capacity. The temperature of the hybrid film increases from 24 to 60 °C in 1 s under one-sun illumination in air. The individual hybrid film exhibits a high water evaporation rate of 1.37 kg m−2 h−1 and a solar thermal efficiency of 87.4% under one-sun after 1 h illumination. The solar thermal efficiency maintains at ∼80% when many pieces of hybrid films self-assemble into a large film (∼40 cm2). The hybrid films have great potential in the desalination of seawater and sewage treatment. Ion concentrations in seawater decrease significantly to drinkable water standards by only one distillation treatment. Organic pollutants, such as rhodamine B and methylene blue, are removed effectively from sewage water by using the hybrid films in a solar steam generator.

Antibacterial and Soluble Paper-Based Skin-Attachable Human Motion Sensor Using Triboelectricity

The environmental pollution issues caused by plastic-based polymers have become serious concerns over the past few decades. Accordingly, the need for using green and ecofriendly polymers in triboelectric nanogenerators (TENGs) is gradually increasing. In this research, the glycerol paper-based sodium lauroyl glutamate (SLG)-TENG with an antibacterial effect and also water and oil solubility has been successfully developed by a facile vacuum filtration method. Silver nanowire (AgNW) and carbon nanotube (CNT) layers were deposited by casting their respective dispersions in isopropyl alcohol (IPA) on SLG. During the fabrication process, concentrations of CNTs and AgNWs were varied from 0.35 to 0.5 wt % for CNTs, and from 0.05 to 0.3 wt % for AgNWs to determine the optimal concentration. From the electrical output measurements, it was observed that the CNT-based SLG-TENG showed a high open-circuit voltage (Voc) and short-circuit current (Isc) at 0.425 wt % while the AgNW-based SLG-TENG showed enhanced electrical properties at 0.15 wt %. A detailed explanation for the existence of the optimal point for CNTs and AgNW-based SLG-TENG is given by using the results of ultraviolet–visible spectroscopy and energy dispersive spectroscopy. Furthermore, the antibacterial effect has been strongly proven from the consequences of bacteria cultivation on SLG. Due to these peculiar properties of SLG-TENG, we have tested its applicability as a skin-attachable sensor, writing sensor, water leakage sensor, and humidity sensor and discussed its results with supporting videos. This work gives new insights into the simple design of biodegradable and antibacterial TENG-based wearable sensors in real life.