Vacuum Filtration Research Articles

Flexible self‐supporting organic cathode with interface engineering for high‐performance and wide‐temperature sodium‐ion batteries

AbstractFlexible electrode design with robust structure and good performance is one of the priorities for flexible batteries to power emerging wearable electronics, and organic cathode materials have become contenders for flexible self‐supporting electrodes. However, issues such as easy electrolyte solubility and low intrinsic conductivity contribute to high polarization and rapid capacity decay. Herein, we have designed a flexible self‐supporting cathode based on perylene‐3,4,9,10‐tetracarboxylic dianhydride (PTCDA), interfacial engineering enhanced by polypyrrole (PPy), and carbon nanotubes (CNTs), forming the interconnected and flexible PTCDA/PPy/CNTs using polymerization reaction and vacuum filtration methods, effectively curbing those challenges. When used as the cathode of sodium‐ion batteries, PTCDA/PPy/CNTs exhibit excellent rate capability (105.7 mAh g−1 at 20 C), outstanding cycling stability (79.4% capacity retention at 5 C after 500 cycles), and remarkable wide temperature application capability (86.5 mAh g−1 at −30°C and 115.4 mAh g−1 at 60°C). The sodium storage mechanism was verified to be a reversible oxidation reaction between two Na+ ions and carbonyl groups by density functional theory calculations, in situ infrared Fourier transform infrared spectroscopy, and in situ Raman spectroscopy. Surprisingly, the pouch cells based on PTCDA/PPy/CNTs exhibit good mechanical flexibility in various mechanical states. This work inspires more rational designs of flexible and self‐supporting organic cathodes, promoting the development of high‐performance and wide‐temperature adaptable wearable electronic devices.

Hydrothermal Co-Liquefaction of Sugarcane Bagasse and Residual Cooking Soybean Oil for Bio-Crude Production

Hydrothermal co-liquefaction (co-HTL) is a process involving two sources of biomasses aiming at bio-crude production. Since there is a lack of studies performed with sugarcane bagasse and residual soybean oil, this study investigated different conditions for the co-HTL of these biomasses, with and without the presence of ethanol as a co-solvent to maximize the bio-crude yield. All co-HTL reactions were carried out in a 300 mL Parr® reactor at temperatures ranging from 200 to 300 °C. After the reaction, a vacuum filtration was performed to separate the bio-char, later washed with ethanol to extract heavy bio-crude, while the liquid-phase was mixed with dichloromethane to recover light bio-crude. Bio-crude yields of around 95 wt.% were obtained at 300 °C using ethanol and water as solvents. The highest bio-char yield (16.6 wt.%) was achieved when using only sugarcane bagasse as the substrate, without the presence of soybean oil. Bio-crude samples obtained at higher temperatures (280 °C and 300 °C) using ethanol as a hydrogen donor presented higher contents of both free fatty acids and fatty acid ethyl esters. This work presents a promising process to produce high-quality bio-crude using an abundant feedstock (sugarcane bagasse) in the presence of a lipid source which could cause environmental problems if poorly handled.

Scalable Fabrication of Quasi-One-Dimensional van der Waals Ta2Pt3Se8 Nanowire Thin Films via Solution Processing for NO2 Gas Sensing over Large Areas.

Solution-based processing of van der Waals (vdW) one- (1D) and two-dimensional (2D) materials is an effective strategy to obtain high-quality molecular chains or atomic sheets in a large area with scalability. In this work, quasi-1D vdW Ta2Pt3Se8 was exfoliated via liquid phase exfoliation (LPE) to produce a stably dispersed Ta2Pt3Se8 nanowire solution. In order to screen the optimal exfoliation solvent, nine different solvents were employed with different total surface tensions and polar/dispersive (P/D) component (P/D) ratios. The LPE behavior of Ta2Pt3Se8 was elucidated by matching the P/D ratios between Ta2Pt3Se8 and the applied solvent, resulting in N-methyl-2-pyrrolidone (NMP) as an optimal solvent owing to the well-matched total surface tension and P/D ratio. Subsequently, Ta2Pt3Se8 nanowire thin films are manufactured via vacuum filtration using a Ta2Pt3Se8/NMP dispersion. Then, gas sensing devices are fabricated onto the Ta2Pt3Se8 nanowire thin films, and gas sensing property toward NO2 is evaluated at various thin-film thicknesses. A 50 nm thick Ta2Pt3Se8 thin-film device exhibited a percent response of 25.9% at room temperature and 32.4% at 100 °C, respectively. In addition, the device showed complete recovery within 14.1 min at room temperature and 3.5 min at 100 °C, respectively.

Discrimination of Xylene Isomers by Precisely Tuning the Interlayer Spacing of Reduced Graphene Oxide Membrane.

Separating xylene isomers is a challenging task due to their similar physical and chemical properties. In this study, we developed a molecular sieve incorporating a reduced graphene oxide (rGO) membrane for the precise differentiation of xylene isomers. We fabricated GO membranes using a vacuum filtration technique followed by thermal-induced reduction to produce rGO membranes with precisely controllable interlayer spacing. Notably, we could finely tune the interlayer spacing of the rGO membrane from 8.0 to 5.0 Å by simply varying the thermal reduction temperature. We investigated the reverse osmosis separation ability of the rGO membranes for xylene isomers and found that the rGO membrane with an interlayer spacing of 6.1 Å showed a high single component permeance of 0.17 and 0.04 L m-2 h-1 bar-1 for para- and ortho-xylene, respectively, exhibiting clear permselectivity. The separation factor reached 3.4 and 2.8 when 90:10 and 50:50 feed mixtures were used, respectively, with permeance 1 order of magnitude higher than that of current state-of-the-art reverse osmosis membranes. Additionally, the membrane showed negligible permeance and selectivity decay even after continuous operation for more than 5 days, suggesting commendable membrane resistance to solvent swelling and operating pressure.

Hydrophobic-treated yolk-shell SnS2@CSs Z-scheme confinement reactor for solar-electro-driven hydrogen peroxide production in neutral media

The diffusion and adsorption properties of the O2/H2O corpuscles at active sites play a crucial role in the fast photo-electrocatalytic reaction of hydrogen peroxide (H2O2) production. Herein, SnS2 nanosheets with abundant interfacial boundaries and large specific areas are encapsulated into hollow mesoporous carbon spheres (CSs) with flexibility, producing a yolk-shell SnS2@CSs Z-scheme photocatalyst. The nanoconfined microenvironment of SnS2@CSs could enrich O2/H2O in catalyst cavities, which allows sufficient internal O2 transfer, improving the surface chemistry of catalytic O2 to O2− conversion and increasing reaction kinetics. By shaping the mixture of SnS2@CSs and polytetrafluoroethylene (PTFE) on carbon felt (CF) using the vacuum filtration method, the natural air-breathing gas diffusion photoelectrode (AGPE) was prepared, and it can achieve an accumulated concentration of H2O2 about 12 mM after a 10 h stability test from pure water at natural pH without using electrolyte and sacrificial agents. The H2O2 product is upgraded through one downstream route of conversion of H2O2 to sodium perborate. The improved H2O2 production performance could be ascribed to the combination of the confinement effect of SnS2@CSs and the rich triple phase interfaces with the continuous hydrophobic layer and hydrophilic layer to synergistically modulate the photoelectron catalytic microenvironment, which enhanced the transfer of O2 mass and offered a stronger affinity to oxygen bubbles. The strategy of combining the confined material with the air-breathing gas diffusion electrode equips a wide practical range of applications for the synthesis of high-yield hydrogen peroxide.

Tailoring amino-functionalized cellulose separators for improved lithium-ion battery performance

This study aims to enhance cellulose separators for energy storage, focusing on achieving high security and superior electrolyte wetting properties. Bacterial cellulose (BC) separators were initially prepared via vacuum filtration. Subsequently, carboxymethyl cellulose (CMC) underwent amino-functionalization by successfully cross-linking polyethyleneimine (PEI) using glutaraldehyde. The amino-functionalized CMC was then composited onto the BC separator. This composite separator demonstrated excellent thermal stability at 200 °C and favorable electrolyte wetting. The amino groups in PEI enhanced Li+ migration by forming hydrogen bonds with PF6− in the electrolyte. Additionally, molecular-level hydrogen bonding between amino groups on PEI and carboxyl/hydroxyl groups in CMC regulated the separator's porosity. The abundant carboxyl groups in CMC facilitated Li+ transfer, notably boosting the lithium-ion battery's electrochemical performance. After 90 charge and discharge cycles, the discharge capacity of the battery assembled with BC/CMC-PEI composite separator is 132.8 mAh/g, which is 25.1 % higher than the 106.1 mAh/g of the battery assembled with traditional PP separator. At a current density of 2C, the minimum discharge capacity of the battery assembled with the composite separator is 71.1 mAh/g, while the minimum discharge capacity of the battery assembled with the PP separator is 53.6 mAh/g. This approach using functional group modification provides a promising approach to improving the performance of lithium-ion batteries.

Long-life and self-cleaning membrane by dissolved oxygen activation in natural conditions

In this study, a dissolved oxygen-activated self-cleaning membrane was obtained by efficiently loading the catalyst (CuZn-C) onto the membrane surface through a simple dip-coating and vacuum filtration process. The results showed that the catalytic membrane presented a high flux recovery rate and achieved 100% retention for anionic dyes. It was confirmed by quenching experiments and electron paramagnetic resonance (EPR) that the prepared membrane exhibited excellent dissolved oxygen activation to generate reactive oxygen species (ROS) for pollutant degradation under natural conditions, without extra oxidants input. This study presented a high-performance membrane, which achieved long lifespan and self-cleaning capability by activating natural dissolved oxygen in water.

Indicative bacterial cellulose films incorporated with curcumin-embedded Pickering emulsions: Preparation, antibacterial performance, and mechanism

Biodegradable, sustainable, and multifunctional intelligent food packaging has attracted extensive attention due to the concerns about the environmental pollution, the health hazard, and the food safety of plastic packaging. Herein, a multifunctional bacterial cellulose (BC)-based film (termed BC-PE-Cur) was fabricated for intelligent food packaging. The film was simply prepared by vacuum filtration and compression of a mixture of the BC and the curcumin (Cur)-embedded Pickering emulsion (PE) stabilized with the natural protein-polysaccharide hybrid nanoparticles (PPH NPs). The Pickering emulsion droplets containing Cur were uniformly distributed within the film and adhered to the film surface, resulting in a uniform dispersion of Cur in the film, and a thicker, rougher film with a laminated pore structure. The BC-PE-Cur film showed excellent antibacterial, antioxidant, UV-shielding, water vapor barrier, and mechanical properties. BC-PE-Cur film can extend the shelf life of basa fish by delaying the lipid peroxidation and inhibiting the growth of spoilage microorganisms. Moreover, during the storage of basa fish, BC-PE-Cur films underwent significant color change due to the production of alkaline substances, which could indicate the freshness of basa fish. This study provides an attractive strategy to construct multifunctional smart bio-based composite films containing non-water-soluble active ingredients for food packaging and freshness monitoring.

Microplastics Contamination of Mackerel and Red Snapper as Commercial Fish from the Takalar Fish Landing, Indonesia

Highlight Research 1. Microplastics were counted and identified based on their shape, size, and color 2. The particles were clarified using FTIR and confirmed to be microplastics based on the type of polymer. 3. The tissue destruction method is more effective with heating treatment. 4. Methods to prevent contamination are implemented so that the research results are guaranteed to be accurate. Abstract Microplastics can be ingested by marine organisms, including fish. Although it has been widely reported, further information regarding microplastic contamination in commercial fish is still needed. This study aimed to analyze the presence and concentration of microplastics in the digestive tract of the mackerel R. kanaguarta and red snapper L. gibbus and to identify the shape, size, color, and type of microplastic polymer. Digestion of the organic materials was performed using a 10% KOH solution, which was then filtered using a vacuum filtration system. The particles were observed using an Olympus microscope and clarified using FTIR. The results of the research showed that R. kanaguarta and L. gibbus landed at the Beba Fish Landing Base (PPI Beba) Takalar were contaminated with microplastics with a microplastic concentration in R. kanaguarta 0.21 ± 0.06 particles/g and L. gibbus 0.11 ± 0.04 particles/g. The microplastics found were fiber and fragment of varying colors, such as black, white, red, and yellow. The size of microplastics was dominant in the size class < 2 mm. The FTIR analysis confirmed the presence of polypropylene (PP), Ethylene/Propylene Copolymer, Nylon, Polyethylene terephthalate (PET), and polyester (PES). This study showed that both commercial fish species were contaminated with microplastics. These findings suggest that microplastics are widespread and contaminate commercial fish caught from Takalar waters. Further research is still needed on other seafood from this region, and analysis of polymer types such as FTIR is important to carry out as one of the standard methods in microplastic research.

Hierarchical heterostructures of MXene and mesoporous hollow carbon sphere for improved ion accessibility and rate performance

The development of electrode materials with a hierarchically porous structure and good electrical connection is key to improving the charging-discharging rate and energy density of supercapacitors. However, the restacking issue of two-dimensional nanomaterials, such as MXene, seriously hinders the diffusion of electrolyte ions. Different from the extensively used sacrificing template method, a hierarchical heterostructure of electrically conducting mesoporous hollow carbon spheres (MHCS) and MXene composite electrode is designed and achieved through simple vacuum filtration without further template removing procedures. This direct preparation strategy not only effectively improves the specific surface area of the electrode but also enhances the abundant surface pores and good conductivity of MHCS, improving the penetration of the electrolyte solution and shortening the ion transport path, leading to a pronounced improvement in specific capacitance and rate performance of the electrodes. Additionally, the influence of sheath thickness of MHCSs on ion transfer rate is deeply discussed. The introduction of carbon nanotubes (CNTs) further improves conductivity and stability while maintaining good flexibility. Consequently, the MXene/MHCS/CNT film delivers a high specific capacitance (395F g−1 at 2 mV s−1), outstanding rate performance (70.9 % at 1000 mV s−1), and excellent cycling stability (98.3 % capacity retention after 10,000 cycles). Furthermore, the assembled symmetric supercapacitor provides a maximum energy density of 14.48 Wh kg−1. This work provides a quick and effective approach for constructing high performance 3D MXene architectures for fast ion transfer electrodes.

Application of Spray Coating in the Fabrication of Free Standing Nanocellulose Films and Barrier Coating on the Paper Substrates

Spray coating is a novel concept for fabricating free-standing film and producing barrier coating on paper substrates. The spraying gives comparable efficacy with vacuum filtration in terms of operation time, film quality, and process intensification approach. The smooth films created by spraying nanocellulose onto the polished impermeable surface could serve as a platform for a variety of sustainable functional devices. Finally, the application of spray-coating barriers and nanocellulose films on paper substrates is the focus of the spray-coating concept designed to create smooth nanocellulose films. One of the most important factors that affect the performance of different cellulose-based functional materials is the smoothness of nanocellulose film coated with sprays in the production of flexible and printed electronics. The uses of nanocellulose film as a high-performance barrier material and the possible replacement of synthetic plastic packaging are expanded by spray coatings. The process of creating a nanocellulose film using spray coating takes less than a minute. Compared to vacuum filtering, this method offers excellent speed potential for nanocellulose films. The wet layer of spray coating takes more than 24 hours to dry in a controlled laboratory environment, using air drying. Future research projects will improve the drying process of wet films. The film spray process serves as a proof of concept, and the quality of the film produced by this method contrasts with vacuum filtration. Studying spray coating wet film drying outside the scope of this research is not part of the scope of this study, and additional research is needed in this area. The shiny film that is created by spraying nanocellulose on the impermeable polished surface can serve as a platform for various sustainable functional devices.

Preparation of whisker carbon nanotube composite paper by vacuum filtration method and its electrical heating performance

Preparation of whisker carbon nanotube composite paper by vacuum filtration method and its electrical heating performance

GO/MoS2/PEI composite membrane for removin salt ions from water

Separation membranes based on graphene oxide (GO) have attracted much attention due to their good separation properties. But its instability in water and rejection of divalent salt ions is a problem that needs to be solved urgently. In this study, molybdenum disulfide (MoS2) is intercalated into graphene oxide by adding polyethyleneimine (PEI) solution drop by drop for cross-linking, and then GO/MoS2/PEI composite membrane is prepared by vacuum filtration. As MoS2 hydrophobicity increases frictionless water flow channels to improve water flux, PEI cross-linking improves membrane stability and rejection of divalent salt ions. The modified composite membrane has a high rejection of 94.8 % for Mg2+, and water flux is increased by 30 % relative to GO/PEI membrane. In addition, the rejection of the composite membrane to different salt solutions is investigated by MgCl2, MgSO4, NaCl and Na2SO4 solutions, and the results obtained are, in order, R(MgCl2) > R(MgSO4) > R(NaCl) > R(Na2SO4). This modified composite membrane has great potential for salt ion removal.

Ecologically Modified Leather of Bacterial Origin.

The research presented here is an attempt to develop an innovative and environmentally friendly material based on bacterial nanocellulose (BNC), which will be able to replace both animal skins and synthetic polymer products. Bacterial nanocellulose becomes stiff and brittle when dried, so attempts have been made to plasticise this material so that BNC can be used in industry. The research presented here focuses on the ecological modification of bacterial nanocellulose with vegetable oils such as rapeseed oil, linseed oil, and grape seed oil. The effect of compatibilisers of a natural origin on the plasticisation process of BNC, such as chlorophyll, curcumin, and L-glutamine, was also evaluated. BNC samples were modified with rapeseed, linseed, and grapeseed oils, as well as mixtures of each of these oils with the previously mentioned additives. The modification was carried out by passing the oil, or oil mixture, through the BNC using vacuum filtration, where the BNC acted as a filter. The following tests were performed to determine the effect of the modification on the BNC: FTIR spectroscopic analysis, contact angle measurements, and static mechanical analysis. As a result of the modification, the BNC was plasticised. Rapeseed oil proved to be the best for this purpose, with the help of which a material with good strength and elasticity was obtained.

High‐Density and Freestanding Porous Carbon Film for Compact Sodium‐Ion Storage

AbstractPorous carbon materials are often difficult to achieve high density while possessing high porosity, which limits their application in compact energy storage. Here, a design of freestanding porous‐yet‐dense carbon films with a tunable density (1.08–1.33 g cm−3) and porosity (specific surface area of 0–423.8 m2 g−1) is presented through an assembly of porous carbon nanosheet with graphene oxide under vacuum filtration. The typical freestanding carbon films simultaneously deliver a high density of 1.08 g cm−3 and a high specific surface area of 423.8 m2 g−1 when the porous carbon nanosheet content is 75 wt.%. As anode materials for sodium‐ion batteries, the optimized freestanding carbon films deliver high volumetric capacity (270 mAh cm−3 at 20 mA g−1), high initial capacity efficiency (81 %) and superior long‐term cycling stability (1300 cycles with a capacity decay rate of 0.012 % per cycle). This study provides a promising direction for creating freestanding electrodes that meet both high‐porosity and high‐density requirements for compact sodium‐ion batteries.

Full life cycle green preparation of collagen-based food packaging films using Halocynthia roretzi as raw material

The extraction of collagen for packaging films typically requires a time-consuming process and the use of substantial chemicals. Herein, we present a full life cycle green preparation method for rapidly producing collagen-based food packaging films using Halocynthia roretzi (HR), a collagen-rich marine organism, as raw material. We first prepared the micro/nano-sized collagen fibers from HR tissue by utilizing urea and sonication as effective hydrogen-bond breakers. Subsequently, the collagen fiber was rapidly fabricated into a film through vacuum filtration. The resulting collagen fiber film (CFF) exhibited a uniform and dense surface, along with good tensile properties, water resistance, and biodegradability. In addition, the deposition of chitosan (CS) on the surface of CFF resulted in a remarkable preservation effect for both strawberries and pork. This full life cycle preparation method for collagen-based films provides a promising and innovative approach to the sustainable preparation of food packaging films.

Utilization of Milkfish Bones and Heads from CV. Maharani Dwi Bayu Kalanganyar Sidoarjo for Making Spicy Fish Sauce

Kalanganyar is a village whose 2/3 area consists of ponds and producers of milkfish, tiger prawns, shrimp paste, processed milkfish and crackers. Most of the milkfish from Kalanganyar are sold fresh, but some are processed into various processed products, including smoked milkfish, shredded milkfish, crackers, soft spiny milkfish and crispy milkfish. One of the producers of crispy milkfish is CV. Maharani Dwi Bayu. Milkfish that is processed into crispy milkfish will leave behind waste in the form of heads, tails and milkfish bones/spines. So far, this waste has not been utilized optimally. To overcome this problem, the heads and bones of milkfish are used as raw materials for making spicy fish sauce. The resulting soy sauce can be used as a complement to smoked milkfish or presto milkfish as a substitute for chili sauce. Training has been carried out on processing fish sauce at CV. MAHARANI DWI BAYU, Jalan Raya Kalanganyar Wetan, Sedati District, Sidoarjo Regency. Apart from holding training on processing fish sauce from milkfish bones and heads, supporting equipment for soy sauce processing was also handed over, namely pressure cookers, vacuum filters, steamers and hot guns. The people of Kalanganyar are very happy and enthusiastic about taking part in training to gain new knowledge and new innovative products.

MXene/rGO/sulfur loaded separator based current collector-free lithium sulfur batteries with high sulfur loading and cycle life

Lithium-Sulfur batteries with high sulfur loading cathodes are highly desirable to achieve greater energy density. In this work, a high loading composite cathode is reported that is made by scalable vacuum filtration route, eliminating the need for a binder, conducting carbon, and metallic current collector. Moreover, capacity fade due to peeling off of coated active material from current collector is avoided, leading to excellent capacity retention. The coated separator affords a porous framework to (i) accommodate volume changes during cycling, (ii) allow higher sulfur loading, (iii) allow electrolyte wetting of active material in addition to (iv) functioning as a traditional separator and current collector by pressing against stainless steel casing. The MXene/reduced graphene oxide/S8 composite with an areal loading of 2.52 mg/cm2 exhibits a specific capacity of 495 mAh/g with a capacity retention of 97.5% after 200 cycles at a charge/discharge rate of 100 mA/g. At 500 mA/g discharge rate, an initial specific capacity of 378 mAh/g was obtained with 239 mAh/g retained after 750 cycles.

Efficient Low-Temperature Nutrient Removal from Agricultural Digestate Using Microalgae

Humanity is facing an energy crisis triggered by the depletion of fossil fuels, rapid industrialization, and the growthof the global population. These trendsput an emphasis on searching for alternative energy sources. Additionally, the rising concentration of carbon dioxide in the atmosphere is driving climate change, which poses serious threats. In this scenario, microalgae emerge as a promising solution for both sustainable energy production and CO2 sequestration. Digestate, a nutrient-rich by-product of anaerobic digestion, is considered a cost-effective nutrient source for microalgae cultivation. Utilizing digestate not only enhances the sustainability and economic feasibility of microalgal biofuels but also offers a method for wastewater treatment. Nevertheless, the application of digestate is limited by its high optical density and substantialamount of total solids.In this study, several pretreatment methods were tested to increase the feasibility of digestate application for microalgae cultivation. Our findings show that various centrifugation methods and vacuum filtration decrease the content of total solids but are not effective in reducing optical density. Although the use of microalgae in treating various wastewaters has shown promising outcomes, the effectiveness of nutrient removal at low temperatures remainslargely unexplored.To fill this gap, green microalga Chlorella sorokiniana was cultivated in pretreated diluted liquid digestate in dynamic springtime weather conditions in a covered open race-way pond integrated into a biogas plant.During the cultivation, high solar irradiance and low temperatures were recorded resulting in suboptimal conditions for C. sorokinianagrowth. Although low productivity of C. sorokiniana was detected, the nutrient removal efficiency was high. C. sorokiniana could efficiently remove 83% of nitrogen and 85% of phosphorus showing very promising results of the use of microalgae for wastewater treatment in high latitude regions.

Greatly Enhanced Thermoelectric Performance of Flexible Cu2-xS Composite Film on Nylon by Se Doping.

In this work, flexible Cu2-xS films on nylon membranes are prepared by combining a simple hydrothermal synthesis and vacuum filtration followed by hot pressing. The films consist of Cu2S and Cu1.96S two phases with grain sizes from nano to submicron. Doping Se on the S site not only increases the Cu1.96S content in the Cu2-xS to increase carrier concentration but also modifies electronic structure, thereby greatly improves the electrical properties of the Cu2-xS. Specifically, an optimal composite film with a nominal composition of Cu2-xS0.98Se0.02 exhibits a high power factor of ~150.1 μW m-1 K-2 at 300 K, which increases by ~138% compared to that of the pristine Cu2-xS film. Meanwhile, the composite film shows outstanding flexibility (~97.2% of the original electrical conductivity is maintained after 1500 bending cycles with a bending radius of 4 mm). A four-leg flexible thermoelectric (TE) generator assembled with the optimal film generates a maximum power of 329.6 nW (corresponding power density of 1.70 W m-2) at a temperature difference of 31.1 K. This work provides a simple route to the preparation of high TE performance Cu2-xS-based films.