Low-cost Preparation Process Research Articles

High conductivity PEDOT:PSS thin films affording improved open circuit voltages in PEDOT:PSS-Si heterojunction solar cells

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)-Si heterojunction solar cells (HSCs) have the characteristics of low cost and simple preparation process, which is expected to realize the manufacture of high-performance solar cells. Among them, The modification of PEDOT:PSS has become the most important and feasible method to improve the photoelectric conversion efficiency (PCE) of PEDOT:PSS-Si HSCs. Here, we design a novel hybrid nanostructure of Co9S8 nanoparticles uniformly loaded onto the surface of multi-walled carbon nanotubes (Co9S8@N,P-MWCNT) as a dopant to improve the performance of PEDOT:PSS. The analysis of experimental data reveals that the dopant could effectively suppress the recombination losses of PEDOT:PSS-Si interface, which is conducive to the improvement of open circuit voltage (Voc). The HSCs reaching a PCE of 13.44%, while achieving a high Voc of 645 mV.

High sensitivity and broad detection range flexible capacitive pressure sensor based on rGO cotton fiber for human motion detection

Recently, flexible pressure sensors have attracted considerable interest in electronic skins, wearable devices, intelligent robots and biomedical diagnostics. However, the design of high sensitivity flexible pressure sensors often relies on expensive materials and complex process technology, which greatly limit their popularity and applications. Even worse, chemical-based sensors are poorly biocompatible and harmful to the environment. Here, we developed a flexible capacitive pressure sensor based on reduced graphene oxide cotton fiber by a simple and low-cost preparation process. The environmentally friendly sensor exhibited a comprehensive performance with not only ultra-high sensitivity (up to 15.84 kPa−1) and a broad sensing range (0–500 kPa), but also excellent repeatability (over 400 cycles), low hysteresis (⩽11.6%), low detection limit (<0.1 kPa) and wide frequency availability (sensitivity from 19.71 to 11.24 kPa−1, frequency from 100 Hz to 10 kHz). Based on its superior performance, the proposed sensor can detect various external stimuli (vertical stress, bending and airflow) and has been successfully applied for facial expression recognition, breathing detection, joint movement and walking detection, showing great potential for application in artificial electronic skin and wearable healthcare devices.

Application of Laser Treatment in MOS-TFT Active Layer Prepared by Solution Method.

The active layer of metal oxide semiconductor thin film transistor (MOS-TFT) prepared by solution method, with the advantages of being a low cost and simple preparation process, usually needs heat treatment to improve its performance. Laser treatment has the advantages of high energy, fast speed, less damage to the substrate and controllable treatment area, which is more suitable for flexible and large-scale roll-to-roll preparation than thermal treatment. This paper mainly introduces the basic principle of active layer thin films prepared by laser treatment solution, including laser photochemical cracking of metastable bonds, laser thermal effect, photoactivation effect and laser sintering of nanoparticles. In addition, the application of laser treatment in the regulation of MOS-TFT performance is also described, including the effects of laser energy density, treatment atmosphere, laser wavelength and other factors on the performance of active layer thin films and MOS-TFT devices. Finally, the problems and future development trends of laser treatment technology in the application of metal oxide semiconductor thin films prepared by solution method and MOS-TFT are summarized.

Multifunctional recycled wet wipe with negatively charged coating for durable separation of oil/water emulsion via interface charge demulsification

Plastic pollution and oily wastewater discharge are the main factors which threaten the ecological environment, and the controlling of the two kinds of pollution consumes a lot of resources. From the perspectives of pollution treatment and saving resources, using solid waste (plastic waste) to treat liquid waste (emulsion) may have economic and environmental protection benefits. Here, a negatively charged hydrogel-coated recycled wet wipe (RWW-NH) is prepared by spraying and crosslinking process, which will be applied in cationic surfactant-contained oily wastewater treatment. The negatively charged hydrogel coating can absorb CTAB molecules, and the recycled wet wipe serving as the porous architecture can promote the coalescence of oil droplets. The obtained composite membrane has superior separation performance for CTAB stabilized emulsion, and the membrane with double layers can continuously separate 4000 mL emulsion with a permeation flux of 3057 L m−2 h−1. Besides, RWW-NH can absorb cationic dyes and heavy metal ions, due to the negative charges and high-density phosphate groups of the coating, respectively. The as-prepared composite membrane with low cost and simple preparation process has both environmental and economic values, which provides a prospective application in environmental treatment.

Highly Sensitive and Reproducible SERS Substrates Based on Ordered Micropyramid Array and Silver Nanoparticles.

The construction of a highly sensitive and reproducible surface-enhanced Raman scattering (SERS) substrate is the key factor that restricts its practical application. In this paper, a three-dimensional (3D) SERS substrate based on ordered micropyramid array and silver nanoparticles (MPA/AgNPs 3D-SERS) was constructed using the roll-to-plate embossing technology and a hydrothermal method, which provided an efficient and low-cost preparation process for the SERS substrate. Using rhodamine 6G (R6G) as a probe molecule, the performance of an MPA/AgNP 3D-SERS substrate was studied in detail, whose minimum detection limit was 10-12 M and the enhancement factor was calculated as 8.8 × 109, indicating its high sensitivity. In addition, the minimum relative standard deviation (RSD) for the MPA/AgNP 3D-SERS substrate was calculated as 4.99%, and SERS performance basically had no loss after 12 days of placement, which indicated that the prepared SERS substrate had excellent stability and repeatability. At last, the thiram detection application of the MPA/AgNP 3D-SERS substrate was also investigated. The results showed that the minimum detection limit was 1 × 10-7 M, and quantitative analysis of pesticide residues could be realized. This research could provide useful guidance for the efficient and low-cost fabrication of highly sensitive and reproducible SERS substrates.

Eco-friendly superwettable functionalized-fabric with pH-bidirectional responsiveness for controllable oil-water and multi-organic components separation

Smart materials with controllable wettability have become one of the current research hotspots. Among them, the pH-responsive superwetting material is considered an ideal material because of its rapid response process and simple response mechanism. However, the pH-responsive materials reported previously could only perform wettability conversion in a single direction. In order to meet the demands of practical applications, it is indispensable to prepare the pH-bidirectional responsive superwetting material which can flexibly transform wettability in both directions. Based on this, a fluorine free and eco-friendly superwetting fabric with pH-bidirectional responsiveness was prepared by free radical polymerization and the combination of micro-nano hierarchical structure. A series of test results verified that the prepared fabric possessed excellent mechanical durability and chemical stability, satisfactory flux and separation efficiency. In addition, this work also successfully employed the prepared pH-bidirectional responsive superwetting fabric to realize the separation of three-phase oil-water-oil mixture. Surprisingly, the prepared fabric was also proved to be effective for the separation of multiple organic components, which was rarely reported in previous researches. Therefore, such pH-bidirectional responsive superwetting fabric will have broad application prospects in the field of oil-water separation and multi-organic components separation under the actual complex environment. In this paper, a functionalized-fabric with pH-bidirectional responsiveness was obtained by a low-cost, environmentally friendly and simple preparation process. The micro-nano hierarchical rough structure and the sensitive groups of acid and alkaline were integrated on a piece of fabric. The surface of this smart fabric exhibited superhydrophobicity-superoleophilicity in a neutral environment, and would transform into superhydrophilicity-underwater superoleophobicity under external stimulations of acid and alkaline, showing a flexible bidirectional wettability transformation. It was worth noting that the obtained fabric could separate various oil-water mixtures and successfully achieve the separation of three-phase oil-water-oil mixtures. Surprisingly, the resulted smart fabric could efficiently separate two noxious components (phenol and aniline) from the mixed organic phase. Therefore, this functionalized fabric will provide new insights for the application of oil-water separation and organic component separation materials, and can be expanded to the fields of pharmaceutical production, dye industry and chemical processes. • Bidirectional wettability conversion in the entire pH-range. • The fabrics can realize high-flux and high-efficient oil-water separation. • In-situ and continuous three-phase oil/water/oil mixtures separation. • The fabrics can separate multiple organic components (phenol, aniline, anisole). • The fabrics exhibit excellent durability and reusability.

In-Situ Preparation of High-Performance CNS/Cu Composites with Molten Salt Route

Carbon nanosheets (CNSs) reinforced copper composites are obtained with a molten salt route for uniform distribution of carbon in the copper matrix. The structures and properties of the composite are thoroughly characterized and tested. The mechanical properties of the composite are greatly improved compared to pure copper. The effects of annealing temperatures and carbon contents on the mechanical properties of composites are investigated and discussed. When the annealing temperature is 800∘C, the composite has excellent comprehensive properties. Its yield strength is 283 MPa, which is 3.14 times that of pure copper, and its hardness is 78[Formula: see text]HV, which is 1.77 times of pure copper. The simple and low-cost preparation process opens up a novel route for the preparation of high-performance copper-based composites.

Biogenetic Acellular Dermal Matrix Maintaining Rich Interconnected Microchannels for Accelerated Tissue Amendment.

Given that many people suffer from extensive skin damage, wound repair has drawn tremendous attention in research. Among the various assistant dressing materials that promote healing, a porcine acellular dermal matrix (PADM), as a skin substitute, can efficiently accelerate healing by promoting cell migration and proliferation. However, a simple, low-cost preparation process remains a challenge facing PADM development, particularly because of the inferior elasticity. To overcome these drawbacks, a CaCl2-ethanol-H2O solution (ternary solution) combined with an additional enzyme treatment was used to obtain a transparent, porous, and elastic PADM that retained the major extracellular matrix composition of the dermis. Our results indicated that alterations in the fiber organization and secondary structural changes in the collagen occurred after treatment. Furthermore, the in vivo wound healing and histological analyses clearly revealed an extremely expedited wound repair process following the application of the biocompatible PADM. In conclusion, this study provides new insights into the development of a transparent PADM with a porous structure and good elasticity that can be used as a skin substitute to accelerate the wound healing process. Moreover, this effective technique could potentially be used to extrapolate other decellularized materials in the future.

Recent Advances in Perovskite Photodetectors for Image Sensing.

In recent years, metal halide perovskites have been widely investigated to fabricate photodetectors for image sensing due to the excellent photoelectric performance, tunable bandgap, and low-cost solution preparation process. In this review, a comprehensive overview of the recent advances in perovskite photodetectors for image sensing is provided. First, the key performance parameters and the basic device types of photodetectors are briefly introduced. Then, the recent developments of image sensors on the basis of different dimensional perovskite materials, including 0D, 1D, 2D, and 3D perovskite materials, are highlighted. Besides the device structures and photoelectric properties of perovskite image sensors, the preparation methods of perovskite photodetector arrays are also analyzed. Subsequently, the single-pixel imaging of perovskite photodetectors and the strategies to fabricate narrowband perovskite photodetectors for color discrimination are discussed. Finally, the potential challenges and possible solutions for the future development of perovskite image sensors are presented.

Optimization of Mordenite Membranes Using Sucrose Precursor for Pervaporation of Water-Ethanol Mixtures.

Post-treated mordenite membranes were prepared using sucrose (C12H22O11) as a carbon precursor to block any pinholes and defects in the zeolite layer. The pervaporation (PV) process was used to separate ethanol from the water. The effects of the sucrose concentration and the pyrolysis temperature (650–850 °C) were investigated, and the resulting high separation performance compared to those post/pre-treated membranes was reported in the literature. In this study, mordenite carbon membranes yielded a water/ethanol separation factor of 990.37 at a water flux of 9.10 g/m2h. The influence of the operating temperature on the performance of the membrane also was considered. It was concluded that the selective adsorption of water through zeolite pores was achieved. The entire preparation procedure was achieved using a rapid, low-cost preparation process.

Cuprous iodide dose dependent passivation of MAPbI3 perovskite solar cells

MAPbI3 has been considered as a candidate for the active layer of perovskite solar cells in recent years. We proposed a device model to investigate the contribution of cuprous iodide (CuI) to MAPbI3 perovskite thin films to power conversion efficiency (PCE) and demonstrated that the dosage of CuI affects the grain size of thin films and the PCE. Through the results of the SEM analysis, we found that the grain boundaries of MAPbI3 perovskite films decreased with increases in the dosage of CuI and the grain size increased significantly from 164 nm ± 49 nm–299 nm ± 127 nm. In addition, the results of the PL measurement showed that the PL intensity decreased after addition of CuI to the MAPbI3 perovskite thin films, suggesting a reduction in the charge recombination. The XRD patterns indicated that the addition of CuI did not influence the main structure of the MAPbI3 perovskite. Interestingly, CuI plays a key role in the passivation of defects in MAPbI3 perovskite thin films, which can reduce non-radiative recombination and increase the fill factor and open-circuit voltage of the device. In this study, we adjusted the grain size and passivated the MAPbI3 thin film by controlling the dosage of CuI. We also increased the power conversion efficiency from 10% to 13%. This type of perovskite solar cell provided a simple, low cost preparation process for practical applications.

Green large-scale production of N/O-dual doping hard carbon derived from bagasse as high-performance anodes for sodium-ion batteries

Sodium-ion batteries are considered as a promising candidate for lithium-ion batteries due to abundant sodium resources and similar intercalation chemistry. Hard carbon derived from biomass with the virtue of abundance and renewability is a cost-effective anode material. Herein, hard carbon is derived from renewable bagasse through a simple two-step method combining mechanical ball milling with carbonization. The hard carbon electrodes exhibit superior electrochemical performance with a high reversible capacity of 315 mA-h/g. Furthermore, the initial capacity of the full cell, HC//NaMn0.4Ni0.4Ti0.1Mg0.1O2, is 253 mA·h/g and its capacity retention rate is 77% after 80 cycles, which further verifies its practical application. The simple and low-cost preparation process, as well as excellent electrochemical properties, demonstrates that hard carbon derived from bagasse is a promising anode for sodium-ion batteries.

Ultrasensitive immunosensor for detecting CEA based on double amplified signal of graphene loaded CoFe 2 O 4 /Ag nanoparticles

Using Ag-CoFe2O4-GO nanocomposite as biosensor interface, a novel unlabelled electrochemical immunosensor was designed to detect tumour marker carcinoembryonic antigen. Here, Ag-CoFe2O4-GO was synthesized by one-pot method as an immunological probe. They have the following advantages: (1) Silver nanoparticles have a strong redox capacity under applied voltage and good biocompatibility, so they can bind more antibodies; (2) GO has a large specific surface area, which can load more Ag NPs and CoFe2O4 nanoparticles, and has excellent conductivity; (3) CoFe2O4 is widely favoured by researchers due to its advantages such as low production cost and simple preparation process, The prepared Ag-CoFe2O4-GO nanocomposite can amplify the electrochemical signal; (4) The presence of GO can effectively prevent the agglomeration of Ag NPs nanoparticles and CoFe2O4 nanoparticles, promote the formation of electron transfer network, and contribute to the electron transfer of sensors. Under optimal condition, the current signal and the concentration of carcinoembryonic antigen were linear in the range of 1 pg mL < sp > −1 < /sp > ∼ 80 ng mL < sp > −1 < /sp , > and the detection limit was 0.3 pg mL < sp > −1 < /sp > (S/N = 3). Under certain conditions, the manufactured immunosensor has good reproducibility, selectivity and excellent stability. Thus it has certain clinical value for the detection of carcinoembryonic antigen.

Kinetic Studies of Methylene Blue Degradation using CaTiO3 Photocatalyst from Chicken Eggshells

This study details the kinetic of photodegradation of methylene blue in aqueous medium using CaTiO3 photocatalyst. The CaTiO3 catalyst was prepared by sol-gel reaction using CaCO3 derived from chicken eggshell and anatase TiO2 powder. The CaTiO3 particles were prepared using a mixture of starting materials in of (1:1); (1:3); (2:5) and (2:7) CaCO3/TiO2 molar ratio at T = 900°C. The physical and microstructural properties of CaTiO3 microstructural were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), Fourier Transform Infrared (FTIR) and UV/vis spectrometer. As prepared CaTiO3 particles with various composition of CaCO3/TiO2 were then applied for removal of dye molecules under simulated UV irradiation. The effect of initial dye concentration, catalyst composition, and degradation time on the adsorption property of CaTiO3 was systematically investigated. The results reveal that methylene blue (MB) molecules are efficiently adsorbed and degraded within 120 min using CaTiO3 catalysts. Considering the low-cost preparation process and considerably high photocatalytic performance obtained in this work, CaTiO3 can further be used as an efficient photocatalyst for organic pollutant removal from industrial wastewater.

Rice paste derived microporous carbon for advanced lithium–sulfur batteries

A nano–sized microporous carbon has been successfully prepared through a carbonization of rice paste followed by heat treatment process and ball–milling. The nano–sized porous carbon with a high specific surface area and abundant micropores can effectively increase the sulfur loading. After loading sulfur, the microporous–carbon/S with a sulfur content of 74.2% exhibited a remarkable initial capacity of 865 mAh g −1 at 0.2 A g −1 and maintained at 689 mAh g −1 over 100 cycles. Moreover, the composite displayed superior rate capabilities of 1132, 1078, 860 and 674 mAh g −1 at 0.1, 0.2, 0.5 and 1.0 A g −1 . The outstanding electrochemical capabilities and facile low–cost preparation process make the nano–sized microporous carbon as an excellent candidate for lithium sulfur batteries. • Nanostructured microporous carbon was developed. • It has a large number of micropores. • Microorous carbon exhibit a high capacity and rate performance. • High performance is ascribed to the microporous nanostructure.

Ultrahigh nitrogen-doped carbon/superfine-Sn particles for lithium ion battery anode

Graphitic carbon nitride (g-C3N4) can be indexed as a high-content N-doped carbon material, appealing great attentions in energy storage devices. However, poor conductivity and serious irreversible capacity loss were found for the g-C3N4 due to its high nitrogen content. Urea, dicyandiamide or melamine can be used as organic precursor to form g-C3N4 because they can be pyrolyzed into g-C3N4 easily. In this work, high nitrogen content (up to 17 at.%)-doped carbon materials embedded with superfine-Sn particle are synthesized by one-step thermal treatment of the g-C3N4 organic precursor and SnCl2 in a simple self-designed quartz tube. Regarding their high nitrogen doping content, large surface area and porous structure, the obtained material could deliver a high specific capacity and excellent capacity retention when applied as lithium ion battery anode. Its excellent rate performance is attributed to the high Li diffusion coefficient demonstrated by the GITT kinetics analysis. This extremely simple and low-cost preparation process could provide a new strategy to obtain high nitrogen content carbon-based materials.

From Amorphous Red Phosphorus to a Few Layers of Black Phosphorus: A Low-cost and Efficient Preparation Process

Abstract: In this work, we present an efficiency synthesis method of phosphorene from red phosphorus by means of black phosphorus. The latter was synthesized by using copper, tin, tin iodide and red phosphorus as precursor at low pressure-temperature. Characterizations with powder X-ray diffraction, scanning electron microscopy (SEM), energy dispersive spectrometry (EDX), high-resolution TEM (HR-TEM) and Raman spectroscopy were performed to confirm the high quality and purity of black phosphorus crystal. Liquid phase method was used to exfoliate black phosphorus to phosphorene in N-methyl-2-pyrrolidone (NMP) as solvent. Atomic force microscopy and STEM were used to confirm the exfoliation of black phophorus in a few layers of phophorene. Keywords: 2D materials, Red phosphorus, Black phosphorus, Phosphorene, Liquid-phase exfoliation.

Experimental data of CaTiO3 photocatalyst for degradation of organic pollutants (Brilliant green dye) - Green synthesis, characterization and kinetic study.

The data presented here focuses on the physicochemical characterization of perovskite CaTiO3 nanoparticles (orthorhombic) as photocatalyts and the kinetic study of their photodegradation performance toward organic pollutant, i.e. brilliant green (BG) which is azo derivatives dye. The CaTiO3 nanoparticles was synthesized using chicken eggshell-derived CaCO3 and anatase TiO2 with molar ratio of (1:1), (1:3), (2:5), and (2:7). The physical and microstructural properties of CaTiO3 were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), Fourier Transform Infrared (FTIR) and UV/vis spectrometer. The effect of initial dye concentration, catalyst composition, and catalyst dosage on the adsorption mechanism of dye on CaTiO3 was investigated in jacketed photoreactor under UV irradiation. The analysis reveals that BG molecules are efficiently chemisorbed, as indicated by pseudo first order kinetic, and degraded within 120 min. Considering the low-cost preparation process and high photocatalytic performance, the resultant CaTiO3 can further be used as an efficient photocatalyst for organic pollutant removal from aqueous and industrial wastewater.

Polypyrrole encapsulation-protected porous multishelled Co3O4 hollow microspheres for advanced all-solid-state asymmetric supercapacitors with boosted reaction kinetics and stability

Transition metal oxides (TMOs) have shown great potential in high-performance supercapacitors (SCs) because of their high theoretical capacities, low cost and simple preparation process. However, considerable challenges still remain in simultaneously improving their electrical conductivity, reaction kinetics and stability. Herein, we deliberately designed a polypyrrole encapsulation-protected porous multishelled Co3O4 hollow microspheres (pMS-Co3O4/PPy) composite via a modified carbon self-templating method and in situ oxidative polymerization route. The unique porous multishelled structure of the pMS-Co3O4 hollow microspheres assembled by interconnected Co3O4 nanoparticles can provide sufficient active sites, shorted ion diffusion paths and efficiently alleviate the structural strain. Meanwhile, the PPy encapsulation-protected nanolayers significantly improve their electrical conductivity, contribute pseudocapacitance and protect Co3O4 nanoparticles from structural pulverization-chemical dissolution into electrolyte. The prepared pMS-Co3O4/PPy electrodes exhibited a high specific capacitance (1292.2 F g−1 at 1 A g−1), excellent rate capability (1205.8 F g−1 at 10 A g−1) and cycle stability (ultrahigh capacitance retention of 91.5% for 5000 cycles), which has rarely been achieved in previously reported Co3O4-based electrodes. Furthermore, the assembled all-solid-state asymmetric supercapacitors (pMS-Co3O4/PPy//AC) delivered a high energy density of 40.2 Wh kg−1 at a power density of 761.7 W kg−1 and superior stability with a capacitance retention of 90.6% for 5000 cycles. This study offers an effective nanostructure design strategy to solve the issues of TMOs and develop high-performance energy storage systems.

Polyvinyl alcohol /Lyocell dual-layer paper-based separator for primary zinc-air batteries

We demonstrate a new polyvinyl alcohol (PVA)/Lyocell dual-layer (PLD) paper-based separator with high-efficiency and low-cost preparation process as a promising alternative to a commercialized composite separator applied in primary Zinc (Zn)-air batteries. The PLD paper-based separator is fabricated by dual-layer forming papermaking process, composed of PVA fiber layer and Lyocell fibrillated fiber layer. The dual-layer porous structure enables the PLD paper to have submicron-sized pores and good electrolyte retention. More notably, the pore size of the PLD paper can be tuned by controlling the specific surface area of Lyocell fibrillated fiber (herein, 7.1 m2 g−1 and 13.9 m2 g−1 Lyocell fibrillated fibers are exploited). Compared to a PVA/Lyocell monolayer (PLM) paper and a PLD paper containing 7.1 m2 g−1 fibrillated fiber, both a commercialized composite separator and a PLD paper containing 13.9 m2 g−1 fibrillated fiber provide superior discharge and high temperature storage performance.