Low-cost Preparation Research Articles

Low-Grade Thermal Energy Harvesting and Self-Powered Sensing Based on Thermogalvanic Hydrogels.

Thermoelectric cells (TEC) directly convert heat into electricity via the Seebeck effect. Known as one TEC, thermogalvanic hydrogels are promising for harvesting low-grade thermal energy for sustainable energy production. In recent years, research on thermogalvanic hydrogels has increased dramatically due to their capacity to continuously convert heat into electricity with or without consuming the material. Until recently, the commercial viability of thermogalvanic hydrogels was limited by their low power output and the difficulty of packaging. In this review, we summarize the advances in electrode materials, redox pairs, polymer network integration approaches, and applications of thermogalvanic hydrogels. Then, we highlight the key challenges, that is, low-cost preparation, high thermoelectric power, long-time stable operation of thermogalvanic hydrogels, and broader applications in heat harvesting and thermoelectric sensing.

Low-cost preparation of ultra-high sensitivity Ce doped SnO2 ethanol gas sensor

Ce-doped (0 wt%, 2 wt%, 4 wt%, 8 wt%) SnO2 nanocomposites were prepared by a simple one-step hydrothermal method. Through various characterization methods, it was found that the SnO2 nanospheres doped with 4 wt% Ce were of high purity and mesoporous. The test results show that the sensor based on 4 wt% Ce-SnO2 has superior performance than others, and it exhibits a high response value (S = 59) to 100 ppm ethanol at 200 °C, short response/recovery times (3 s/7s), and excellent selectivity and long-term stability. The material is expected to be excellent materials for ethanol detection in the field of gas-sensitive sensors.

Electrode-free piezoelectric nanogenerator based on carbon black/polyvinylidene fluoride–hexafluoropropylene composite achieved via interface polarization effect

Flexible piezoelectric nanogenerators (PENGs) with high sensitivity, easy deformability, anti-corrosion features, and facile fabrication are highly advantageous for biological tissue sensing/monitoring applications in complex environments. The large-scale and low-cost preparation of flexible piezoelectric polymers requires additional electrode layers for charge collection, compromising the flexibility and corrosion resistance of the PENGs while increasing their fabrication difficulty and cost. In this study, we developed an electrode-free PENG based on a composite film composed of polyvinylidene fluoride–hexafluoropropylene (PVDF-HFP) as the matrix, and carbon black (CB) as the filler. With an appropriate content of approximately 5 wt%, and under the interface polarization effect, the CB particles in the composite film acted as both the inner electrode and the piezoelectric enhancer, thus realizing a sensing functionality without the use of an additional electrode. The effects of the positions of CB particles in the PVDF matrix on the potential distribution, and the functions of CB polarization in the inner electrode and piezoelectric enhancer were simulated using COMSOL Multiphysics software. An excellent piezoelectric performance was achieved, including a current of 0.66 μA, voltage of 17.6 V, and charge of 4.7 nC. Further, electrode-free PENGs, with the multi-self-polarization PVDF-HFP matrix exhibit a promising application as sensors for effectively monitoring human activities and complex environments and can be effectively repaired (up to 80 %) via a facile spray-coating process.

Profiling of amines in biological samples using polythioester-functionalized magnetic nanoprobe.

Introduction: The metabolic balance of amines is closely related to human health. It remains a great challenge to analyze amines with high-throughput and high-coverage. Methods: Polythioester-functionalized magnetic nanoprobes (PMPs) have been prepared under mild conditions and applied in chemoselective capture of amides. With the introduction of polythioester, PMPs demonstrate remarkably increased capture efficiency, leading to the dramatically improved sensitivity of mass spectrometry detection. Results: The analysis method with PMPs treatment has been applied in rapid detection of more than 100 amines in lung adenocarcinoma cell lines, mouse organ tissues, and 103 human serum samples with high-throughput and high-coverage. Statistical analysis shows that arginine biosynthesis differed between lung adenocarcinoma cell lines. Discussion: Phenylalanine, tyrosine and tryptophan biosynthesis differed between tissues. The combination indicators demonstrate a great diagnostic accuracy for distinguishing between health and lung disease subjects as well as differentiating the patients with benign lung disease and lung cancer. With powerful capture ability, low-cost preparation, and convenient separation, the PMPs demonstrate promising application in the intensive study of metabolic pathways and early diagnosis of disease.high-throughput and high-coverage. Here, polythioester-functionalized magnetic nanoprobes (PMPs) have been prepared under mild conditions and applied in chemoselective capture of amides. With the introduction of polythioester, PMPs demonstrate remarkably increased capture efficiency, leading to the dramatically improved sensitivity of mass spectrometry detection. The analysis method with PMPs treatment has been applied in rapid detection of more than 100 amines in lung adenocarcinoma cell lines, mouse organ tissues, and 103 human serum samples with high-throughput and high-coverage. Statistical analysis shows that arginine biosynthesis differed between lung adenocarcinoma cell lines. Phenylalanine, tyrosine and tryptophan biosynthesis differed between tissues. The combination indicators demonstrate a great diagnostic accuracy for distinguishing between health and lung disease subjects as well as differentiating the patients with benign lung disease and lung cancer. With powerful capture ability, low-cost preparation, and convenient separation, the PMPs demonstrate promising application in the intensive study of metabolic pathways and early diagnosis of disease.

Construction of Bi/Polyoxometalate doped TiO2 composite with efficient visible-light photocatalytic performance: Mechanism insight, degradation pathway and toxicity evaluation

Exploration of visible-light-responsive, efficient and durable photocatalysts is of great concern for removing organic dyes and antibiotics from the wastewater. Herein, a series of mesoporous TiO2-doped with polyoxometalates [H3PMo12O40] (PMo12) and loaded with Bi nanoparticles (NPs) composites were fabricated through a convenient electrospinning/calcination and hydrothermalmethods, which was labelled as × wt% Bi/PMo12 doped TiO2 (abbr. x% Bi/PT, x = 10, 20 and 30, respectively). In these composites, polyoxometalate PMo12 acts as a dopant to reduce the band gap value of TiO2, effectively expanding its visible light absorption and enhance its photocatalytic redox ability. Moreover, the Schottky junction between Bi NPs and PT further promotes the separation efficiency of the photoinduced carriers. Therefore, these as-prepared catalysts demonstrated outstanding and persistent photocatalytic activity for removing tetracycline (TC), enrofloxacin (EFA) and methylorange (MO) with visible-light (λ > 420 nm) illumination. Especially, 20 % Bi/PT specimen presented the optimal catalytic performance, whose degradation efficiencies for TC, EFA and MO reached 86.0 %, 90.9 % and 92.5 % with k = 0.03019, 0.01275 and 0.01199 min−1, respectively. The superoxide radical (⋅O2–), hydroxyl radical (⋅OH) and holes (h+) were proved to be the dominating active species in contaminants degradation through the trapping tests and electron spin resonance (ESR) measurements. Furthermore, the possible TC degradation pathways were established based on the identification of degradation products by high performance liquid chromatography-mass spectrometry (HPLC-MS). The toxicity of intermediates was also assessed through QSAR prediction. According to the energy band structure analysis, the corresponding photocatalytic mechanism was revealed. The current work provides several new insights for the design and preparation of low cost, efficient, stable and versatile photocatalysts.

Preparation of porous carbon materials from black liquor lignin and its utilization as CO2 adsorbents

Lignin-based porous carbon materials are estimated as promising CO2 capture adsorbents with thanks to their charateristics as abundant distribution, low-cost preparation and high stability. In this work, a series of porous carbon materials were synthesized from the pulping waste (black liquor lignin) through chemical activation and template method. The morphological structure, porosity and surface chemical properties of the obtained porous carbon materials identified by SEM, XRD, Raman, BET and XPS were highly influenced by the synthesis methods. The porous carbon material prepared by KOH activation (C-BLL-KOH) possessed the most disorder carbon structure, along with the largest BET surface area up to 1336.5 m2/g and the highest microporosity accounting for 93.2% of the total pore volume, which is beneficial for capturing CO2. The sulfur-contained functional groups in chemically-activated carbon materials were dominated by oxidized sulfur species and oxygen element was mainly in the form of hydroxyl groups. CO2 adsorption performance of these lignin-based porous carbon materials was carried out at different temperatures (0 °C, 25 °C and 50 °C) to investigate the effect of synthesis method. The most remarkable CO2 capture capacity was achieved for C-BLL-KOH, which was up to 5.20 mmol/g at 0 °C, 3.60 mmol/g at 25 °C and 2.23 mmol/g at 50 °C at a CO2 partial pressure of 100 kPa. This result suggested the KOH activation was an effective route to convert black liquor lignin to porous carbon materials as potential absorbents for CO2 capture.

Host-Defense-Peptide-Mimicking β-Peptide Polymer Acting as a Dual-Modal Antibacterial Agent by Interfering Quorum Sensing and Killing Individual Bacteria Simultaneously

Host defense peptides (HDPs) are one of the potentially promising agents for infection diseases due to their broad spectrum and low resistance rate, but their clinical applications are limited by proteolytic instability, high-cost, and complicated synthesis process. Here, we report a host-defense-peptide-mimicking β-peptide polymer that resists proteolysis to have enhanced the activity under physiological conditions, excellent antimicrobial efficiency even at high density of bacteria, and low cost for preparation. The β-peptide polymer demonstrated quorum sensing (QS) interference and bactericidal effect against both bacterial communities and individual bacterium to simultaneously block bacterial communication and disrupt bacterial membranes. The hierarchical QS network was suppressed, and main QS signaling systems showed considerably down-regulated gene expression, resulting in excellent biofilm eradication and virulence reduction effects. The dual-modal antibacterial ability possessed excellent therapeutic effects in Pseudomonas aeruginosa pneumonia, which could inhibit biofilm formation and exhibit better antibacterial and anti-inflammatory efficiency than clinically used antibiotics, levofloxacin. Furthermore, the β-peptide polymer also showed excellent therapeutic effect Escherichia coli pyogenic liver abscess. Together, we believed that the β-peptide polymer had a feasible clinical potential to treat bacterial infection diseases.

Experimental study on irradiation of perovskite solar cells

Solar cell is an important energy source for spacecraft. It is significant to study its resistance to space particle irradiation. In the past ten years, the research hotspot of solar cells has focused on the perovskite solar cells (PSCs) because of their advantages of long carrier lifetime, high light absorption performance, low cost and easy preparation. By now the photoelectric conversion efficiency of PSCs has reached to 25.5%. Recently, PSCs were found to be robust to space particle irradiation, which makes them possible to be used in the satellites and spacecraft. The antiradiation effects of perovskite solar cells with different cell structures and preparation processes have been studied, but the obtained experimental results are different. In this work, the experiments on radiations of protons, electrons and gamma rays of the same PSCs are carried out. The photoelectric characteristics before and after space particle irradiation are characterized, so as to analyze the radiation effect of PSCs. The experimental results show that the PSCs are sensitive to electron radiation and gamma radiation. With the increase of electron fluence and gamma total dose, the degradation of photoelectric characteristics of PSCs intensifies gradually. For gamma radiation, PSCs exhibit the most significantly radiation sensitivity. The PSCs are found to be robust to the proton irradiation. With the increase of proton fluence, the short-circuit currents of PSCs change little, the open-circuit voltages remain essentially unchanged, and the cell efficiency can be stably maintained at 94% of the pre-irradiation performance. Based on the above experimental data, a semi-empirical formula is established, and the radiation damage law of PSCs can be predicted with less experimental data, which will support the space application of PSCs.

A room temperature ferroelectric material with photoluminescence: (1,3-dicyclohexylimidazole)2MnCl4.

Molecular ferroelectric materials have been widely used in capacitors and sensors due to their low cost, light weight, flexibility and good biocompatibility. Organic-inorganic hybrid complexes, on the other hand, have received a great deal of attention in the luminescence field due to their low cost and simple preparation. The combination of ferroelectricity and photoluminescence in organic-inorganic hybrid materials not only leads to tunable optical properties, but also enriches potential applications of multifunctional ferroelectrics in optoelectronic devices. Here, we report a new luminescent ferroelectric material (1,3-dicyclohexylimidazole)2MnCl4 (DHIMC). Thermogravimetric analysis (TGA) was used to measure the mass change of the material at a measurement rate of 20 K min-1 from room temperature to 900 K, and we found that this material has good thermostability, which is up to 383 K. Meanwhile, UV-vis measurements showed that it is also a fluorescent material emitting a strong green fluorescence at the wavelength of 525 nm. The ferroelectricity of the crystal was determined by two different methods: the Sawyer-Tower method and the double-wave method (DWM). Particularly, the single crystal experiences a phase transition from the ferroelectric phase to the paraelectric phase during the heating/cooling process at 318 K/313 K and the space group changes from P1̄ (centrosymmetric) to P1 (non-centrosymmetric). This work will enrich multifunctional luminescent ferroelectric materials and their application in display and sensing.

Charge transfer doping of graphene oxide with nickel oxide nanoparticles for stable and efficient carbon-based, all-inorganic CsPbBr3 perovskite solar cells.

All-inorganic CsPbBr3 perovskite solar cells have received growing attention in the photovoltaic field due to their high stability, low cost, and simple preparation processes. However, the high-density defects in perovskite films and the large energy differences at interfaces have been the main challenges for achieving high power conversion efficiency and good stability. In this work, nickel oxide (NiOx) decorated graphene oxide (GO) is used as a hole collector at the perovskite/carbon interface for a carbon-based CsPbBr3 perovskite solar cell. The crystallinity of the CsPbBr3 perovskite layer and the hole extraction ability are markedly enhanced because of the p-type charge transfer doping of GO from oxygenic groups to NiOx. Finally, the all-inorganic CsPbBr3 perovskite solar cell achieves a power conversion efficiency of 8.59%. More importantly, the best solar cell free of encapsulation retains 94.2% of its initial efficiency in an air environment over 21 days.

Facile sulfation of cellulose via recyclable ternary deep eutectic solvents for low-cost cellulose nanofibril preparation.

Here we present a new method to treat cellulose with a sulfamic acid-urea-choline chloride (ternary deep eutectic solvent) system, which can realize both swelling and sulfation of cellulose. This can greatly reduce the energy consumption in the process of cellulose nanoization, and use it to successfully prepare food packaging films for eliminating odors. We hope that due its simplicity and resource-efficiency, this method will have a widespread influence on currently used (nano) cellulose modification protocols.

Preparation of sodium alginate-polyvinyl alcohol@PVDF hybrid membrane for efficient oil-water separation

Oily sewage is widespread in petrochemical and machinery manufacturing industries. Direct discharge not only wastes water and oil resources, pollutes the ecological environment, but also affects the survival and health of humans and other organisms. The traditional oil-water separation method has strong limitations, poor economy and low separation efficiency. Sodium alginate (SA) and polyvinyl alcohol (PVA) were uniformly coated on the surface of PVDF membrane, and superhydrophilic SA-PVA@PVDF hybrid membrane was prepared by multiple cyclic self-assembly. The oil-water separation experiment was carried out by using the membrane. The initial separation efficiency was 99.8%, and the overall separation efficiency remained above 98.3% after 10 cycles of regeneration experiments. This study provides a new idea for the low-cost, green and simple preparation of superhydrophilic-underwater superoleophobic separation materials.

A low-cost and high-yield green preparation method of graphdiyne and hydrogen-substituted graphdiyne and their photocatalytic properties

Graphdiyne (GDY), a new two-dimensional (2D) carbon hybrid material, because it can function as both an electron donor and acceptor and possesses a certain intrinsic band gap due to its unique sp and sp2 conjugate hybridization.

A simplified and facile preparation method for the [Ca24Al28O64]4+(e-)4 electride.

Wide application of novel materials often requires low-cost preparation methods. In this study, we present a simplified and facile preparation method for the [Ca24Al28O64]4+(e-)4 electride material (C12A7:e-). Successful preparation of the C12A7:e- electride was confirmed by XRD patterns and magnetic behavior analysis. The concentration of electrons in the prepared C12A7:e- powder was calculated to be approximately 2.23 × 1021 cm-3, as evaluated by iodometry and TPD. DFT calculations provided insight into the unique electronic structure of C12A7:e-. Additionally, the substitution of the Ca reductant with CaH2 led to a reduction in the solid-state reaction temperature from 1100 to 950 °C, which can be attributed to thermodynamic effects such as a reduction in ΔG°.

Photoresponse of CVD grown crystalline quantum dot-embedded covalent organic framework thin film.

Covalent organic frameworks (COFs) are a new family of novel 2D materials which are highly sought after for integration into future sensors and other devices for their highly porous structures and large surface areas. However, low-temperature large-area growth of these semiconductive materials with a clean surface for direct device applications is still a challenging task. To provide an on-chip photonic device, a COF366-Quantum dot (COF366-QDs) thin-film-based device fabricated by in situ chemical vapor deposition (CVD) is presented. The high-resolution transmission electron microscopy (HRTEM) displays the formation of the periodic, crystalline and porous framework of the COF layer with mono-dispersed QDs of average particle size of ∼2.5-3 nm. The fabricated COF366-QD layer acts as a photoactive layer in the photonic device with an Au-COFQD-Au structure where a conduction path is formed between the metal electrodes through a network of COF layer with embedded QDs. The device shows photoactive response under 514 nm visible light with a very low dark current of 4.36 × 10-11 A with a minimum light detection capability of 160 nW and a responsivity of ∼3.42 A W-1. The photonic device was highly stable for successive switching cycles with very low attenuation. To our knowledge, this is the first report of a Quantum dot embedded COF366 thin-film by chemical vapor deposition. The proposed interfacing of COF366-QD thin-films on silicon substrate using in situ low-temperature CVD technique can be highly valuable for the development of transfer-free, clean, and low-cost preparation of industrial-scale organic electronics, optoelectronic device applications, and lab-on-chip based technologies for a wide range of future applications.

Applications of Molecular Imprinting Technology in the Study of Traditional Chinese Medicine.

Traditional Chinese medicine (TCM) is one of the most internationally competitive industries. In the context of TCM modernization and internationalization, TCM-related research studies have entered a fast track of development. At the same time, research of TCM is also faced with challenges, such as matrix complexity, component diversity and low level of active components. As an interdisciplinary technology, molecular imprinting technology (MIT) has gained popularity in TCM study, owing to the produced molecularly imprinted polymers (MIPs) possessing the unique features of structure predictability, recognition specificity and application universality, as well as physical robustness, thermal stability, low cost and easy preparation. Herein, we comprehensively review the recent advances of MIT for TCM studies since 2017, focusing on two main aspects including extraction/separation and purification and detection of active components, and identification analysis of hazardous components. The fundamentals of MIT are briefly outlined and emerging preparation techniques for MIPs applied in TCM are highlighted, such as surface imprinting, nanoimprinting and multitemplate and multifunctional monomer imprinting. Then, applications of MIPs in common active components research including flavonoids, alkaloids, terpenoids, glycosides and polyphenols, etc. are respectively summarized, followed by screening and enantioseparation. Related identification detection of hazardous components from TCM itself, illegal addition, or pollution residues (e.g., heavy metals, pesticides) are discussed. Moreover, the applications of MIT in new formulation of TCM, chiral drug resolution and detection of growing environment are summarized. Finally, we propose some issues still to be solved and future research directions to be expected of MIT for TCM studies.

Prediction of the future challenge and development direction for perovskite cell

New clean energy is an important topic of energy development, while solar cells have always been an important branch of clean energy, and perovskite solar cells have been the focus of researchers because of their simple process, low cost, and flexible preparation. In this paper, we will introduce the background, structure, fabrication methods, superiority, and downside of perovskite cells, and predict possible future challenges and directions for the development of perovskite cells.

Perovskite Cells Based on Carbon Quantum Dots: Structure, Optimization

Perovskite ( ) photo voltaic cells (PSCs) based totally on blended perovskite minerals have attracted lots interest on the grounds that their inception. Due to its giant absorption coefficient, low cost, and convenient preparation, many researchers have conducted enormous lookup on it and explored whether or not exceptional buildings and supplies can enhance the performance of PSCs. Through the continuous efforts of researchers, the effectivity of PSCs has expanded from 3.8% when it was first born in 2009 to 25.5% now.Perovskite cells do, however, also have a number of flaws and room for development, including ility, insufficient photovoltaic performance, and perovskite skinny film crystal defects.Researchers have additionally tried many methods to enhance them, and one of the more tremendous techniques is to use carbon quantum dots (CQDs) as correction layers to enhance their performance. In this paper, the performance enhancement of CQDs on perovskite cells will be comprehensively confirmed from factors such as electron transport layer (ETL), perovskite thin films and hole transport layer (HTL) and the future PSCs will be prospected based on the modern-day results.

Two Facile Aniline-Based Hypercrosslinked Polymer Adsorbents for Highly Efficient Iodine Capture and Removal

Effective capture and safe disposal of radioactive iodine (129I or 131I) during nuclear power generation processes have always been a worldwide environmental concern. Low-cost and high-efficiency iodine removal materials are urgently needed. In this study, we synthesized two aniline-based hypercrosslinked polymers (AHCPs), AHCP-1 and AHCP-2, for iodine capture in both aqueous and gaseous phases. They are obtained by aniline polymerization through Friedel-Crafts alkylation and Scholl coupling reaction, respectively, with high chemical and thermal stability. Notably, AHCP-1 exhibits record-high static iodine adsorption (250 wt%) in aqueous solution. In the iodine vapor adsorption, AHCP-2 presents an excellent total iodine capture (596 wt%), surpassing the most reported amorphous polymer adsorbents. The rich primary amine groups of AHCPs promote the rapid physical capture of iodine from iodine water and iodine vapor. Intrinsic features such as low-cost preparation, good recyclability, as well as excellent performance in iodine capture indicate that the AHCPs can be used as potential candidates for the removal of iodine from radioactive wastewater and gas mixtures.

Self-Healing, Solvent-Free, Anti-Corrosion Coating Based on Skin-like Polyurethane/Carbon Nanotubes Composites with Real-Time Damage Monitoring

Self-healing anti-corrosion materials are widely regarded as a promising long-term corrosion protection strategy, and this is even more significant if the damage can be monitored in real-time and consequently repaired. Inspired by the hierarchical structure of human skin, self-healing, solvent-free polyurethane/carbon nanotubes composites (SFPUHE-HTF-CNTs) with a skin-like bilayer structure were constructed. The SFPUHE-HTF-CNTs were composed of two layers, namely, a hydrophobic solvent-free polyurethane (SFPUHE-HTF) containing disulfide bonds and fluorinated polysiloxane chain segments consisting of a self-healing layer and CNTs with good electrical conductivity consisting of a corrosion protection layer, which also allowed for the real-time monitoring of damage. The results of corrosion protection experiments indicated that the SFPUHE-HTF-CNTs had a low corrosion current density (8.94 × 10-9 A·cm-2), a positive corrosion potential (-0.38 V), and a high impedance modulus (|Z| = 4.79 × 105 Ω·cm2). The impedance modulus could still reach 4.54 × 104 Ω·cm2 after self-healing, showing excellent self-healing properties for anti-corrosion protection. Synchronously, the SFPUHE-HTF-CNTs exhibited a satisfactory damage sensing performance, enabling the real-time monitoring of fractures at different sizes. This work realized the effective combination of self-healing with corrosion protection and damage detection functions through a bionic design, and revealed the green, and low-cost preparation of advanced composites, which have the advantage of scale production.