The abundance of solar thermal energy and the widespread demands for waste heat recovery make thermoelectric generators (TEGs) very attractive in harvesting low‐cost energy resources. Meanwhile, ...thermoelectric refrigeration is promising for local cooling and niche applications. In this context there is currently a growing interest in developing organic thermoelectric materials which are flexible, cost‐effective, eco‐friendly and potentially energy‐efficient. In particular, the past several years have witnessed remarkable progress in organic thermoelectric materials and devices. In this review, thermoelectric properties of conducting polymers and small molecules are summarized, with recent progresses in materials, measurements and devices highlighted. Prospects and suggestions for future research efforts are also presented. The organic thermoelectric materials are emerging candidates for green energy conversion.
Organic thermoelectric materials are emerging candidates for direct energy conversion between heat and electricity. Based on organic conducting materials, which are abundant, organic thermoelectric generators (TEGs) are promising for the dawn of a new era in green energy.
Fundamentals of water electrolysis, and recent research progress and trends in the development of earth‐abundant first‐row transition‐metal (Mn, Fe, Co, Ni, Cu)‐based oxygen evolution reaction (OER) ...and hydrogen evolution (HER) electrocatalysts working in acidic, alkaline, or neutral conditions are reviewed. The HER catalysts include mainly metal chalcogenides, metal phosphides, metal nitrides, and metal carbides. As for the OER catalysts, the basic principles of the OER catalysts in alkaline, acidic, and neutral media are introduced, followed by the review and discussion of the Ni, Co, Fe, Mn, and perovskite‐type OER catalysts developed so far. The different design principles of the OER catalysts in photoelectrocatalysis and photocatalysis systems are also presented. Finally, the future research directions of electrocatalysts for water splitting, and coupling of photovoltaic (PV) panel with a water electrolyzer, so called PV‐E, are given as perspectives.
Fundamentals of water electrolysis, and recent research progress and trends in the development of earth‐abundant first‐row transition‐metal (Mn, Fe, Co, Ni, Cu)‐based oxygen evolution reaction (OER) and hydrogen evolution (HER) electrocatalysts working in acidic, alkaline, or neutral conditions are reviewed.
In recent years, the abuse of antibiotics has led to the pollution of soil and water environment, not only poultry husbandry and food manufacturing will be influenced to different degree, but also ...the human body will produce antibody. The detection of antibiotic content in production and life is imperative. In this review, we provide comprehensive information about chemical sensors and biosensors for antibiotic detection. We classify the currently reported antibiotic detection technologies into chromatography, mass spectrometry, capillary electrophoresis, optical detection, and electrochemistry, introduce some representative examples for each technology, and conclude the advantages and limitations. In particular, the optical and electrochemical methods based on nanomaterials are discussed and evaluated in detail. In addition, the latest research in the detection of antibiotics by photosensitive materials is discussed. Finally, we summarize the pros and cons of various antibiotic detection methods and present a discussion and outlook on the expansion of cross-scientific areas. The synthesis and application of optoelectronic nanomaterials and aptamer screening are discussed and prospected, and the future trends and potential impact of biosensors in antibiotic detection are outlined.
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Efficient, earth‐abundant, and acid‐stable catalysts for the oxygen evolution reaction (OER) are missing pieces for the production of hydrogen via water electrolysis. Here, we report how the ...limitations on the stability of 3d‐metal materials can be overcome by the spectroscopic identification of stable potential windows in which the OER can be catalyzed efficiently while simultaneously suppressing deactivation pathways. We demonstrate the benefits of this approach using gamma manganese oxide (γ‐MnO2), which shows no signs of deactivation even after 8000 h of electrolysis at a pH of 2. This stability is vastly superior to existing acid‐stable 3d‐metal OER catalysts, but cannot be realized if there is a deviation as small as 50‐mV from the stable potential window. A stable voltage efficiency of over 70 % in a polymer–electrolyte membrane (PEM) electrolyzer further verifies the availability of this approach and showcases how materials previously perceived to be unstable may have potential application for water electrolysis in an acidic environment.
Window of opportunity: Spectroscopic measurements allowed the identification of a stable potential window in which γ‐MnO2 is able to catalyze the oxygen evolution reaction under acidic conditions for more than 8000 hours. This shows how the limitations on the stability of 3d‐metal materials acting as electrocatalysts can be overcome.
Modification of the electronic structures of two benchmark donor–acceptor (D–A) copolymers poly(4,4′-bis(2-ethylhexyl)dithieno3,2-b:2′,3′-dsilole)-2,6-diyl-alt-(2,1,3-benzothiadiazole)-4,7-diyl ...(PSBTBT) and poly{2,5-bis(2-hexyldecyl)-2,3,5,6-tetrahydro-3,6-dioxopyrrolo3,4-cpyrrole-1,4-diyl}-alt-{2,2′:5′,2″-terthiophene-5,5″-diyl} (PDPP3T) by chemical doping is reported. Simply by dipping polymer films into dopant solution, high electrical conductivity is achieved and thermoelectric property of the films is optimized. Despite their deep HOMO levels, optical absorption extending continuously to 2000 nm is observed in PSBTBT, and a high power factor around 25 μW m–1 K–2 is obtained in PDPP3T. Furthermore, temperature-dependent measurement of electrical conductivity and Seebeck coefficients is carried out to understand transport mechanisms and energetic distribution of carrier density of states (DOS). In parallel, doping treatment and corresponding characterizations are performed on donor polymers poly(3-hexylthiophene) (P3HT) and poly(2,5-bis(3-dodecylthiophen-2-yl)thieno3,2-bthiophene) (PBTTT-C12) for comparison. Ultimately, based on comprehensive characterizations and comparisons of the four polymers in terms of bulk mobility, DOS, film microstructures, and molecular structures, etc., a primitive correlation between solution-processable polymeric semiconductors and thermoelectric properties of their doped products is established.
•Different polyaniline (PANI) nanostructures doped with different acids have been prepared.•p-Toluenesulfonic acid (p-TSA) doped nanowires have ZT value as high as 2.75×10−5.•The performance of ...nanowires is better than that of nanorods.
Polyaniline (PANI) nanostructures doped with different acids have been prepared through a soft template method. The structures, morphologies and thermoelectric (TE) properties of the as-prepared PANI nanostructures have been carefully investigated. Our results showed that doping level, types of doping acids, and morphologies of as-prepared nanostructures did have strong effect on TE properties. For example, we found that higher doping level in HCl-doped PANI nanowires did not give better thermoelectric performance although it is true in some curtain doping range. AcOH-doped samples became worse than HCl-doped ones due to the poor doping ability of AcOH. As to p-toluenesulfonic acid (p-TSA) doped nanowires, ZT value is 2.75×10−5 at 300K, which is 4 times higher than that of HCl-doped one because doped bulky anions make PANI chains more order. As to the morphology effect, two p-TSA doped samples (nanowires and nanorods) at the same doping level were prepared and the nanowires showed the better Seebeck coefficient and lower thermal conductivity. Comparing with nanorods, Seebeck coefficient of nanowires increased 164% while thermal conductivity reduced by 25% for nanowires. The ZT value for nanowires is 5 times higher than that of nanorods.
Studies on the association between blood fibrinogen levels and adverse outcomes in patients with acute ischemic stroke have produced controversial results. This meta-analysis aimed to examine the ...association of elevated fibrinogen levels with adverse outcomes in acute ischemic stroke patients.
Two authors comprehensively searched the articles indexed in PubMed and Embase databases until December 31, 2021. All cohort studies that assessed the value of fibrinogen level in predicting poor functional outcomes or all-cause mortality in acute ischemic stroke patients were included.
Nine studies reporting on ten articles involving 16,998 patients met the inclusion criteria. For the highest versus lowest fibrinogen group, the pooled adjusted risk ratio (RR) was 1.48 (95% confidence intervals CI 1.17-1.87) for poor functional outcomes defined by the modified Rankin Scale ≥ 3. In addition, elevated fibrinogen was not significantly associated with an increased risk of all-cause mortality (RR 1.76; 95% CI 1.42-2.20). Subgroup analysis suggested that there was no clear association between elevated fibrinogen levels and PFO in younger acute ischemic stroke patients (RR 1.16; 95% CI 0.87-1.53).
Elevated fibrinogen level at baseline is possibly an independent predictor of short-term poor functional outcome and long-term all-cause mortality, particularly in elderly acute ischemic stroke patients. Blood fibrinogen level may serve as a useful biomarker for risk classification of acute ischemic stroke patients.
Thermoelectric materials have attracted more attention in recent years, which can be corroborated by the increasing scientific publications. Moreover, the optimistic prediction for the thermoelectric ...industry proves that the practicability of thermoelectric technology is further acknowledged. Recently, benefitting from the rapid development of organic electronics, the research of organic thermoelectric (OTE) materials is receiving particular interest. Cooperation and complementation between organic and inorganic thermoelectric materials could promote the broader application of thermoelectric effect. To realize high conversion efficiency of thermoelectric device, high‐performance p‐ and n‐type OTE materials are both necessary. However, the instability of most n‐type organic materials in air impedes their application for high‐performance thermoelectric conversion. Therefore, more efforts should be made to promote relevant research and applications. Herein, the research progress on OTE materials (n‐type) and devices is reviewed to show readers some details of n‐type OTE research and give some guidelines for further explorations.
Lightweight and flexible organic thermoelectric materials are attracting more attention, driven by the growing demands for maintenance of free power for wearable electronics and internet of things. Remarkable developments have been achieved in the past years for n‐type organic thermoelectric materials. The research progress is reviewed to show the state‐of‐art achievements and give a brief view of this field.
Flexible thin films of poly(nickel‐ethylenetetrathiolate) prepared by an electrochemical method display promising n‐type thermoelectric properties with the highest ZT value up to 0.3 at room ...temperature. Coexistence of high electrical conductivity and high Seebeck coefficient in this coordination polymer is attributed to its degenerate narrow‐bandgap semiconductor behavior.
•Two flexible free-standing polypyrrole (PPy) nanotube films were prepared by using template method.•In this paper, for the first time, we fabricated free-standing PPy nanotube-based films for ...thermoelectric (TE) applications.•The ZT value of free-standing PPy nanotube film is 5.71×10−4 at 310K and ZTmax is 7.84×10−4 at 370K.
Flexible and lightweight organic thermoelectric (TE) devices have potential applications in self-powered health monitoring for humans and wearable self-powered gas/chemical detection. Two flexible and free-standing polypyrrole (PPy) nanotube films (PPy-1 and PPy-2) have been fabricated and the structures, morphologies and thermoelectric properties of the as-prepared PPy films have been carefully investigated. Our results show that the smaller size and longer length of PPy nanotubes are helpful to enhance the electrical conductivity and Seebeck coefficient while size and length have less effect on thermal conductivity.
