As a new and popular material, single‐atom catalysts (SACs) exhibit excellent activity, selectivity, and stability for numerous important reactions, and show great potential in heterogeneous ...catalysis due to their high atom utilization efficiency and the controllable characteristics of the active sites. The composition and coordination would determine the geometric and electronic structures of SACs, and thus greatly influence the catalytic performance. Based on atom economy, rational design and controllable synthesis of SACs have become central tasks in the fields of low‐cost and green catalysis. Herein, an introduction to the recent progress in the precise synthesis of SACs including the regulation of the coordination structure and the choice of different systems is presented. Thereafter, the potentials of SACs in different applications are comprehensively summarized and discussed. Furthermore, a detailed discussion of the recent developments regarding the large‐scale preparation of SACs is provided, including the major issues and prospects for industrialization. Finally, the main challenges and opportunities of rapid large‐scale industrialization of SACs are briefly discussed.
The development and exploration of highly efficient single‐atom catalysts (SACs) is of enormous significance for achieving industrialization. The advanced progress of precise synthesis and practical application of SACs is summarized. Thereafter, the main challenges and future opportunities of large‐scale synthesis of SACs are discussed.
We report a supramolecular strategy to prepare conductive hydrogels with outstanding mechanical and electrochemical properties, which are utilized for flexible solid‐state supercapacitors (SCs) with ...high performance. The supramolecular assembly of polyaniline and polyvinyl alcohol through dynamic boronate bond yields the polyaniline–polyvinyl alcohol hydrogel (PPH), which shows remarkable tensile strength (5.3 MPa) and electrochemical capacitance (928 F g−1). The flexible solid‐state supercapacitor based on PPH provides a large capacitance (306 mF cm−2 and 153 F g−1) and a high energy density of 13.6 Wh kg−1, superior to other flexible supercapacitors. The robustness of the PPH‐based supercapacitor is demonstrated by the 100 % capacitance retention after 1000 mechanical folding cycles, and the 90 % capacitance retention after 1000 galvanostatic charge–discharge cycles. The high activity and robustness enable the PPH‐based supercapacitor as a promising power device for flexible electronics.
For whom the gel toils: Inspired by the dynamic network structure of animal dermis, a strong and robust conductive hydrogel is prepared by supramolecular assembly of polyaniline and polyvinyl alcohol. Flexible solid‐state supercapacitors based on the hydrogel show excellent capacitance and energy density and outstanding mechanical robustness.
Single-atom catalysts often exhibit unexpected catalytic activity for many important chemical reactions because of their unique electronic and geometric structures with respect to their bulk ...counterparts. Herein we adopt metal–organic frameworks (MOFs) to assist the preparation of a catalyst containing single Ni sites for efficient electroreduction of CO2. The synthesis is based on ionic exchange between Zn nodes and adsorbed Ni ions within the cavities of the MOF. This single-atom catalyst exhibited an excellent turnover frequency for electroreduction of CO2 (5273 h–1), with a Faradaic efficiency for CO production of over 71.9% and a current density of 10.48 mA cm–2 at an overpotential of 0.89 V. Our findings present some guidelines for the rational design and accurate modulation of nanostructured catalysts at the atomic scale.
Ovarian cancer is one of the most common gynecologic malignancy with poor prognosis. Recently, long noncoding RNAs (lncRNAs) have been identified as key regulators in cancer development. The current ...study investigated the role of lncRNA P73 antisense RNA 1T (TP73‐AS1) in ovarian cancer. Quantitative real‐time polymerase chain reaction determined the expression levels of TP‐73AS1, matrix metallopeptidases (MMPs) messenger RNA. Cell proliferative ability, cell invasion, and migration were CCK‐8 and colony formation, and transwell invasion and migration assays, respectively. The protein levels of matrix metallopeptidase 2 (MMP2) and MMP9 were measured by Western blot. TP73‐AS1 was upregulated in the ovarian cancer tissues and ovarian cancer cells, and upregulation of TP73‐AS1 was associated with poor prognosis. Knockdown of TP73‐AS1 significantly suppressed cell proliferation, invasion, and migration of SKOV3 cells, and overexpression of TP73‐AS1 promoted cell proliferation, invasion, and migration of OVCA429 cells. In addition, knockdown of TP73‐AS1 suppressed the in vivo tumor growth. Tumor metastasis RT2 profiler polymerase chain reaction array showed that MMP2 and MMP9 was significantly upregulated by TP73‐AS1 overexpression in ovarian cancer cells. TP73‐AS1 overexpression enhanced the expression of MMP2 and MMP9 in ovarian cancer cells. Knockdown of MMP2 and MMP9 attenuated the effects of TP73‐AS1 overexpression on cell invasion and migration. The clinical data showed that MMP2 and MMP9 were upregulated and positively correlated with TP73‐AS1 expression in ovarian cancer tissues. Collectively, our results demonstrated the oncogenic role of TP73‐AS1 in ovarian cancer, and targeting TP73‐AS1 may represent a novel approach in battling against ovarian cancer.
TP73‐AS1 was upregulated in the ovarian cancer tissues and ovarian cancer cells, and the long noncoding RNA TP73‐AS1 promotes ovarian cancer cell proliferation and metastasis via modulation of MMP2 and MMP9.
Platinum (Pt)-based catalysts have been unanimously considered the most efficient catalysts for the oxygen reduction reaction (ORR) in proton-exchange membrane fuel cells (PEMFCs). Unfortunately, the ...exorbitant cost of Pt hampers the widespread adoption and development of PEMFCs. Scientists have devoted tremendous efforts to achieving higher catalytic activity with less Pt usage by constructing delicate nanostructures. Substituting Pt with cheaper metals may be a feasible solution but suffers from a relatively low intrinsic activity. Recently, single-atom catalysts (SACs), which possess the highest metal utilization and excellent activity because of the minimum size of metal and unique coordination structure, are developing rapidly and have been regarded as a potential alternative to Pt-based materials. Here, we review the development of conventional Pt- and nonprecious-metal-based ORR catalysts and summarize recent achievement in SACs for the ORR. A brief perspective on the remaining challenges and future directions of SACs is also presented.
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Proton-exchange membrane fuel cells (PEMFCs) are now of great interest because of zero emission and high efficiency. Current PEMFCs require an unaffordable amount of Pt-based catalysts to overcome the sluggish kinetics of the oxygen reduction reation (ORR) on cathodes, hampering the widespread adoption of PEMFCs. Tremendous efforts have been devoted to achieving higher catalytic activity with less Pt usage by nanoscale engineering. Substituting Pt with cheaper metals may be also a feasible solution but suffers from low intrinsic activity. Recently, single-atom catalysts (SACs), which possess the highest metal utilization and excellent activity because of the minimum size of metal and unique coordination structure, have been regarded as potential alternatives. Here, we review the development of Pt- and nonprecious-metal-based ORR nanocatalysts and summarize recent achievements in SACs for the ORR. At last, a brief perspective on the remaining challenges and future directions of SACs for the ORR is presented.
Proton-exchange membrane fuel cells (PEMFCs) are considered the ideal devices for direct chemical-to-electrical energy conversion but suffer from the sluggish kinetics of the oxygen reduction reaction (ORR) on cathodes. For an overview of the recent progress in this field, this review introduces the mechanism and electrochemical evaluation of the ORR, elaborates on the development of conventional Pt- and nonprecious-metal-based catalysts for the ORR, summarizes recent achievements in the ORR, and presents the remaining challenges as well as future directions of single-atom catalysts.
Sepsis is caused by infection, which can ultimately lead to multiple organ dysfunction and even life-threatening. Early recognition and early treatment can significantly improve the prognosis of ...sepsis patients. However, the effect of using a single biomarker for early diagnosis of sepsis is still not ideal. In recent years, researchers have turned their attention to artificial intelligence technology for early diagnosis of sepsis. This paper briefly introduces the advantages and disadvantages of sepsis related inflammatory indicators, biomarkers, and scoring systems of disease severity for early identification of sepsis, and focuses on the research progress and limitations of artificial intelligence technology for early diagnosis of sepsis, aiming to seek new methods and ideas for early diagnosis of sepsis.
The design of active, selective, and stable CO2 reduction electrocatalysts is still challenging. A series of atomically dispersed Co catalysts with different nitrogen coordination numbers were ...prepared and their CO2 electroreduction catalytic performance was explored. The best catalyst, atomically dispersed Co with two‐coordinate nitrogen atoms, achieves both high selectivity and superior activity with 94 % CO formation Faradaic efficiency and a current density of 18.1 mA cm−2 at an overpotential of 520 mV. The CO formation turnover frequency reaches a record value of 18 200 h−1, surpassing most reported metal‐based catalysts under comparable conditions. Our experimental and theoretical results demonstrate that lower a coordination number facilitates activation of CO2 to the CO2.− intermediate and hence enhances CO2 electroreduction activity.
A remarkable carbon dioxide electroreduction catalytic performance with superior activity and high selectivity was achieved on atomically dispersed Co sites through coordination environment regulating. First step in picture: C–N fragments, 1000 °C; second step: NH3 treatment.
Although biotechnologies for astaxanthin production from Haematococcus pluvialis have been developed for decades and many production facilities have been established throughout the world, the ...production cost is still high. This paper is to evaluate the current production processes and production facilities, to analyze the R&D strategies for process improvement, and to review the recent research advances shedding light on production cost reduction. With these efforts being made, we intent to conclude that the production cost of astaxanthin from Haematococcus might be substantially reduced to the levels comparable to that of chemical astaxanthin through further R&D and the future research might need to focus on strain selection and improvement, cultivation process optimization, innovation of cultivation methodologies, and revolution of extraction technologies.
•Comprehensive description of current production methodologies of astaxanthin production from Haematococcus.•Inclusive review of recent R&D efforts in process optimization of astaxanthin production from Haematococcus.•Critical analysis of innovative production methodologies.•Research proposals for further developing the biotechnology.
Here we report a precise control of isolated single ruthenium site supported on nitrogen-doped porous carbon (Ru SAs/N–C) through a coordination-assisted strategy. This synthesis is based on the ...utilization of strong coordination between Ru3+ and the free amine groups (−NH2) at the skeleton of a metal–organic framework, which plays a critical role to access the atomically isolated dispersion of Ru sites. Without the assistance of the amino groups, the Ru precursor is prone to aggregation during the pyrolysis process, resulting in the formation of Ru clusters. The atomic dispersion of Ru on N-doped carbon can be verified by the spherical aberration correction electron microscopy and X-ray absorption fine structure measurements. Most importantly, this single Ru sites with single-mind N coordination can serve as a semihomogeneous catalyst to catalyze effectively chemoselective hydrogenation of functionalized quinolones.
Noble metal nanomaterials have been widely used as catalysts. Common techniques for the synthesis of noble metal often result in crystalline nanostructures. The synthesis of amorphous noble metal ...nanostructures remains a substantial challenge. We present a general route for preparing dozens of different amorphous noble metal nanosheets with thickness less than 10 nm by directly annealing the mixture of metal acetylacetonate and alkali salts. Tuning atom arrangement of the noble metals enables to optimize their catalytic properties. Amorphous Ir nanosheets exhibit a superior performance for oxygen evolution reaction under acidic media, achieving 2.5-fold, 17.6-fold improvement in mass activity (at 1.53 V vs. reversible hydrogen electrode) over crystalline Ir nanosheets and commercial IrO
catalyst, respectively. In situ X-ray absorption fine structure spectra indicate the valance state of Ir increased to less than + 4 during the oxygen evolution reaction process and recover to its initial state after the reaction.
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