Electrochemical reduction of CO2 to multicarbon (C2+) products is desirable because of the higher energy density and economic value of C2+ products and the significant scientific issue for coupling ...of multicarbons. However, efficient conversion of CO2 into C2+ products remains challenging because of the difficulty in C–C coupling. Recently, numerous papers have reported carbon-based materials for C2+ products production from CO2 electrochemical reduction. Because of the unique properties of carbon-based materials in C2+ production, carbon-based materials can be used as a potential alternative for the electrocatalytic conversion of CO2. This Review summarized recent progresses in the formation of C2+ oxygenates from CO2 reduction on carbon-based materials. In this Review, we highlighted the strategies available for achieving C–C coupling on carbon-based electrocatalysts and revealed the relationships between intermediate adsorption energy and the selectivity of oxygenate production from CO2 reduction. Moreover, we provided the understandings for fabricating active sites of CO2 reduction on carbon-based materials and related mechanisms of C2+ oxygenate generation. The remaining challenges and opportunities for the electrochemical conversion of CO2 into C2+ oxygenates were discussed.
Immunomodulation of macrophages against cancer has emerged as an encouraging therapeutic strategy. However, there exist two major challenges in effectively activating macrophages for antitumor ...immunotherapy. First, ligation of signal regulatory protein alpha (SIRPα) on macrophages to CD47, a “don't eat me” signal on cancer cells, prevents macrophage phagocytosis of cancer cells. Second, colony stimulating factors, secreted by cancer cells, polarize tumor‐associated macrophages (TAMs) to a tumorigenic M2 phenotype. Here, it is reported that genetically engineered cell‐membrane‐coated magnetic nanoparticles (gCM‐MNs) can disable both mechanisms. The gCM shell genetically overexpressing SIRPα variants with remarkable affinity efficiently blocks the CD47‐SIRPα pathway while the MN core promotes M2 TAM repolarization, synergistically triggering potent macrophage immune responses. Moreover, the gCM shell protects the MNs from immune clearance; and in turn, the MN core delivers the gCMs into tumor tissues under magnetic navigation, effectively promoting their systemic circulation and tumor accumulation. In melanoma and breast cancer models, it is shown that gCM‐MNs significantly prolong overall mouse survival by controlling both local tumor growth and distant tumor metastasis. The combination of cell‐membrane‐coating nanotechnology and genetic editing technique offers a safe and robust strategy in activating the body's immune responses for cancer immunotherapy.
A novel genetically edited nanoparticle is developed to trigger macrophage‐mediated antitumor immunity through a powerful two‐step strategy: blocking the CD47‐SIRPα pathway in the first step followed by repolarizing tumor‐associated macrophages in the second. This work offers a simple, safe, and effective strategy for activating the body's immune responses for cancer immunotherapy.
BiOCl single-crystalline nanosheets with exposed {001} and {010} facets were selectively synthesized via a facile hydrothermal route. The resulting BiOCl single-crystalline nanosheets with exposed ...{001} facets exhibited higher activity for direct semiconductor photoexcitation pollutant degradation under UV light, but the counterpart with exposed {010} facets possessed superior activity for indirect dye photosensitization degradation under visible light.
The generation of extremely short isolated attosecond pulses requires both a broad spectral bandwidth and control of the spectral phase. Rapid progress has been made in both aspects, leading to the ...generation of light pulses as short as 67 as in 2012, and broadband attosecond continua covering a wide range of extreme ultraviolet and soft X-ray wavelengths. Such pulses have been successfully applied in photoelectron and photoion spectroscopy and recently developed attosecond transient absorption spectroscopy to study electron dynamics in matter. In this Review, we discuss significant recent advances in the generation, characterization and applications of ultrabroadband, isolated attosecond pulses with spectral bandwidths comparable to the central frequency. These pulses can in principle be compressed to a single optical cycle.
Ferroptosis is a newly discovered form of regulated cell death dependent on iron and reactive oxygen species (ROS). It directly or indirectly affects the activity of glutathione peroxidases (GPXs) ...under the induction of small molecules, causing membrane lipid peroxidation due to redox imbalances and excessive ROS accumulation, damaging the integrity of cell membranes. Ferroptosis is mainly characterized by mitochondrial shrinkage, increased density of bilayer membranes, and the accumulation of lipid peroxidation. Myocardial ischemia-reperfusion injury (MIRI) is an unavoidable risk event for acute myocardial infarction. Ferroptosis is closely associated with MIRI, and this relationship is discussed in detail here. This review systematically summarizes the process of ferroptosis and the latest research progress on the role of ferroptosis in MIRI to provide new ideas for the prevention and treatment of MIRI.
We theoretically and experimentally demonstrate that carbon self-doping could induce intrinsic electronic and band structure change of g-C(3)N(4)via the formation of delocalized big π bonds to ...increase visible light absorption and electrical conductivity as well as surface area and thus enhance both photooxidation and photoreduction activities.
In this study, we demonstrate that the photocatalytic sodium pentachlorophenate removal efficiency of Bi2WO6 under visible light can be greatly enhanced by bismuth self-doping through a simple ...soft-chemical method. Density functional theory calculations and systematical characterization results revealed that bismuth self-doping did not change the redox power of photogenerated carriers but promoted the separation and transfer of photogenerated electron-hole pairs of Bi2WO6 to produce more superoxide ions, which were confirmed by photocurrent generation and electron spin resonance spectra as well as superoxide ion measurement results. We employed gas chromatography-mass spectrometry and total organic carbon analysis to probe the degradation and the mineralization processes. It was found that more superoxide ions promoted the dechlorination process to favor the subsequent benzene ring cleavage and the final mineralization of sodium pentachlorophenate during bismuth self-doped Bi2WO6 photocatalysis by producing easily decomposable quinone intermediates. This study provides new insight into the effects of photogenerated reactive species on the degradation of sodium pentachlorophenate and also sheds light on the design of highly efficient visible-light-driven photocatalysts for chlorophenol pollutant removal.
Electrochemical reduction of CO2 to chemical feedstocks is an attractive solution that prevents CO2 accumulation in the atmosphere, but it remains a great challenge to develop the cost-effective ...catalysts. Herein, we synthesized oxide-derived Cu/carbon (OD Cu/C) catalysts by a facile carbonization of Cu-based MOF (HKUST-1). The resulting materials exhibited highly selective CO2 reduction to alcohol compounds with total faradic efficiencies of 45.2–71.2% at −0.1 to −0.7 V versus reversible hydrogen electrode (RHE). High-yield methanol and ethanol has been achieved on OD Cu/C-1000 with the production rates of 5.1–12.4 and 3.7–13.4 mg L–1 h–1, respectively. Notably, the onset potential for C2H5OH formation is near −0.1 V (versus RHE), corresponding to ∼190 mV of overpotential, which is among the lowest overpotentials reported to date for the reduction of CO2 to C2H5OH. The improvements in activity and selectivity of the oxide-derived Cu/carbon might be attributed to the synergistic effect between the highly dispersed copper and the matrix of porous carbon. These findings provide a new insight into design of practical catalysts for decreasing atmospheric CO2 levels and synthesizing liquid fuels.
The oxygen reduction reaction (ORR) is one of the key steps in clean and efficient energy conversion techniques such as in fuel cells and metal–air batteries; however, several disadvantages of ...current ORRs including the kinetically sluggish process and expensive catalysts hinder mass production of these devices. Herein, we develop carbonized nanoparticles, which are derived from monodisperse nanoscale metal organic frameworks (MIL-88B-NH3), as the high performance ORR catalysts. The onset potential and the half-wave potential for the ORR at these carbonized nanoparticles is up to 1.03 and 0.92 V (vs RHE) in 0.1 M KOH solution, respectively, which represents the best ORR activity of all the non-noble metal catalysts reported so far. Furthermore, when used as the cathode of the alkaline direct fuel cell, the power density obtained with the carbonized nanoparticles reaches 22.7 mW/cm2, 1.7 times higher than the commercial Pt/C catalysts.
Display omitted
•The F-doped hierarchically porous carbon (FPC) was synthesized by a facile method.•The F content and species was tuned to enhance H2O2 selectivity.•A high-yield electrosynthesis of ...H2O2 could be achieved on FPC.•Incorporation of covalent CF2, 3 into carbon materials was crucial to H2O2 synthesis.
Electrochemical synthesis of hydrogen peroxide (H2O2) via two-electron pathway of oxygen reduction reaction is a promising alternative to the current anthraquinone process. The H2O2 production from O2 is a competing reaction with four-electron O2 reduction to H2O, and the selectivity is related to the adsorption energy of the OOH intermediate on electrocatalysts surface. Generally, the properties for binding of OOH intermediate on catalysts can be controlled by changing its electronic structure. Herein, the electronic structure of porous carbon materials was tuned by doping different types and contents of fluorine species. The yield of H2O2 generation depended on the F content and the best catalytic activity toward H2O2 electrosynthesis was obtained with F content of 3.41 at.%. The resultant F-doped porous carbon (FPC) catalysts exhibited good H2O2 selectivity of 97.5–83.0% and the H2O2 production rate could reach 112.6–792.6 mmol h−1 g−1 over the potential range of 0.2 V to −0.3 vs. RHE (pH 1). The density functional theory (DFT) calculations and experiments revealed that the incorporation of CF2, 3 into carbon plane promotes the activation of O2 molecule and facilitates desorption of OOH intermediate, which was crucial to H2O2 synthesis.
PDF
