The development of a high‐performance electrocatalyst for oxygen evolution reaction (OER) is imperative but challenging. Here, a partial sulfidation route to construct Ni2Fe‐LDH/FeNi2S4 ...heterostructure on nickel foam (Ni2Fe‐LDH/FeNi2S4/NF) by adjusting the hydrothermal duration is reported. The heterostructures afford abundant hydroxide/sulfide interfaces that offer plentiful active sites, rapid charge and mass transfer, favorable adsorption energy to oxygenated species (OH− and OOH) evidenced by the density functional theory calculations, which synergistically boost the alkaline water oxidation. In the 1.0 m KOH solution, Ni2Fe‐LDH/FeNi2S4/NF exhibits an excellent OER catalytic activity with a much smaller overpotential (240 mV) to reach the current density of 100 mA cm−2 than single‐phase Ni2Fe‐LDH/NF (279 mV) or FeNi2S4/NF (271 mV). More impressively, 2000 cycles of cyclic voltammetry scan for water oxidation results in the formation of a sulfate layer over the catalyst. The corresponding post‐catalyst demonstrates better OER activity and durability than the initial one in the alkaline simulated seawater electrolyte. The post‐Ni2Fe‐LDH/FeNi2S4/NF delivers smaller overpotential (250 mV) at 100 mA cm−2 and longer stability time than the original form (260 mV). The post‐formed sulfate passivating layer is responsible for the outstanding corrosion resistance of the salty‐water oxidation anode since it can effectively repel chloride.
Ni2Fe‐LDH/FeNi2S4/NF is prepared by a partial sulfidation of Ni2Fe‐LDH/NF. Abundant hydroxide/sulfide interfaces boost the alkaline water oxidation. Impressively, cyclic voltammetry activation results in the formation of a sulfate layer that largely enhances the corrosion resistance of the catalyst in the alkaline salty‐water electrolytes.
Regulating the metal‐support interaction of the anchored metal nanoclusters is recognized as valid approach to optimize the electrocatalytic performance through tuning the interfacial electronic ...structure. However, developing novel support and understanding the interfacial electron accumulation on modulating the reaction kinetics are still elusive. Herein, highly‐dispersed Ruthenium (Ru) nanoclusters anchored onto phosphorous doped molybdenum boride (Ru/P‐MoB) is developed through ultrafast microwave‐plasma (60 s) approach. The synthesized Ru/P‐MoB impressively promote the hydrogen evolution with low overpotentials of 34, 45, and 40 mV to drive 10 mA cm−2 in alkaline freshwater, alkaline seawater and acid media. Specially, it presents superior turnover frequency and mass/specific activity relative to Pt/C, Ru/C, and Ru/MoB. Moreover, the anion exchange membrane (AEM) electrolyzer cell based on Ru/P‐MoB can achieve 500 and 1000 mA cm−2 with small voltages of 1.71 and 1.78 V with good durability. Experimental and density functional theoretical (DFT) analysis reveal that the strong metal‐support interactions (Ru─Mo and Ru─P bonds) with generated interfacial electron‐enriched Ru, and then favoring the water‐molecule adsorption/dissociation and optimal H intermediate adsorption free energy. This work provides novel designing avenue to exploit electrocatalysts with outstanding catalytic performance under high current density at practical high‐temperature.
The interfacial electron‐enriched Ru endows the synthesized Ru/P‐MoB with excellent electrocatalytic performance for HER in alkaline freshwater/seawater and acid media. Moreover, the AEM electrolyzer cell based on Ru/P‐MoB can achieve 500 and 1000 mA cm−2 with small voltages of 1.71 and 1.78 V with good durability.
Senescence is a complex physiological process that can be induced by a range of factors, and cellular damage caused by reactive oxygen species (ROS) is one of the major triggers. In order to learn ...and solve age-related diseases, tracking strategies through biomarkers, including senescence-associated β-galactosidase (SA-β-gal), with high sensitivity and accuracy, have been considered as a promising solution. However, endogenous β-gal accumulation is not only associated with senescence but also with other physiological processes. Therefore, additional assays are needed to define cellular senescence further. In this work, a fancy fluorescent probe
SA-HCy-1
for accurately monitoring senescence is developed, with SA-β-gal and HClO as targets under high lysosomal pH conditions (pH > 6.0) specifically, on account of the role β-gal commonly played as an ovarian cancer biomarker. Therefore, precise tracking of cellular senescence could be achieved in view of these three dimensions, with response in dual fluorescence channels providing a ratiometric sensing pattern. This elaborate strategy has been verified to be suitable for biological applications by skin photo-aging evaluation and cellular passage tracing, displaying a significantly improved sensitivity compared with the commercial X-gal kit measurement.
A NIR fluorescent probe for monitoring senescence was developed with SA-β-gal and HClO as targets under high lysosomal pH conditions. The precise tracking of cellular/
in vivo
senescence was achieved with a ratiometric sensing pattern.
Layered double hydroxides containing metal cations are applied for chemical vapor deposition synthesis of single-walled carbon nanotubes. Particularly, a bimetallic FeCo layered double hydroxides ...affords synthesis of subnanometer single-walled carbon nanotubes with dominant (6, 5) tubes, the abundance of which is further improved by a two-phase extraction approach.
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•Layered double hydroxides are applied for growing carbon nanotubes.•Low reaction temperature favors the synthesis of (6, 5) tube.•Synergism between Fe and Co accounts for the narrow chirality distribution.•A two-phase extraction technique is used to enrich small diameter tubes.
High-quality single-walled carbon nanotubes (SWNTs) were synthesized on layered double hydroxides (LDHs) containing Fe and FeCo by CO chemical vapor deposition (CVD). Systematic investigations were performed to study the effects of temperature and catalyst composition on the diameter and chirality distributions of SWNTs. It was revealed that both catalysts produced subnanometer SWNTs at low reaction temperatures, correlated with the catalyst performances and reaction parameters. Particularly, SWNTs with enriched (6, 5) species were synthesized at 600 °C from LDHs containing bimetallic FeCo. Besides, the SWNT chirality distribution was further narrowed by a two-phase extraction method and the extracted (6, 5) SWNTs occupy about 57% of all semiconducting species. This work extends the development of robust LDH-based catalysts for chirality-selective synthesis of SWNTs, which paves the way to large scale production of subnanometer SWNTs for potential applications in electronics and optoelectronics.
Carbon fibers are placed onto substrate surface with dispersed Co particles to promote the growth efficiency of single-walled carbon nanotubes (SWNTs). During chemical vapor deposition (CVD) process, ...micro-spaces are fabricated between the carbon fibers and the substrate surface, which modify the Knudsen number of CO and increase its efficient contact with cobalt oxide nanoparticles, enhancing the reduction of catalysts and the nucleation of SWNTs. Compared with surface grown SWNTs without covering carbon fibers, SWNTs grown under carbon fibers demonstrate a much higher catalyst efficiency, i.e. a SWNT density as high as ∼140 SWNTs/μm2. X-ray photoelectron spectroscopy characterizations confirm that the presence of carbon fibers promotes the reduction of cobalt oxide catalyst particles and carbon dissolution inside catalyst particles, which are crucial for catalyst activation and subsequent SWNT nucleation. This work provides a new strategy for the efficient growth of SWNTs, which benefits high-density growth of SWNTs required for future nanoelectronics applications.
Micro-space generated by placing carbon fibers on top of supported catalyst particles promotes the reduction of catalyst and the carbon cap “lift off”, resulting in the efficient growth of single-walled carbon nanotubes by chemical vapor deposition. Display omitted
Herein, we introduced a nitrogen-alkali lignin-doped phenolic resin (N@AL
n
PR) to produce palladium nanoparticles through an
in situ
reduction of palladium in an aqueous phase, without the need for ...additional reagents or a reducing atmosphere. The phenolic resin nanospheres and the resulting palladium nanoparticles were extensively characterized. Alkali lignin created a highly conducive environment for nitrogen incorporation, dispersion, reduction, and stabilization of palladium, leading to a distinct catalytic performance of palladium nanoparticles in vanillin hydrodeoxygenation. Under specific conditions of 1 mmol of vanillin, 40 mg of catalyst, 1 MPa H
2
, 90 °C, and 3 h, the optimized Pd/N@AL
30
PR catalyst exhibited a nearly complete conversion of vanillin, 98.9% selectivity toward
p
-creosol, and good stability for multiple reuses. Consequently, an environmentally friendly lignin-based catalyst was developed and used for the efficient hydrodeoxygenation conversion of lignin-based platform compounds.
Homogenously dispersing single-walled carbon nanotubes (SWNTs) in solvents has been one critical step towards exploiting their exceptional properties in high-performance components. However, the ...solubility of SWNTs is severely limited by the inert tube surfaces and strong tube-tube van der Waals attractions. Starting with carbon nanotubides, i.e., negatively charged SWNTs reduced by alkali metals, we herein propose a sonication-free approach to prepare an aqueous dispersion of SWNTs. The approach combines the spontaneous dissolution of nanotubides in polar aprotic solvents with polyvinylpyrrolidone wrapping and dialysis in deionized H2O, which results in well-dispersed, neutralized SWNTs. The gelation of concentrated SWNT dispersion leads to the formation of hydrogels, which is subsequently transformed into SWNT aerogels through lyophilization. The prepared SWNT aerogels exhibit high-mass-sorption capacities for organic solvent absorption, paving the way towards harvesting the extraordinary properties of SWNTs.
Rheumatoid arthritis (RA) is well-known as a kind of autoimmune disease, which brings unbearable pain to the patients by multiple organ complications besides arthritis. To date, RA can be hardly ...cured, but early diagnosis and standard treatment can relieve symptoms and pain. Therefore, an effective tool to assist the early diagnosis of RA deserves considerable attention. On account of the overexpressed ONOO– during the early stage of RA, a near-infrared (NIR) receptor, Lyso-Cy, is proposed in this work by linker chemistry to expand the conjugated rhodamine framework by cyanine groups. Contributed by the pH-sensitive spiral ring in rhodamine, receptor Lyso-Cy has been found to be workable in lysosomes specifically, which was confirmed by the pH-dependent spectra with a narrow responding region and a well-calculated pK a value of 5.81. We presented an excellent ratiometric sensing protocol for ONOO– in an acidic environment, which was also available for targeting ONOO– in lysosomes selectively. This innovative dual-targeting responsive design is expected to be promising for assisting RA diagnosis at an early stage with respect to the joint inflammatory model established in this work at the organism level.
Photocatalytic H2 evolution as a resultful way to figure out energy problems is still inhibited by carrier separation efficiency and catalyst service life. Here, we report a hierarchical S-Scheme ...heterostructure of layered graphite carbon nitride and CdS nanoparticles coated with carbon film (g-C3N4/CdS@C) by a simple hydrothermal method for highly efficient visible-light-driven H2 evolution. The S-Scheme, comprising g-C3N4 and CdS, synergistically enhances the efficiency of carrier separation while maintaining the redox capacity of both components. The introduction of carbon film enhances the migration rate of carriers, in the meantime inhibits the photo corrosion of CdS to enhance the stability of catalyst. The g-C3N4/CdS@C achieves the H2 generation rate of 6.4 mmol g−1 h−1 and the apparent quantum yield of 12.7%, superior to most works on g-C3N4. This work provides a delicate S-Scheme photocatalyst and offers a valid strategy for prolonging the lifetime of transition metal sulfide-based materials.
•g-C3N4/CdS@C was synthesized via a facile one-pot hydrothermal method.•S-Scheme significantly improves the efficiency of carrier transfer and separation.•Photocorrosion of CdS can be suppressed by the introduction of carbon film.•g-C3N4/CdS@C exhibits superior photocatalytic activity and stability in HER.
