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Developing highly active single-atom sites catalysts for electrochemical reduction of CO2 is an effective and environmental-friendly strategy to promote carbon-neutral energy cycle and ameliorate global climate issues. Herein, we develop an atomically dispersed N, S co-coordinated bismuth atom sites catalyst (Bi-SAs-NS/C) via a cation and anion simultaneous diffusion strategy for electrocatalytic CO2 reduction. In this strategy, the bonded Bi cation and S anion are simultaneously diffused into the nitrogen-doped carbon layer in the form of Bi2S3. Then Bi is captured by the abundant N-rich vacancies and S is bonded with carbons support at high temperature, formed the N, S co-coordinated Bi sites. Benefiting from the simultaneous diffusion of Bi and S, different electronegative N and S can be effectively co-coordinated with Bi, forming the uniform Bi-N3S/C sites. The synthesized Bi-SAs-NS/C exhibits a high selectivity towards CO with over 88% Faradaic efficiency in a wide potential range, and achieves a maximum FECO of 98.3% at −0.8 V vs. RHE with a current density of 10.24 mA·cm−2, which can keep constant with negligible degradation in 24 h continuous electrolysis. Experimental results and theoretical calculations reveal that the significantly improved catalytic performance of Bi-SAs-NS/C than Bi-SAs-N/C is ascribed to the replacement of one coordinated-N with low electronegative S in Bi-N4C center, which can greatly reduce the energy barrier of the intermediate formation in rate-limiting step and increase the reaction kinetics. This work provides an effective strategy for rationally designing highly active single-atom sites catalysts for efficient electrocatalysis with optimized electronic structure.

Herein, we report a general strategy based on host-guest interactions to fabricate atomically dispersed biomimetic catalysts, which were evaluated by diboration of phenylacetylene. The structure and function of these mimics are quite similar to those of enzymes, namely, the atomically dispersed metal serves as an active site, the external macromolecular structure plays a role as an enzyme catalytic pocket to stabilize the reaction intermediates and the interactions between the intermediates and functional groups near to the active site can reduce the reaction activation energy.

Metal–organic framework (MOF) derived single-atom catalysts (SACs) feature unique active sites and adjustable topological structures, exhibiting high electrocatalytic performance in carbon dioxide reduction reactions (CO2RR). By modulating elements and atomic structures of MOF-derived SACs, the reaction pathway of CO2RR can be precisely regulated with designed conversion on CO, formate, methanol, methane, ethanol, acetone and other substances. In this review, the latest advances in MOF-derived SACs for CO2RR are comprehensively discussed. Main fabrication strategies of MOF-derived SACs, especially metal node strategy, coordination capture strategy and space restriction strategy, are introduced. Further regulations of the coordination environment of central atoms, including symmetrical M–N4 atomic interfaces, asymmetrical M–Nx atomic interfaces and hetero-atom doped atomic interfaces as well as the influence on catalytic performances are systematically discussed. For deep exploration of the mechanism of catalytic activity, new characterization techniques on SACs are illustrated, with emphasis on identifying the catalytic sites, geometrical structures and their dynamic behavior. Based on this, we finally present recent convincing studies of MOF-derived SACs on CO2RR categorized by the catalyzed products (C1 species and C2+ species). We hope this review will provide new insights on future research of SACs and CO2RR.

Metal phthalocyanine has been extensively studied as a catalyst for degradation of carbamazepine (CBZ). However, metal phthalocyanine tends to undergo their own dimerization or polymerization, thereby reducing their activity points and affecting their catalytic properties. In this study, a catalytic system consisting of O-bridged iron perfluorophthalocyanine dimers (FePcF16-O-FePcF16), multi-walled carbon nanotubes (MWCNTs) and H2O2 was proposed. The results showed MWCNTs loaded with FePcF16-O-FePcF16 can achieve excellent degradation of CBZ with smaller dosages of FePcF16-O-FePcF16 and H2O2, and milder reaction temperatures. In addition, the results of experiments revealed the reaction mechanism of non-hydroxyl radicals. The highly oxidized high-valent iron-oxo (Fe(IV)=O) species was the main reactive species in the FePcF16-O-FePcF16/MWCNTs/H2O2 system. It is noteworthy that MWCNTs can improve the dispersion of FePcF16-O-FePcF16, contributing to the production of highly oxidized Fe(IV)=O. Then, the pathway of CBZ oxidative degradation was speculated, and the study results also provide new ideas for metal phthalocyanine-loaded carbon materials to degrade emerging pollutants.

Selective hydrogenation is widely used in medicine, chemical production, printing and dyeing, health care products and other fields. A catalyst with excellent performance can not only improve the yield, but also produce great economic benefits. Single atom catalysts (SACs) can reduce the waste of metal resources in the synthesis process and have excellent catalytic performance in the catalytic reaction process. With the reduction of the particle size from nanoclusters to the single atom level, a sharp increase of surface energy and 100% atomic utilization provide a guarantee for their catalytic activity. However, these two factors are not the only reason for the excellent catalytic performance of SACs. Herein, the applications of SACs in the selective hydrogenation of unsaturated bonds (including carbon–carbon, nitrogen–oxygen, carbon–oxygen and carbon–nitrogen) are reviewed, and the factors affecting their catalytic activity are investigated by comparing the catalytic properties. Meanwhile, the effects of the synthesis method, composition content, monatomic coordination and charge relationship between the metal and carrier on the catalytic performance were introduced by combining different characterization and testing methods. A particular emphasis is given to the research progress of SACs in recent years and their future development and challenges.

Photocatalytic conversion of CO2 into value-added chemicals is considered to be a promising strategy to capture greenhouse gas as well as produce energy. The exploration of efficient and stable photocatalysts is crucial to promote CO2 reduction. Herein, we report the synthesis of a heterogeneous catalyst by integration of iron phthalocyanine (FePc) with g-C3N4via a simple reflux method, in which FePc works as the catalytic center and g-C3N4 acts as the photosensitizer. After 12 h of light irradiation, the CO yield by using the FePc/g-C3N4 catalyst is found to be 1696.96 μmol g−1 and no liquid products are detected. The mechanism for CO2 photoreduction over the FePc/g-C3N4 hybrid catalyst is proposed. To enhance its practicality and portability, we further load the powder catalyst on polyester fibers (PET). The obtained FePc/g-C3N4@PET exhibits high activity for CO2 reduction under both simulated and natural sunlight, with a CO yield of 493.35 μmol g−1 and 490.53 μmol g−1, respectively in 12 h. This work may pave the way to develop an approach for fabricating high-efficient 2D artificial photosynthetic systems for CO2 reduction.

The electrochemical CO2 reduction reaction (CO2RR) is of importance for reducing global CO2 emissions. Herein, we reported a highly active CO2RR catalyst, namely Co–N–Ni/NPCNSs, which is considered as an advanced single-site catalyst with Co–N–Ni bimetallic sites connected by a N bridge between Co and Ni. The N-bridged Co–N–Ni bimetallic sites were confirmed by the X-ray absorption spectroscopy. The Co–N–Ni/NPCNSs catalyst shows a higher turnover frequency of 2049 h−1 at a low overpotential of 370 mV and CO faradaic efficiency of 96.4% compared to that of Co–N/NPCNSs (1205 h−1 and 61.5%) and Ni–N/NPCNSs (404 h−1 and 45.0%) with single Co–N4 and Ni–N4 sites, respectively. In situ synchrotron radiation Fourier transform infrared spectra and DFT calculations show that N-bridged Co–N–Ni bimetallic sites promote the formation of COOH* intermediates, thus accelerating CO2RR.

We report for the first time that biomimetic polydopamine (PDA) nanoparticles are catalytically active for formaldehyde (HCHO) reforming into hydrogen (H2), where O2 acts as a co-catalyst. The catechol in PDA can activate O2 molecules to form ˙OOH and semiquinone radicals, which facilitate water dissociation and HCHO decomposition to realize efficient H2 production. This work offers new insights into the design of organic catalysts for aqueous-phase hydrogen evolution reactions.

Interface engineering has been demonstrated to have a great effect on designing high performance catalysts. In particular, the interface design at the atomic scale is always a fortress to be overcome by researchers. Herein, we in situ introduced triphenylphosphine into cobalt atom sites in a metal–organic framework via encapsulation and successfully synthesized a cobalt single-atom catalyst with a co-coordinated atomic interface structure of P and N (Co/Co1P1N3). Adopted as a counter electrode (CE) in dye-sensitized solar cells (DSSCs), Co/Co1P1N3 demonstrates a power conversion efficiency (PCE) of 8.51%, outperforming Co/Co1N4 (6.62%) counter electrode and commercial Pt (7.88%). We discover that the electron donation from the P dopant can reduce the electrostatic attraction between Co and I− ions, which favor I− desorption processes, sequentially boosting the activity of Co/Co1P1N3.

The hydrogen oxidation reaction (HOR) has recently attracted great attention, yet the poor performance of HOR over the platinum group metal-free (PGMs-free) catalysts in alkaline conditions strongly impedes the development of hydroxide-exchange membrane fuel cells. Here, we demonstrate that the phase and interface engineering of nickel carbide (Ni3C) nanobranches can significantly enhance the alkaline HOR performance. Specifically, such interface engineering is realized through a facile annealing treatment of a branched Ni3C nanostructure. As a promising PGMs-free HOR catalyst, the strong interfacial synergy of Ni/Ni3C significantly enhances the HOR performance in alkaline media, with the HOR activity being comparable to that of a commercial Pt/C catalyst, and it demonstrates excellent CO tolerance. Mechanism studies show that the interfacial synergy facilitates electron transfer from Ni to Ni3C and thus regulates the absorption strengths of *H and *OH. This work opens up a new avenue for the design of high-performance PGM-free catalysts for electrocatalysis and beyond.

We successfully fabricate a novel concave nanostructure that is composed of atomically dispersed Ru atoms in Pt3Sn nanoconcaves (Ru-Pt3Sn NCs), which shows enhanced performance in methanol electroxidation compared to commercial Pt/C. This could be ascribed to the stable intermetallic structure and active surface structure, as well as the synergy among Pt, Sn and Ru.

Heterogeneous catalysts with atomically precise metal sites have enabled unique insight into structure-property relationships in materials science. Herein, we report the construction and selective hydrogenation performance of a single-atom palladium catalyst by confining the palladium atoms into the six-fold N-coordinating cavities of graphitic carbon nitride (g-C3N4) through a facile spatial confinement-reduction approach under mild reducing conditions. Spherical aberration correction electron microscopy and extended X-ray absorption fine structure measurements confirm the presence of atomically dispersed palladium atoms stabilized by the g-C3N4 support. Its exceptional catalytic activity was demonstrated by the hydrogenation of styrene (98% conversion, 1.5 h) and furfural (conversion of 64% and selectivity of 99%, 4 h) and hydrodechlorination of 4-chlorophenol (99% conversion and 99% selectivity, 10 min). This palladium catalyst can be reused at least five times with negligible deterioration of its activity. Importantly, the palladium atoms retained their atomic dispersion following the thermal treatment. Moreover, this synthetic method can be scaled up while retaining similar catalytic activity. Fundamental insights are provided to elucidate how the material's structure significantly impacts the catalytic performance at the atomic scale.

A simple sequence repeat (SSR) marker was used to assess the genetic diversity and population structure of an endangered relic species Emmenopterys henryi Oliv., endemic to China. A total of 124 samples from six populations were analyzed using eight pairs of SSR primers. Total 114 alleles were detected with an average of 14.3 alleles per locus. The presence of null alleles can result in low genetic diversity parameters (He and allelic richness) for all loci and mostly likely caused the deviation from Hardy–Weinberg equilibrium (HWE). The Polymorphism information content (PIC) values were higher which indicates that selection of SSR markers were suitable choice for assessing the genetic diversity in E. henryi. Our results revealed that the natural populations of E. henryi have a high degree of genetic diversity. Genetic diversity amongst the six E. henryi populations in decreasing order were: GJY > LS > DWS > WYS > HS > JGS. Further, genetic structure and the Neighbor-Joining (NJ) cluster analysis indicated that there were cross-mixing among the 124 samples. Four populations (i.e., HS, DWS, JGS and WYS) were clustered in one group, whereas LS and GJY population were clustered separately as two groups. A Principal Component Analysis (PCA) also showed a similar clustering trend. The results of Fst (0.085) and AMOVA indicated that the genetic variation resided within the populations and existence of frequent gene exchanges among populations. Based on these results, populations with abundant genetic variation and rare alleles should be conserved in situ and ex situ. Furthermore, seeds from the different populations with high levels of genetic diversity could be collected and propagated in order to capture the maximum available genetic diversity. The present study on genetic diversity of E.henryi could be helpful in expanding the understanding on species survival and also for developing an effective long term conservation strategy.

Summary Surface vacancy engineering played a significant role in tailoring the structure and improving the performance of semiconductor nanocrystals (SNCs). Developing controllable vacancy engineering strategies to overcome kinetic energy barriers in multi-step reactions is anticipated to explore further synthesis mechanisms and functional nanomaterials. Herein, we exploited an effective surface-vacancy-engineering-initialized cation exchange (SVEICE) strategy to realize energy-unfavored cation exchange reactions from ternary CuInX2 (X = S, Se) to Cu, In dual-doped binary CdX, or ZnX SNCs, unprecedentedly. The sequential and selective creation of Cu and In vacancies on multi-component SNC surface is critical to break through kinetic energy barriers. The emission of dual-doped CdS:Cu/In SNCs crossed visible-NIR region due to the radiative transition from doped In level to Cu-doped e- or t-level, and the radiative recombination process could also be tailored by this strategy. Further energy analysis and experiments confirmed its versatility.

The film-forming behavior of falling film flow with a high-viscosity fluid in clamped channels was investigated numerically and experimentally. The present work puts forward and deeply investigates...

The demand for high-performance non-precious-metal electrocatalysts to replace the noble metal-based catalysts for oxygen reduction reaction (ORR) is intensively increasing. Herein, single-atomic copper sites supported on N-doped three-dimensional hierarchically porous carbon catalyst (Cu1/NC) was prepared by coordination pyrolysis strategy. Remarkably, the Cu1/NC-900 catalyst not only exhibits excellent ORR performance with a half-wave potential of 0.894 V (vs. RHE) in alkaline media, outperforming those of commercial Pt/C (0.851 V) and Cu nanoparticles anchored on N-doped porous carbon (CuNPs/NC-900), but also demonstrates high stability and methanol tolerance. Moreover, the Cu1/NC-900 based Zn-air battery exhibits higher power density, rechargeability and cyclic stability than the one based on Pt/C. Both experimental and theoretical investigations demonstrated that the excellent performance of the as-obtained Cui/NC-900 could be attributed to the synergistic effect between copper coordinated by three N atoms active sites and the neighbouring carbon defect, resulting in elevated Cu d-band centers of Cu atoms and facilitating intermediate desorption for ORR process. This study may lead towards the development of highly efficient non-noble metal catalysts for applications in electrochemical energy conversion.

The design of non-noble metal heterogeneous catalyst with superior performance for selective hydrogenation or transfer hydrogenation of nitroarenes to amines is significant but challenging. Herein, a single-atom Fe supported by nitrogen-doped carbon (Fe1/N-C) catalyst is reported. The Fe1/N-C sample shows superior performances for the selective hydrogenation and transfer hydrogenation of nitrobenzene to aniline at different temperatures. Density functional theory (DFT) calculations show that the superior catalytic activity for the selective hydrogenation at lower temperatures could be attributed to the effective activation of the reactant and intermediates by the Fe1/N-C. Moreover, the excellent performance of Fe1/N-C for the selective transfer hydrogenation could be attributed to that the reaction energy barrier for dehydrogenation of isopropanol can be overcome by elevated temperatures.

Main-group element indium (In) is a promising electrocatalyst which triggers CO2 reduction to formate, while the high overpotential and low Faradaic efficiency (FE) hinder its practical application. Herein, we rationally design a new In single-atom catalyst containing exclusive isolated Inδ+ -N4 atomic interface sites for CO2 electroreduction to formate with high efficiency. This catalyst exhibits an extremely large turnover frequency (TOF) up to 12500 h-1 at -0.95 V versus the reversible hydrogen electrode (RHE), with a FE for formate of 96 % and current density of 8.87 mA cm-2 at low potential of -0.65 V versus RHE. Our findings present a feasible strategy for the accurate regulation of main-group indium catalysts for CO2 reduction at atomic scale.

Electrocatalysis of four-electron oxygen reduction reaction (ORR) provides a promising approach for energy transfer, storage and oxygen monitoring. However, it is always accompanied by the reductio...

Herein, we report a negative pressure pyrolysis to access dense single metal sites (Co, Fe, Ni etc.) with high accessibility dispersed on three-dimensional (3D) graphene frameworks (GFs), during which the differential pressure between inside and outside of metal-organic frameworks (MOFs) promotes the cleavage of the derived carbon layers and gradual expansion of mesopores. In situ transmission electron microscopy and Brunauer-Emmett-Teller tests reveal that the formed 3D GFs possess an enhanced mesoporosity and external surface area, which greatly favor the mass transport and utilization of metal sites. This contributes to an excellent oxygen reduction reaction (ORR) activity (half-wave potential of 0.901 V vs. RHE). Theoretical calculations verify that selective carbon cleavage near Co centers can efficiently lower the overall ORR theoretical overpotential in comparison with intact atomic configuration.

Herein, we report efficient single copper atom catalysts that consist of dense atomic Cu sites dispersed on a three-dimensional carbon matrix with highly enhanced mesoporous structures and improved active site accessibility (Cu-SA/NC(meso)). The ratio of +1 to +2 oxidation state of the Cu sites in the Cu-SA/NC(meso) catalysts can be controlled by varying the urea content in the adsorption precursor, and the activity for ORR increases with the addition of Cu

Single-atom site (SA) catalysts on N-doped carbon (CN) materials exhibit prominent performance for their active sites being M-Nx. Due to the commonly random doping behaviors of N species in these CN, it is a tough issue to finely regulate their doping types and clarify their effect on the catalytic property of such catalysts. Herein, we report that the N-doping type in CN can be dominated as pyrrolic-N and pyridinic-N respectively through compounding with different metal oxides. It is found that the proportion of distinct doped N species in CN depends on the acidity and basicity of compounded metal oxide host. Owing to the coordination by pyrrolic-N, the SA Cu catalyst displays an enhanced activity (two-fold) for transfer hydrogenation of quinoline to access the valuable molecule tetrahydroquinoline with a good selectivity (99%) under mild conditions. The higher electron density of SA Cu species induced by the predominate pyrrolic-N coordination benefits the hydrogen transfer process and reduces the energy barrier of the hydrogenation pathway, which accounts for the improved catalytic effeciency.

Single-atom catalysts not only maximize metal atom efficiency, they also display properties that are considerably different to their more conventional nanoparticle equivalents, making them a promising family of materials to investigate. Herein we developed a general host–guest strategy to fabricate various metal single-atom catalysts on nitrogen-doped carbon (M1/CN, M = Pt, Ir, Pd, Ru, Mo, Ga, Cu, Ni, Mn). The iridium variant Ir1/CN electrocatalyses the formic acid oxidation reaction with a mass activity of 12.9 $${{{\rm{A}}\,{\rm{mg}}^{-1}_{{\rm{Ir}}}}}$$ whereas an Ir/C nanoparticle catalyst is almost inert (~4.8 × 10−3 $${{{\rm{A}}\,{\rm{mg}}^{-1}_{{\rm{Ir}}}}}$$). The activity of Ir1/CN is also 16 and 19 times greater than those of Pd/C and Pt/C, respectively. Furthermore, Ir1/CN displays high tolerance to CO poisoning. First-principle density functional theory reveals that the properties of Ir1/CN stem from the spatial isolation of iridium sites and from the modified electronic structure of iridium with respect to a conventional nanoparticle catalyst. Single-atom catalysts maximize metal atom efficiency and exhibit properties that can be considerably different to their nanoparticle equivalent. Now a general host–guest strategy to make various single-atom catalysts on nitrogen-doped carbon has been developed; the iridium variant electrocatalyses the formic acid oxidation reaction with high mass activity and displays high tolerance to CO poisoning.

Oxygen-involved electrochemical reactions are crucial for plenty of energy conversion techniques. Herein, we rationally designed a carbon-based Mn-N2C2 bifunctional electrocatalyst. It exhibits a half-wave potential of 0.915 V versus reversible hydrogen electrode for oxygen reduction reaction (ORR), and the overpotential is 350 mV at 10 mA cm-2 during oxygen evolution reaction (OER) in alkaline condition. Furthermore, by means of operando X-ray absorption fine structure measurements, we reveal that the bond-length-extended Mn2+-N2C2 atomic interface sites act as active centers during the ORR process, while the bond-length-shortened high-valence Mn4+-N2C2 moieties serve as the catalytic sites for OER, which is consistent with the density functional theory results. The atomic and electronic synergistic effects for the isolated Mn sites and the carbon support play a critical role to promote the oxygen-involved catalytic performance, by regulating the reaction free energy of intermediate adsorption. Our results give an atomic interface strategy for nonprecious bifunctional single-atom electrocatalysts.

The rational design of efficient single-atomic (SA) catalysts is essential and highly desirable but impeded by the lack of sufficient acknowledge between structure and property. To this end, it is critical to clarify the effect of the coordination structure of active metal centers on the catalytic activities for the design of such catalysts. Here, we report that different coordination structures of SA Pt catalysts can dramatically influence their activities for anti-Markovnikov hydroboration of alkenes. Compared with the other two coordination structures (Pt-N4 and Pt-O2), the SA Pt species coordinated with three O atoms (Pt-O3) display the highest turnover number value of 3288 for the hydroboration reaction to access the important alkylboronic esters. Density functional theory calculations reveal that a superior catalytic activity can be expected for alkene hydroboration over the three O coordinated Pt species due to the lowest reaction energy (Δ G ) limiting step from the reaction phase diagram.

Developing a convenient and effective method to prepare single-atom catalysts at mild synthetic conditions remains a challenging task. Herein, a voltage-gauged electrofiltration method was demonstr...

Self-assembly of colloidal nanocrystals (NCs) into large-scale superlattices with complex and controllable structures has attracted extensive attention due to their collective properties and promising device applications. Plasmonic NCs are very popular for long-range ordered superstructures by virtue of their collective nanogaps for electromagnetic field enhancement, in particular bulk-scale single-layer assembly. Large-area two-dimensional (2D) quasinanosheets (QNSs) composed of mono-component Au NCs or multi-component Au@ZnS core-shell hetero-nanocrystals (HNCs) were successfully prepared, via careful solvent evaporation-induced interfacial self-assembly. The entire self-assembly process was carried out on the liquid-air surface and mediated simply by tuning the operating temperatures and concentrations of the NCs. Specifically, monolayer and double-layer 2D QNSs in tens of micrometers scale with different stacking models were fabricated by precisely controlling the solvent evaporation rate and colloidal concentration.

Designing low-cost, high-efficiency, platinum-free electrocatalysts for the hydrogen oxidation reaction (HOR) in an alkaline electrolyte is of great importance for the development of anion exchange membrane fuel cells. Herein, we report a novel HOR catalyst, RuNi1, in which Ni is atomically dispersed on the Ru nanocrystals. To note, the as-prepared RuNi1 catalyst exhibits excellent catalytic activity and stability for HOR in alkaline media, which is superior to those of Ru-Ni bimetallic nanocrystals, pristine Ru, and commercial Pt/C catalysts. Density functional theory (DFT) calculations suggest that isolation of Ni atoms on Ru nanocrystals not only optimizes the hydrogen-binding energy but also decreases the free energy of water formation, thus leading to excellent electrocatalytic activity of RuNi1 catalyst. The results show that engineering a catalyst at an atomic level is highly effective for rational design of electrocatalysts with high performance.

The engineering coordination environment offers great opportunity in performance tunability of isolated metal single-atom catalysts. For the most popular metal-Nx (MNx) structure, the replacement of N atoms by some other atoms with relatively weak electronegativity has been regarded as a promising strategy for optimizing the coordination environment of an active metal center and promoting its catalytic performance, which is still a challenge. Herein, we proposed a new synthetic strategy of an in situ phosphatizing of triphenylphosphine encapsulated within metal-organic frameworks for designing atomic Co1-P1N3 interfacial structure, where a cobalt single atom is costabilized by one P atom and three N atoms (denoted as Co-SA/P-in situ). In the acidic media, the Co-SA/P-in situ catalyst with Co1-P1N3 interfacial structure exhibits excellent activity and durability for the hydrogen evolution reaction (HER) with a low overpotential of 98 mV at 10 mA cm-2 and a small Tafel slope of 47 mV dec-1, which are greatly superior to those of catalyst with Co1-N4 interfacial structure. We discover that the bond-length-extended high-valence Co1-P1N3 atomic interface structure plays a crucial role in boosting the HER performance, which is supported by in situ X-ray absorption fine structure (XAFS) measurements and density functional theory (DFT) calculation. We hope this work will promote the development of high performance metal single-atom catalysts.

Metastasis is the leading cause of death in melanoma patients. Aerobic glycolysis is a common metabolic feature in tumor and is closely related to cell growth and metastasis. Kaempferol (KAM) is one of the active ingredients in the total flavonoids of Chinese traditional medicine Sparganii Rhizoma. Studies have shown that it interferes with the cell cycle, apoptosis, angiogenesis and metastasis of tumor cells, but whether it can affect the aerobic glycolysis of melanoma is still unclear. Here, we explored the effects and mechanisms of KAM on melanoma metastasis and aerobic glycolysis. KAM inhibited the migration and invasion of A375 and B16F10 cells, and reduced the lung metastasis of melanoma cells. Extracellular acidification rates (ECAR) and glucose consumption were obviously suppressed by KAM, as well as the production of ATP, pyruvate and lactate. Mechanistically, the activity of hexokinase (HK), the first key kinase of aerobic glycolysis, was significantly inhibited by KAM. Although the total protein expression of HK2 was not significantly changed, the binding of HK2 and voltage-dependent anion channel 1 (VDAC1) on mitochondria was inhibited by KAM through AKT/GSK-3β signal pathway. In conclusion, KAM inhibits melanoma metastasis via blocking aerobic glycolysis of melanoma cells, in which the binding of HK2 and VDAC1 on mitochondria was broken.

Significance The Fenton-like process based on peroxymonosulfate (PMS) has been widely investigated and recognized as a promising alternative in recent years for the degradation of persistent organic pollutants. However, the sluggish kinetics of PMS activation results in prohibitive costs and substantial chemical inputs, impeding its practical applications in water purification. This work demonstrates that tuning the electronic structure of single-atom sites at the atomic level is a powerful approach to achieve superior PMS activation kinetics. The Cu-based catalyst with the optimized electronic structure exhibits superior performance over most of the state-of-the-art heterogeneous Fenton-like catalysts, while homogeneous Cu(II) shows very poor activity. This work provides insights into the electronic structure regulation of metal centers and structure–activity relationship at the atomic level.

BackgroundDietary factors are fundamental in tumorigenesis throughout our lifetime. A spicy diet has been ambiguous about the development of cancers, especially in the study of colon cancer metastasis. It is unclear whether long-term, high dose intake of capsaicin could promote cancer metastasis. Here, we utilized a metastasis mouse model to test the potential pro-metastasis role of capsaicin. ResultsLong-term continuous administration of capsaicin diet to mice will promote the formation of liver pre-metastatic niche to facilitate colon cancer cells metastasis. Bacteria translocation to liver is clearly observed. Capsaicin increases intestinal barrier permeability and disrupts gut vascular barrier by altering the composition and abundance of gut microbiota. Capsaicin not only changes the abundance of mucin-related bacteria like Akkermanisa and Muribaculaceae, but also bacteria involved in bile acids metabolism. Dysregulated bile acids profile is related to NKT cells recruitment in pre-metastatic niche, primary bile acid α-MCA could enhance the recruitment of NKT cells, while secondary bile acids GUDCA and THDCA impairs the recruitment of NKT cells. ConclusionThese findings reveal long term consumption of capsaicin would increase the risk of cancer metastasis through modulating the gut microbiota. Capsaicin disrupts gut barrier and promotes the translocation of bacteria to liver, while altered bile acids metabolism affects NKT cells recruitment in liver, forming a pre-metastatic niche and promoting cancer metastasis.

As some of the most promising alternatives to traditional non-degradable materials, photodegradable materials have advantages of environmental benignity and rapid degradation under simple conditions. In this work, nontoxic TiO

It is of great significance for improving electron transmission performance by changing of the outer ring structure of iron phthalocyanine. Herein, 4 (pyridine-2, 3-yl) iron phthalocyanine (FepyPc), as N-rich pyridyl-iron phthalocyanine derivative, was introduced to degrade pharmaceutical contaminants. The catalytic degradation of organic pollutants with FepyPc was studied by activating peroxymonosulfate (PMS) at room temperature. The results clarified that the removal rate of carbamazepine (CBZ) was close to 100% within 60 min and the calculated apparent rate constant was about 2 times larger than FePc, which proved that FepyPc had superior performance. Four active species were identified for the degradation of CBZ, including superoxide radical (•O

The literature has treated the dip coating of yield stress fluids with the Bingham number ( B i = τ c / K γ ˙ n , where τc, K, γ ˙ and n are the yield stress, consistency factor, shear rate and power-law exponent, respectively.) being larger than 1, and has ignored the influence of shear-dependent component ( K γ ˙ n ). This work simulated the dip-coating process for various simple yield stress fluids with Bi numbers below 1, and showed the importance of yield stress and shear-dependent component for the hydrodynamics inside the bath as well as the film thickness. The yielded-unyielded boundaries as well as the profiles of flow velocity and shear stress profiles were theoretically determined under final steady state. The main flow characteristics of drainage in the meniscus were captured. Under the negligible effect of surface tension on the film coating, a semi-empirical model of film thickness considering drainage effect is proposed with good prediction performance.

1,2-Dichloroethane (1,2-DCE) is a toxic volatile organic compound, which is harmful to the environment and human health. Herein, we develop a single-atom Ru catalyst anchored on the mesoporous schistose γ-Al

A Pd-doped Pt3Sn-based single atom alloy catalyst (Pd-Pt3Sn) was synthesized via a hydrothermal method. The overpotential of Pd-Pt3Sn is lower than that of commercial Pd/C and IrO2 catalysts at 10 mA cm-2. This is due to the synergistic effect between Pt, Sn and Pd and the influence of electronic effects on their catalytic performance.