Only rarely have polyoxometalates been found to form core–shell nanoclusters. Here, we succeeded in isolating a series of rare giant and all‐inorganic core–shell cobalt polyoxoniobates (Co−PONbs) ...with diverse shapes, nuclearities and original topologies, including 50‐nuclearity {Co12Nb38O132}, 54‐nuclearity {Co20Nb34O128}, 62‐nuclearity {Co26Nb36O140} and 87‐nuclearity {Co33Nb54O188}. They are the largest Co−PONbs and also the polyoxometalates containing the greatest number of Co ions and the largest cobalt clusters known thus far. These molecular Co−PONbs have intriguing and atomically precise core–shell architectures comprising unique cobalt oxide cores and niobate oxide shells. In particular, the encapsulated cobalt oxide cores with different nuclearities have identical compositions, structures and mixed‐valence Co3+/Co2+ states as the different sized Co−O moieties of the bulk cubic‐spinel Co3O4, suggesting that they can serve as various molecular models of the cubic‐spinel Co3O4. The successful construction of the series of the Co−PONbs reveals a feasible and versatile synthetic method for making rare core–shell heterometallic PONbs. Further, these new‐type core–shell bimetal species are promising cluster molecular catalysts for visible‐light‐driven CO2 reduction.
A series of rare Co−Nb‐based core–shell polyoxometalates containing 50, 54, 62 and 87 metal polyhedra is prepared. The cobalt oxide cores correspond to increasingly large molecular analogues of infinite cubic‐spinel Co3O4. They are the largest cobalt polyoxoniobates and the polyoxometalates with the greatest number of Co ions and the highest‐nuclearity cobalt clusters known thus far. They are shown to be efficient photocatalysts for CO2 reduction.
Although carbonates are the primary form of carbon subducted into the mantle, their fate during recycling is debated. Here we report the first coupled high‐precision Zn and Mo isotope data for ...Cenozoic intraplate basalts from western China. The exceptionally high δ66Zn values (+0.39 to +0.50‰) of these lavas require involvement of recycled carbonates in the mantle source. Variable δ98Mo compositions (−0.39 to +0.27‰) are positively correlated with Mo/Ce, best interpreted as mixing between isotopically light Mo from dehydrated oceanic crust and heavy Mo from recycled carbonates, which is also supported by positive coupling between δ66Zn and δ98Mo. Modeling reveals that involvement of ≤5% carbonate‐bearing oceanic crust fully resolves the observed δ66Zn–δ98Mo mantle heterogeneity probed by intracontinental basalts. Our study demonstrates that combined δ66Zn–δ98Mo data sets for mantle‐derived magmas can track recycled surficial carbonates in Earth's interior, providing a powerful geochemical tool for deep carbon science.
Plain Language Summary
Carbon is an element of life and studying its geological cycle is crucial for understanding Earth's evolution including formation of a life‐supporting atmosphere. Here we report the first combined high‐precision Zn and Mo isotope data for Cenozoic intraplate lavas from western China, showing that the basalts record ≤5% carbonate‐bearing oceanic crust components in their mantle source. Our results provide new evidence for surficial carbonates being delivered into the deep upper mantle, which adds to the debate about the deepest extent of the terrestrial carbon cycle.
Key Points
First combined zinc (Zn) and molybdenum (Mo) isotope data for mantle‐derived magmas to track the fate of subducted carbonates
Zn−Mo isotopic compositions of Cenozoic Tarim basalts suggest surficial carbonates being delivered into the deep upper mantle
We highlight the utility of combined Zn−Mo isotope data as a powerful tool in deep carbon science
A blockchain-based smart contract has the potential to allow the performance of credible transactions without third parties. This paper presents a universal framework for a blockchain platform that ...enables peer-to-peer (P2P) energy trading in the retail electricity market. Focusing attention on seeking energy-matching pairs from the supply and demand sides, and encouraging direct energy trading between producers and consumers, the P2P energy trading mechanism is proposed. The designed multidimensional blockchain platform implements a complete energy trading process. As smart contracts strictly execute the trading and payment rules without human interaction, the security and fairness of energy trading are significantly enhanced. Case studies in the Ethereum private chain demonstrate that the proposed mechanism has obvious advantages in reflecting market quotations, balancing profits of players, and facilitating the utilization of renewables. Based on such characteristics, players are incentivized to participate in the P2P energy trading. Moreover, the authentic gas consumption and computational time to the smart contract indicate that this platform is able to achieve an efficient and effective transaction with multi-player participation.
•This paper presented a P2P energy trading mechanism with the double auction.•A universal blockchain platform for decentralized energy trading was proposed.•The designed smart contract provides secure and automatic energy trading services.•Simulation results showed the feasibility and efficiency of the proposed platform.
Development of special organic materials that are able to absorb light energy in the second near-infrared window (NIR-II) is significantly important for treating deep-tissue-buried diseases or ...supplying power to implantable electronic devices. Herein, a narrow bandgap donor–acceptor (D-A) conjugated polymer with thiophene-fused benzodifurandione-based oligo(p-phenylenevinylene) (TBDOPV) as acceptor part and 2,2′-bithiophene (DT) as donor part was developed and exploited as a photothermal conversion material with high extinction coefficient and robust photostability in the NIR-II window. According to transient absorption analysis results, the photothermal conversion ability of this polymer is attributed to the fast internal conversion (IC) process. The high photothermal conversion efficiency makes this polymer a promising NIR-II adsorbing antenna to remotely actuate thermo-dependent devices, e.g., high-performance photothermal–electrical and photothermal–mechanical converters.
Given the comparatively lower rotational barriers, the catalytic asymmetric construction of axially chiral biaryl structures, especially those containing a five‐membered heterocycle, still remains a ...challenge. Herein, we described a general and modular protocol to access atropisomeric arylpyrazole scaffolds containing a phosphorus unit by a dipeptide phosphonium salt catalyzed reaction involving an oxidative central‐to‐axial chirality conversion. This reaction features excellent yields and enantioselectivities, broad substrate scope, and a low catalyst loading, delivering axially chiral phosphine compounds.
A highly enantioselective reaction has been developed for the construction of axially chiral arylpyrazole skeletons with phosphorus unit. The reaction proceeds through a sequential Huisgen‐type cycloaddition/aromatization process with central‐to‐axial chirality conversion using a dipeptide‐phosphonium salt catalyst. Arylpyrazole‐based atropisomeric phosphorus compounds are obtained in high yields with excellent enantioselectivities.
Light-up luminescence sensors have been employed in real-time in situ visual detection of target molecules including volatile organic compounds (VOCs). However, currently employed light-up sensors, ...which are generally based on the aggregation-induced emission (AIE) or solvent-induced energy transfer effect, exhibit limited sensitivity for light-up detection and poor recycling performances thereby significantly hindering their industrial applications. Inspired by the low-temperature enhanced luminescence phenomenon, we herein propose and show that a guest-lock-induced luminescence enhancement mechanism can be used to realize the ultrafast light-up detection of target VOCs. Through introduction of chlorinated hydrocarbons to lock the molecular vibrations within a designed Cu4I4-based metal–organic framework (MOF), luminescence intensity could be enhanced significantly at room temperature. This guest-lock-induced luminescence enhancement is brought about by weak supramolecular interactions between the host framework and the guest molecules, allowing highly sensitive and specific detection of the guest vapor with ultrafast response time (<1 s). Single-crystal X-ray diffraction (SCXRD) analysis of guest molecules-loaded MOFs and density functional theory (DFT) calculations were employed to investigate the host–guest interactions involved in this phenomenon. Moreover, the above MOF sensor successfully achieved real-time detection of a toxic chloroaromatic molecule, chlorobenzene. The guest-lock-induced light-up mechanism opens up a route to discovering high-performance ultrafast light-up luminescent sensors for real-time detection applications.
A diffuse magmatic province covering central‐eastern Asia continent displays a compositional transition at 120–100 Ma and probably reflects melting initiation in isotopically enriched lithospheric ...mantle, followed by melting of the asthenosphere. However, the cause for the transition across such a vast landmass remains poorly constrained. Here, analyses of newly found Chaoge basalts (∼95 Ma, central Asia) and compiled data from across the basaltic province are combined to reveal the factors controlling the basalt dichotomy. The Chaoge basalts are considered to originate from a hot pyroxenite‐bearing asthenosphere with potential temperatures of ∼1,450°C, overlapping the source thermochemical conditions for most post‐transition basaltic rocks. The asthenosphere in 120–100 Ma is suggested to be hotter and to have controlled the compositional transition in the studied basaltic province. We suggest that asthenospheric warming resulted from prolonged continental thermal blanketing and can account for other diffuse igneous provinces with similar compositional variations and tectonic histories.
Plain Language Summary
A diffuse magmatic province covering central‐eastern Asia continent occupies a time span from Late Mesozoic to the present and consists of many basaltic fields, each including numerous small‐volume monogenic basaltic extrusions. The spatially and temporally dispersed basaltic rocks show a concurrent compositional transition at 120–100 Ma but the related causes remain unclear. Here, the newly found Chaoge basalts (∼95 Ma, central Asia) and a data synthesis of the Cretaceous‐Cenozoic basaltic province reveal the factors controlling the basalt dichotomy. The Chaoge basalts and other post‐transition equivalents are shown to be derived from hot pyroxenite‐bearing asthenospheric domains with potential temperatures higher than the ambient mantle. Such overheated asthenosphere is inferred to have existed at 120–100 Ma and controlled the basalt dichotomy. That is, the melting initiated in strongly metasomatized lithospheric mantle to produce the pre‐transition basalts under a normal thermal mantle state, followed by a magmatic hiatus due to the drainage of the fusible components; later melting occurred in the overheated asthenosphere to produce the post‐transition basaltic rocks. We suggest that this overheating‐driven basaltic dichotomy is a natural outcome of prolonged thermal blanketing of large continental lithosphere and should have general relevance.
Key Points
Newly reported ∼95 Ma basalts in central Asia record melting of hot (∼1,450°C) pyroxenite‐bearing asthenosphere
Overheated asthenosphere (>1,450°C) controlled the 120–100 Ma compositional transition of basaltic rocks across central‐eastern Asia
The asthenospheric warming is ascribed to prolonged thermal blanketing of coherent continental lithosphere
In this review, we summarize the origin and advancements of iridium-catalyzed asymmetric allylic substitution reactions during the past two decades. Since the first report in 1997, Ir-catalyzed ...asymmetric allylic substitution reactions have attracted intense attention due to their exceptionally high regio- and enantioselectivities. Ir-catalyzed asymmetric allylic substitution reactions have been significantly developed in recent years in many respects, including ligand development, mechanistic understanding, substrate scope, and application in the synthesis of complex functional molecules. In this review, an explicit outline of ligands, mechanism, scope of nucleophiles, and applications is presented.
•The 800-Ma Shimian mafic-ultramafic mélange is an SSZ-type ophiolite.•South China was not located in the centre of Rodinia.•A giant Andean-type arc system existed along the NW margin of Rodinia.
The ...configuration of the supercontinent Rodinia has long been a matter of debate; the key controversy is the position of South China in Rodinia. We report an incomplete Neoproterozoic ophiolite sequence, including gabbros and serpentinized peridotites intruded by mafic dikes, near Shimian (Sichuan Province), along the western margin of the Yangtze Block in South China. Serpentinized peridotites have very low REE (0.14–1.16ppm) and trace element concentrations, and are interpreted as parts of a depleted mantle sequence. Chromites from the serpentinized peridotites have low TiO2 (<0.3wt%) and Fe2O3 (<7.6wt%), and moderate Cr/(Cr+Al) (0.48–0.67) and Mg/(Mg+Fe2+) (0.42–0.67) ratios and are clearly indicative of strong depletion of the host peridotites, similar to those of supra-subduction zone (SSZ). Mafic dikes and gabbros contain zircon grains with similar U-Pb ages of ∼800Ma, and are chemically akin to MORB-like tholeiitic basalts and boninite-series volcanic rocks reported in other SSZ ophiolites and in the Izu-Bonin-Mariana arc system. Therefore, the serpentinized peridotite, mafic dikes and gabbros together appear to form a SSZ-type ophiolite assemblage preserving the accretion of oceanic lithosphere to the western Yangtze Block. The age and location of the Shimian ophiolite rule out the possibility that South China was located in the centre of Rodinia. Instead, the Neoproterozoic arc-affinity igneous rocks at the western margin of the Yangtze Block are well correlated with those in Greater India and Madagascar. These three blocks thus together formed a giant Andean-type arc system along the NW margin of Rodinia that existed for more than 100Mys.
CdS nanoparticle-decorated covalent triazine-based frameworks (CdS NPs/CTF-1) were controllably synthesized via a facile one-pot solvothermal method. Due to the Lewis basic nature of well-defined ...nitrogen sites in triazine units of CTF-1, highly dispersed and size-controlled CdS NPs were obtained and stabilized on the surface of CTF-1 layers. The as-prepared CdS NPs/CTF-1 assembly showed higher photocatalytic activity in a hydrogen evolution reaction under visible light irradiation as compared with pure CdS and CTF-1 and their physical mixture. The superior photocatalytic performance observed over CdS NPs/CTF-1 was ascribed to the highly dispersed CdS NPs with strong interaction to CTF-1 layers. The strong NP-on-layer interactions between CdS and CTF-1 in the CdS NPs/CTF-1 assembly can not only facilitate the photogenerated charge separation rates, but can also shape CdS with a nanosized structure and high stability. This study develops a new strategy to improve the photocatalytic performance and conquer the photocorrosion of CdS, and also provides some guidance for us in the development of other CTF-incorporated nanocomposite photocatalysts.
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