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Cubic Cu1.4S nanoparticles were synthesized on a large scale by laser ablation of salt powder dispersed in an organic solvent. A metastable Cu1.4S phase was formed at high temperature in a reductive solvent and was maintained at room temperature due to the quenching effect of the pulsed laser. The cubic Cu1.4S nanoparticles show good stability after being exposed to ambient atmosphere for as long as 1 month. [ABSTRACT FROM AUTHOR]

The dehydrogenation of C3H8 in the presence of CO2 is an attractive catalytic route for C3H6 production. In studying the various possibilities to utilise CO2 to convert hydrocarbons using the sustainable energy source of solar thermal energy, thermodynamic calculations were carried out for the dehydrogenation of C3H8 using CO2for the process operating in the temperature range of 300–500 °C. Importantly, the results highlight the enhanced potential of C3H8 as compared to its lighter and heavier homologues (C2H6 and C4H10, respectively). To be utilised in this CO2 utilisation reaction the Gibbs free energy (ΔrGϑm) of each reaction in the modelled, complete reacting system of the dehydrogenation of C3H8 in the presence of CO2 also indicate that further cracking of C3H6 will affect the ultimate yield and selectivity of the final products. In a parallel experimental study, catalytic tests of the dehydrogenation of C3H8 in the presence of CO2 over 5 wt%-Cr2O3/ZrO2 catalysts operating at 500 °C, atmospheric pressure, and for various C3H8 partial pressures and various overall GHSV (Gas Hourly Space Velocity) values. The results showed that an increase in the C3H8 partial pressure produced an inhibition of C3H8 conversion but, importantly, a promising enhancement of C3H6 selectivity. This phenomenon can be attributed to competitive adsorption on the catalyst between the generated C3H6 and inactivated C3H8, which inhibits any further cracking effect on C3H6 to produce by-products. As a comparison, the increase of the overall GHSV can also decrease the C3H8 conversion to a similar extent, but the further cracking of C3H6 cannot be limited. [ABSTRACT FROM AUTHOR]

A laser-activated-catalyst (LAC) technique was developed to grow CdSe nanowires in liquid medium at room temperature. The gold catalysts dispersed in the precursor solution were activated by a pulsed laser so as to decompose the precursor and catalyse the nanowire growth simultaneously. The LAC technique can achieve accurate positioning of nanowires, which is beneficial for device fabrication. [ABSTRACT FROM AUTHOR]

Broccoli ( Brassica oleracea L.) is a vegetable with numerous nutritional properties, with sulforaphane (SFN) being the most abundant and unique bioactive ingredient. SFN has anti-inflammatory, antioxidant, and anti-cancer activities. In this study, a series of SFN derivatives were synthesized and screened for improved antidepressant effects. Among these, the SFN derivatives SLL-III-9 and SLL-III-120 were the best candidates, and the potential antidepressant mechanism of SFN, SLL-III-9, and SLL-III-120 associated with their effects in a chronic unpredictable mild stress (CUMS) mouse model was explored based on the microbiota-gut-brain axis. All three compounds were able to relieve depression-like behaviors in CUMS mice and regulate the composition of the gut bacteria Firmicutes, Actinobacteria, Parabasalia, and Tenericutes at the phylum level and Bacteroidales bacterium , Lachnospiraceae bacterium A4 , Muribaculum intestinale , Muribaculaceae bacterium , and Prevotella sp. MGM1 at the species level, possibly altering their function associated with the anti-inflammatory effect. Additionally, SFN and its derivatives upregulated the expression of the tight junction proteins ZO-1, occludin, and claudin and increased the concentration of IL-10, dopamine (DA), 5-hydroxytryptamine (5-HT) and the brain-derived neurotrophic factor (BDNF), while downregulating the expressions of proteins related to the NF-κB/NLRP3 pathway and reducing the concentration of TNF-α. Further in vitro studies revealed significant inhibition of the production of inflammatory factors IL-1β, IL-18, IL-6, and TNF-α in LPS-activated BV2 cells via the NF-κB/NLRP3 pathway when these cells were treated with SFN or its two derivatives. Taken together, the results suggested that SFN and its two derivatives, SLL-III-9 and SLL-III-120, could be considered potential compounds for the development of a promising and safe agent for combating depression.

We have undertaken a vibrational study of the structure of interfacial water and its potential dependence using H 2 O : D 2 O mixtures to explore the O-H and O-D stretching modes of HOD as well as the bending modes of HOD and H 2 O. Due to the symmetry reduction, some of the complexity characteristic of the vibrational spectrum of water is removed in HOD. Coupled with potential-dependent ab initio simulations of the gold-water interface, this has enabled a deeper insight into the hydrogen-bond network of interfacial water and into how it is affected by the applied potential. Possibly the most important conclusions of our work are (i) the absence of any ice-like first layer of interfacial water at any potential and (ii) that interfacial water reorients around a stable backbone of hydrogen bonds roughly parallel to the electrode surface. At E > pzc, interfacial water molecules are oriented with the oxygen lone pairs towards the surface and form exclusively or nearly exclusively hydrogen-donating hydrogen bonds with other water molecules. At E < pzc, the oxygen lone pairs instead point away from the surface, but the population of hydrogen-donating water molecules does not vanish. In fact, the population of hydrogen-accepting water molecules only dominates at considerably negative charge densities, due to the weak interaction of the hydrogen atoms of interfacial water molecules with the Au surface., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Electromagnetic fields are used in water treatment and desalination to regulate scale formation and extend the lifetime of membranes. External electric and magnetic fields can promote or suppress mineral nucleation and growth. However, the molecular-scale mechanisms of such processes remain unknown. Computing the free energies needed to form ion pairs under external fields provides important insights into understanding the elemental steps during the initial formation of mineral scales. In this paper, we used molecular dynamics combined with metadynamics simulations to investigate the free energies of forming the [Ca-CO 3 ] 0 ion pair, a fundamental building block of carbonate scales, under a range of magnetic (up to 10 T) and electric (up to 10 V m -1 ) fields in water. The presence of constant magnetic or electric fields favored the ion pairing reaction and lowered the free energies by up to 3% to 6%. The internal energy and entropic components of the free energy showed significant changes and exhibited non-linear behavior with increasing field strength. The [Ca-CO 3 ] 0 ion pairing is an entropy-driven process in the absence of an external field, but the mechanism shifts to an internal energy-driven process under selected external fields, suggesting possible changes in the nucleation pathways.

Two-dimensional materials and their van der Waals heterostructures have emerged as a research focal point for constructing various innovative electronic devices due to their distinct photonic and electronic properties. Among them, anti-ambipolar devices, characterized by their unique nonlinear electrical behavior, have garnered attention as novel multifunctional components, positioning them as potential contenders for building multi-state logic devices. Utilizing the properties of few-layer As 0.4 P 0.6 and PdSe 2 , we have constructed an anti-ambipolar heterojunction device. At 300 K, the device exhibits a peak voltage ( V peak ) of -3 V and a peak-to-valley ratio (PVR) close to 8 × 10 3 , and the PVR can be modulated by bias voltage. Furthermore, by characterizing the anti-ambipolar attributes at different temperatures ranging from 80 K to 330 K, we have elucidated the thermally tunable feature of the device. At 330 K, a certain PVR (∼10 3 ) and a large V peak (∼-16 V) are obtained, while a PVR exceeding 10 8 has been achieved at 80 K. This temperature-related sensitivity empowers the device with significant potential and thermal tunability in various applications.

Molecular modification strategy exhibits great potential for electrocatalytic CO 2 reduction. Here, DFT calculations were applied to study the mechanism of CO 2 electroreduction on glycine modified copper. The results indicate that the interaction between the modified molecule and the intermediate could change the reaction energy of CO 2 electroreduction.

A photoinduced EnT-mediated generation of sulfonamidyl radicals has been accomplished using rationally designed iminophenylacetic acid oxime ester reagents under metal-free conditions. This approach offers a mild, regio- and diastereoselective synthesis of N -sulfonyl diamines via diamination of alkenes and (hetero)arenes.

Surgery is one of the most important paradigms for tumor therapy, while fluorescence imaging (FI) offers real-time intraoperative guidance, greatly boosting treatment prognosis. The imaging fidelity heavily relies on not only imaging facilities but also probes for imaging-guided surgery (IGS). So far, a great number of IGS probes with emission in visible (400-700 nm) and near-infrared (NIR 700-1700 nm) windows have been developed for pinpointing disease margins intraoperatively. Herein, the state-of-the-art fluorescent probes for IGS are timely updated, with a special focus on the fluorescent probes under clinical examination. For a better demonstration of the superiority of NIR FI over visible FI, both imaging modalities are critically compared regarding signal-to-background ratio, penetration depth, resolution, tissue autofluorescence, photostability, and biocompatibility. Various types of fluorescence IGS have been summarized to demonstrate its importance in the medical field. Furthermore, the most recent progress of fluorescent probes in NIR-I and NIR-II windows is summarized. Finally, an outlook on multimodal imaging, FI beyond NIR-II, efficient tumor targeting, automated IGS, the use of AI and machine learning for designing fluorescent probes, and the fluorescence-guided da Vinci surgical system is given. We hope this review will stimulate interest among researchers in different areas and expedite the translation of fluorescent probes from bench to bedside.

Alzheimer's disease (AD) is one of the most fatal and irreversible neurodegenerative diseases, which causes a huge emotional and financial burden on families and society. Despite the progress made with recent clinical use of inhibitors of acetylcholinesterase and amyloid-β (Aβ) antibodies, the curative effects of AD treatment remain unsatisfactory, which is probably due to the complexity of pathogenesis and the multiplicity of therapeutic targets. Thus, modulating complex pathological networks could be an alternative approach to treat AD. Here, a neutrophil membrane-coated MOF nanozyme (denoted as Neu-MOF/Fla) is biomimetically engineered to disturb the malignant Aβ deposition-inflammation cycle and ameliorate the pathological network for effective AD treatment. Neu-MOF/Fla could recognize the pathological inflammatory signals of AD, and deliver the photo-triggered anti-inflammatory CO and MOF based hydrolytic nanozymes to the lesion area of the brain in a spontaneous manner. Based on the in vitro and in vivo studies, Neu-MOF/Fla significantly suppresses neuroinflammation, mitigates the Aβ burden, beneficially modulates the pro-inflammatory microglial phenotypes and improves the cognitive defects of AD mice models. Our work presents a good example for developing biomimetic multifunctional nanotherapeutics against AD by means of amelioration of multiple symptoms and improvement of cognitive defects., Competing Interests: The authors declare no competing financial interests., (This journal is © The Royal Society of Chemistry.)

The practical application of α-Fe 2 O 3 in water splitting is hindered by significant charge recombination and slow water oxidation. To address this issue, a CoSAs-g-C 3 N 4 /Fe 2 O 3 (CoSAs: cobalt single atoms) photoanode was fabricated in this study through the co-modification of CoSAs and g-C 3 N 4 to enhance photoelectrochemical (PEC) water splitting. The coupling between g-C 3 N 4 and α-Fe 2 O 3 resulted in the formation of a heterojunction, which provided a strong built-in electric field and an additional driving force to mitigate charge recombination. Moreover, g-C 3 N 4 served as a suitable carrier for single atoms, which effectively anchored CoSAs through N/C coordination. The highly dispersed CoSAs provided abundant active sites, which further promoted surface holes extraction and oxidation kinetics, resulting in higher PEC performance and photostability. This study indicates the benefits of these collaborative strategies and provides more efficient designs for solar energy conversion in PEC systems., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

The practical utilization rates of conventional pesticide formulations by target organisms are very low, which results in the pollution of ecological environments and the formation of pesticide residues in agricultural products. Water-based nanopesticide formulations could become alternative and effective formulations to eventually resolve the main issues of conventional pesticide formulations. In this feature article, we describe the design concept of smart (stimuli-responsive) controlled-release nanopesticides, which are created toward hierarchical targets (pests, pathogens, and foliage) in response to multidimensional stimuli from physiological and environmental factors (such as sunlight) of target organisms and plants, for achieving enhanced insecticidal and fungicidal efficacies. The pore sizes and functionalities of metal-organic frameworks (MOFs) can be fine-tuned through the choice of metal-containing units and organic ligands. Tailor-made MOF nanoparticles with large microporous or mesoporous sizes, as well as good biocompatibility and high thermal, mechanical, and chemical durabilities, are used to load pesticides within these pores followed by coating of plant polyphenols and natural polymers for stimuli-responsive controlled pesticide release. This feature article highlights our works on smart controlled-release MOF-based nanopesticides and also includes related works from other laboratories. The future challenges and promising prospects of smart controlled-release MOF-based nanopesticides are also discussed.

Stimuli-responsive upconversion nanoparticle (UCNP)-poly- N -isopropylacrylamide (pNIPAM)/DNA core-shell microgels with tunable sizes and programmable functions have been prepared. Thanks to the near-infrared (NIR)-responsive UCNP cores and thermosensitive polymeric shells, functional DNA-incorporated microgels with high DNA activity and loading efficiency are obtained, and the activity of the loaded DNA structures can be smartly regulated by NIR illumination and temperature simultaneously.

A near-infrared fluorescent nanoprobe consisting of Nile blue-capped ZIF-90 is first proposed for real-time imaging of mitochondrial ATP. Owing to the strong binding of ATP with Zn 2+ , the structure of the probe is disrupted, leading to the release of fluorescent NB.

Promoting angiogenesis following biomaterial implantation is essential to bone tissue regeneration. Herein, the composite scaffolds composed of zein, whitlockite (WH), and levofloxacin (LEVO) were fabricated to augment bone repair by facilitating osteogenesis and angiogenesis. First, three-dimensional composite scaffolds containing zein and WH were prepared using the salt-leaching method. Then, as a model antibiotic drug, the LEVO was loaded into zein/WH scaffolds. Moreover, the addition of WH enhanced the adhesion, differentiation, and mineralization of osteoblasts. The zein/WH/LEVO composite scaffolds not only had significant osteoinductivity but also showed excellent antibacterial properties. The prepared composite scaffolds were then implanted into a calvarial defect model to evaluate their osteogenic induction effects in vivo . Micro-CT observation and histological analysis indicate that the scaffolds can accelerate bone regeneration with the contribution of endogenous cytokines. Based on amounts of data in vitro and in vivo , the scaffolds present profound effects on improving bone regeneration, especially for the favorable osteogenic, intensive angiogenic, and alleviated inflammation abilities. The results showed that the synthesized scaffolds could be a potential material for bone tissue engineering., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Background : Alzheimer's disease (AD) exerts tremendous pressure on families and society due to its unknown etiology and lack of effective treatment options. Our previous study had shown that Se-methylselenocysteine (SMC) improved the cognition and synaptic plasticity of triple-transgenic AD (3 × Tg-AD) mice and alleviated the related pathological indicators. We are dedicated to investigating the therapeutic effects and molecular mechanisms of SMC on mitochondrial function in 3 × Tg-AD mice. Methods : Transmission electron microscopy (TEM), western blotting (WB), mitochondrial membrane potential (Δ Ψ m ), mitochondrial swelling test, and mitochondrial oxygen consumption test were used to evaluate the mitochondrial morphology and function. Mitophagy flux and autophagy flux were assessed with immunofluorescence, TEM and WB. The Morris water maze test was applied to detect the behavioral ability of mice. Results : The destroyed mitochondrial morphology and function were repaired by SMC through ameliorating mitochondrial energy metabolism, mitochondrial biogenesis and mitochondrial fusion/fission balance in 3 × Tg-AD mice. In addition, SMC ameliorated mitochondria by activating mitophagy flux via the BNIP3/NIX pathway and triggering autophagy flux by suppressing the Ras/Raf/MEK/ERK/mTOR pathway. SMC remarkably increased the cognitive ability of AD mice. Conclusions : This research indicated that SMC might exert its therapeutic effect by protecting mitochondria in 3 × Tg-AD mice.

To date, five siRNA-based medications have received clinical approval and have demonstrated remarkable therapeutic efficacy in treating various diseases. However, their application has been predominantly limited to liver-specific diseases due to constraints in siRNA delivery capabilities. In this study, we have developed a siRNA delivery system utilizing clinically approved mPEG- b -PLGA, a cationic lipid, and an ionizable lipid. We optimized this system by carefully adjusting their mass ratios, resulting in highly efficient gene silencing. Furthermore, the optimized nanoparticle formulation, which encapsulates siRNA targeting CD47, induces a robust immune response. This response effectively suppresses the progression of melanoma tumors by blocking this critical immune checkpoint.

Building a high-performance sensing platform is the key to developing sensitive sensors. Herein, a highly sensitive self-powered electrochemical sensor (SPES) was constructed using a WO 3 ·H 2 O film as the cathode prepared by a hydrothermal method and Zn as the anode, and it could be applied to sensitive detection of microcystin (MC-RR). The WO 3 ·H 2 O film with a larger specific surface area could boost the oxygen reduction reaction (ORR), which could achieve signal amplification and significantly increase the sensitivity of the sensors. Under the optimal conditions, there was a good linear relationship between the increased electrical power density and the logarithm of MC-RR concentration with a detection limit of 1.31 × 10 -15 M (S/N = 3). This method had good anti-interference ability and stability when applied to the determination of MC-RR content in actual samples, which could boost the potential application of electrochemical sensors in the field of environmental monitoring.

The smallest Hückel aromatic ring cyclopropenium substituted by electron-donating C-amino groups produced a aminocyclopropenium electron-rich cation. A bifunctional aminocyclopropenium halide catalyst installed with bis-(hydroxyethyl) functions on the amino group was then designed. A typical (diethanolamino)cyclopropenium halide catalyst C5·I was screened optimally for the cycloaddition of carbon disulfide into an epoxide to produce cyclic dithiocarbonate with an excellent conversion (95%) and high selectivity (92%). The electrostatic enhancement of alkyl C-H HBD capability was implemented via vicinal positive charges on the cyclopropenium core, and the acidity of the terminal O-H hydrogen proton increased by intramolecular H-bonding between the two hydroxy groups on the diethanolamino group (O-H⋯O-H). Then, a hybrid H-bond donor comprising enhanced alkyl C-H and hydroxy O-H was formed. The hybrid HBD offered by aminocyclopropenium was vital in activating the epoxide and stabilizing the intermediate, resulting in reduced O/S scrambling. Moreover, weakly coordinated iodide anion served as a nucleophilic reagent to open the ring of the epoxide. The cooperative catalytic mechanism of the HBD cation and halide anion was supported by NMR titrations and control experiments. Eleven epoxides with various substituents were converted into the corresponding cyclic thiocarbonate with high conversion and selectivity under mild conditions (25 °C, 6 h) without a solvent. The cycloaddition of carbon disulfide with epoxides catalyzed by aminocyclopropenium developed a new working model for hydrogen bonding organocatalysis., Competing Interests: The authors declare no competing financial interest., (This journal is © The Royal Society of Chemistry.)

To overcome the limitation of photocatalysts with dual functionality of water oxidation and proton reduction, we proposed a novel bismuth-based Ba 2 BiV 3 O 11 (BBVO) photocatalyst, which can simultaneously drive the proton reduction reaction under UV light and water oxidation reaction under visible light. After doping with sulfur through an in situ vulcanization strategy, the light absorption and charge separation efficiencies of the sulfur-doped BBVO were significantly improved, thus boosting its oxygen evolution activity (64 μmol h -1 ) by more than 16 times compared with independent BBVO. The experimental results demonstrate that BBVO can be employed as a very promising bismuth-based photocatalyst for solar energy conversion.

Toll-like receptor 4 (TLR4) is a pivotal innate immune recognition receptor that regulates intricate signaling pathways within the immune system. Neoseptin-3 (Neo-3), a recently identified small-molecule agonist for mouse TLR4/MD2, exhibits chiral recognition properties. Specifically, the L-enantiomer of Neo-3 (L-Neo-3) effectively activates the TLR4 signaling pathway, while D-Neo-3 fails to induce TLR4 activation. However, the underlying mechanism by which TLR4 enantioselectively recognizes Neo-3 enantiomers remains poorly understood. In this study, in silico simulations were performed to investigate the mechanism of chiral recognition of Neo-3 enantiomers by TLR4/MD2. Two L-Neo-3 molecules stably resided within the cavity of MD2 as a dimer, and the L-Neo-3 binding stabilized the (TLR4/MD2) 2 dimerization state. However, the strong electrostatic repulsion between the hydrogen atoms on the chiral carbon of D-Neo-3 molecules caused the relative positions of two D-Neo-3 molecules to continuously shift during the simulation process, thus preventing the formation of D-Neo-3 dimer as well as their stable interactions with the surrounding residues in (TLR4/MD2) 2 . Considering that L-Neo-3 could not sustain a stable dimeric state in the bulk aqueous environment, it is unlikely that L-Neo-3 entered the cavity of MD2 as a dimeric unit. Umbrella sampling simulations revealed that the second L-Neo-3 molecule entering the cavity of MD2 exhibited a lower binding energy (-25.75 kcal mol -1 ) than that of the first L-Neo-3 molecule (-14.31 kcal mol -1 ). These results imply that two L-Neo-3 molecules enter the cavity of MD2 sequentially, with the binding of the first L-Neo-3 molecule facilitating the entry of the second one. This study dissects the binding process of Neo-3 enantiomers, offering a comprehensive understanding of the atomic-level mechanism underlying TLR4's chiral recognition of Neo-3 molecules.

Flexible strain sensors have drawn a lot of interest in various applications including human mobility tracking, rehabilitation/personalized health monitoring, and human-machine interaction, but suffer from interference of electromagnetic (EM). To overcome the EM interference, flexible force sensors without sensitive electronic elements have been developed, with drawbacks of bulky modules that hinders their applications in remote measurement with power-free environment. Therefore, it is highly desirable to fabricate a compact wireless flexible force sensor but it is still a challenge. Here, we demonstrate a fluorescent flexible force sensor based on aggregation-induced emission (AIE) doped liquid crystal elastomer (LCE) experimentally. The proposed force sensor film can be used to measure force through the variation of fluorescent intensity induced by the extension or contraction of LCE film, which leads to reduce or increase of the aggregation degree of AIE molecules within. This compact wireless force sensor features lightweight, low-cost, high flexibility, passivity and anti-EM interference, which also enables the naked eye observation. The proposed sensor provides inspiration and a platform for a new concept of non-contact detection, showing application potential in human-friendly interactive electronics and remote-control integration platform.

Due to the advantages of good aqueous dispersion and biocompatibility, carbon dots (CDs) are promising candidates for a wide range of applications in the biological field. Notably, CDs derived from biosafe organic precursors will contribute both new types of CDs and new bioactivities. Herein, metformin (MET), a first-line drug for the treatment of type II diabetes, was selected as an organic precursor to fabricate a new type of CDs, namely, semi-carbonized MET (MCDs). These MCDs derived from MET possess a completely new antibacterial activity against Staphylococcus aureus ( SA ) and Escherichia coli ( E. coli ) compared with that of MET and achieve complete antibacterial activity at 200 μg mL -1 . The broad-spectrum antibacterial mechanism of MCDs involves two aspects. For the Gram-positive bacteria SA , MCDs mainly affect the transport of nutrients by adsorbing onto the surface of bacteria, thereby inhibiting bacterial growth. For the Gram-negative bacteria E. coli , MCDs can easily pass through their thin cell walls and stimulate the bacteria to produce excess ROS, eventually leading to the death of the bacteria. This work may open a new way for the future design and development of CDs prepared from biosafe organic precursors with specific functions.

The hydrogen oxidation reaction is an important process in anion exchange membrane fuel cells with alkaline solutions. The pursuit of efficient catalysts for alkaline hydrogen oxidation has attracted considerable attention. In this study, we present a precursor route for the synthesis of a new Ir-based catalyst (Ir-Ni/NiO/C), in which Ir nanoclusters were immobilized on the generated Ni/NiO/C support derived from a metal-organic framework. The small size of Ir clusters facilitates the exposure of catalytically active sites. The electronic interplay between the Ir nanoclusters and the Ni/NiO/C support optimized the hydrogen binding energy (HBE) and hydroxide binding energy (OHBE) on the surface, which is unattainable on the contrasting Ir-C, Ir-Ni/C, and Ir-NiO/C products. The optimized catalyst shows excellent mass activity for alkaline hydrogen oxidation, which is 3.1 times that of the Pt/C catalyst. This study presents a promising pathway for the development of advanced HOR catalysts.

Selective laser melting (SLM) additive manufacturing technology with different oxygen contents leads to the appearance of spherical solids of different sizes on the surface of the part, which affects the mechanical properties of the part, surface roughness, etc. In this study, the SLM molding technique was applied using three different 316L metal powders with different oxygen contents. The spheroidization properties and morphology of the samples were observed using a Quanta 200 environmental scanning electron microscope (ESEM), and the samples were observed microscopically and subjected to EDX spectroscopy using metallographic microscopy, and the mechanical properties were investigated. The results of the study showed that when using gas atomized powders, no spheroidization occurred when the oxygen content of the powders was 5.44 ± 0.01% in all cases, whereas using water atomized powders produced spherical structures with larger dimensions. This observation was closely related to the shape and particle size of the powder. When 316L metal powder with an oxygen content of 4.52 ± 0.01% was used for molding, small spherical structures appeared on the surface of the samples. When metal powder with an oxygen content of 5.44 ± 0.01% was used for the molding, larger spherical structures appeared on the surface of the samples. When the powder with an oxygen content of 5.90 ± 0.01% was used for the molding, more small spherical structures and some large spherical structures appeared on the surface of the samples. This suggests that higher oxygen levels may inhibit the occurrence of spheroidization. EDX spectroscopic analysis revealed that the white matter on the surface of the samples without spheroidization was mainly composed of Fe and Cr, whereas the white matter on the surface of the large-sized spherical structures was mainly composed of Si and Mn, which may be related to the oxygenophilicity of the various substances., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Pd-based bimetallic or multimetallic nanocrystals are considered to be potential electrocatalysts for cathodic oxygen reduction reaction (ORR) in fuel cells. Although much advance has been made, the synthesis of component-controlled Pd-Sn alloy nanocrystals or corresponding nanohybrids is still challenging, and the electrocatalytic ORR properties are not fully explored. Herein, component-controlled synthesis of Pd x Sn y nanocrystals (including Pd 3 Sn, Pd 2 Sn, Pd 3 Sn 2, and PdSn) has been realized, which are in situ grown or deposited on pre-treated multi-walled carbon nanotubes (CNTs) to form well-coupled nanohybrids (NHs) by a facile one-pot non-hydrolytic system thermolysis method. In alkaline media, all the resultant Pd x Sn y /CNTs NHs are effective at catalyzing ORR. Among them, the Pd 3 Sn/CNTs NHs exhibit the best catalytic activity with the half-wave potential of 0.85 V ( vs. RHE), good cyclic stability, and excellent methanol-tolerant capability due to the suited Pd-Sn alloy component and its strong interaction or efficient electronic coupling with CNTs. This work is conducive to the advancement of Pd-based nanoalloy catalysts by combining component engineering and a hybridization strategy and promoting their application in clean energy devices., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Solar energy can be harvested using biological light-driven ion pumps for the sustainability of life. It remains a significant challenge to develop high-performance artificial light-driven ion pumps for solar energy harvesting in all solid-state materials. Here, we exploit the benefits of short channel lengths and efficient light absorption to demonstrate efficient photo-driven ion transport in slightly reduced vertical graphene oxide membranes (GOMs). Remarkably, this photo-driven ion pump exhibits excellent ability, countering a 10-fold electrolyte concentration gradient. We propose a plausible mechanism where light illumination enhances the electric potential of ion channels on GOMs triggered by the separation of photoexcited charge carriers between the sp 2 and sp 3 carbon clusters. This results in the establishment of an electric potential difference across the effective ion channels composed of sp 3 carbon clusters, thus driving the directional transport of cations from the illuminated side to the non-illuminated side. The promising results of this study provide new possibilities for the application of vertical 2D nanofluidic membranes in areas such as artificial photosynthesis, light harvesting, and water treatment.

By introducing enantiomerically pure mono-bidentate N-donor ligands (L R /L S ) into Yb(btfa) 3 (H 2 O) 2 and Yb(dbm) 3 (H 2 O), respectively, two pairs of chiral Yb III enantiomers, namely Yb(btfa) 3 L R /Yb(btfa) 3 L S (D-1/L-1) and [Yb(dbm) 3 L R ]·[Yb(dbm) 3 (C 2 H 5 OH)]/[Yb(dbm) 3 L S ]·[Yb(dbm) 3 (C 2 H 5 OH)] (D-2/L-2) were isolated, where btfa - = 3-benzoyl-1,1,1-trifluoroacetonate, dbm - = dibenzoylmethanate, and L R /L S = (-)/(+)-4,5-pinenepyridyl-2-pyrazine. D-1/L-1 possess mononuclear structures in which the Yb III ions are eight-coordinated, while D-2/L-2 show cocrystal structures containing Yb(dbm) 3 (L R /L S ) and Yb(dbm) 3 (C 2 H 5 OH) moieties in which the two Yb III ions are eight and seven-coordinated, respectively. They not only feature different molecular structures but also present distinct linear and nonlinear optical performances. Chiral mononuclear D-1 has better near infrared photo-luminescence (NIR-PL) and circularly polarized luminescence (CPL) performances than chiral cocrystal D-2. More remarkably, D-1/L-1 show large second-harmonic generation (SHG) responses (up to 1.25/1.28 × KDP) 18/16 times those of D-2/L-2 (0.07/0.08 × KDP). In addition, D-2/L-2 represent the first examples of lanthanide cocrystal complexes with NIR-PL, NIR-CPL and SHG properties.

Organic upconversion devices (UCDs) are a cutting-edge technology and hot topic because of their advantages of low cost and convenience in the important applications of near-infrared (NIR) detection and imaging. However, to realize utilization of triplet excitons (T 1 ), previous UCDs have the drawback of heavily relying on toxic and costly heavy-metal-doped emitters. More importantly, due to poor performance of the detecting unit and/or emitting unit, improving their detectivity ( D *) and photon-to-photon conversion efficiency ( η p-p ) is still a challenge for real applications. Here, we report a high-performance dual-functional purely organic UCD that has an outstanding D * approaching 10 13 Jones and a high η p-p of 20.1% in the NIR region, which are some of the highest values among those reported for UCDs. The high performance is credited to the excellent D * of the detecting unit, exceeding 10 14 Jones, and is also attributed to efficient T 1 utilization via a dual reverse intersystem crossing channel and high optical out coupling achieved via a high horizontal dipole ratio in the emitting unit. The high D * and η p-p enable the UCD to detect 850 nm light at as little as 0.29 μW cm -2 and with a high display contrast of over 70 000 : 1, significantly improving the potential of practical applications of UCDs in NIR detection and imaging. Furthermore, a fast rise time and fall time of 8.9 and 14.8 μs are also achieved. Benefiting from the high performance, consequent applications of low-power pulse-state monitoring and fine-structure bio-imaging are successfully realized with high quality results by using our organic UCDs. These results demonstrate that our design not only eliminates dependence of UCDs on heavy-metal emitters, but also takes their performance and applications to a high level.

The shortage of freshwater resources in the world today has limited the development of water splitting, and our eyes have turned to the abundant seawater. The development of relatively low-toxicity and high-efficiency catalysts is the most important area in seawater electrolysis. In this paper, the preparation of NiS 2 @Co 4 S 3 @FeS via a hydrothermal method on nickel foam has been studied for the first time. In the process of vulcanization, Fe will first generate FeS by virtue of its high affinity for vulcanization. Once Fe is vulcanized, the residual sulfur will be used to generate NiS 2 , while the vulcanization of Co requires a higher sulfur concentration and reaction temperature; thus, Co 4 S 3 will be generated last. NiS 2 @Co 4 S 3 @FeS is confirmed to have excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalytic properties in alkaline seawater. Its unique structure allows it to expose more reaction centres, and the synergies between the multiple metals optimize the charge distribution of the material and accelerate the OER and HER kinetics. NiS 2 @Co 4 S 3 @FeS requires overpotentials of only 122 mV and 68 mV for the OER and HER when reaching 10 mA cm -2 , which is superior to most catalysts reported to date for seawater electrolysis, and the material displays acceptable stability. In an electrolytic cell composed of both positive and negative electrodes, when the current density is 10 mA cm -2 , the NiS 2 @Co 4 S 3 @FeS material displays a low overpotential of only 357 mV for seawater splitting. Density functional theory shows that the FeS electrode has the optimum Gibbs free energy of H to accelerate reaction kinetics, and the synergistic catalysis of the NiS 2 , Co 4 S 3 and FeS materials promotes the hydrogen production activity of the NiS 2 @Co 4 S 3 @FeS electrode. This work proposes a novel idea for designing environmentally friendly seawater splitting catalysts.

A photo-driven self-powered aptasensor was constructed based on a matching capacitor and the ZnIn 2 S 4 /Ti 3 C 2 heterojunction as the photoanode and Cu 2 O as the photocathode in a dual-photoelectrode sensing matrix for multiple signal amplification for the ultrasensitive detection of microcystin-RR (MC-RR). The introduction of Ti 3 C 2 MXene nanosheets on the photoanode surface can not only accelerate the transfer and separation of photoinduced electron/hole pairs, thus enhancing the output signal of the photo-driven self-powered system, but also provide a larger specific surface area for the immobilization of the bio-recognition unit aptamer. More importantly, for a portable and miniaturized device, a micro-workstation with the size of a universal serial bus (USB) disk and a novel short-circuit current access was proposed to capture the instantaneous output electrical signal for real-time data tracking. In such a way, a sensitivity of 2.7 mA pM -1 was achieved when the matching capacitor was integrated into the self-powered system, which was 22 times that without a capacitor. After the interaction between MC-RR and the corresponding aptamer, a 'signal-off' detection configuration was formed via the steric hindrance effect. Therefore, such a multiple signal amplification system realized the ultrasensitive and selective determination of MC-RR successfully. Under optimal conditions, the linear range of the self-powered aptasensor was 0.1 to 100 pM and the detection limit was 0.033 pM (S/N = 3). The aptasensor was applied to the detection of MC-RR in fish, exhibiting good reproducibility (≈3.88%), paving the way for detecting microcystins in real-life samples.

Urea electrolysis can be used to treat wastewater containing urea and alleviate the energy crisis, so it is one of the best ways to solve environmental and energy problems. This paper reports the synthesis of M doped NiVS (M = Co, Ce and Cr) composites by a simple hydrothermal process for the first time. What is noteworthy is that the Ce-NiVS material as a catalytic electrode requires only 141 mV overpotential for the hydrogen evolution reaction (HER) and 1.291 V potential for the urea oxidation reaction (UOR) at a current density of 10 mA cm -2 in 1.0 M KOH and 0.5 M urea mixed alkaline solution. Using Ce-NiVS/NF as both the anode and cathode for urea electrolysis, a current density of 10 mA cm -2 is driven by a voltage of only 1.55 V, which is better than most previous catalysts. Experimental results demonstrate that the excellent catalytic activity of Ce-NiVS materials is due to the formation of a large number of active sites and the improvement of conductivity due to doping with Ce. Density functional theory calculation shows that the VS 4 material has a small Gibbs free energy of hydrogen adsorption, which plays a major role in the hydrogen production process, and Ce-NiS has a higher density of states (DOS) near the Fermi level, indicating that Ce-NiS has better electronic conductivity. The synergistic catalysis of VS 4 and Ce-NiS promoted the hydrogen production performance of the Ce-NiVS material. This work provides guidance for the optimization and design of low-cost electrocatalysts to replace expensive precious metal-based electrocatalysts for overall urea electrolysis.

By employing enantiomerically pure mono-bidentate N-donors (L R /L S ) as chiral bridging ligands to react with Cu(ClO 4 ) 2 (H 2 O) 6 in CH 3 CN-DMF mixed solvent, respectively, a pair of ionic one-dimensional (1D) Cu(II) chain enantiomers formulated as {[CuL R (CH 3 CN)(DMF)H 2 O](ClO 4 ) 2 } n /{[CuL S (CH 3 CN)(DMF)H 2 O](ClO 4 ) 2 } n (D-1/L-1) were isolated and structurally characterized, where L R /L S = (-)/(+)-4,5-pinenepyridyl-2-pyrazine. They crystallize in the noncentrosymmetric (NCS) P 2 1 2 1 2 1 space group of an orthorhombic system due to the introduction of chiral L R /L S , and the ClO 4 - groups as counteranions reside in crystal lattices, thus leading to charge separation with large dipole moments in their molecular structures. Based on crystal samples, investigation on their nonlinear optical (NLO) behaviors showed that D-1 and L-1 display simultaneously much larger second- and third-harmonic generation (SHG and THG) responses than their analogues based on the same chiral N-donors (L R /L S ) and Cu(NO 3 ) 2 (H 2 O) 3 with NO 3 - acting as the coordination group to bind Cu(II) ions. The SHG intensities of D-1/L-1 are 0.62/0.60 × KDP (KH 2 PO 4 ), and THG intensities of D-1/L-1 are 238/228 × α-SiO 2 . Our finding indicates that coordination polymers (CPs) with charge separation and NCS structures, i.e. , ionic CPs with NCS arrangements are the ideal NLO crystalline materials for the simultaneous observation of large SHG and THG responses, thus providing a new approach to obtain NLO-active CP crystalline materials with high-performance SHG and THG responses.

Bismuth is a promising anode material for sodium-ion batteries (SIBs) due to its high capacity and suitable working potential. However, the large volume change during alloying/dealloying would lead to poor cycling performance. Herein, we have constructed a 3D hierarchical structure assembled by bismuth nanosheets, addressing the challenges of fast kinetics, and providing efficient stress and strain relief room. The uniform bismuth nanosheets are prepared via a molten salt-assisted aluminum thermal reduction method. Compared with the commercial bismuth powder, the bismuth nanosheets present a larger specific surface area and interlayer spacing, which is beneficial for sodium ion insertion and release. As a result, the bismuth nanosheet anode presents excellent sodium storage properties with an ultralong cycle life of 6500 cycles at a high current density of 10 A g -1 , and an excellent capacity retention of 87% at an ultrahigh current rate of 30 A g -1 . Moreover, the full SIBs that paired with the Na 3 V 2 (PO 4 ) 3 /rGO cathode exhibited excellent performance. This work not only presents a novel strategy for preparing bismuth nanosheets with significantly increased interlayer spacing but also offers a straightforward synthesis method utilizing low-cost precursors. Furthermore, the outstanding performance demonstrated by these nanosheets indicates their potential for various practical applications., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Water electrolysis is relatively an environmentally friendly hydrogen production technology, but due to the slow transfer of four electrons in the anodic oxidation reaction, it needs a theoretical voltage of up to 1.23 V. Therefore, in this experiment, a series of transition metal oxides, ACo 2 O 4 (A = Fe, Cu, Zn, Ni), was synthesized on Ni foam current collectors by a hydrothermal and calcination method, and the material was applied in urea electrolysis to produce hydrogen. What is noteworthy is that the CuCo 2 O 4 electrode has a unique flower-like nanoneedle structure, and has a larger electrochemical active area, more reactive active sites, and a faster charge transfer rate. In 1.0 M KOH and 0.5 M urea solution, CuCo 2 O 4 provides a potential of only 1.268 V at a current density of 10 mA cm -2 during the urea oxidation reaction (UOR), while in 1.0 M KOH solution, with the same current density, the oxygen evolution reaction (OER) is required to provide a potential of 1.53 V, indicating that the UOR can effectively replace the OER. Density functional theory calculations show that the CuCo 2 O 4 material exhibits Gibbs free energy of the hydrogen closest to zero, thus promoting the electrochemistry performance of the electrode. In a cell composed of CuCo 2 O 4 //CuCo 2 O 4 , the current density of 10 mA cm -2 can be achieved by providing a potential of only 1.509 V. This work offers a novel scheme for reducing energy consumption of the OER and improving catalytic performance of the UOR.

A general and straightforward method for the regioselective construction of C-3 heteroaryl-containing imidazo[1,2- a ]pyridines via cross-dehydrogenative coupling under transition-metal-free conditions has been reported, utilizing N , N -dimethylaniline as the methylenation source and furnishing the C(sp 2 )-C(sp 3 ) functionalized products in good to excellent yields. Mechanism studies indicate that a radical pathway is responsible for this transformation., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Milk can improve sleep, and the effects of different animal milks vary. Accordingly, we evaluated the effectiveness of goat milk and cow milk in alleviating insomnia. The findings demonstrated that both goat milk and cow milk significantly increased the length of time that mice with insomnia slept compared to the model group and lowered the relative abundance of Colidextribacter , Escherichia - Shigella , and Proteus in these mice. A notable finding was that goat milk considerably increased the relative abundance of Dubosiella , Bifidobacterium , Lactobacillus , and Mucispirillum , whereas cow milk dramatically increased the relative abundance of Lactobacillus and Acinetobacter . Diazepam therapy could lengthen the slumber of mice; however, analysis of bacteria indicated that although the relative abundance of dangerous bacteria such as Mucispirillum , Parasutterella , Helicobacter , and Romboutsia increased, that of Blautia and Faecalibaculum decreased. Both Listeria and Clostridium experienced a large increase in relative abundance. Additionally, goat milk provided efficient restoration of neurotransmitters including 5-HT, GABA, DA, and NE. Besides that, the expression of genes and proteins for CREB, BDNF, and TrkB in the hypothalamus was up-regulated, and the pathophysiology of the hypothalamus was improved. Overall, the effects of goat and cow milk on insomnia in mouse models differed, and goat milk is preferred over cow milk.

In the field of membrane separation, the environmental concerns caused by spent membranes are becoming increasingly serious, which contradicts the concept of sustainable development. Based on this, a biodegradable poly(butylene adipate- co -terephthalate) (PBAT) membrane was used for the first time in the pervaporation separation of phenol, a high boiling point organic compound (HBOC). By using the PBAT membrane, outstanding separation efficiency was achieved, and environmental pollution and disposal issues were also avoided. The separation process and mechanism of the PBAT membrane were systematically studied through the experiment together with molecular dynamics (MD) simulation. The swelling experiment and intermolecular interaction energy calculation demonstrated that the PBAT membrane had a strong affinity for phenol. Further simulation concluded that higher phenol concentration increased the number of hydrogen bonds so that the membrane was more greatly swollen. Meanwhile, the simulations on the adsorption, diffusion and permeation predicted that the PBAT membrane had excellent separation performance for phenol. Besides MD simulation, the influences of feed concentration and temperature on pervaporation performance were also investigated by experiment. The results showed that the flux of each component increased with the feed concentration. This phenomenon was attributed to the preferential adsorption of phenol by the PBAT membrane, which resulted in large free volumes and cavities within the membrane, accelerating the diffusion of molecules. In addition, it was found that the optimal operating temperature was 333 K with the best separation performance. This study confirms that the biodegradable PBAT membrane is valuable for the recovery of high boiling point organic compounds (HBOCs) such as phenol.

Tribocorrosion is one of the most common forms of failure of biomedical titanium alloys. As the passive film of titanium alloys is highly dependent on oxygen conditions, the passivation behavior and the microstructure of the passive film of Ti-6Al-4V under tribocorrosion in 1 M HCl with a low dissolved oxygen concentration (DOC) were studied by means of electron probe microanalysis (EPMA), Ar-ion etched X-ray photoelectron spectroscopy (XPS), focused ion beam (FIB) milling and high resolution transmission electron microscopy (HRTEM). The results showed that the protective ability of the regenerated passive film decreased sharply under low DOC. Al and V ions dissolved in excess, and a large number of oxygen atoms entered the matrix, leading to internal oxidation. Structural characterization indicated that Ti atoms occupied more metal lattice points in the regenerated passive film and that the high dislocation density in the deformed layer caused by wear facilitated the diffusion of Al and V. Finally, the first-principles calculation showed that Al had the minimum vacancy formation energy., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The development of efficient and stable non-precious-metal-based electrocatalysts is essential for practical water splitting applications. The electrolysis of water for hydrogen production is a green and efficient method, while urea electrolysis can improve energy conversion efficiency. In this paper, W-Ni 3 S 2 /NiS catalysts with heterogeneous structures were synthesized via a one-step hydrothermal method using a W-doping-induced phase transition strategy. The doping of W modulates the morphology of the catalyst, which can form uniform nanorod arrays and improve the activity of the electrocatalyst. In an alkaline solution of 1 M KOH and 0.5 M urea, W-Ni 3 S 2 /NiS requires a potential of only 1.309 V to achieve a current density of 10 mA cm -2 . An electrolyzer containing urea with W-Ni 3 S 2 /NiS as both the cathode and anode can drive a current density of 10 mA cm -2 with a potential of only 1.569 V and has relatively good stability after testing for 20 h. Experimental results show that the improvement in the catalytic activity is due to the rapid charge transfer, exposure of more active sites and better conductivity. Density functional theory calculations show that the W-Ni 3 S 2 material exhibits higher urea adsorption energy, indicating that urea is preferentially adsorbed on its surface. The NiS material shows more state density near the Fermi level, indicating that the introduction of this material enhances the conductivity of the W-Ni 3 S 2 /NiS material. The synergistic catalysis of the two materials promoted the improvement of the catalytic activity. This work provides new ideas for the development of highly efficient and stable catalysts by means of doping and interface construction.

Short-chain chlorinated paraffins (SCCPs) were listed for elimination under the Stockholm Convention in 2017 due to their persistence and toxicity. Although Canada and other Stockholm signatories have prohibited the manufacture, usage and import of SCCPs since 2013, they can still be detected at high concentrations in indoor dust. To identify the sources of the SCCPs in the Canadian indoor environment, short-, medium- and long-chain chlorinated paraffins (SCCPs, MCCPs, LCCPs, respectively) were measured using a sensitive LC-ESI-orbitrap method. SCCPs were detected in 84 of the 96 products purchased in Canada after 2013 (87.5%) including electronic devices, clothing, plastics (toys), and paintings. Concentrations of SCCPs were up to 0.93% (9.34 mg g -1 ). SCCPs were also detected in newly purchased toys at 0.005-2.02 mg g -1 , indicating the potential for children's exposure. Profiles of chlorinated paraffins differed among categories of products. For example, C 13 -SCCPs were most common in toys, while electronic devices like headphones showed comparable concentrations of SCCPs and MCCPs. Additionally, four new carboxylate derivatives of CPs were detected in an electronic device sample. These are the first data to show the ubiquitous occurrences of SCCPs in a wide range of products currently marketed in Canada, suggesting continuing indoor exposure to SCCPs despite their prohibition.

Nd 0.6 Sr 0.4 Co 1- x Cu x O 3- δ ( x = 0, 0.05, 0.1, 0.15, 0.2) (NSCC x ) was prepared by replacing Co with Cu. Its chemical compatibility, electrical conductivity, and electrochemical properties were studied by X-ray powder diffractometry, scanning electron microscopy, and X-ray photoelectron spectroscopy. The conductivity, AC impedance spectra, and output power of the single cell were tested in an electrochemical workstation. Results showed that the thermal expansion coefficient (TEC) and electrical conductivity of the sample decreased with the increase in Cu content. The TEC of NSCC 0.1 decreased by 16.28% in the temperature range of 35 °C-800 °C, and its conductivity was 541 S cm -1 at 800 °C. Furthermore, a single cell was constructed with NSCC x as the cathode, NiO-GDC as the anode, and GDC as the electrolyte. The peak power of the cell at 800 °C was 444.87 mW·cm -2 , which was similar to that of the undoped sample. Compared with the undoped NSCC, NSCC 0.1 showed lower TEC while maintaining its output power. Therefore, this material can be used as a cathode for solid oxide fuel cells., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The synergistic effect of epigallocatechin-3-gallate (E) and quercetin (Q) enhances the therapeutic efficacy on related diseases; however, the instability and lower bioavailability of E and Q limited their application. Therefore, E and Q were co-encapsulated in hydrogel beads (H) with sodium alginate (SA) and soybean protein isolate (SPI) to improve their stability and bioavailability. The anti-inflammatory effect and molecular mechanism of action of E and Q co-loaded H in inflammatory bowel disease (IBD) were also investigated. The results showed that EQH-treated macrophages produced the lowest NO and TNF-α at 18.64 μmol L -1 and 5855.25 ng mL -1 , respectively. The protein expression of p-NF κB-p65 was the lowest in EQH, indicating that EQH inhibits the activation of the pro-inflammatory NF-κB signaling pathway. The colon length of IBD model rats fed EH, QH, and EQH increased; histological analysis revealed intact layers of colonic epithelial cells with no observable tissue damage. The TNF-α and IL-1β levels in the plasma of the EQH-treated rats decreased, indicating the inhibition of the TLR4 and NF-κB signaling pathways, and Q's level in the colon was the highest at 0.04 mg mL -1 . This study provides a theoretical basis for the application of E and Q in IBD.

In order to study the effects of silylene ligands on the catalytic activity of carbonyl hydrosilylation catalyzed by cobalt phosphine complexes, readily available model catalysts are required. In this contribution, a comparative study of the hydrosilylation of aldehydes and ketones catalyzed by tris(trimethylphosphine) cobalt chloride, CoCl(PMe 3 ) 3 (1), and bis(silylene) cobalt chloride, Co(LSi:) 2 (PMe 3 ) 2 Cl (2, LSi: = {PhC(N t Bu) 2 }SiCl), is presented. It was found that both complexes 1 and 2 are good catalysts for the hydrosilylation of aldehydes and ketones under mild conditions. This catalytic system has a broad substrate scope and selectivity for multi-functional substrates. Silylene complex 2 shows higher activity than complex 1, bearing phosphine ligands, for aldehydes, but conversely, for ketones, the activity of complex 1 is higher than that of complex 2. It is worth noting that in the process of mechanistic studies the intermediates (PMe 3 ) 3 Co(H)(Cl)(PhH 2 Si) (3) and (LSi:) 2 (PMe 3 )Co(H)(Cl)(PhH 2 Si) (4) were isolated from the stoichiometric reactions of 1 and 2 with phenylsilane, respectively. Further experiments confirmed that complex 3 is a real intermediate. A possible catalytic mechanism for the hydrosilylation of carbonyl compounds catalyzed by 1 was proposed based on the experimental investigation and literature reports, and this mechanism was further supported by DFT studies. The bis(silylene) complex 4 showed complicated behavior in solution. A series of experiments were designed to study the catalytic mechanism for the hydrosilylation of carbonyl compounds catalyzed by complex 2. According to the experimental results, the hydrosilylation of aldehydes catalyzed by 1 proceeds via a different mechanism than that of the analogous reaction with complex 2 as the catalyst. In the case of ketones, complex 4 is a real intermediate, indicating that both 1 and 2 catalyze the reaction by the same mechanism. The molecular structures of 3 and 4 were determined by single crystal X-ray diffraction analysis.