A Planar-Structured Dinuclear Cobalt(II) Complex with Indirect Synergy for Photocatalytic CO2-to-CO Conversion.

Dinuclear metal synergistic catalysis (DMSC) has been proved an effective approach to enhance catalytic efficiency in photocatalytic CO2 reduction reaction, while it remains challenge to design dinuclear metal complexes that can show DMSC effect. The main reason is that the influence of the microenvironment around dinuclear metal centres on catalytic activity has not been well recognized and revealed. Herein, we report a dinuclear cobalt complex featuring a planar structure, which displays outstanding catalytic efficiency for photochemical CO2-to-CO conversion. The turnover number (TON) and turnover frequency (TOF) values reach as high as 14457 and 0.40 s-1 respectively, 8.6 times higher than those of the corresponding mononuclear cobalt complex. Control experiments and theoretical calculations revealed that the enhanced catalytic efficiency of the dinuclear cobalt complex is due to the indirect DMSC effect between two CoII ions, energetically feasible one step two-electron transfer process by Co2 I,I intermediate to afford Co2 II,II(CO2 2-) intermediate and fast mass transfer closely related with the planar structure.

Unveiling the role of proton concentration in dinuclear metal complexes for boosting photocatalytic CO2 reduction.

The reaction kinetics of photocatalytic CO2 reduction is highly dependent on the transfer rate of electrons and protons to the CO2 molecules adsorbed on catalytic centers. Studies on uncovering the proton effect in catalysts on photocatalytic activity of CO2 reduction are significant but rarely reported. In this paper, we, from the molecular level, revealed that the photocatalytic activity of CO2 reduction is closely related to the proton availability in catalysts. Specifically, four dinuclear Co(II) complexes based on Robson-type ligands with different number of carboxylic groups (-nCOOH; n = 0, 2, 4, 6) were designed and synthesized. All these complexes show photocatalytic activity for CO2 reduction to CO in a water-containing system upon visible-light illumination. Interestingly, the CO yields increase positively with the increase of the carboxylic-group number in dinuclear Co(II) complexes. The one containing -6COOH shows the best photocatalytic activity for CO2 reduction to CO, with the TON value reaching as high as 10,294. The value is 1.8, 3.4, and 7.8 times higher than those containing -4COOH, -2COOH, and -0COOH, respectively. The high TON value also makes the dinuclear Co(II) complex with -6COOH outstanding among reported homogeneous molecular catalysts for photocatalytic CO2 reduction. Control experiments and density functional theory calculation indicated that more carboxylic groups in the catalyst endow the catalyst with more proton relays, thus accelerating the proton transfer and boosting the photocatalytic CO2 reduction. This study, at a molecular level, elucidates that more carboxylic groups in catalysts are beneficial for boosting the reaction kinetics of photocatalytic CO2 reduction.

Efficacy of radiofrequency ablation combined with sorafenib for treating liver cancer complicated with portal hypertension and prognostic factors.

BACKGROUND: Patients with liver cancer complicated by portal hypertension present complex challenges in treatment. AIM: To evaluate the efficacy of radiofrequency ablation in combination with sorafenib for improving liver function and its impact on the prognosis of patients with this condition. METHODS: Data from 100 patients with liver cancer complicated with portal hypertension from May 2014 to March 2019 were analyzed and divided into a study group (n = 50) and a control group (n = 50) according to the treatment regimen. The research group received radiofrequency ablation (RFA) in combination with sorafenib, and the control group only received RFA. The short-term efficacy of both the research and control groups was observed. Liver function and portal hypertension were compared before and after treatment. Alpha-fetoprotein (AFP), glypican-3 (GPC-3), and AFP-L3 levels were compared between the two groups prior to and after treatment. The occurrence of adverse reactions in both groups was observed. The 3-year survival rate was compared between the two groups. Basic data were compared between the survival and non-surviving groups. To identify the independent risk factors for poor prognosis in patients with liver cancer complicated by portal hypertension, multivariate logistic regression analysis was employed. RESULTS: When comparing the two groups, the research group's total effective rate (82.00%) was significantly greater than that of the control group (56.00%; P < 0.05). Following treatment, alanine aminotransferase and aspartate aminotransferase levels increased, and portal vein pressure decreased in both groups. The degree of improvement for every index was substantially greater in the research group than in the control group (P < 0.05). Following treatment, the AFP, GPC-3, and AFP-L3 levels in both groups decreased, with the research group having significantly lower levels than the control group (P < 0.05). The incidence of diarrhea, rash, nausea and vomiting, and fatigue in the research group was significantly greater than that in the control group (P < 0.05). The 1-, 2-, and 3-year survival rates of the research group (94.00%, 84.00%, and 72.00%, respectively) were significantly greater than those of the control group (80.00%, 64.00%, and 40.00%, respectively; P < 0.05). Significant differences were observed between the survival group and the non-surviving group in terms of Child-Pugh grade, history of hepatitis, number of tumors, tumor size, use of sorafenib, stage of liver cancer, histological differentiation, history of splenectomy and other basic data (P < 0.05). Logistic regression analysis demonstrated that high Child-Pugh grade, tumor size (6-10 cm), history of hepatitis, no use of sorafenib, liver cancer stage IIIC, and previous splenectomy were independent risk factors for poor prognosis in patients with liver cancer complicated with portal hypertension (P < 0.05). CONCLUSION: Patients suffering from liver cancer complicated by portal hypertension benefit from the combination of RFA and sorafenib therapy because it effectively restores liver function and increases survival rates. The prognosis of patients suffering from liver cancer complicated by portal hypertension is strongly associated with factors such as high Child-Pugh grade, tumor size (6-10 cm), history of hepatitis, lack of sorafenib use, liver cancer at stage IIIC, and prior splenectomy.

Cited2 inhibited hypoxia-induced proliferation and migration of PASMCs via the TGF-ß1/Cited2/PPARγ pathway.

Objectives: Proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) contribute to hypoxia-induced pulmonary hypertension (HPH). The transcription factor Cbp/p300-interacting transactivator with Glu/Asp-rich carboxy-terminal domain 2 (Cited2) has been implicated in the control of tumor cells and mesenchymal stem cell (MSC) and cardiomyocyte growth or migration. Whether Cited2 is involved in the proliferation and migration of PASMCs and the underlying mechanisms deserve to be explored. Materials and Methods: Cited2 expression was detected in rat PASMCs under hypoxia conditions and HPH rat models. The effect of Cited2 on the proliferation and migration of PASMC was detected by overexpression or knockdown of the Cited2 gene. After PAMSCs were treated with recombinant TGF-ß1 and the lentivirus vector overexpressing Cited2, expression of peroxisome proliferator-activated receptor gamma (PPARγ) was examined by western blotting. Results: We revealed that hypoxia down-regulated the expression of Cited2 in PASMCs and rat pulmonary arteries. Cited2 overexpression inhibited the proliferation and migration of PASMCs under hypoxia, while Cited2 knockdown induced the proliferation and migration of PASMCs. Cited2 inhibits the negative regulation of the TGF-ß1 pathway on PPARγ to inhibit the proliferation and migration of PASMCs. Conclusion: These findings suggest that increased Cited2 expression contributes to the inhibition of PASMCs proliferation and migration by regulating TGF-ß1-mediated target gene expression in HPH and provides a new target for molecular therapy of HPH.

[Acupuncture regulates autophagy in hippocampal neurons of cerebral ischemia/reperfusion injured rats by activating type â ¢ PI3K/Beclin-1 pathway].

OBJECTIVE: To observe the effects of acupuncture on the expression of type Ⅲ phosphatidylinositol 3-hydroxykinase (PI3K) and Beclin-1 in hippocampus of rats with cerebral ischemia/reperfusion injury (CI/RI), so as to explore the mechanism of acupuncture in regulating type Ⅲ PI3K pathway to activate autophagy in the hippocampal neurons of CI/RI rats. METHODS: SD rats were randomly divided into sham operation group (n=11) and operation group. Then after successful modeling, rats in the operation group were randomly divided into model, acupuncture, model+3-MA and acupuncture+3-MA groups, with 11 rats in each group. The model of CI/RI was established by occlusion of the middle cerebral artery. Rats in the model+3-MA and acupuncture+3-MA groups were injected with 3-MA (400 nmol/ 5 µL) 5 µL into the lateral ventricle 30 min before reperfusion. Rats in the acupuncture and acupuncture+3-MA groups were punctured with filiform needles at "Dazhui" (GV14), "Shuigou" (GV26) and "Baihui" (GV20) and stimulated manually once every 15 min. The acupuncture intervention was conducted for 30 min each time, once every 12 h for a total of 7 times. The degree of neurological impairment was evaluated 2 h after reperfusion and after intervention by Garcia score. After intervention, the percentage of cerebral ischemic area was observed by TTC staining, the protein expression levels of type Ⅲ PI3K, Beclin-1, microtubule-associated protein 1 light chain 3B (LC3B), lysosome associated membrane protein 2 (Lamp2) and P62 in ischemic hippocampal tissue were detected by Western blot, the ultrastructure of neurons in ischemic hippocampus was observed by transmission electron microscopy (TEM). RESULTS: Compared with the sham operation group, the Garcia score was decreased (P<0.01), the percentage of cerebral ischemic area was increased (P<0.01), the expression levels of type Ⅲ PI3K, Beclin-1, LC3B-Ⅱ/Ⅰ, Lamp2 proteins were decreased (P<0.01), and the expression level of P62 protein was increased (P<0.01) in ischemic hippocampal tissue in the model group. Compared with the model group, the Garcia score was increased (P<0.01), the percentage of cerebral ischemic area was decreased (P<0.01), the expression levels of type Ⅲ PI3K, Beclin-1, LC3B-Ⅱ/Ⅰ, Lamp2 proteins were increased (P<0.01, P<0.05) and the expression level of P62 was decreased (P<0.01) in ischemic hippocampal tissue in the acupuncture group； the percentage of cerebral ischemic area was increased (P<0.05), the expressions of type Ⅲ PI3K and Beclin-1 were decreased (P<0.01) and the expression level of P62 protein was increased (P<0.05) in ischemic hippocampal tissue in the mo-del+3-MA group. Compared with the model +3-MA group, the Garcia score was increased (P<0.05), the percentage of cerebral ischemic area was decreased (P<0.01), the expression levels of type Ⅲ PI3K, Beclin-1, LC3B-Ⅱ/Ⅰ in ischemic hippo-campal tissue were increased (P<0.01, P<0.05) in the acupuncture+3-MA group. Compared with the acupuncture group, the Garcia score was decreased, the percentage of cerebral ischemic area was increased (P<0.05, P<0.01), the expression levels of type Ⅲ PI3K, Beclin-1, Lamp2 proteins were decreased (P<0.01, P<0.05) and P62 protein was increased (P<0.05) in ischemic hippocampal tissue in the acupuncture+3-MA group. The results of TEM showed that the edema of neurons was heavier, and few hypolysosomes existed in the model group; there was no obvious damage to neuronal structure, intracellular matrix was abundant, and a few lysosomes existed in the acupuncture group; the neuronal cells had mild edema and primary lysosomes were present in the acupuncture +3-MA group. CONCLUSION: Acupuncture can improve the symptoms of neurological impairment and reduce the percentage of cerebral ischemic area in rats with CI/RI. The mechanism may be related to regulating type Ⅲ PI3K/Beclin-1 pathway, up-regulating the expressions of autophagy related factors LC3B-Ⅱ and Lamp2, and down-regulating the expression of P62.

Computational Study of Single Metal Atom Anchored on Black Phosphorus for Methane Oxidation to Methanol by Nitrous Oxide.

Direct conversion of methane to high-value-added transportable methanol is a great challenge, which requires high energy input to break the strong C-H bond. Developing efficient catalysts for methane oxidation to methanol under mild conditions is of vital importance. In this work, single transition metal atoms (TM=Fe, Co, Ni, Cu) anchored on black phosphorus (TM@BP) were studied as catalysts to assist the methane oxidation to methanol by means of first-principles calculations. The results indicate that Cu@BP exhibits an outstanding catalytic activity through the radical reaction pathways and the formation of the Cu-O active site is rate-determining with an energy barrier of 0.48 eV. Meanwhile, electronic structure calculations and dynamic simulations show that Cu@BP offers excellent thermal stability. Our calculations provide a new approach for the rational design of single atom catalysts for methane oxidation to methanol.

Computational Study of Double Transition Metal Atom Anchored on Graphdiyne Monolayer for Nitrogen Electroreduction.

Converting N2 to NH3 is an essential reaction but remains a great challenge for industries. Developing more efficient catalysts for N2 reduction under mild conditions is of vital importance. In this work, double transition metal atoms (TM=Mo, W, Nb and Ru) anchored on graphdiyne monolayer (TM2 @GDY) as electrocatalysts are designed, and the corresponding reaction mechanisms of N2 electroreduction are systematically investigated by means of first-principles calculations. The results show that the double TM atoms can be strongly anchored on the acetylenic ring of GDY and Ru2 @GDY exhibits the highest catalytic activity for NRR with a maximum free energy change of 0.55 eV through the enzymatic pathway. The significant charge transfer between the substrate and the adsorbed N2 molecule is responsible for the superior catalytic activity. This work could provide a new approach for the rational design of double-atom catalysts for NRR and other related reduction reactions.

Ordered heterogeneity of molecular photosensitizer toward enhanced photocatalysis.

SignificanceThe photosensitizer is one of the important components in the photocatalytic system. Molecular photosensitizers have well-defined structures, which is beneficial in revealing the catalysis mechanism and helpful for further structural design and performance optimization. However, separation and recycling of the molecular photosensitizers is a great problem. Loading them into/on two/three-dimensional supports through covalent bonds, electrostatic interactions, and supramolecular interactions is a method that enhances their separation and recycling capability. Nonetheless, the structures of the resulting composites are unclear. Thus, the development of highly crystalline heterogeneity methods for molecular photosensitizers, albeit greatly challenging, is meaningful and desirable in photocatalysis, through which heterogeneous photosensitizers with well-defined structures, definite catalysis mechanisms, and good catalytic performance would be expected.

Construction of Low-Cost Z-Scheme Heterostructure Cu2 O/PCN for Highly Selective CO2 Photoreduction to Methanol with Water Oxidation.

Solar-driven CO2 reaction with water oxidation into alcohols represents a promising approach to achieve real artificial photosynthesis. However, rapid recombination of photogenerated carriers seriously restricts the development of artificial photosynthesis. Herein, a facile method is explored to construct low-cost Z-Scheme heterostructure Cu2 O/polymeric carbon nitride (PCN) by in situ growth of Cu2 O hollow nanocrystal on PCN. The protective PCN layer and Z-schematic charge flow can make robust Cu2 O/PCN photocatalysts, and the spatial separation of electrons and holes with high redox potentials of ECB (-1.15 eV) and EVB (1.65 eV) versus NHE can efficiently drive CO2 photoreduction to methanol in pure water, which is further confirmed by DFT calculation. The Z-scheme heterostructure Cu2 O/PCN exhibits a high methanol yield of 276 µmol g-1 in 8 h with ca. 100% selectivity, much superior to that of isolated Cu2 O and PCN, and all the reported Cu2 O-based heterostructures. This work provides a unique strategy to efficiently and selectively promote the conversion of CO2 and H2 O into high-value chemicals by constructing a low-cost Z-scheme heterostructure.

Stand-Alone CdS Nanocrystals for Photocatalytic CO2 Reduction with High Efficiency and Selectivity.

The development of a cost-effective photocatalyst is highly anticipated to achieve efficient photocatalytic CO2 reduction with superior selectivity, which is still facing the lack of valid settlements. Herein, 4-mercaptopyridine (PD) as the building block of a capping ligand is tightly decorated on the surface of CdS nanocrystals (CdS-PD) using a facile ligand-exchange strategy, to exploit a cost-effective photocatalyst for photocatalytic CO2 reduction without any cocatalysts. The conjugated structure of PD can facilitate the delocalization of photogenerated electrons in CdS nanocrystals, bringing forth an improved charge separation efficiency. More importantly, N-protonated PD can enable the easy formation of a six-membered ring intermediate with CO2 assisted by water, which can serve as the efficient active site to achieve photocatalytic CO2 reduction. In the absence of a cocatalyst, stand-alone CdS-PD nanocrystals exhibit an excellent CO yield of 20.35 mmol g-1 h-1 concomitant with a high selectivity of 95.3% for the CO2-to-CO conversion under visible light, which are remarkably superior than those of CdS nanocrystals possessing traditional alkyl-chain and other conjugated capping ligands.

Reversed Charge Transfer and Enhanced Hydrogen Spillover in Platinum Nanoclusters Anchored on Titanium Oxide with Rich Oxygen Vacancies Boost Hydrogen Evolution Reaction.

The catalytic activity of metal clusters is closely related with the support; however, knowledge on the influence of the support on the catalytic activity is scarce. We demonstrate that Pt nanoclusters (NCs) anchored on porous TiO2 nanosheets with rich oxygen vacancies (VO -rich Pt/TiO2 ) and deficient oxygen vacancies (VO -deficient Pt/TiO2 ), display significantly different catalytic activity for the hydrogen evolution reaction (HER), in which VO -rich Pt/TiO2 shows a mass activity of 45.28 A mgPt -1 at -0.1 V vs. RHE, which is 16.7 and 58.8 times higher than those of VO -deficient Pt/TiO2 and commercial Pt/C, respectively. DFT calculations and in situ Raman spectra suggest that porous TiO2 with rich oxygen vacancies can simultaneously achieve reversed charge transfer (electrons transfer from TiO2 to Pt NCs) and enhanced hydrogen spillover from Pt NCs to the TiO2 support, which leads to electron-rich Pt NCs being amenable to proton reduction of absorbed H*, as well as the acceleration of hydrogen desorption at Pt catalytic sites-both promoting the HER. Our work provides a new strategy for rational design of highly efficient HER catalysts.

Tailoring Crystal Facets of Metal-Organic Layers to Enhance Photocatalytic Activity for CO2 Reduction.

It is common that different crystal facets in metal and metal oxide nanocrystals display different catalytic performances, whereas such phenomena have been rarely documented in metal-organic frameworks (MOFs). Herein, we demonstrate for the first time that a nickel metal-organic layer (MOL) exposing rich (100) crystal facets (Ni-MOL-100) shows a much higher photocatalytic CO2 -to-CO activity than the one exposing rich (010) crystal facets (Ni-MOL-010) and its bulky counterpart (bulky Ni-MOF), with a catalytic activity up to 2.5 and 4.6 times more active than Ni-MOL-010 and bulky Ni-MOF, respectively. Theoretical studies reveal that the two coordinatively unsaturated NiII ions with a close distance of 3.50 Šon the surface of Ni-MOL-100 enables synergistic catalysis, leading to more favorable energetics in CO2 reduction than that of Ni-MOL-010.

[Effect of 5-aminoimidazole-4-formamide Ribonucleotide Combined with Interferon on Chronic Myeloid Leukemia K562 Cells].

OBJECTIVE: To study the effect of 5-aminoimidazole-4-formamide ribonucleotide (AICAR) combined with interferon (IFN-α-2b) on the proliferation and apoptosis of chronic myeloid leukemia K562 cells, and explore its possible mechanism. METHODS: CCK-8 method was used to detect the inhibition of cell proliferation. Wright Giemsa method was used to stain and cell morphology was observed by light microscopy. FITC Annexin V/PI double staining method was used to analyze the change of apoptosis rate. Immunocytochemistry method was used to detect the expression of wild-type P53 protein. RESULTS: Different concentration of AICAR was inhibitory effect on K562 cells at different time point of action for 24 h, 48 h, and 72 h, and the inhibition was time and dose-dependent (r=0.71, r=0.84). The combination of AICAR and IFN-α-2b could effectively inhibit the proliferation and promote apoptosis of K562 cells. The inhibition rate of K562 cells was (45.26±2.54)%, and the early apoptosis rate was (33.72±0.23)%, which was statistically significantly different from the control group, AICAR or IFN-ɑ-2b alone (P<0.05). The combination of two drugs promoted the expression of wild-type p53 protein. CONCLUSION: AICAR and/or IFN-ɑ-2b can inhibit the cell proliferation and promote the apoptosis of K562 cells. The combination of two drugs shows synergistic antitumor effect, and its mechanism may be related to the promotion of high expression of wild-type p53 protein.

Rare imaging findings of hypersensitivity pneumonitis: A case report.

BACKGROUND: Hypersensitivity pneumonitis (HP) is an immune-mediated syndrome caused by allergen inhalation. High-resolution computed tomography (HRCT) of HP may show diffuse ground-glass opacity, centrilobular ground-glass nodules, areas of air-trapping, thin-walled cysts, or fibrotic changes. CASE SUMMARY: A 47-year-old male patient went to the hospital complaining of cough and gradual aggravation of shortness of breath. HRCT of the lung showed that multiple nodules and ground-glass high-density shadows were present in both lungs. In addition, circular high-density shadows of various sizes were widely distributed in both lungs with relatively normal lung markings inside them. But other tests did not have a positive finding that can clarify the cause. Therefore, the patient underwent a lung biopsy. The pathological results showed that the lesions tended to be HP. After 4 mo of follow-up, the lesions in the patient's lungs were absorbed spontaneously, and the symptoms of cough and shortness of breath have disappeared. The review results suggested that the patient's disease was self-healing, which was consistent with the characteristics of HP. CONCLUSION: For some patients with HP, abnormal HRCT findings, such as the lesions in the lungs, can be absorbed on their own, which is an important clue in the diagnosis of the disease. Early diagnosis by lung biopsy is necessary when antigen exposure is unknown.

Controlled Synthesis of a Vacancy-Defect Single-Atom Catalyst for Boosting CO2 Electroreduction.

The reaction of precursors containing both nitrogen and oxygen atoms with NiII under 500 °C can generate a N/O mixing coordinated Ni-N3 O single-atom catalyst (SAC) in which the oxygen atom can be gradually removed under high temperature due to the weaker Ni-O interaction, resulting in a vacancy-defect Ni-N3 -V SAC at Ni site under 800 °C. For the reaction of NiII with the precursor simply containing nitrogen atoms, only a no-vacancy-defect Ni-N4 SAC was obtained. Experimental and DFT calculations reveal that the presence of a vacancy-defect in Ni-N3 -V SAC can dramatically boost the electrocatalytic activity for CO2 reduction, with extremely high CO2 reduction current density of 65 mA cm-2 and high Faradaic efficiency over 90 % at -0.9 V vs. RHE, as well as a record high turnover frequency of 1.35×105  h-1 , much higher than those of Ni-N4 SAC, and being one of the best reported electrocatalysts for CO2 -to-CO conversion to date.

[Identification and differential expression of miRNA related to seed dormancy of Paris polyphylla var. chinensis].

The purpose of this study was to explore the expression pattern of miRNA in the process of embryo dormancy and provide a reference for the mechanism of regulating seed dormancy and germination by miRNA. We used high-throughput sequencing technology, bioinformatics analysis and real-time fluorescent quantitative PCR(qPCR) technology to sequence, screen and identify miRNAs of dormant and dormant embryos. The results showed that there were 23 811 977, 24 276 695, 20 611 876 and 20 601 811 unique sequences in the four sample libraries during the period of dormancy and dormancy release. MiRNAs are mainly distributed between 21 and 24 nt, among which the length of 24 nt occurred most frequently. A total of 31 known miRNAs were identified, belonging to 13 different families. 93 new miRNAs were predicted by bioinformatics software. Ten miRNAs(mir156 a-5 p, mir160 a-5 p, mir160 h-1, mir169 a-5 p, mir157 d, mir159 a-1, mir395-3, mir156 f-5 p, mir156-2 and mir171 a-3 p) were screened out. In this study, 10 miRNAs related to seed dormancy release were identified. The target genes mainly involved carbohydrate metabolism, plant hormone signal transduction, cell division and growth. The results of qRT-PCR showed that the sequencing results were consistent with the actual results.

A broadband and strong visible-light-absorbing photosensitizer boosts hydrogen evolution.

Developing broadband and strong visible-light-absorbing photosensitizer is highly desired for dramatically improving the utilization of solar energy and boosting artificial photosynthesis. Herein, we develop a facile strategy to co-sensitize Ir-complex with Coumarins and boron dipyrromethene to explore photosensitizer with a broadband covering ca. 50% visible light region (Ir-4). This type of photosensitizer is firstly introduced into water splitting system, exhibiting significantly enhanced performance with over 21 times higher than that of typical Ir(ppy)2(bpy)+, and the turnover number towards Ir-4 reaches to 115840, representing the most active sensitizer among reported molecular photocatalytic systems. Experimental and theoretical investigations reveal that the Ir-mediation not only achieves a long-lived boron dipyrromethene-localized triplet state, but also makes an efficient excitation energy transfer from Coumarin to boron dipyrromethene to trigger the electron transfer. These findings provide an insight for developing broadband and strong visible-light-absorbing multicomponent arrays on molecular level for efficient artificial photosynthesis.

Dinuclear Metal Synergistic Catalysis Boosts Photochemical CO2 -to-CO Conversion.

The solar-driven CO2 reduction is a challenge in the field of "artificial photosynthesis", as most catalysts display low activity and selectivity for CO2 reduction in water-containing reaction systems as a result of competitive proton reduction. Herein, we report a dinuclear heterometallic complex, [CoZn(OH)L1 ](ClO4 )3 (CoZn), which shows extremely high photocatalytic activity and selectivity for CO2 reduction in water/acetonitrile solution. It achieves a selectivity of 98 % for CO2 -to-CO conversion, with TON and TOF values of 65000 and 1.8 s-1 , respectively, 4, 19, and 45-fold higher than the values of corresponding dinuclear homometallic [CoCo(OH)L1 ](ClO4 )3 (CoCo), [ZnZn(OH)L1 ](ClO4 )3 (ZnZn), and mononuclear [CoL2 (CH3 CN)](ClO4 )2 (Co), respectively, under the same conditions. The increased photocatalytic performance of CoZn is due to the enhanced dinuclear metal synergistic catalysis (DMSC) effect between ZnII and CoII , which dramatically lowers the activation barriers of both transition states of CO2 reduction.

Highly efficient and selective visible-light driven CO2-to-CO conversion by a Co-based cryptate in H2O/CH3CN solution.

Herein, we report a mononuclear Co(ii) cryptate which exhibits highly efficient and selective photocatalytic CO2-to-CO conversion in H2O/CH3CN solution. The TON and selectivity reach as high as 51 392 and 98%, respectively.

Engineering the Coordination Environment of Single-Atom Platinum Anchored on Graphdiyne for Optimizing Electrocatalytic Hydrogen Evolution.

Two Pt single-atom catalysts (SACs) of Pt-GDY1 and Pt-GDY2 were prepared on graphdiyne (GDY)supports. The isolated Pt atoms are dispersed on GDY through the coordination interactions between Pt atoms and alkynyl C atoms in GDY, with the formation of five-coordinated C1 -Pt-Cl4 species in Pt-GDY1 and four-coordinated C2 -Pt-Cl2 species in Pt-GDY2. Pt-GDY2 shows exceptionally high catalytic activity for the hydrogen evolution reaction (HER), with a mass activity up to 3.3 and 26.9 times more active than Pt-GDY1 and the state-of-the-art commercial Pt/C catalysts, respectively. Pt-GDY2 possesses higher total unoccupied density of states of Pt 5d orbital and close to zero value of Gibbs free energy of the hydrogen adsorption (|ΔGPtH* |) at the Pt active sites, which are responsible for its excellent catalytic performance. This work can help better understand the structure-catalytic activity relationship in Pt SACs.