Interface-confined intermediate phase in TiO2 enables efficient photocatalysis.

As a prototypical photocatalyst, TiO[Formula: see text] has been extensively studied. An interesting yet puzzling experimental fact was that P25-a mixture of anatase and rutile TiO[Formula: see text]-outperforms the individual phases; the origin of this mysterious fact, however, remains elusive. Employing rigorous first-principles calculations, here we uncover a metastable intermediate structure (MIS), which is formed due to confinement at the anatase/rutile interface. The MIS has a high conduction-band minimum level and thus substantially enhances the overpotential of the hydrogen evolution reaction. Also, the corresponding band alignment at the interface leads to efficient separation of electrons and holes. The interfacial confinement additionally creates a wide distribution of the band gap in the vicinity of the interface, which in turn improves optical absorption. These factors all contribute to the enhanced photocatalytic efficiency in P25. Our insights provide a rationale to the puzzling superior photocatalytic performance of P25 and enable a strategy to achieve highly efficient photocatalysis via interface engineering.

Crystal Facet Engineering on SrTiO3 Enhances Photocatalytic Overall Water Splitting.

Single-crystal semiconductor-based photocatalysts exposing unique crystallographic facets show promising applications in energy and environmental technologies; however, crystal facet engineering through solid-state synthesis for photocatalytic overall water splitting is still challenging. Herein, we develop a novel crystal facet engineering strategy through solid-state recrystallization to synthesize uniform SrTiO3 single crystals exposing tailored {111} facets. The presynthesized low-crystalline SrTiO3 precursors enable the formation of well-defined single crystals through kinetically improved crystal structure transformation during solid-state recrystallization process. By employing subtle Al3+ ions as surface morphology modulators, the crystal surface orientation can be precisely tuned to a controlled percentage of {111} facets. The photocatalytic overall water splitting activity increases with the exposure percentage of {111} facets. Owing to the outstanding crystallinity and favorable anisotropic surface structure, the SrTiO3 single crystals with 36.6% of {111} facets lead to a 3-fold enhancement of photocatalytic hydrogen evolution rates up to 1.55 mmol·h-1 in a stoichiometric ratio of 2:1 than thermodynamically stable SrTiO3 enclosed with isotropic {100} facets.

Anionic Metal-Organic Framework Derived Cu Catalyst for Selective CO2 Electroreduction to Hydrocarbons.

Metal-organic frameworks (MOFs)-related Cu materials are promising candidates for promoting electrochemical CO2 reduction to produce valuable chemical feedstocks. However, many MOF materials inevitable undergo reconstruction under reduction conditions; therefore, exploiting the restructuring of MOF materials is of importance for the rational design of high-performance catalyst targeting multi-carbon products (C2). Herein, a facile solvent process is choosed to fabricate HKUST-1 with an anionic framework (a-HKUST-1) and utilize it as a pre-catalyst for alkaline CO2RR. The a-HKUST-1 catalyst can be electrochemically reduced into Cu with significant structural reconstruction under operating reaction conditions. The anionic HKUST-1 derived Cu catalyst (aHD-Cu) delivers a FEC2H4 of 56% and FEC2 of ≈80% at -150 mA cm-2 in alkaline electrolyte. The resulting aHD-Cu catalyst has a high electrochemically active surface area and low coordinated sites. In situ Raman spectroscopy indicates that the aHD-Cu surface displays higher coverage of *CO intermediates, which favors the production of hydrocarbons.

Investigation of copper-induced intestinal damage and proteome alterations in Takifugu rubripes: Potential health risks and environmental toxicology detection.

Copper is one of the predominant water pollutants. Excessive exposure to copper can cause harm to animal health, affecting the central nervous system and causing blood abnormalities. Cuproptosis is a novel form of cell death that differs from previous programmed cell death methods. However, the impact of copper on the intestines remains unclear. Therefore, we investigated the effects of different concentrations of copper exposure on the intestinal proteome of Takifugu rubripes (T. rubripes). Relevant biomarkers were used to detect cuproptosis. We revealed the crosstalk relationship between cuproptosis and self-rescue at different concentrations, and discussed the feasibility of using potential cuproptosis indicators as anti-infection factors. We observed intestinal damage in the three copper exposure groups, especially in T. rubripes treated with 100 and 500 µg/L copper, with shedding and breakage of intestinal villus and fuzzy and loose structure of intestinal mucosa. The presence of copper stress not only causes cuproptosis but also oxidative damage caused by reactive oxygen species (ROS). The results of quantitative proteomics by TMT showed that compared to the 50 and 100 µg/L copper exposure groups, the expression of glutaminase, pyruvate kinase, and skin mucus lectin in the 500 µg/L group was significantly increased. The positive mediators COX5A and CTNNB1, as well as the negative mediators CD4 and FDXR, were found to be differentially expressed. Using the protein expression trends of cuproptosis indicator factors FDX1 and DLAT to indicate the concentration of copper ions in the environment. In addition, we found a new effect of promoting ferroptosis: providing additional copper ions can activate the phenomenon of ferroptosis. Our results expand our understanding of the potential health risks of copper in T. rubripes. At the same time, it is of great significance for the process of copper poisoning and the development of new environmental toxicology detection reagents.

Phosphorylation Modification, Structural Characterization, Antioxidant and DNA Protection Capacities of Polysaccharides from Asarum Sieboldii Miq.

Polysaccharide from Asarum sieboldii Miq (ASP) was extracted and five phosphorylation polysaccharides with different degree of substitution were obtained, namely ASPP1, ASPP2, ASPP3, ASPP4, and ASPP5 (ASPPs). The physical and chemical structure and biological activities were studied. The results suggested that the carbohydrate and protein content were reduced while uronic acid was increased after phosphorylation modification. The molecular weight of ASPPs was significantly lower than that of ASP. ASPPs were acidic heteropolysaccharides mainly composed of galacturonic acid, galactose, glucose, fructose, and arabinose. The UV-vis spectrum indicated that the polysaccharides did not contain nucleic acid or protein after modification. The Fourier transform infrared spectrum demonstrated that ASPPs contained characteristic absorption peaks of P=O and P-O-C near 1270 and 980 cm-1 . ASPPs presented a triple helix conformation, but it was not presented in ASP. The scanning electron microscopy analysis showed that the surface topography and particle structure of ASP were different after modification. Compared with ASP, ASPPs enhanced the activity to scavenge DPPH and ABTS free radicals and possessed more protective ability to DNA oxidation caused by OH⋅, GS⋅, and AAPH free radicals. These results suggest that chemical modification is beneficial for the exploitation and utilization of natural polysaccharides.

In situ/Operando Synchrotron Radiation Analytical Techniques for CO2/CO Reduction Reaction: From Atomic Scales to Mesoscales.

Electrocatalytic carbon dioxide/carbon monoxide reduction reaction (CO(2)RR) has emerged as a prospective and appealing strategy to realize carbon neutrality for manufacturing sustainable chemical products. Developing highly active electrocatalysts and stable devices has been demonstrated as effective approach to enhance the conversion efficiency of CO(2)RR. In order to rationally design electrocatalysts and devices, a comprehensive understanding of the intrinsic structure evolution within catalysts and micro-environment change around electrode interface, particularly under operation conditions, is indispensable. Synchrotron radiation has been recognized as a versatile characterization platform, garnering widespread attention owing to its high brightness, elevated flux, excellent directivity, strong polarization and exceptional stability. This review systematically introduces the applications of synchrotron radiation technologies classified by radiation sources with varying wavelengths in CO(2)RR. By virtue of in situ/operando synchrotron radiationanalytical techniques, we also summarize relevant dynamic evolution processes from electronic structure, atomic configuration, molecular adsorption, crystal lattice and devices, spanning scales from the angstrom to the micrometer. The merits and limitations of diverse synchrotron characterization techniques are summarized, and their applicable scenarios in CO(2)RR are further presented. On the basis of the state-of-the-art fourth-generation synchrotron facilities, a perspective for further deeper understanding of the CO(2)RR process using synchrotron radiation analytical techniques is proposed.

Polar Aromatic Two-dimensional Dion-Jacobson Halide Perovskites for Efficient Photocatalytic H2 Evolution.

Polar materials with spontaneous polarization (Ps) have emerged as highly promising photocatalysts for efficient photocatalytic H2 evolution owing to the Ps-enhanced photogenerated carrier separation. However, traditional inorganic polar materials often suffer from limitations such as wide band gaps and poor carrier transport, which hinders their photocatalytic H2 evolution efficiency. Here, we rationally synthesized a series of isostructural two-dimensional (2D) aromatic Dion-Jacobson (DJ) perovskites, namely (2-(2-Aminoethyl)pyridinium)PbI4 (2-APDPI), (3-(2-Aminoethyl)pyridinium)PbI4 (3-APDPI), and (4-(2-Aminoethyl)pyridinium)PbI4 (4-APDPI), where 2-APDPI and 4-APDPI crystalize in polar space groups with piezoelectric constants (d33) of approximately 40 pm V-1 and 3-APDPI adopts a centrosymmetric structure. Strikingly, owing to the Ps-facilitated separation of photogenerated carriers, polar 2-APDPI and 4-APDPI exhibit a 3.9- and 2.8-fold increase, respectively, in photocatalytic H2 evolution compared to the centrosymmetric 3-APDPI. As a pioneering study, this work provides an efficient approach for exploring new polar photocatalysts and highlights their potential in promoting photocatalytic H2 evolution.

A Machine Learning Framework for Diagnosing and Predicting the Severity of Coronary Artery Disease.

Background: Although machine learning (ML)-based prediction of coronary artery disease (CAD) has gained increasing attention, assessment of the severity of suspected CAD in symptomatic patients remains challenging. Methods: The training set for this study consisted of 284 retrospective participants, while the test set included 116 prospectively enrolled participants from whom we collected 53 baseline variables and coronary angiography results. The data was pre-processed with outlier processing and One-Hot coding. In the first stage, we constructed a ML model that used baseline information to predict the presence of CAD with a dichotomous model. In the second stage, baseline information was used to construct ML regression models for predicting the severity of CAD. The non-CAD population was included, and two different scores were used as output variables. Finally, statistical analysis and SHAP plot visualization methods were employed to explore the relationship between baseline information and CAD. Results: The study included 269 CAD patients and 131 healthy controls. The eXtreme Gradient Boosting (XGBoost) model exhibited the best performance amongst the different models for predicting CAD, with an area under the receiver operating characteristic curve of 0.728 (95% CI 0.623-0.824). The main correlates were left ventricular ejection fraction, homocysteine, and hemoglobin (p < 0.001). The XGBoost model performed best for predicting the SYNTAX score, with the main correlates being brain natriuretic peptide (BNP), left ventricular ejection fraction, and glycated hemoglobin (p < 0.001). The main relevant features in the model predictive for the GENSINI score were BNP, high density lipoprotein, and homocysteine (p < 0.001). Conclusions: This data-driven approach provides a foundation for the risk stratification and severity assessment of CAD. Clinical Trial Registration: The study was registered in www.clinicaltrials.gov protocol registration system (number NCT05018715).

[Traditional Chinese medicine used as anti-aging agent by targeting nuclear factor erythroid 2-related factor 2 signaling pathway].

The imbalance of redox homeostasis is a major characteristic of aging and contributes to the pathogenesis of various aging-related diseases. As a regulatory hub of redox homeostasis, nuclear factor erythroid 2-related factor 2 (NRF2) can attenuate oxidative stress by activating the transcription of many antioxidant enzymes. China is the birthplace of traditional Chinese medicine (TCM) which has been wildly used as medicine for thousands of years. Recently, TCM as anti-aging medicine has attracted enormous attention. Focusing on the NRF2 signaling pathway, this paper summarizes the correlation between various anti-aging TCM and the NRF2 signaling, and discusses the common key mechanisms by which TCM slows the aging process by targeting the NRF2 signaling network.

[Action mechanisms of Xiaoluowan (II) in the treatment of epididymitis: A network pharmacology-based study].

OBJECTIVE: To explore the potential action mechanisms of Xiaoluowan (II) (XLW-II) in the treatment of epididymitis through a network pharmacology approach. METHODS: We searched various databases for relevant targets associated with epididymitis and XLW-II and obtained the common targets of epididymitis and XLW-II on the Venny platform. We acquired the protein-protein interactions (PPI) using the STRING data and had them visualized with the Cytoscape software. After topological analysis, we retrieved the key targets, followed by gene ontology (GO) and KEGG pathway enrichment analyses using the DAVID database. RESULTS: A total of 2 38 drug targets, 2 150 disease targets and 85 common targets were identified. The core targets for the treatment of epididymitis with XLW-II identified by PPI network analysis included TNF, IL6, IL1B, MMP9, AKT1, PTGS2 and TP53. GO function analysis revealed the involvement of the common targets in such biological processes as response to hypoxia, regulation of apoptotic processes, inflammatory response, and positive regulation of the MAPK cascade. KEGG pathway analysis suggested that the signaling pathways such as the cancer pathway, PI3K-Akt pathway, protein glycosylation pathway in cancer, Ras pathway and chemokine pathway might be related to the action mechanisms of XLW-II in the treatment of epididymitis. CONCLUSION: The potential targets and signaling pathways of Xiaoluowan (II) in the treatment of epididymitis were identified on the basis of network pharmacology, which has provided a novel insight into its action mechanisms and offered a new direction for further relevant studies.

[Research on the mechanism of Miao ethnicity medicine formula of Oxalis corniculata against chronic non-bacterial prostatitis].

Objective： To explore the mechanism of Miao ethnicity medicine formula of Oxalis corniculata against chronic non-bacterial prostatitis. Methods: The rat model of chronic abacterial prostatitis was induced by stimulation with 2% sterile carrageenan solution. After modeling, the rats were randomly divided into two groups, Model control group (Model group) and oxalis group. Another normal control group was set up. The rats in the Model group and the normal control group were given 0.01ml/g normal saline by gavage, and the rats in the oxalis alis group were given 1ml/100g (1 g/kg) of Oxalis corniculata L warm water decoction by gavage once a day for 28 days. Twenty-four hours after the last administration, 10ml blood was collected from the abdominal aorta of the rats, and prostate tissue samples were collected from the rats. hematoxylin-eosin (HE) staining was used to observe the morphological structure of the prostate in normal and prostatitis rats. ELISA was used to detect the levels of serum and prostate cytokines. The protein expressions of 4-HNE , ALDH2 and FGF2 were detected by Western blot. Results: Compared with the blank group, the model group showed obvious hyperplasia of fibrous tissue in the interstitium of the prostate tissue, disordered glandular structure, papillary hyperplasia of epithelial cells in the acini, infiltration of a small amount of lymphocytes, monocytes and other inflammatory cells in the acini, and increased pathological scores. The protein expressions of 4-HNE , ALDH2 , MCP-1 and FGF2 in prostate tissue were significantly increased. Compared with the model group, the prostate tissue of the oxalis group was slightly damaged, with a small amount of fibrous hyperplasia and inflammatory cell infiltration. The protein expressions of 4-HNE , ALDH2 , MCP-1 and FGF2 were decreased in prostate tissue. Conclusion： Oxalis corniculata L can effectively repair the pathological morphology of prostate tissue in rats with CNP, and its mechanism may be related to activating 4-HNE protein and reducing oxidative stress injury of prostate tissue in rats.

[Exploring the mechanism of levocarnitine in the treatment of epididymitis based on network pharmacology and molecular docking technology].

OBJECTIVE: To explore the potential mechanism of action of levocarnitine in the treatment of epididymitis based on network pharmacology and experimental research. METHODS: The target proteins related to epididymitis and levocarnitine were retrieved through multiple databases, and the common targets were obtained using Venny software. The protein-protein interactions were obtained using the STRING database. Cytoscape software was used for visualization, and key targets were selected after topological analysis. GO and KEGG pathway enrichment analysis was performed using the DAVID database. Molecular docking was performed using Autodock Vina. RESULTS: A total of 130 drug targets and 2 151 disease targets were obtained, with 47 common targets. Protein-protein interaction network analysis identified core targets of levocarnitine in the treatment of epididymitis, including AKT1, HSP90AA1, ALB, CASP3, GSK3B, and GSR. KEGG pathway analysis suggested that metabolic pathways, lipid metabolism and atherosclerosis, cancer pathways, fluid shear stress and atherosclerosis, measles, chemical carcinogens-reactive oxygen species, purine metabolism, PI3K-Akt, and other signaling pathways may be associated with the mechanism of levocarnitine in the treatment of epididymitis. CONCLUSION: This study revealed through network pharmacology that levocarnitine may act on multiple signaling pathways by targeting AKT1, HSP90AA1, ALB, CASP3, GSK3B, GSR, etc., thereby potentially exerting therapeutic effects on epididymitis.

[Biological mechanisms of Oxalis corniculata regulating human prostate cancer PC-3 cells: An investigation based on the NF-κB pathway].

OBJECTIVE: To investigate the biological mechanisms underlying the effect of the Chinese herbal medicine Oxalis corniculata on human prostate cancer PC-3 cells. METHODS: Through in vitro experiment, we treated human prostate cancer PC-3 cells with different concentrations of Oxalis corniculata, assessed the viability of the cells by MTT assay, examined their apoptosis by flow cytometry, evaluated their migration and invasiveness by Transwell assay, and determined the expressions of the proteins p65, p-p65, IκBα and p-IκBα in the NF-κB pathway using protein imprinting technology. RESULTS: Compared with the blank control, Oxalis corniculata significantly inhibited the proliferation and induced the apoptosis of the PC-3 cells (P< 0.05), suppressed their migration and invasiveness in a dose-dependent manner (P< 0.05), and upregulated the expression of IκBα and downregulated those of p-p65 and p-IκBα in the NF-κB pathway (P< 0.05). CONCLUSION: Oxalis corniculata can inhibit the proliferation, migration and invasiveness and induce the apoptosis of human prostate cancer PC cells, which may be attributed to its abilities of inhibiting the expressions of p-p65 and p-IκBα and regulating the activity of the NF-κB pathway.

[Mechanism of Xiaoluanwan(II) in treating mouse epididymitis through the regulation of NLRP3 inflammasome].

OBJECTIVE: This study aimed to investigate the mechanism of Xiaoluanwan(II) in treating lipopolysaccharide(LPS)-induced epididymitis and its impact on the NLRP3 inflammasome. METHODS: The murine epididymitis model was established through local injection of LPS. The study included a control group (n=5), a model group (n=5), a model group treated with Xiaoluanwan(II) (Ⅱ) (n=5), and a saline group treated with Xiaoluanwan(II) (n=5). After 14 consecutive days of oral administration of Xiaoluanwan(II) or physiological saline, pathological changes in the epididymal tissues, expression levels of NLRP3 inflammasome and Caspase-1, as well as associated protein levels were examined. RESULTS: Compared to the model group, Xiaoluanwan(II) significantly alleviated inflammatory cell infiltration and lesions, as evidenced by a reduction in the protein expression levels of NLRP3, Caspase-1, Cleaved-Caspase-1, IL-1ß, IL-18, GSDMD, and p-p38 MAPK (P<0.05 or P<0.01), thereby mitigating the inflammatory response. CONCLUSION: Xiaoluanwan(II) alleviates epididymal inflammation and ameliorates mouse epididymal epithelial injury by modulating the NLRP3-mediated cell pyroptosis pathway.

Functional role of TrIL-1ß in Takifugu rubripes defense against Cryptocaryon irritans infection.

The Japanese puffer, Takifugu rubripes, is a commercially important fish species in China that is under serious threat from white spot disease (cyptocaryoniasis), which leads to heavy economic losses. We previously found that interleukin-1ß (IL-1ß), an important cytokine with a potential role in resistance against pathogens, was one of the most significantly differentially up-regulated proteins in the gills and spleen of T. rubripes infected by the protozoan parasite Cryptocaryon irritans. In this study, we assessed the potential function of T. rubripes IL-1ß (TrIL-1ß) in fish infected with C. irritans. Phylogenetic analysis indicated that the TrIL-1ß protein sequence was most closely related to that of Atlantic salmon (Salmo salar) (67.2 %). The incubation experiments revealed that TrIL-1ß may reduce trophont activity by destroying membranes. Immunofluorescence experiments showed that recombinant TrIL-1ß promoted the expression of endogenous IL-1ß, which penetrated and disrupted the cell membranes of trophonts. Transmission electron microscopy showed that the IL-1ß group had less tissue damage compared with control groups of fish. IL-1ß-small interfering RNA and IL-1ß overexpression experiments were performed in head kidney primary cells, and challenge experiments were performed in vitro. Quantitative RT-PCR results showed that TrIL-1ß regulated and activated MyD88/NF-κB and MyD88/MAPK/p38 signaling pathways during C. irritans infection. TrIL-1ß also promoted the differential expression of IgM, showing that it was involved in humoral immunity of T. rubripes. The cumulative mortality experiment show that TrIL-1ß could protect fish against C. irritans infection. These results enrich current knowledge about the molecular structure of TrIL-1ß. They also suggested that recombinant TrIL-1ß could be used as an adjuvant in a subunit vaccine against C. irritans infection, which is of profound importance for the prevention and control of parasitic diseases in T. rubripes.

Establishment of a prognosis predictive model for liver cancer based on expression of genes involved in the ubiquitin-proteasome pathway.

BACKGROUND: The ubiquitin-proteasome pathway (UPP) has been proven to play important roles in cancer. AIM: To investigate the prognostic significance of genes involved in the UPP and develop a predictive model for liver cancer based on the expression of these genes. METHODS: In this study, UPP-related E1, E2, E3, deubiquitylating enzyme, and proteasome gene sets were obtained from the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, aiming to screen the prognostic genes using univariate and multivariate regression analysis and develop a prognosis predictive model based on the Cancer Genome Atlas liver cancer cases. RESULTS: Five genes (including autophagy related 10, proteasome 20S subunit alpha 8, proteasome 20S subunit beta 2, ubiquitin specific peptidase 17 like family member 2, and ubiquitin specific peptidase 8) were proven significantly correlated with prognosis and used to develop a prognosis predictive model for liver cancer. Among training, validation, and Gene Expression Omnibus sets, the overall survival differed significantly between the high-risk and low-risk groups. The expression of the five genes was significantly associated with immunocyte infiltration, tumor stage, and postoperative recurrence. A total of 111 differentially expressed genes (DEGs) were identified between the high-risk and low-risk groups and they were enriched in 20 and 5 gene ontology and KEGG pathways. Cell division cycle 20, Kelch repeat and BTB domain containing 11, and DDB1 and CUL4 associated factor 4 like 2 were the DEGs in the E3 gene set that correlated with survival. CONCLUSION: We have constructed a prognosis predictive model in patients with liver cancer, which contains five genes that associate with immunocyte infiltration, tumor stage, and postoperative recurrence.

DNA Methylation Analysis Reveals Potential Mechanism in Takifugu rubripes Against Cryptocaryon irritans Infection.

Takifugu rubripes (T. rubripes) is a valuable commercial fish, and Cryptocaryon irritans (C. irritans) has a significant impact on its aquaculture productivity. DNA methylation is one of the earliest discovered ways of gene epigenetic modification and also an important form of modification, as well as an essential type of alteration that regulates gene expression, including immune response. To further explore the anti-infection mechanism of T. rubripes in inhibiting this disease, we determined genome-wide DNA methylation profiles in the gill of T. rubripes using whole-genome bisulfite sequencing (WGBS) and combined with RNA sequence (RNA-seq). A total of 4659 differentially methylated genes (DMGs) in the gene body and 1546 DMGs in the promoter between the infection and control group were identified. And we identified 2501 differentially expressed genes (DEGs), including 1100 upregulated and 1401 downregulated genes. After enrichment analysis, we identified DMGs and DEGs of immune-related pathways including MAPK, Wnt, ErbB, and VEGF signaling pathways, as well as node genes prkcb, myca, tp53, and map2k2a. Based on the RNA-Seq results, we plotted a network graph to demonstrate the relationship between immune pathways and functional related genes, in addition to gene methylation and expression levels. At the same time, we predicted the CpG island and transcription factor of four immune-related key genes prkcb and mapped the gene structure. These unique discoveries could be helpful in the understanding of C. irritans pathogenesis, and the candidate genes screened may serve as optimum methylation-based biomarkers that can be utilized for the correct diagnosis and therapy T. rubripes in the development of the ability to resist C. irritans infection.

Ultrahigh Bifunctional Photocatalytic CO2 Reduction and H2 Evolution by Synergistic Interaction of Heteroatomic Pt-Ru Dimerization Sites.

Diatomic-site catalysts (DASCs) inherit the excellent performance of single-atom catalysts (SACs) by utilizing two adjacent atomic metal species to achieve functional complementarity and synergistic effects that improve the carbon dioxide reduction reaction (CO2RR) and H2 evolution reaction (HER) kinetics. Herein, we report a method to further improve the catalytic efficiency of Pt by using Pt and Ru single atoms randomly anchored on a g-C3N4 surface, yielding partial Pt-Ru dimers. The synthesized catalyst exhibits extraordinary photocatalytic activity and stability in both the CO2RR and HER processes. In-depth experimentation, the pH-dependent chemical exchange saturation transfer (CEST) imaging nuclear magnetic resonance (NMR) method, and theoretical analyses reveal that the excellent performance is attributed to orbital coupling between the Pt atoms and the neighboring Ru atoms (mainly dxy and dxz), which decreases the orbital energy levels and weakens the bond strength with intermediates, resulting in improved CO2RR and HER performance. This study successfully applies the pH-dependent CEST imaging NMR method to catalytic reactions, and CO2 adsorption is directly observed using CEST 2D imaging maps. This work presents significant potential for a variety of catalytic reaction applications by systematically designing bimetallic dimers with higher activity and stability.

Enriched Oxygen Coverage Localized within Ir Atomic Grids for Enhanced Oxygen Evolution Electrocatalysis.

Inefficient active site utilization of oxygen evolution reaction (OER) catalysts have limited the energy efficiency of proton exchange membrane (PEM) water electrolysis. Here, an atomic grid structure is demonstrated composed of high-density Ir sites (≈10 atoms per nm2) on reactive MnO2-x support which mediates oxygen coverage-enhanced OER process. Experimental characterizations verify the low-valent Mn species with decreased oxygen coordination in MnO2-x exert a pivotal impact in the enriched oxygen coverage on the surface during OER process, and the distributed Ir atomic grids, where highly electrophilic Ir─O(II-δ)- bonds proceed rapidly, render intense nucleophilic attack of oxygen radicals. Thereby, this metal-support cooperation achieves ultra-low overpotentials of 166 mV at 10 mA cm-2 and 283 mV at 500 mA cm-2, together with a striking mass activity which is 380 times higher than commercial IrO2 at 1.53 V. Moreover, its high OER performance also markedly surpasses the commercial Ir black catalyst in PEM electrolyzers with long-term stability.