Insight into mechanism for remarkable photocatalytic hydrogen evolution of Cu/Pr dual atom co-modified TiO2.

The development of high-activity photocatalysts is crucial for the current large-scale development of photocatalytic hydrogen applications. Herein, we have developed a strategy to significantly enhance the hydrogen photocatalytic activity of Cu/Pr di-atom co-modified TiO2 architectures by selectively anchoring Cu single atoms on the oxygen vacancies of the TiO2 surface and replacing a trace of Ti atoms in the bulk with rare earth Pr atoms. Calculation results demonstrated that the synergistic effect between Cu single atoms and Pr atoms regulates the electronic structure of Cu/Pr-TiO2, thus promoting the separation of photogenerated carriers and their directional migration to Cu single atoms for the photocatalytic reaction. Furthermore, the d-band center of Cu/Pr-TiO2, which is located at -4.70 eV, optimizes the adsorption and desorption behavior of H*. Compared to TiO2, Pr-TiO2, and Cu/TiO2, Cu/Pr-TiO2 displays the best H* adsorption Gibbs free energy (-0.047 eV). Furthermore, experimental results confirmed that the photogenerated carrier lifetime of Cu/Pr-TiO2 is not only the longest (2.45 ns), but its hydrogen production rate (34.90 mmol g-1 h-1) also significantly surpasses those of Cu/TiO2 (13.39 mmol g-1 h-1) and Pr-TiO2 (0.89 mmol g-1 h-1). These findings open up a novel atomic perspective for the development of optimal hydrogen activity in dual-atom-modified TiO2 photocatalysts.

Changeable Active Sites by Pr Doping CuSA-TiO2 Photocatalyst for Excellent Hydrogen Production.

Photocatalytic water splitting for clean hydrogen production has been a very attractive research field for decades. However, the insightful understanding of the actual active sites and their impact on catalytic performance is still ambiguous. Herein, a Pr-doped TiO2-supported Cu single atom (SA) photocatalyst is successfully synthesized (noted as Cu/Pr-TiO2). It is found that Pr dopants passivate the formation of oxygen vacancies, promoting the density of photogenerated electrons on the CuSAs, and optimizing the electronic structure and H* adsorption behavior on the CuSA active sites. The photocatalytic hydrogen evolution rate of the obtained Cu/Pr-TiO2 catalyst reaches 32.88 mmol g-1 h-1, 2.3 times higher than the Cu/TiO2. Innovatively, the excellent catalytic activity and performance is attributed to the active sites change from O atoms to CuSAs after Pr doping is found. This work provides new insight for understanding the accurate roles of single atoms in photocatalytic water splitting.

Interface Engineering Induced Electron Redistribution at PtNs /NiTe-Ns Interfaces for Promoting pH-Universal and Chloride-Tolerant Hydrogen Evolution Reaction.

Exploring highly efficient hydrogen evolution reaction (HER) electrocatalysts for large-scale water electrolysis in the full potential of hydrogen (pH) range is highly desirable, but it remains a significant challenge. Herein, a simple pathway is proposed to synthesize a hybrid electrocatalyst by decorating small metallic platinum (Pt) nanosheets on a large nickel telluride nanosheet (termed as PtNs /NiTe-Ns). The as-prepared PtNs /NiTe-Ns catalyst only requires overpotentials of 72, 162, and 65 mV to reach a high current density of 200 mA cm-2 in alkaline, neutral and acidic conditions, respectively. Theoretical calculations reveal that the combination of metallic Pt and NiTe-Ns subtly modulates the electronic redistribution at their interface, improves the charge-transfer kinetics, and enhances the performance of Ni active sites. The synergy between the Pt site and activated Ni site near the interface in PtNs /NiTe-Ns promotes the sluggish water-dissociation kinetics and optimizes the subsequent oxyhydrogen/hydrogen intermediates (OH*/H*) adsorption, accelerating the HER process. Additionally, the superhydrophilicity and superaerophobicity of PtNs /NiTe-Ns facilitate the mass transfer process and ensure the rapid desorption of generated bubbles, significantly enhancing overall alkaline water/saline water/seawater electrolysis catalytic activity and stability.

Anchored Cu single atoms on porous g-C3N4 for superior photocatalytic H2 evolution from water splitting.

One of the most promising strategies for producing hydrogen is photocatalytic water splitting, in which the photocatalyst is a key component. Among many semiconductor photocatalysts, g-C3N4 has attracted great attention due to its narrow band gap, excellent stability and low cost. However, practical application is limited by its poor intrinsic activity. In this work, a high-performance porous g-C3N4 (PCN) photocatalyst with anchored Cu single atoms (CuSAs) was synthesized by a one-step co-heating approach. The obtained Cu1.5-PCN displays an excellent hydrogen evolution rate (HER) of 2142.4 µmol h-1 g-1 under visible light (=420 nm), which is around 15 and 109 times higher than those of PCN and bulk g-C3N4, respectively. In addition, it also shows good stability during H2 evolution. The results of experimental research and DFT simulations indicate that the single Cu ions formed bonds with the N-ring and these remain stable. Meanwhile, the special electronic structure of the Cu-N charge bridge extends the light absorption band to the visible-light region (380-700 nm). This high-performance and low-cost photocatalyst has great potential in solar energy conversion.

Etching dopant elements to construct active-site-rich Mo2C for the hydrogen evolution reaction.

We propose a strategy to etch dopants to construct Mo2C with more unsaturated coordination of Mo atoms and lattice distortion for enhanced catalytic activity. It is more effective than doping and etching pure Mo2C and provides a novel strategy for the preparation of catalysts with high catalytic activity.

Excellent performance supercapacitors with the compounding of Ni(OH)2 and ZIF-67 derived Co-C-N nanosheets as flexible electrode materials.

Owing to the advantages of high theoretical capacity, low cost, and excellent chemical stability, Ni(OH)2 is considered as a potential candidate for electrode materials of supercapacitors. However, its further applications are limited by its adverse surface chemical properties. In this paper, a composite material consisting of ZIF-67 derived Co-C-N nanosheets and Ni(OH)2 was synthesized facilely on carbon cloth in situ, and based on the collective advantages of the various components, excellent electrochemical performance could be achieved when used as a flexible electrode material of supercapacitors. In detail, the as-obtained sample Ni(OH)2/Co-C-N/CC exhibits an ultrahigh specific capacitance of 2100 F g-1 at a current density of 1 A g-1. Moreover, the further assembled asymmetric supercapacitor device exhibits a maximum energy density of 78.6 W h kg-1 at a power density of 749.4 W kg-1. Furthermore, the device also shows outstanding cycling stability with 90.2% capacitance retention after 5000 cycles of charge-discharge. Basically, the remarkable performance can be attributed to the well-developed structure, abundant active sites, complex beneficial components, and their intrinsic properties. Significantly, rational design can broaden the research directions of corresponding electrode materials.

New Strategy and Excellent Fluorescence Property of Unique Core-Shell Structure Based on Liquid Metals/Metal Halides.

The further applications of liquid metals (LMs) are limited by their common shortcoming of silver-white physical appearance, which deviates from the impose stringent requirements for color and aesthetics. Herein, a concept is proposed for constructing fluorescent core-shell structures based on the components and properties of LMs, and metal halides. The metal halides endow LMs with polychromatic and stable fluorescence characteristics. As a proof-of-concept, LMs-Al obtained by mixing of LMs with aluminum (Al) is reported. The surface of LMs-Al is transformed directly from Al to a multi-phase metal halide of K3 AlCl6 with double perovskites structure, via redox reactions with KCl + HCl solution in a natural environment. The formation of core-shell structure from the K3 AlCl6 and LMs is achieved, and the shell with different phases can emit a cyan light by the superimposition of the polychromatic spectrum. Furthermore, the LMs can be directly converted into a fluorescent shell without affecting their original features. In particular, the luminescence properties of shells can be regulated by the components in LMs. This study provides a new direction for research in spontaneous interfacial modification and fluorescent functionalization of LMs and promises potential applications, such as lighting and displays, anti-counterfeiting measures, sensing, and chameleon robots.

Unique Surface Fluorescence Induced from the Core-Shell Structure of Gallium-Based Liquid Metals Prepared by Thermal Oxidation Processing.

Liquid metals (LMs) have emerged as promising functional materials that combine the properties of both liquid and metal. These characteristics enabled them to find applications in many fields. However, the LMs usually can only display a silver-white physical appearance, which limits their further applications in the fields with the imposition of stringent requirements for color and aesthetics. Herein, we report that the surface of LMs was transformed directly from metal to fluorescent semiconductor layer by an example of eutectic GaInSn (eGaInSn) induced by thermal oxidation. Specifically, a core-shell structure is formed from the fluorescent layer and the LMs. The shell endows the LMs with fluorescence without affecting their interior fluidity and conductivity. In particular, the formation process as well as the degree of crystallization, phase transformation, and light emission of the fluorescent oxide shell on the surface of LMs is regulated by the component content. A thorough analysis of surface morphology, composition, structure, and properties of the fluorescent shell suggests that the Ga2O3 layer is formed on the surface of gallium-based LMs after their immersion in deionized water. Subsequently, thermal oxidation results in the formation of the ß-Ga2O3 shell on the surface of liquid metals. Importantly, abundant oxygen vacancies (VO) in ß-Ga2O3 as the donors and the gallium vacancies (VGa), gallium-oxygen vacancy pairs (VO-VGa), defect energy levels, and intrinsic defects as the acceptors enabled the light emission. The fluorescent LMs have promising potential for flexible lighting and displays, anticounterfeiting measures, sensing, and chameleon robots.

Performance and mechanism of nickel hydroxide catalyzed reduction of N-nitrosodimethylamine by iron.

Since iron (Fe) was first proven to have a strong reduction ability, it has been successfully applied to remove pollutants from water. In this study, nickel hydroxide (Ni(OH)2), a catalyst commonly used in hydrogen evolution reactions, was added to improve the activity of Fe to remove N-nitrosodimethylamine (NDMA). The results showed that with the increasing Ni(OH)2 dosages, the reactions accelerated. The NDMA removal rates increased when the pH value was 6 or 7. Further, when the dissolved oxygen concentration was in the range of 0-12.0 mg∙L-1, it had little effect on the Fe/Ni(OH)2 system, and all the reactions obeyed pseudo-first-order kinetics. 1,1-dimethylhydrazine and dimethylamine were formed during NDMA degradation. The capture of active substances and electron spin resonance method confirmed that the main active species were active hydrogen atoms, which participated in the removal of NDMA. Ni(OH)2 acting as a catalyst was confirmed using wide-angle X-ray diffraction, X-ray photoelectron spectroscopy and Ni2+ dissolution. Further, catalytic hydrogenation was proposed as the main removal mechanism as Ni(OH)2 promotes the corrosion of Fe and dissociation of water, thereby generating more active hydrogen atoms. In addition, Ni(OH)2 may activate both Fe and NDMA. This technique could be employed as an alternative for NDMA reduction and expand the application field of Ni(OH)2.

Hybrid cobalt-manganese oxides prepared by ordered steps with a ternary nanosheet structure and its high performance as a binder-free electrode for energy storage.

Binder-free electrodes for supercapacitors have attracted much attention as no additive is required in their preparation processes. Herein, a hybrid metal oxide composed of graphene oxide (Co3O4/MnO2/GO) was successfully prepared. Briefly, electrochemical deposition and sintering were applied to grow Co3O4 nanosheets on nickel foam. Subsequently, MnO2 nanosheets were deposited on Co3O4 nanosheets via the thermal decomposition of a KMnO4 aqueous solution. Finally, graphene oxide was added to improve the performance of the composite. Particularly, the as-obtained Co3O4/MnO2/GO sample grown on nickel foam possessed a ternary nanosheet structure, and when applied as a binder-free electrode in a supercapacitor, it exhibited an excellent electrochemical performance. Firstly, the electrode exhibited an ultrahigh capacitance value of 2928 F g-1 at 1 A g-1 in a three-electrode system. Besides, the electrode showed a promising rate performance of 853 F g-1 at a high current density of 20 A g-1. Moreover, the electrode displayed a relatively high energy density of 97.92 W h kg-1 at a power density of 125 W kg-1 and long cycle life of 93% retention after 5000 cycles at 10 A g-1 in a two-electrode system. Thus, all the electrochemical tests suggest that the Co3O4/MnO2/GO binder-free electrode is a potential candidate for energy storage.

Platinum-Supported Cerium-Doped Indium Oxide for Highly Sensitive Triethylamine Gas Sensing with Good Antihumidity.

Triethylamine is extremely harmful to human health, and chronic inhalation can lead to respiratory and hematological diseases and eye lesions. Hence, it is essential to develop a triethylamine gas-sensing technology with high response, selectivity, and stability for use in healthcare and environmental monitoring. In this work, a simple and low-cost sensor based on the Pt- and Ce-modified In2O3 hollow structure to selectively detect triethylamine is developed. The experimental results reveal that the sensor based on 1% Pt/Ce12In exhibits excellent triethylamine-sensing performance, including its insusceptibility to water, reduced operating temperature, enhanced response, and superior long-term stability. This work suggests that the enhancement of sensing performance toward triethylamine can be attributed to the high relative contents of OV and OC, large specific surface area, catalytic effect, the electronic sensitization of Pt, and the reversible redox cycle properties of Ce. This sensor represents a unique and highly sensitive means to detect triethylamine, which shows great promise for potential applications in food safety inspection and environmental monitoring.

Nanoporous Carbon Derived from Green Material by an Ordered Activation Method and Its High Capacitance for Energy Storage.

Carbon materials have been widely used as electrode materials for supercapacitors, while the current carbon precursors are mainly derived from fossil fuels. Biomass-derived carbon materials have become new and effective materials for electrodes of supercapacitors due to their sustainability, low pollution potential, and abundant reserves. Herein, we present a new biomass carbon material derived from water hyacinth by a novel activation method (combination of KOH and HNO3 activation). According to the electrochemical measurements, the material presents an ultrahigh capacitance of 374 F g-1 (the current density is 1 A g-1). Furthermore, the material demonstrates excellent rate performance (105 F g-1 at a higher density of 20 A g-1) and ideal cycling stability (87.3% capacity retention after 5000 times charge-discharge at 2 A g-1). When used for a symmetrical supercapacitor device, the material also shows a relatively high capacity of 330 F g-1 at 1 A g-1 (a two-electrode system). All measurements suggest the material is an effective and noteworthy material for the electrodes of supercapacitors.

Abiotic reduction of p-chloronitrobenzene by sulfate green rust: influence factors, products and mechanism.

The reduction of p-chloronitrobenzene (p-CNB) by sulfate green rust (GRSO4 ) was systematically studied. The results revealed that GRSO4 has a good removal effect on p-CNB. The removal efficiencies of p-CNB by GRSO4 improved with the increase of the pH value. The removal efficiencies in the presence of ions were better than that of GRSO4 alone, while natural organic matter (NOM) could adsorb p-CNB, which competed with GRSO4 . The reductions of p-CNB by GRSO4 under different conditions followed pseudo-first-order reaction kinetics except for the reactions in the presence of NOM. p-CNB was converted into p-chloroaniline (p-CAN), which produced p-nitrosochlorobenzene and p-chlorophenylhydroxylamine as the intermediate products. The results of the X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed GRSO4 was gradually transformed into goethite. Fe(ii) in the GRSO4 structure was the main electron donor involved in the reaction.

Separation of misalignment aberrations in interferometric testing for the surface measurement of the frustum of a cone.

The separation of misalignment aberrations is a crucial step in interferometric testing for the acquisition of the real surface. In this paper, a Fizeau interference system and a conical mirror with a certain angle were used to achieve the shape measurement of the inner surface of the frustum of a cone. Based on the ray-tracing method, the relationship between the adjustment errors and misalignment aberrations was established, and the misalignment aberrations could be removed by using the error separation model that accords with the least-square algorithm theory. The simulation and practical measurement results indicate that the approach proposed is valid and feasible.

Ag Nanoparticles Sensitized In2O3 Nanograin for the Ultrasensitive HCHO Detection at Room Temperature.

Formaldehyde (HCHO) is the main source of indoor air pollutant. HCHO sensors are therefore of paramount importance for timely detection in daily life. However, existing sensors do not meet the stringent performance targets, while deactivation due to sensing detection at room temperature, for example, at extremely low concentration of formaldehyde (especially lower than 0.08 ppm), is a widely unsolved problem. Herein, we present the Ag nanoparticles (Ag NPs) sensitized dispersed In2O3 nanograin via a low-fabrication-cost hydrothermal strategy, where the Ag NPs reduces the apparent activation energy for HCHO transporting into and out of the In2O3 nanoparticles, while low concentrations detection at low working temperature is realized. The pristine In2O3 exhibits a sluggish response (Ra/Rg = 4.14 to 10 ppm) with incomplete recovery to HCHO gas. After Ag functionalization, the 5%Ag-In2O3 sensor shows a dramatically enhanced response (135) with a short response time (102 s) and recovery time (157 s) to 1 ppm HCHO gas at 30 °C, which benefits from the Ag NPs that electronically and chemically sensitize the crystal In2O3 nanograin, greatly enhancing the selectivity and sensitivity.

Expression of ERCC1, TYMS, RRM1, TUBB3, non-muscle myosin II, myoglobin and MyoD1 in lung adenocarcinoma pleural effusions predicts survival in patients receiving platinum-based chemotherapy.

The association between the expression of excision repair cross­complementing gene 1 (ERCC1), thymidylate synthase (TYMS), ribonuleotide reductase M1 (RRM1), ßIII­tubulin (TUBB3), non­muscle myosin II, myoglobin and MyoD1 in metastatic lung adenocarcinoma, and clinical outcomes with platinum­based chemotherapy treatment is not well­established. Recently, increasing attention has been focused on the involvement of ERCC1, TYMS, RRM1 and TUBB3 in the development of drug resistance. There has been less research into the role of muscle myosin II, myoglobin and MyoD1 in the pathogenesis of lung cancer, although these genes are known to have important functions within tumor cells. In the current study, malignant pleural effusion from 116 patients with untreated lung adenocarcinoma diagnosed between 2011 and 2012, were collected. The protein expression levels of ERCC1, TYMS, RRM1 and TUBB3 were evaluated with immunocytochemistry and western blot analysis. The expression levels of non­muscle myosin II, myoglobin and MyoD1 were measured in a subset of 50 patients, treated with platinum­based chemotherapy. The association of each of these seven factors with one another, as well as with patient survival were analyzed. Immunohistochemistry demonstrated that the percentage of pleural fluid samples from patients with lung adenocarcinoma expressing ERCC1, TYMS, RRM1 and TUBB3 was 37, 36.2, 82.7 and 69.8%, respectively. In the subset of 50 patients in whom the remaining factors were analyzed, the percentage expressing non­muscle myosin II was 48%, for myoglobin the figure was 40% and for MyoD1 it was 38%. There was a positive correlation between each pair of the above seven molecules with the exception of TYMS and RRM1. Expression of ERCC1, TYMS, TUBB3, non­muscle myosin II, myoglobin and MyoD1 genes was associated with decreased survival in patients with metastatic lung adenocarcinoma. Expression of ERCC1, TYMS, TUBB3, non­muscle myosin II, myoglobin and MyoD1 was also associated with decreased survival rates of patients with lung adenocarcinoma treated with platinum­based chemotherapy. These factors may be used as clinical biomarkers to predict the biological behavior and chemoresistance of tumor cells, and the survival of patients with lung carcinoma.

[Performance of computer-assisted imaging system in detection of squamous intraepithelial lesion of uterine cervix].

OBJECTIVE: To evaluate the performance of computer-assisted imaging system in the detection of cervical squamous intraepithelial lesion and quality-assurance. METHODS: Manual PAP screening (n = 140 580) and image-assisted screening (n = 32 885) were compared for the detection rates of squamous cell abnormalities, the atypical squamous cells (ASC) to squamous intraepithelial lesion (SIL) ratio, the positive rates of high risk human papillomavirus (HR-HPV) test in the case of atypical squamous cells of undetermined significance (ASC-US), and the correlation between cytopathology and histopathology. RESULTS: Compared with manual screening, computer-assisted imaging system showed increased overall positive detection by 0.32%, decreased detection of ASC by 0.21%, increased detection of low-grade squamous intraepithelial lesion (LSIL) by 0.22%, increased detection of high-grade squamous intraepithelial lesion or worse (HSIL) by 0.31%, and decreased ASC to SIL ratio from 2.59 to 1.60. Computer-assisted imaging system did not change the HR-HPV positive rate of the patients who were ASC-US, or the coincidence rate between cytopathology and histopathology. Moreover, the productivity of the laboratory operation increased 58.33%. CONCLUSION: Computer-assisted imaging system significantly increases the overall positive detection rate of cervical SIL, improves accuracy and work efficiency of screening, decreases the ASC/SIL rate, and strengths the quality-assurance of laboratory testing.

[Expression and significance of p-AKT, p-GSK3ß and ß-catenin in epithelial carcinoma of ovary].

OBJECTIVE: To investigate the expressions of phosphorylated protein kinase B (p-AKT), phosphorylated glycogen synthase kinase 3ß (p-GSK3ß) and ß-catenin proteins and to evaluate their relationship with the clinical pathological characteristics in epithelial tumors of the ovary. METHODS: The expression of p-AKT, p-GSK3ß, and ß-catenin was detected with immunohistochemical staining (EnVision method) in 10 cases of benign epithelial neoplasia, 10 cases of borderline epithelial neoplasia and 70 cases of ovarian carcinoma. The relationship of the expression of p-AKT, p-GSK3ß and ß-catenin with the clinical pathological features was analyzed. RESULTS: The positive expression rates of p-AKT, p-GSK3ß and ß-catenin in epithelial ovarian carcinoma were 67.1% (47/70), 60.0% (42/70) and 71.4% (50/70), respectively. Compared to the results of benign and borderline epithelial neoplasia, the expression of the three proteins in carcinoma of the ovary was significantly different (all P < 0.05).Positive correlation was found between p-AKT and p-GSK3ß, p-GSK3ß and ß-catenin, and p-AKT and ß-catenin in epithelial ovarian carcinoma (r = 0.546, 0.581, 0.500, respectively; all P < 0.05). Compared to the results of benign and borderline epithelial neoplasia, the expression of p-AKT protein in epithelial ovarian carcinoma was significantly different (all P < 0.05). The expression of p-AKT was correlated with the differentiation of epithelial ovarian carcinoma (P < 0.05), but no relationship was found between its expression and histological classification and FIGO staging (P > 0.05). The expression of p-GSK3ß and ß-catenin in epithelial ovarian carcinoma were both higher than that in benign and borderline epithelial neoplasia (P < 0.05), and correlated with tumor differentiation and FIGO staging (P < 0.05), but no relationship were found between their expression with histological classification (P > 0.05). CONCLUSIONS: Positive correlations are found between p-AKT, p-GSK3ß and ß-catenin in epithelial ovarian carcinoma. The activation of ß-catenin is possibly correlated with inactivation of p-GSK3ß that binds to p-AKT.

Downregulation of NIN/RPN12 binding protein inhibit the growth of human hepatocellular carcinoma cells.

The ribosome assembly factor NIN/RPN12 binding protein (Nob1) has been suggested to be essential for processing of the 20S pre-rRNA to the mature 18S rRNA, and is also reported to participate in proteasome biogenesis. However, it is unclear whether Nob1 is involved in tumor cells growth. The aim of this study was to determine whether the suppression of Nob1 by short hairpin RNA (shRNA) inhibits the growth of human hepatocellular carcinoma (HCC) cells. Recombinant lentiviral shRNA expression vector carrying Nob1 was constructed and then infected into human HCC cell line SMMC-7721. The growth properties of SMMC-7721/pGCSIL-GFP-shNC and pGCSIL-GFP-shNob1 cells were determined by MTT, BrdU incorporation assay, and flow cytometric analysis. In addition, the colony formation and tumor growth ability in nude mice were detected to define the function of Nob1 in cell transformation and tumorigenesis. Our data showed that the growth and proliferation of SMMC-7721/pGCSIL-GFP-shNob1 cells were significantly reduced compared with the SMMC-7721/pGCSIL-GFP-shNC. In addition, the colony formation was impaired after the suppression of Nob1 in SMMC-7721 cells. And in vivo, the tumor formation ability of the SMMC-7721/pGCSIL-GFP-shNob1 cells was significantly reduced compared with the control cells. Our data support that Nob1 is an important regulator of the tumorigenic properties of human HCC and could be used as a candidate therapeutic target in human HCC.