Latest ArticlesA facile solvo-thermal approach was successfully employed to prepare titanium oxide (TiO2) nano-aggregates with simultaneous copper particles anchoring. The as-synthesized composite could convert CO2 into CH4 and CO products under simulated solar irradiation. The impact of copper loading amounts on the photo-reduction capability was evaluated. It was found proper amount of Cu loading could enhance the activity of CO2 photo-reduction. As a result, the optimal composite (TiO2-Cu-5%) consisting of TiO2 supported with 5% (mole ratio) Cu exhibits 2.2 times higher CH4 yield and 3 times higher CO yield compared with pure TiO2. Conduction band calculated from the band gap and valence X-ray photoelectron spectroscopy (XPS) indicated TiO2 nano-aggregates have suitable band edge alignment with respect to the CO2/CH4 and CO2/CO redox potential. Furthermore, with involving of Cu particles, an efficient separation of photo-generated charges was achieved on the basis of photocurrent response and photoluminescence spectra results, which contributed to the improved photo-catalytic performance. The present work suggested that the Cu-decorated TiO2 could serve as an efficient photo-catalyst for solar-driven CO2 photo-reduction.
Spin-crossover (SCO) complexes with multiple spin states are promising candidates for high-order magnetic storage and multiple switches. Here, by employing the N, Nʹ-4-dipyridyloxalamide (dpo) ligand, we synthesize two Hofmann-type metal-organic frameworks (MOFs) [Fe(dpo){Ag(CN)2}2]·3DMF (1) and [Fe(dpo){Ag(CN)2}2]·0.5MeCN·2DEF (2), which exhibit guest dependent four-step SCO behaviors with the sequences of LS → ~LS2/3HS1/3 → LS1/2HS1/2 → ~LS3/10HS7/10 → HS and LS → ~LS2/3HS1/3 → LS1/2HS1/2 → ~LS1/4HS3/4 → HS, respectively. Therefore, the incorporation of hydrogen-donating/hydrogen-accepting groups into the Hofmann-type MOFs may effectively explore the multi-step SCO materials by tuning hydrogen-bonding interactions.
Magnetic particles (MPs) are the most widely used commercialized engineering particles, which gained great success in various biological applications. Inspired by their intrinsic Fe isotope composition, we discovered a commercialized MPs-internal standard's novel function to realize the accurate quantification of biomolecules. The bioassay of carcinoembryonic antigen (CEA) was chosen as a modal system. The Fe isotope in MPs and Au isotope in report probes were simultaneously and sensitively detected by the elemental mass spectrometry. 197Au/57Fe isotopic ratios and CEA concentrations showed good linearity in the range of 0.6–300 ng/mL, with a detection limit of 0.09 ng/mL (3σ). The accuracy and precision of the proposed MPs-based immunoassay were greatly improved, by eliminating potential MPs loss during magnetic separation and absolute intensity fluctuations. Considering the exceptional availability and universality of commercialized MPs, the proposed method might open a new avenue for MPs' biological applications.
Highly dispersed silicotungstic acid-derived WO3 composited with ZrO2 supported on SBA-15 (WZ/SBA-15) as an ordered mesoporous solid acid catalyst was prepared via a facile incipient wetness impregnation (IWI) method that active ingredients, ZrO2 and WO3, were impregnated into the channels of SBA-15 simultaneously with a subsequent calcination process. The relationship between catalyst nature and performance was explored by high resolution transmission electron microscopy (HRTEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), FT-IR, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), N2 adsorption-desorption, NH3 temperature-programmed desorption (NH3-TPD), and FT-IR of pyridine adsorption (Py-IR) characterization techniques. The catalytic performance of W12Z15/SBA-15 is not only greater than that of single component solid acid catalysts, WO3/SBA-15 and ZrO2/SBA-15, but also W12/Z15/SBA-15 prepared by impregnating active ingredients, ZrO2 and WO3, into SBA-15 in sequence. The outstanding performance of W12Z15/SBA-15 is derived from the strong interaction between ZrO2 and WO3, which results in more acid sites, and relatively high specific surface area, large pore volume, and ordered mesoporous structure of SBA-15. The characterization and reaction results clearly demonstrate that the synergy of ZrO2 and WO3 has a clear boost for the alkenylation. The optimized W12Z15/SBA-15-500 achieves a 99.4% conversion of phenylacetylene and a 92.3% selectivity of main product α-arylstyrene for the alkenylation of p-xylene with phenylacetylene, with very low level of oligomers producing at the same time. Moreover, W12Z15/SBA-15-500 shows excellent catalytic stability and regeneration. Therefore, W12Z15/SBA-15-500 is a promising solid acid catalyst for the alkenylation.
H2S selective catalytic oxidation technology is a prospective way for the treatment of low concentration acid gas with simple process operation and low investment. However, undesirable results such as large formation of SO2 and catalyst deactivation inevitably occur, due to the temperature rise of fixed reaction bed caused by the exothermic reaction. Catalyst with high activity in wide operating temperature window, especially in high temperature range, is urgently needed. In this paper, a series of copper-substituted hexaaluminate catalysts (LaCux, x = 0, 0.5, 1, 1.5, 2, 2.5) were prepared and investigated for the H2S selective oxidation reaction at high temperature conditions (300-550℃). The LaCu1 catalyst exhibited excellent catalytic performance and great stability, which was attributed to the best reductive properties and proper pore structure. Besides, two facile deep processing paths were proposed to eliminate the remaining H2S and SO2 in the tail gas.
The unique heterojunction photocatalyst of graphite carbon nitride (g-C3N4) modified ultrafine TiO2 (g-C3N4/TiO2) was successfully fabricated by electrochemical etching and co-annealing method. However, the effects of various environmental factors on the degradation of TC by g-C3N4/TiO2 and the internal reaction mechanism are still unclear. In this study, the effects of initial pH, anions, and cations on the photocatalytic degradation of tetracycline hydrochloride (TC) by g-C3N4/TiO2 were systematically explored, and the scavenging experiment and intermediate detection were conducted to better reveal the mechanism on photocatalytic degradation of TC. The results showed that the removal efficiency of photocatalytic degradation of TC by g-C3N4/TiO2 could reach 99.04% under Xenon lamp irradiation within 120 min. The unique g-C3N4/TiO2 heterojunction photocatalyst showed excellent photocatalytic performance for the degradation of TC at pH 3~7, and possesses outstanding anti-interference ability to NO3−, Cl−, Na+, Ca2+ and Mg2+ ions in natural waters during the photocatalytic degradation TC process. Superoxide radicals (O2·−) and hydroxyl radicals (·OH) were proved as the main reactive species for TC degradation, and the possible mechanism of the unique photocatalytic system for g-C3N4/TiO2 was also proposed. The above results can provide a reliable basis and theoretical guidance for the design and application of visible photocatalyst with high activity to degrade the actual wastewater containing TC.
The regeneration of the injured nerve and recovery of its function have brought attention in the medical field. Electrical stimulation (ES) can enhance the cellular biological behavior and has been widely studied in the treatment of neurological diseases. Microfluidic technology can provide a cell culture platform with the well-controlled environment. Here a novel microfluidic/microelectrode composite microdevice was developed by embedding the microelectrodes to the microfluidic platform, in which microfluidics provided a controlled cell culture platform, and ES promoted the NSCs proliferation. We performed ES on rat neural stem cells (NSCs) to observe the effect on their growth, differentiation, proliferation, and preliminary explored the ES influence on cells in vitro. The results of immunofluorescence showed that ES had no significant effect on the NSCs specific expression, and the NSCs specific expression reached 98.9% ±0.4% after three days of ES. In addition, ES significantly promoted cell growth and the cell proliferation rate reached 49.41%. To conclude, the microfluidic/microelectrode composite microdevice can play a positive role in the nerve injury repair and fundamental research of neurological diseases.
Numerous approaches have been used to modify graphitic carbon nitride (g-C3N4) for improving its photocatalytic activity. In this study, we demonstrated a facial post-calcination method for modified graphitic carbon nitride (g-C3N4-Ar/Air) to direct tuning band structure, i.e., bandgap and positions of conduction band (CB)/valence band (VB), through the control of atmospheric condition without involving any additional elements or metals or semiconductors. The synthesized g-C3N4-Ar/Air could efficiently degrade sulfamethazine (SMT) under simulated solar light, i.e., 99.0% removal of SMT with rate constant k1 = 2.696 h−1 within 1.5 h (4.9 times than pristine g-C3N4). Material characterizations indicated that the damaged/partial-collapsed structure and decreased nanosheet-interlayer distance for g-C3N4-Ar/Air resulted in the shift of band structure due to the denser stacking of pristine g-C3N4 through oxidative exfoliation and planarization by air calcination. In addition, the bandgap of g-C3N4-Ar/Air was slightly shrunk from 2.82 eV (pristine g-C3N4) to 2.79 eV, and the CB was significantly upshifted from −0.44 eV (pristine g-C3N4) to −0.81 eV, suggesting the powerful ability for donating the electrons for O2 to form •O2−. Fukui index (f –) based on theoretical calculation indicated that the sites of SMT molecule with high values, i.e., N9, C4 and C6, preferred to be attacked by •O2− and •OH, which is confirmed by the intermediates' analysis. The tuning method for graphitic carbon nitride provides a simple approach to regulate the charge carrier lifetime then facilitate the utilization efficiency of solar light, which exhibits great potential in efficient removal of emerging organic contaminants from wastewater.
Although carbon nanozymes have attracted great interest due to their good biocompatibility, low cost, and high stability, designing high-active carbon nanozymes still faces great challenges. Herein, ultrathin nitrogen-doped carbon nanosheets with rich defects (d-NC) were prepared through a high-temperature annealing process, using potassium chloride and ammonium chloride as templates. Owing to the large specific surface area, rich defects and the high exposure of active sites, the proposed d-NC nanozymes exhibited excellent peroxidase-like activity. The d-NC nanozymes possess maximal reaction velocity and their specific activity is 9.4-fold higher than that of nitrogen-doped carbon nanozymes, indicating that the induced defects can boost the catalytic performance. Benefited from the good peroxidase-like activities of d-NC nanozymes, the colorimetric sensing platforms were constructed for the detection of urease activity and fluoride ion, exhibiting satisfactory stability and selectivity. This study not only offers a way to synthesize carbon nanozymes with improved enzyme-like activities but also broadens their applications in colorimetric biosensing.
Chemodynamic therapy (CDT) has attracted tremendous interest in cancer therapy because it is independent of oxygen and photoirradiation. However, the therapeutic efficacy of CDT is restricted by insufficient H2O2 levels in tumor cells. Herein, employing endogenous GSH as a template and cationic polymeric chitosan (CS) as crosslinker and stabilizer exhibiting easy cell uptake, red luminescent gold nanoclusters (denoted CS-GSH@AuNCs) were successfully synthesized in HeLa cells. The in situ synthesized CS-GSH@AuNCs exhibited both superoxidase dismutase (SOD) and peroxidase (POD)-like activity, which could promote the production of H2O2 from superoxide anion radicals (O2·−) and then ·OH. The combination of GSH elimination and H2O2 elevation boosted the generation of ·OH, which could trigger cancer cell apoptosis and death. The enzyme-like activity of CS-GSH@AuNCs could be effectively activated under acidic conditions, and showed a high killing effect on tumor cells but minimal toxicity to normal cells. The developed GSH consumption and ·OH promotion theranostic platform is an innovative route for enhanced CDT by the amplification of oxidative stress.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
