Latest ArticlesElectrochemical oxidation is an effective method to degrade persistent organic pollutants. However, due to the limited catalytic activity of traditional thin film electrodes, the anodic oxidation process is slow and usually requires high energy consumption. Herein, Ti/SnO2-Sb electrode with regulated surface structure was reported to enhance the performance for electrochemical oxidation of persistent organic pollutants. The electrode deposited with SnO2-Sb nanoneedles (Ti/N-SnO2-Sb) showed higher oxidation activity. Its kinetic constant for perfluorooctanoic acid (PFOA) oxidation was 2.0 h−1 and the total organic carbon removal rate was 81.7% (4 h) at a relatively low current density of 6 mA/cm2. Compared with Ti/SnO2-Sb thin film and nanoparticles, Ti/N-SnO2-Sb significantly improved the electrochemical active area and •OH yield, and simultaneously reduced the electron transfer resistance, which enabled it to oxidize PFOA more rapidly even at a lower potential. This work provides a new strategy for promoting the electrochemical oxidation performance.
Photothermal therapy (PTT) is a cutting-edge cancer treatment that can kill cancer cells in hypoxic environments without relying on oxygen. Seeking of the ideal photothermal agents with a high absorption coefficient in the near-infrared region, and a high excellent photothermal conversion efficiency is of great significance. Sulfone-Rhodanmine dye has showed an impressive absorption wavelength over 700 nm, but suffered from a stability issue. In this study, we synthesized five sulfone rhodamines and investigated the substitution effects on stability. SO2R2 showed high stability and strong absorbance at 714 nm with an excellent photothermal conversion efficiency of 53.06%, making it suitable for accurate photoacoustic imaging-guided photothermal therapy in vivo.
N1-methyladenosine (m1A) is an important RNA modification that functions in various biological processes by interacting with cellular proteins. However, the binding proteins of N1-methyldeoxyadenosine (1mdA) in DNA remain largely unknown. Herein, we employed a quantitative proteomics strategy to identify the potential binding proteins of 1mdA in human cells. Our results revealed that serine‑threonine kinase receptor-associated protein (STRAP) can bind to 1mdA-carrying DNA. We further demonstrated that STRAP participates in alkylating agent-induced DNA damage response and can promote the repair of 1mdA embedded in DNA. Moreover, we investigated the effects of STRAP on 1mdA-induced perturbation in transcription using a shuttle vector- and next-generation sequencing-based assay, and found that STRAP is involved in the transcriptional bypass of 1mdA in human cells. Together, our study revealed STRAP as a novel 1mdA-binding protein in human cells and provided new insight into the biological implications of STRAP and 1mdA modification in human diseases.
Nitroaromatic hydrogenation catalysis without precious metals remains a longstanding challenge. The rate of electron transfer is the crucial factor affecting hydrogenation catalysis. Herein, an ionic Cd-based metal-organic framework (I-Cd-MOF) exhibiting a unique structure with one-dimensional (1D) opening nanochannels and good electron transfer ability was synthesized for catalyzing hydrogenation of 4-nitrophenol (4-NP). The catalytic activity of the unique I-Cd-MOF without noble metals is detected, which is higher than most reported noble metal catalysts. Remarkably, the reaction rate of I-Cd-MOF (4.28 min−1) is about 47.6 times higher than that of the Cd-based neutral MOF (N-Cd-MOF) with the similar crystalline structure. Liquid chromatograph mass spectrometer (LC-MS) and theoretical results demonstrate that 4-NP and five intermediates are stabilized in the channels of I-Cd-MOF, which increases the possibility of contact with H* and H2 generated at the Cd sites. The I-Cd-MOF was extended to other nitroaromatic hydrogenation catalysis, which still displays excellent activity. More importantly, the I-MOF@Filter membrane was successfully constructed for continuous hydrogenation catalytic reactions, which maintains a high catalytic performance after 7 cycles of recycling without washing. This work fills in the application of the I-MOFs in hydrogenation catalytic reactions and provides an effective way for the rapid and green degradation of nitroaromatic compounds.
Luminescent materials that can be reversibly switched by electric field stimulation are attractive since the potential application for optoelectronic devices. Here we report a triplet-triplet annihilation upconversion (TTA-UC) system with electrophoretic response which is developed as the electrophoretic ink. The TTA-UC system consists of an ionic derivative of 9, 10-diphenyl anthracene (DPA) as the annihilator and Pt(Ⅱ) octaethylporphyrin (PtOEP) as the sensitizer. Upon applying an electric field, migration and enrichment of positively charged DPA derivatives towards the cathode results in a 20% enhancement of TTA-UC. A quasi-solid film for electrically writing is made using the electrophoretic TTA system as the ink and a platinum electrode as a pen. The prototype of TTA-UC ink demonstrates unique luminescence functions upon electrically writing and erasing, providing a promising strategy to develop electronic devices for display, information storage and encryption.
Nitrene transfer reactions are powerful tools in synthetic organic chemistry. In recent years, transition-metal catalyzed nitrene transfer reactions with carbamates as the nitrene precursors have been widely pursued. Such species undergoes facile C−H amination, aziridination, and bifunctionalization of alkenes under the catalysis of different transition metals including Rh, Fe, Ru and others, enabling the efficient construction of various nitrogen-containing molecules. In this review, the recent developments in nitrene transfer reactions with carbamates via N−O bond cleavage were introduced based on different types of reaction, and the key mechanistic information and synthetic applications of the methodologies were discussed.
Biomass is the most bountiful renewable carbon resource on earth. Photocatalytic transformation is a promising method to utilize biomass to obtain high-value-added chemicals and it has more obvious advantages compared with thermochemical and biological processes due to the milder operational conditions, fewer reagents and equipment. Semiconductor material is one of the most common kinds of heterogeneous biomass photocatalysts, which has the advantages of high selectivity, stable catalytic performance, long activation time, and low cost. In this paper, the significant research progress on the photocatalytic transformation of biomass with semiconductor materials to produce high-value-added chemicals is reviewed, and the three most typical semiconductor photocatalysts (TiO2, CdS, and g-C3N4) are detailed. The photocatalytic mechanism and photocatalytic system optimization including structural modification, metal co-catalyst loading, and introduction of heterojunction are presented. Besides, the main problems, the development direction and trend of semiconductor materials in photocatalytic transformations of biomass in the future are prospected, which provide guidance and inspiration for the further development of semiconductor photocatalysts and make contributions to the progress in efficient utilization of biomass.
Pretreatment of the carrier for supported catalysts can effectively improve the strong metal-support interaction (SMSI) and increase the dispersion of precious metals, which are critical to many important catalytic reactions. In this work, we tuned SMSI on Pd/TiO2 catalysts through inducing surface defects of TiO2 by pretreated with different atmospheres (H2/N2, N2, O2/N2) at the high temperature (800 ℃). Multiple characterization results illustrated that surface defects anchored Pd species and thus enhanced their dispersion. During reduction, Ti3+ species formed and transferred onto the metallic Pd species and then induced SMSI, which effectively stabilize Pd species in the metallic state. The stronger MSI, the more stability of Pd species. As a case, Pd/TiO2–800H2, with strongest MSI, displayed the best HCHO oxidation performance at low temperature (10 ℃).
Small-molecule drugs are widely used in daily life. There are still issues with the current industrial synthesis techniques for small-molecule drugs, such as the use of expensive metal catalysts, convoluted reaction processes, and non-recyclable catalysts. The benefits of photocatalytic organic synthesis over conventional techniques are mild conditions, environmental friendliness, and great selectivity. Porous framework materials can precisely modulate catalytic sites’ electronic state and ligand structure to improve photocatalytic performance. In particular, MOFs, COFs and PCCs based photocatalysts have received extensive research interest due to their unique morphology, structural adjustability, high photocatalytic performance, unique recyclability, excellent chemical stability, easy synthesis and low cost. Therefore, a key area for future research is the development of porous framework materials as photocatalysts for the synthesis of small-molecule drugs or drug precursors.