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排序方式: 共有2345条查询结果,搜索用时 15 毫秒
991.
Boyan Liu Xin Wang Yingjuan Zhang Liangcheng Xu Tingsheng Wang Xiong Xiao Prof. Songcan Wang Prof. Lianzhou Wang Prof. Wei Huang 《Angewandte Chemie (International ed. in English)》2023,62(10):e202217346
Sluggish oxygen evolution kinetics are one of the key limitations of bismuth vanadate (BiVO4) photoanodes for efficient photoelectrochemical (PEC) water splitting. To address this issue, we report a vanadium oxide (VOx) with enriched oxygen vacancies conformally grown on BiVO4 photoanodes by a simple photo-assisted electrodeposition process. The optimized BiVO4/VOx photoanode exhibits a photocurrent density of 6.29 mA cm−2 at 1.23 V versus the reversible hydrogen electrode under AM 1.5 G illumination, which is ca. 385 % as high as that of its pristine counterpart. A high charge-transfer efficiency of 96 % is achieved and stable PEC water splitting is realized, with a photocurrent retention rate of 88.3 % upon 40 h of testing. The excellent PEC performance is attributed to the presence of oxygen vacancies in VOx that forms undercoordinated sites, which strengthen the adsorption of water molecules onto the active sites and promote charge transfer during the oxygen evolution reaction. This work demonstrates the potential of vanadium-based catalysts for PEC water oxidation. 相似文献
992.
Peiqing Sun Kunlun Li Xiao Liu Jing Wang Dr. Xusheng Qiu Prof. Wei Wei Prof. Jing Zhao 《Angewandte Chemie (International ed. in English)》2023,62(14):e202300085
Pathogenic microorganisms in the environment are a great threat to global human health. The development of disinfection method with rapid and effective antibacterial properties is urgently needed. In this study, a biomimetic silver binding peptide AgBP2 was introduced to develop a facile synthesis of biocompatible Ag2S quantum dots (QDs). The AgBP2 capped Ag2S QDs exhibited excellent fluorescent emission in the second near-infrared (NIR-II) window, with physical stability and photostability in the aqueous phase. Under 808 nm NIR laser irradiation, AgBP2-Ag2S QDs can serve not only as a photothermal agent to realize NIR photothermal conversion but also as a photocatalyst to generate reactive oxygen species (ROS). The obtained AgBP2-Ag2S QDs achieved a highly effective disinfection efficacy of 99.06 % against Escherichia coli within 25 min of NIR irradiation, which was ascribed to the synergistic effects of photogenerated ROS during photocatalysis and hyperthermia. Our work demonstrated a promising strategy for efficient bacterial disinfection. 相似文献
993.
Hui Yang Dr. Lili Xia Xuanxuan Ye Jiayi Xu Dr. Tianfeng Liu Dr. Linping Wang Assoc. Prof. Shuai Zhang Prof. Wei Feng Prof. Dongshu Du Prof. Yu Chen 《Angewandte Chemie (International ed. in English)》2023,62(26):e202303539
Hypertension, as a leading risk factor for cardiovascular diseases, is associated with oxidative stress and impairment of endogenous antioxidant mechanisms, but there is still a tremendous knowledge gap between hypertension treatment and nanomedicines. Herein, we report a specific nanozyme based on ultrathin two-dimensional (2D) niobium carbide (Nb2C) MXene, termed Nb2C MXenzyme, to fight against hypertension by achieving highly efficient reactive oxygen species elimination and inflammatory factors inhibition. The biocompatible Nb2C MXenzyme displays multiple enzyme-mimicking activities, involving superoxide dismutase, catalase, glutathione peroxidase, and peroxidase, inducing cytoprotective effects by resisting oxidative stress, thereby alleviating inflammatory response and reducing blood pressure, which is systematically demonstrated in a stress-induced hypertension rat model. This strategy not only opens new opportunities for nanozymes to treat hypertension but also expands the potential biomedical applications of 2D MXene nanosystems. 相似文献
994.
Jinwen Hu Wenzhe Shang Cuncun Xin Jingya Guo Xusheng Cheng Songlin Zhang Suchan Song Dr. Wei Liu Dr. Feng Ju Prof. Jungang Hou Prof. Yantao Shi 《Angewandte Chemie (International ed. in English)》2023,62(27):e202304754
Understanding the nature of single-atom catalytic sites and identifying their spectroscopic fingerprints are essential prerequisites for the rational design of target catalysts. Here, we apply correlated in situ X-ray absorption and infrared spectroscopy to probe the edge-site-specific chemistry of Co−N−C electrocatalyst during the oxygen reduction reaction (ORR) operation. The unique edge-hosted architecture affords single-atom Co site remarkable structural flexibility with adapted dynamic oxo adsorption and valence state shuttling between Co(2−δ)+ and Co2+, in contrast to the rigid in-plane embedded Co1−Nx counterpart. Theoretical calculations demonstrate that the synergistic interplay of in situ reconstructed Co1−N2-oxo with peripheral oxygen groups gives a rise to the near-optimal adsorption of *OOH intermediate and substantially increases the activation barrier for its dissociation, accounting for a robust acidic ORR activity and 2e− selectivity for H2O2 production. 相似文献
995.
Yali Liu Yuenan Zheng Danyang Feng Liangliang Zhang Ling Zhang Xiaowei Song Prof. Zhen-An Qiao 《Angewandte Chemie (International ed. in English)》2023,62(29):e202306261
The development of efficient catalyst for selective oxidation of hydrocarbon to functional compounds remains a challenge. Herein, mesoporous Co3O4 (mCo3O4-350) showed excellent catalytic activity for selective oxidation of aromatic-alkanes, especially for oxidation of ethylbenzene with a conversion of 42 % and selectivity of 90 % for acetophenone at 120 °C. Notably, mCo3O4 presented a unique catalytic path of direct oxidation of aromatic-alkanes to aromatic ketones rather than the conventional stepwise oxidation to alcohols and then to ketones. Density functional theory calculations revealed that oxygen vacancies in mCo3O4 activate around Co atoms, causing electronic state change from Co3+(Oh)→Co2+(Oh). Co2+(Oh) has great attraction to ethylbenzene, and weak interaction with O2, which provide insufficient O2 for gradual oxidation of phenylethanol to acetophenone. Combined with high energy barrier for forming phenylethanol, the direct oxidation path from ethylbenzene to acetophenone is kinetically favorable on mCo3O4, sharply contrasted to non-selective oxidation of ethylbenzene on commercial Co3O4. 相似文献
996.
Qiu-Yi Li Yun-Hu Deng Chen Cao Yu-Xuan Hong Xin-Ran Xue Min-Jie Zhang Dr. Yu Ge Prof. Brendan F. Abrahams Prof. Jian-Ping Lang 《Angewandte Chemie (International ed. in English)》2023,62(33):e202306719
Due to its high reactivity and oxidative strength, singlet oxygen (1O2) is used in a variety of fields including organic synthesis, biomedicine, photodynamic therapy and materials science. Despite its importance, the controlled trapping and release of 1O2 is extremely challenging. Herein, we describe a one-dimensional coordination polymer, CP1 , which upon irradiation with visible light, transforms 3O2 (triplet oxygen) to 1O2. CP1 consists of CdII centers bridged by 9,10-bis((E)-2-(pyridin-4-yl)vinyl)anthracene ligands which undergo a [4+2] cycloaddition reaction with 1O2, resulting in the generation of CP1−1O2 . Using microwave irradiation, CP1−1O2 displays efficient release of 1O2, over a period of 30 s. In addition, CP1 exhibits enhanced fluorescence and has an oxygen detection limit of 97.4 ppm. Theoretical calculations reveal that the fluorescence behaviour is dominated by unique through-space conjugation. In addition to describing a highly efficient approach for the trapping and controlled release of 1O2, using coordination polymers, this work also provides encouragement for the development of efficient fluorescent oxygen sensors. 相似文献
997.
Jieting Ding Danyu Guo Nanshu Wang Prof. Hao-Fan Wang Prof. Xianfeng Yang Prof. Kui Shen Prof. Liyu Chen Prof. Yingwei Li 《Angewandte Chemie (International ed. in English)》2023,62(43):e202311909
Metal–organic frameworks (MOFs) have been increasingly applied in oxygen evolution reaction (OER), and the surface of MOFs usually undergoes structural transformation to form metal oxyhydroxides to serve as catalytically active sites. However, the controllable regulation of the reconstruction process of MOFs remains as a great challenge. Here we report a defect engineering strategy to facilitate the structural transformation of MOFs to metal oxyhydroxides during OER with enhanced activity. Defective MOFs (denoted as NiFc′xFc1-x) with abundant unsaturated metal sites are constructed by mixing ligands of 1,1′-ferrocene dicarboxylic acid (Fc′) and defective ferrocene carboxylic acid (Fc). NiFc′xFc1-x series are more prone to be transformed to metal oxyhydroxides compared with the non-defective MOFs (NiFc′). Moreover, the as-formed metal oxyhydroxides derived from defective MOFs contain more oxygen vacancies. NiFc′Fc grown on nickel foam exhibits excellent OER catalytic activity with an overpotential of 213 mV at the current density of 100 mA cm−2, superior to that of undefective NiFc′. Experimental results and theoretical calculations suggest that the abundant oxygen vacancies in the derived metal oxyhydroxides facilitate the adsorption of oxygen-containing intermediates on active centers, thus significantly improving the OER activity. 相似文献
998.
Yang Wang Minghao Wang Ting Chen Weisheng Yu Prof. Hongfei Liu Han Cheng Prof. Wentuan Bi Prof. Min Zhou Prof. Yi Xie Prof. Changzheng Wu 《Angewandte Chemie (International ed. in English)》2023,62(47):e202308070
Nitrogen-coordinated iron (Fe−N4) materials represent the most promising non-noble electrocatalysts for the cathodic oxygen reduction reaction (ORR) of fuel cells. However, molecular-level structure design of Fe−N4 electrocatalyst remains a great challenge. In this study, we develop a novel Fe−N4 conjugated organic polymer (COP) electrocatalyst, which allows for precise design of the Fe−N4 structure, leading to unprecedented ORR performance. At the molecular level, we have successfully organized spatially proximate iron-pyrrole/pyrazine (FePr/Pz) pairs into fully conjugated polymer networks, which in turn endows FePr sites with firmly covalent-bonded matrix, strong d-π electron coupling and highly dense distribution. The resulting pyrazine-linked iron-coordinated tetrapyrrole (Pz−FeTPr) COP electrocatalyst exhibits superior performance compared to most ORR electrocatalysts, with a half-wave potential of 0.933 V and negligible activity decay after 40,000 cycles. When used as the cathode electrocatalyst in a hydroxide exchange membrane fuel cell, the Pz−FeTPr COP achieves a peak power density of ≈210 mW cm−2. We anticipate the COP based Fe−N4 catalyst design could be an effective strategy to develop high-performance catalyst for facilitating the progress of fuel cells. 相似文献
999.
Wanling Liu Yihong Zhang Gen Wei Minxuan Zhang Tong Li Quanyi Liu Zijun Zhou Yan Du Prof. Dr. Hui Wei 《Angewandte Chemie (International ed. in English)》2023,62(33):e202304465
Senescent cells are the critical drivers of atherosclerosis formation and maturation. Mitigating senescent cells holds promise for the treatment of atherosclerosis. In an atherosclerotic plaque microenvironment, senescent cells interact with reactive oxygen species (ROS), promoting the disease development. Here, we hypothesize that a cascade nanozyme with antisenescence and antioxidant activities can serve as an effective therapeutic for atherosclerosis. An integrated cascade nanozyme with superoxide dismutase- and glutathione peroxidase-like activities, named MSe1, is developed in this work. The obtained cascade nanozyme can attenuate human umbilical vein endothelial cell (HUVEC) senescence by protecting DNA from damage. It significantly weakens inflammation in macrophages and HUVECs by eliminating overproduced intracellular ROS. Additionally, the MSe1 nanozyme effectively inhibits foam cell formation in macrophages and HUVECs by decreasing the internalization of oxidized low-density lipoprotein. After intravenous administration, the MSe1 nanozyme significantly inhibits the formation of atherosclerosis in apolipoprotein E-deficient (ApoE−/−) mice by reducing oxidative stress and inflammation and then decreases the infiltration of inflammatory cells and senescent cells in atherosclerotic plaques. This study not only provides a cascade nanozyme but also suggests that the combination of antisenescence and antioxidative stress holds considerable promise for treating atherosclerosis. 相似文献
1000.
Wenming Wang Qinghong Huang Juanyin Liu Zhiqing Zou Zhilin Li Hui Yang 《Electrochemistry communications》2008,10(9):1396-1399
A facile, one-step reduction route was developed to synthesize Pd-rich carbon-supported Pd–Pt alloy electrocatalysts of different Pd/Pt atomic ratios. As-prepared Pd–Pt/C catalysts exhibit a single phase fcc structure and an expansion lattice parameter. Comparison of the oxygen reduction reaction (ORR) on the Pd–Pt/C alloy catalysts indicates that the Pd3Pt1/C bimetallic catalyst exhibits the highest ORR activity among all the Pd–Pt alloy catalysts and shows a comparative ORR activity with the commercial Pt/C catalyst. Moreover, all the Pd–Pt alloy catalysts exhibited much higher methanol tolerance during the ORR than the commercial Pt/C catalyst. High methanol tolerance of the Pd–Pt alloy catalysts could be attributed to the weak adsorption of methanol induced by the composition effect, to the presence of Pd atoms and to the formation of Pd-based alloys. 相似文献