Nano Research
·
2016
·Vol. 9
·期 4
·1182-1192
·
IF 8.893
Li Lixiong,Huang Shuangshuang,Song Jianjun,Yang Nating,Liu Jingwei,Chen Yuyun,Sun Yuhan,Jin Rongchao,Zhu Yan
Ultrasmall Au 10 clusters have a unique electronic structure and can act as a charge reservoir to donate electrons or accept charges. This is particularly important for catalysis, since it leads to facile charge transfer across the interface between the gold species and the oxide substrate. To determine the electronic and structural effects of Au 10 on the catalytic oxidation, a TiO 2 charge carrier was chosen as the substrate to anchor Au 10 for olefin oxidation. Au 10 supported on TiO 2 -RP (RP = pyramid-capped columnar structure) exhibited superior catalytic activity to Au 10 /TiO 2 nanotubes and Au 10 /P25. In addition, the supported Au 10 clusters gave rise to higher activity than supported Au 20 , Au 144 clusters, and 5 nm Au nanocrystals. The superior catalytic ability of Au 10 /TiO 2 -RP arises from the charge/discharge effect of the Au 10 /TiO 2 -RP interface, which effectively improves the formation of active oxygen species on electron-rich gold atoms at the terminal position of Au 10 , and promotes the activation of olefin C=C bonds on the electron-deficient gold atoms of Au 10 .
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
Frontiers in Physics
·
2020
·
IF 2.638
Zhang Xiaoqin,Zhang Wenna,Xu Yuanmei,Jin Mingliang
Ultrasmall precious metal clusters have attracted extensive attention for providing a very specific surface and promoting electron transfer. In this work, ultrasmall Au clusters based on defective TiO2 nanosheets (Au/D-TiO2) were prepared and introduced into photocatalytic hydrogen evolution. Different defects of TiO2 nanosheets (D-TiO2) were constructed using a heating process and then loaded with Au clusters. Compared with bare TiO2, Au clusters established on defective TiO2 nanosheets with a narrower band gap showed higher light absorption performances, resulting in obviously enhanced photocatalytic hydrogen production performances. The Au/D-TiO2 displayed the greatly enhanced photocatalytic hydrogen evolution activity of 3,142.33 μmol h−1 g−1, which was over 45 times than the pure TiO2. The results showed that the catalysts had good prospects in the field of photocatalytic hydrogen production.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2018
·
IF 9.89
Yali Liu,Pengfei Zhang,Junmin Liu,Tao Wang,Qisheng Huo,Li Yang,Lei Sun,Zhen-An Qiao,Sheng Dai
Gold clusters with ultrasmall size and special structure are highly attractive for heterogeneous catalysis. However, stabilizing gold clusters under thermal treatment remains a major hurdle on the way toward real-world application. Herein, we report an effective approach that stabilizing gold clusters (Au25 and Au144) within mesoporous ceria nanospheres via a two phase overcoating process. High-resolution aberration-corrected STEM studies indicated that gold clusters were encapsulated and confined in the intersectional channels of ceria, and the encapsulated clusters were demonstrated to be resistant to sintering under high-temperature thermal treatment. The solvent-free aerobic oxidation of toluene and ethylbenzene was carried out to illustrate the performance of gold clusters in catalysis, and these materials showed excellent catalytic activities and afforded much higher turnover frequencies (up to 5634 and 55 027 turnovers for toluene and ethylbenzene oxidation), which are, as far as we know, much higher than the values of state-of-art catalysts. Density functional theory calculations revealed that the encapsulated gold clusters effectively reduced the energy required for the dissociation of O2 molecules, leading to the excellent catalytic activity.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Zhiyang Zhang,Mi Hu,Qingfeng Gui,Jing Gu,Wenlong Xu,Qingbo Xiao,Wei Huang
Adipic acid is a valuable chemical used to product Nylon-66, and one of the greenest ways to synthesize it is catalyzing the oxidation of cyclohexane by molecular oxygen in the absence of any other chemicals. However, it is challenging to convert cyclohexane effectively with high selectivity to adipic acid using the available catalysts. In response to the dilemma of achieving satisfactory conversion and selectivity at the same time, a remarkable Au@NaX catalyst is proposed using an improved in-situ crystallization method that exhibits Au clusters surrounded by X-zeolite channels. A 29.5% conversion of cyclohexane and an 85.6% selectivity to adipic acid can be obtained in a one-pot oxidation of cyclohexane at 140 °C, 20 bar O 2 , far exceeding most published results. Since determined by detailed characterizations and DFT calculations, the effective dynamic collaboration between Au clusters and zeolite inner micro-environment is the decisive role for superior catalytic performance. Specifically, the surrounding zeolite channel encourages the adsorption and activation of cyclohexane over the confined Au clusters, resulting in an unprecedented activity. The continuous oxidation of cyclohexanol and cyclohexanone to adipic acid is also vulnerable on the enclosed Au clusters, and the subsequent adipic acid can be further stabilized as a result of the strong interaction of –COOH with Na ± in zeolite channels surrounding enclosed Au clusters. It prevents AA from poisoning active sites and generates a higher selectivity for the desired adipic acid. Our study highlighted the critical significance of the dynamic interaction between metal clusters and the zeolite channel microenvironment. It would shed light on the further high-performance catalysts designs for selective oxidation.
研究领域:
催化化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2020
·Vol. 12
·期 10
·2752-2759
·
IF 4.853
Xiangjian Meng,Wandi Kuang,Weiliang Qi,Zhixing Cheng,Tiju Thomas,Siqi Liu,Chun Yang,Minghui Yang
Graphical Just a bit of gold : The Ni 3 N−Au c −TiO 2 catalyst exhibits a better hydrogen evolution rate under full band light irradiation as compared to those of binary Ni 3 N−TiO 2 and Au c −TiO 2 . The amount of Au c is ultralow (0.00025 wt%) with Ni 3 N in the optimum photocatalyst Ni 3 N−Au c −TiO 2 , which shows the loading of noble metal is reduced by 99.95 wt% compared with the optimal load of Pt (0.5 wt%). Platinum (Pt) is a widely used co-catalyst with excellent performance for photocatalytic hydrogen evolution. However, it is not suitable for industrial production because of its prohibitive cost. Currently, there are two means to overcome this challenge. One is to, find alternative cocatalysts for Pt. The other is to develop ultrasmall of noble metal clusters, which reduces the amount of noble metal loading required. This reduces the loading amount of noble metals and improves their atomic efficiency. In this work, we have integrated both these approaches to generate a non-noble metal co-catalyst nickel nitride (Ni 3 N) and Au clusters (Au c ). The composite cocatalyst (Ni 3 N−Au c ) thus obtained promotes photocatalytic hydrogen production of TiO 2 . The (Ni 3 N−Au c −TiO 2 ) composite with an ultralow amount of Au c (0.00025 wt%) shows photocatalytic hydrogen production rates that are even higher than that of Pt−TiO 2 . The loading requirement of noble metal is reduced by 99.95 wt% compared to the optimal load of Pt; further indicating the cost efficiency possible through this method.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2016
·
IF 3.205
Wei Yan,Zhenghua Tang,Likai Wang,Qiannan Wang,Hongyu Yang,Shaowei Chen
PdAu alloyed clusters supported on carbon nanosheets were prepared and employed as efficient electrocatalysts for oxygen reduction reaction (ORR). PdAu clusters protected by glutathione were synthesized, while the structure and composition of the alloys were tuned through the variation of Pd-to-Au ratio. The PdAu clusters were loaded into carbon nanosheets and calcined at elevated temperature. The protecting ligands were completely removed after calcination , and uniform hybrid materials were formed. The as-prepared nanocomposites were characterized by transmission electron microscopy (TEM), scanning tunneling electron microscopy (STEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) as well as other techniques. The composites demonstrated effective ORR activity in alkaline media . Among a series of samples, the composite with a metal mass loading of 30% and the ratio of Pd-to-Au (1:2) exhibited the highest activity, and its performance is comparable to that of commercial Pt/C, superior to PdAu clusters, carbon nanosheets as well as other supported alloyed samples, in terms of onset potential, diffusion limited current density as well as number of electron transfer . Notably, the long-term stability of the composite is markedly higher than Pt/C. The strategy can be extended for the preparation of other supported bi-metallic nanoclusters with controllable composition and optimized electrocatalytic activity for fuel cell applications .
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Journal of Biophotonics
·
2017
·Vol. 11
·期 2
·e201700015
·
IF 4.328
Yuxiang Ma,Qian Wang,Qiuyun Zhu,Mengyang Liu,Dan Chen,Zhihao Han,Congying Zhang,Liwei Lv,Yueqing Gu
Reactive oxygen species (ROS) are largely produced under pathological situations. To understand the etiology of disease, it is urgent to develop efficacious probes for detecting ROS. Herein, a novel nanoconjugate detection system constructed from gold clusters (AuNCs) and quantum dots (QDs) for fluorescence ratiometric-sensing ROS was reported. Upon interacting with ROS, the red emission fluorescence (645 nm from QDs) in the detection system gradually decreased, while the green fluorescence (480 nm from AuNCs) changed little. The fluorescence ratio at the 2 wavelengths (I 480 nm /I 645 nm ) was linearly correlated with the ROS, which could be used for the real-time ratiometric detection of ROS. The developed nanoconjugates could be applied to monitor the ROS in inflammatory cells for its ability of generating abundant ROS and uptaking ability to nanoparticles. The stimulated ROS in inflammatory cells were monitored by AuNC-QD and the results were consistent with the traditional 2′, 7′-dichlorofluorescin diacetate method, confirming the reliability of the developed method. Featured with the merits of higher photostability, low background, high accuracy of ratiometric detection, the AuNC-QD conjugate demonstrated its potential to be the probe for real-time ROS detection in inflammatory cells.
研究领域:
生物化学
·
医学诊断
·
纳米生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2021
·Vol. 11
·期 2
·162
·
IF 4.146
Huayin Li,Yuan Tan,Xingkun Chen,Wenshao Yang,Chuanqi Huang,Jie Li,Yunjie Ding
Methyl methacrylate (MMA) is an important monomer in fine chemicals. The synthesis of MMA by one-step oxidative esterification from methacrolein with methanol over a heterogeneous catalyst with high activity, selectivity and stability is highly desirable. Herein, Zn-Al-hydrotalcites (HTs)-supported atomically precise Au25nanoclusters with different molar ratios of Zn2+/Al3+were prepared and used as the precursors for this reaction. They exhibited good performances in comparison with the gold catalysts prepared by the deposition precipitation method. The structural and electronic properties were evaluated by various characterization technologies, including X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), in situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) of CO adsorption, X-ray photoelectron spectroscopy (XPS), and CO2temperature-programmed desorption (TPD). The combined characterization results suggested that the adsorption property of gold and the basicity of the catalyst contributes to their high activities. Substrates extended experiments and stability tests implied the potential application of Zn-Al-mixed oxides supported gold catalysts, which paves a new way for supported gold catalyst in the one-step oxidation esterification reaction.Keywords:gold cluster;hydrotalcite;methacrolein;methyl methacrylate;oxidative esterification
研究领域:
化学工程
·
催化化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 33
·13682-13690
·
IF 0
Shengjie Xu,Peiyi Wu
In this work, a well-dispersed Au cluster/reduced graphene oxide (RGO) composite was synthesized using citric acid (CA) as a reducing and binding agent. The as-prepared composite was systemically characterized by TEM, XPS, TGA and FTIR. TEM image showed Au clusters uniformly distributed on the RGO sheet with an average size of 1.8 nm. The Au clusters/RGO composite exhibited excellent catalytic performance for the oxygen reduction reaction (ORR). Moreover, the electrocatalytic comparison indicated that the long-term durability and methanol tolerance of this composite was superior to the commercial Pt/C catalyst. Therefore, such a composite might be an alternative and more promising non-Pt electrocatalyst for fuel cells.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
BIOSENSORS & BIOELECTRONICS
·
2017
·
IF 7.78
Yang Liu,Meng Cai,Weiping Wu,Yuting Fang,Pei She,Shouming Xu,Jianguo Li,Kang Zhao,Jingjuan Xu,Ning Bao,Anping Deng
Herein, we reported a disposable electroanalytical device for competitive enzyme-linked immunosorbent assay (ELISA) of phenylethanolamine A (PA). Conductive carbon tape coated with gold cluster served as the working electrode , while the counter and reference electrodes were fabricated on the filter paper by the screen-printing technique. Separating fabrication of the working electrode from other electrodes could make it possible for full utilization of the working electrode modification in bulk and no contamination of the immune-reagents on the counter and reference electrodes. The gold cluster played an important role in both immobilizing antigen and accelerating electron transfer . The eight-channel devices were utilized to detect PA on the strategy of competitive ELISA. The detection range and the limit of detection (LOD) using differential pulse voltammetry for PA were 0.005–60 ng mL −1 and 2.6 pg mL −1 , respectively. And also, the linear range for PA performed by square wave voltammetry was 0.05–60 ng mL −1 with the LOD value as 0.028 ng mL −1 . The results clearly demonstrated that the proposed electroanalytical devices could be successfully applied in immunoassay and might be further developed for determination of different analytes based on ELISA format.
研究领域:
分析化学
·
免疫学
✓ 已验证
DOI
PubMed
高影响因子
TALANTA
·
2019
·
IF 4.916
Yanlin Du,Hui Liu,Jiaming Liang,Dongye Zheng,Jiong Li,Shubing Lan,Ming Wu,Aixian Zheng,Xiaolong Liu
Herein, a bovine serum albumin-stabilized gold clusters-MnO 2 nanocomposite (BSA@AuNCs–MnO 2 ) was constructed. Manganese dioxide (MnO 2 ) was generated in situ on the gold clusters (BSA@AuNCs) based on the redox reaction between bovine serum albumin (BSA) and potassium permanganate (KMnO 4 ). The fluorescence of BSA@AuNCs can be quenched by the in-situ grown MnO 2 , which has strong light absorption ability. It is worth noting that the quenched fluorescence of the BSA@AuNCs can be restored in the presence of glutathione (GSH), and MnO 2 was reduced to Mn 2+ in return. Encouragingly, 1 μM GSH can cause a detectable fluorescence change. This sensitivity is comparable to other nanomaterials based fluorescent probes . Furthermore, this nanocomposite has obvious superiorities, such as good uniformity, simple preparation and mild reaction. The nanocomposite also has good stability and specificity, which can be further used for visualizing of intracellular GSH.
研究领域:
生物化学
·
纳米医学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2023
·
IF 8.4
Wanjun Long,Yuting Guan,Guanghua Lei,Zikang Hu,Hengye Chen,Yuanbin She,Haiyan Fu
In this work, we constructed a machine learning-assisted dual-channel visual sensor array for identifying the origin of Lilium bulbs (BH). Nanogold clusters (AuNCs) and quantum dots (QDs) were selected and combined into sensor arrays. The amino acids existed in lilium bulbs could induce aggregation-induced fluorescence enhancement effect (AIEE) of AuNCs through hydrogen bonding . The hydrogen protons released from the amino acids and phenolic acids could interact with the COO - group of QDs, resulting in aggregation-caused quenching (ACQ) of QDs. Due to the different contents of amino acids and phenolic acids in BH from different origins, the sensor array can produce distinct and different fluorescent colors , such as red, blue, green and purple. In conjunction with pattern recognition by the RF model, the sensor array clearly identifies the origin of BH with 94.4% prediction accuracy. The visual sensor array constructed in this work exhibited the advantages of simplicity, speed, accuracy and portability, showing potential application prospects in identifying the origin of food and traditional Chinese medicine.
研究领域:
植物学
·
食品科学
·
中药学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）