Nature Communications
·
2023
·Vol. 14
·期 1
·1-10
·
IF 16.6
Shao Penghui,Chang Ziwen,Li Min,Lu Xiang,Jiang Wenli,Zhang Kai,Luo Xubiao,Yang Liming
Silver ions in wastewater streams are a major pollutant and a threat to human health. Given the increasing demand and relative scarcity of silver, these streams could be a lucrative source to extract metallic silver. Wastewater is a complex mixture of many different metal salts, and developing recyclable sorbents with high specificity towards silver ions remains a major challenge. Here we report that molybdenum oxide (MoO x ) adsorbent with mixed-valence (Mo(V) and Mo(VI)) demonstrates high selectivity (distribution coefficient of 6437.40 mL g −1 ) for Ag + and an uptake capacity of 2605.91 mg g −1 . Our experimental results and density functional theory calculations illustrate the mechanism behind Ag + adsorption and reduction. Our results show that Mo(V) species reduce Ag + to metallic Ag, which decreases the energy barrier for subsequent Ag + reductions, accounting for the high uptake of Ag + from wastewater. Due to its high selectivity, MoO x favorably adsorbs Ag + even in the presence of interfering ions. High selective recovery of Ag + from wastewater (recovery efficiency = 97.9%) further supports the practical applications of the sorbent. Finally, MoO x can be recycled following silver recovery while maintaining a recovery efficiency of 97.1% after five cycles. The method is expected to provide a viable strategy to recover silver from wastewater.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2018
·
IF 4.484
Xueyan Chen,Min Chen,Guangzhi He,Fei Wang,Guangyan Xu,Yaobin Li,Changbin Zhang,Hong He
Ag-based catalysts are efficient materials for formaldehyde (HCHO) oxidation in the low-temperature range. It has been reported that K addition can increase the catalytic performance of Ag-based catalysts, whereas the specific role of K doping remains ambiguous. In this work, Ag/Al2O3 and K–Ag/Al2O3 catalysts with different K doping levels were prepared and subsequently tested for catalytic HCHO oxidation. It was observed that K doping has a dramatic promotion effect on the activity of the Ag/Al2O3 catalyst. The 2K–Ag/Al2O3 sample was the most active catalyst, over which HCHO could be completely converted into CO2 and H2O in a gas hourly space velocity of 100 000 mL/(gcat h) at 65 °C. The catalysts were next characterized by X-ray powder diffraction, Brunauer–Emmett–Teller, transmission electron microscopy, H2-temperature-programmed reduction, UV–vis, X-ray absorption fine structure, and in situ diffuse reflectance infrared Fourier transform spectroscopy methods. The characterization results show that addition of K species increased the content of metallic Ag species in Ag/Al2O3 catalysts and promoted the adsorption and activation of oxygen species, whereas excessive doping with K+ resulted in the agglomeration of Ag particles and loss of some metallic sites. Therefore, the 2K–Ag/Al2O3 catalyst demonstrated the best performance among the series of K-doped catalysts. Promotion of O2 activation by K doping, rather than enhanced Ag dispersion or surface OH activation or exposure of more Ag(111) facets, was found to be the key factor in the improved catalytic performance of K–Ag/Al2O3 catalysts.
研究领域:
环境催化
·
材料化学
·
大气污染控制
·
纳米催化
·
表面科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Xueyan Chen,Honghong Wang,Min Chen,Xiaoxiao Qin,Hong He,Changbin Zhang
Ag-based catalysts are shown to be efficient for formaldehyde (HCHO) oxidation at low temperature, while the role of active Ag species in this reaction remains a controversial issue. In this work, we prepared Ag/TiO 2 catalysts with TiO 2 of different crystal structures (anatase or rutile) as supports and tested their performances in HCHO oxidation. We observed that the crystal structure of the TiO 2 support had a significant influence on the activity of the Ag/TiO 2 catalysts, and Ag/A (anatase) exhibited dramatically superior activity compared with Ag/R (rutile). More interestingly, we observed a clear inflection point in the HCHO conversion curve for the Ag/R catalyst. Combining the results of BET, XRD, TEM, XAFS, H 2 -TPR characterization and DFT calculations, we show that HCHO oxidation on Ag/TiO 2 catalysts is a co-function process of multiple active sites including surface oxygen, Ag 2 O, and metallic Ag species. The low-temperature non-renewable surface oxygen and Ag 2 O species mainly contribute to HCHO oxidation in the low-temperature range, while metallic Ag species are primarily responsible for the reaction at high temperature since metallic Ag is capable of activation of oxygen at high temperature. The relative contents of surface oxygen, Ag 2 O and metallic Ag species are different on the Ag/A and Ag/R catalysts. The dispersion degree of metallic Ag species also differs on the Ag/A and Ag/R, therefore their capacities for oxygen activation are quite dissimilar. The above factors combine to result in distinct catalytic behaviors for Ag/A and Ag/R in HCHO oxidation, as well as the appearance of an inflection point.
研究领域:
催化化学
·
环境化学
·
材料科学
·
表面科学
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2020
·Vol. 101
·期 9
·3595-3604
·
IF 2.614
Ting-tiao Pan,Wang Guo,Ping Lu,Deyu Hu
BACKGROUND Pesticide residues in agricultural products and foods pose a serious threat to human health, and therefore a simple, rapid and direct method is urgently needed for pesticide residue detection. In addition to realizing the detection of acetamiprid in cabbage extract solution, the main target of this study was to establish an in situ surface-enhanced Raman scattering (SERS) method, which could directly detect acetamiprid residue on cabbage leaf without the need for extraction. Acetamiprid was first used to contaminate the surface of fresh cabbage leaf, and then bimetallic silver-coated gold nanoparticles (Au@AgNPs) were added on the contaminated spots and dried for SERS measurement. RESULTS Results suggested that acetamiprid can be detected in cabbage extract and on cabbage leaf surface in situ using the SERS method based on the Au@AgNPs substrate. The limit of detection was 0.08 μg mL −1 in cabbage extract and 0.14 mg kg −1 on cabbage leaf, the recovery ranged from 80.5% to 105.5% and the relative standard deviation was in the range 4.37–10.63%. CONCLUSIONS The proposed SERS method provides an in situ , nondestructive and rapid way to detect acetamiprid residue on the surface of fruits and vegetables, which could serve as an auxiliary approach for early screening of contaminated produce in field or on site in the future. © 2020 Society of Chemical Industry
研究领域:
分析化学
·
食品科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Yating Li,Miao Zhang,Xingbo Shi,Zhihui Wu
Food safety problems caused by foodborne pathogens pose a serious threat to human health and its sensitive detection is an urgent issue. Herein, a polydopamine film-based electrochemical biosensor was constructed for ultrasensitive detection of Listeria monocytogenes ( L. monocytogenes ). Bimetallic silver-gold sea urchin-like hollow nanoparticles (BUHNPs) were first synthesized and loaded on the surface of a glassy carbon electrode, and then aptamers (apt) were modified on the BUHNPs , followed by depositing of dopamine to form polydopamine of bacterial imprinted polymers (PDA BIPs) film, and finally three-dimensional molecularly imprinted films with cavities were achieved after template elution. The presence of L. monocytogenes resulted in a change in the current signal, indicating that the bacteria had entered the cavity. The biosensor was able to detect L.monocytogenes at 10 1 -10 6 CFU·mL −1 with a detection limit of 1.0 CFU·mL −1 . The sensor can achieve rapid detection within 7 min, and the synergistic effect of BIP and aptamer enhances the recognition of the target, showing a great potential for the detection of L. monocytogenes in real food samples.
研究领域:
分析化学
·
纳米技术
·
食品科学
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2023
·Vol. 19
·期 29
·2207436
·
IF 13.3
Qing Yu Liu,Ying Wu,Zhen Qi Bu,Min Xia Quan,Jiao Yang Lu,Wei Tao Huang
Bimetallic nanomaterials (BNMs) have been used in sensing, biomedicine, and environmental remediation, but their multipurpose and comprehensive applications in molecular logic computing and information security protection have received little attention. Herein, This synthesis method is achieved by sequentially adding reactants under ice bath conditions. Interestingly, Ag-Cr NPs can dynamically selectively sense anions and reductants in multiple channels. Especially, ClO − can be quantitatively detected by oxidizing Ag-Cr NPs with detection limits of 98.37 nM (at 270 nm) and 31.83 nM (at 394 nm). Based on sequential-dependent synthesis process of Ag-Cr NPs, Boolean logic gates and customizable molecular keypad locks are constructed by setting the reactants as the inputs, the states of the resulting solutions as the outputs. Furthermore, dynamically selective response patterns of the Ag-Cr NPs can be converted into binary strings to exploit molecular crypto-steganography to encode, store, and hide information. By integrating the three dimensions of authorization, encryption, and steganography, 3 in 1 advanced information protection based on Ag-Cr nanosensing system can be achieved, which can enhance the anti-cracking ability of information. This research will promote the development and application of nanocomposites in the field of information security and deepen the connection between molecular sensing and the information world.
研究领域:
纳米技术
·
材料科学
·
化学传感
·
信息安全
·
分子计算
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）