查找使用阿拉丁产品的科研文献

Multicomponent hydroxides supported Cu/Cu2O nanoparticles for high efficient photocatalytic ammonia synthesis

Huaiwei Zhang,Yifan Chen,Ying Pan,Liang Bao,Jing-yuan Ge

Environmentally friendly photocatalytic N 2 fixation process has attracted considerable attention. Developing efficient photocatalysts with high electron-hole separation rates and gas adsorption capacities remains quite challenging. Herein, a facile fabrication strategy of Cu-Cu 2 O and multicomponent hydroxide S-scheme heterojunctions with carbon dot charge mediators is reported. The rational heterostructure   brings excellent N 2 absorption ability and high photoinduced electron/hole separation efficiency, and the ammonia produced yield reach above 210 µmol·g cal -1 ·h −1 during the nitrogen photofixation process. More superoxide and hydroxyl radicals are generated simultaneously in the as-prepared samples under light illumination. This work offers a reasonable construction method to further develop suitable photocatalysts for ammonia synthesis .

Preparation and Photocatalytic Properties of CQDs-Modified 26-Facet Cu/Cu2O Composites

Sun Wenwen,Guo Ruyue,Shi Chaojie,Li Xuechen,Wu Jiayi,Tian He,Li Huayi,He Jie,Yang Zhengchun,Li Jiahui,Sun Shanfeng

In this study, we prepared carbon quantum dots (CQDs)-modified 26-facet Cu/Cu 2 O composites and investigated their photocatalytic degradation effect on methyl orange (MO). The microstructure and composition of the reduction products were analyzed. The test results validate the successful modification of CQDs on the surface of Cu/Cu 2 O composites. Further, through electrochemical performance analysis among the materials with different thiourea dioxide (TD) contents, 3TD (n × 0.00075 mol of thiourea dioxide is defined as nTD) exhibits the strongest electron transfer ability; thus, 3TD was selected to further combine with CQDs to examine the photocatalytic performance of Cu/Cu 2 O composites. We analyzed the photocatalytic behavior of the composites by monitoring the degradation of the MO solution. Based on the photocatalytic performance test, the CQDs/3TD composite exhibits excellent photocatalytic activity. Following 120 min of visible light irradiation, the degradation rate of MO with the addition of loaded CQDs increased from 25 to 73%. Materials with both adsorption and photocatalytic properties were successfully prepared, which resolved the regeneration of adsorbents to a certain extent and further accelerated the degradation of dyes. Graphical Abstract

Facile design of oxide-derived Cu nanosheet electrocatalyst for CO2 reduction reaction

Juhee Jang,Shangqian Zhu,Ernest Pahuyo Delmo,Tiehuai Li,Qinglan Zhao,Yinuo Wang,Lili Zhang,Hongwen Huang,Jingjie Ge,Minhua Shao

Despite of superior performance of the oxide-derived copper (OD-Cu) in producing valuable hydrocarbons during CO 2 RR, its fabrication process is still ambiguous and complicated. In this work, we develop a simple microwave-assisted method to synthesize the oxide-derived Cu nanosheet (OD-Cu NS) and reveal that the oxidation state of Cu species is controlled by varying the Cu precursor amount. Notably, the simultaneous formation of nano-sized Cu domains influence the surface roughness of OD-Cu NS. The partially oxidized Cu surface exhibits a superior faradaic efficiency (FE) of C 2+ products up to 72%, along with a partial current density of 55 mA cm −2 in a neutral KHCO 3 solution. More importantly, the as-obtained OD-Cu NS shows a synergetic effect on dissociating of CO 2 molecules by the strong binding energy and promoting of C 2+ compounds productivity by the enlarged electrochemical surface area. This work provides a new insight for designing efficient OD-Cu catalysts toward CO 2 RR.

Multi-stimuli responsive Cu-MOFs@Keratin drug delivery system for chemodynamic therapy

Du Jinsong,Chen Guanping,Yuan Xinyi,Yuan Jiang,Li Li

Although the potential of metal-organic framework (MOF) nanoparticles as drug delivery systems (DDS) for cancer treatment has been established by numerous studies, their clinical applications are still limited due to relatively poor biocompatibility. We fabricated a multifunctional Cu-MOFs@Keratin DDS for loaded drug and chemodynamic therapy (CDT) against tumor cells. The Cu-MOFs core was prepared using a hydrothermal method, and then loaded with the anticancer drug DOX and wrapped in human hair keratin. The Cu-MOFs@Keratin was well characterized by transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and X-ray photoelectron spectroscopy (XPS). Characterization and pharmacokinetic studies of Cu-MOFs@Keratin were performed in vitro and in vivo. The keratin shell reduced the cytotoxicity and potential leakage of Cu-MOFs to normal cells, and allowed the drug-loaded nanoparticles to accumulate in the tumor tissues through enhanced permeability and retention effect (EPR). The particles entered the tumor cells via endocytosis and disintegrated under the stimulation of intracellular environment, thereby releasing DOX in a controlled manner. In addition, the Cu-MOFs produced hydroxyl radicals (·OH) by consuming presence of high intracellular levels of glutathione (GSH) and H2O2, which decreased the viability of the tumor cells.

Insights into Electrocatalytic Nitrate Reduction to Ammonia via Cu-Based Bimetallic Catalysts

Jing Zhao,Lijuan Liu,Ya Yang,Dan Liu,Xiaobo Peng,Shijing Liang,Lilong Jiang

Cu-based bimetallic catalysts have been studied in the electrocatalytic nitrate (NO3–) reduction reaction (NO3–RR) for a long time. However, few studies have focused on horizontal comparison of CuNi, CuCo, and CuFe (abbreviated as CuM) bimetallic catalysts in electrocatalytic NO3–RR for ammonia synthesis. Herein, we prepare the three series of Cu-based bimetallic catalysts, with different atom ratios of Cu/M (Cu/M = 7/3, 5/5, or 3/7) and ordered mesoporous carbon (OMC) as support (denoted as CuM/OMC). The characterization results reveal that the metallic particles of Cu and M components possess an intimate relationship on the CuM/OMC catalysts. The electrocatalytic NO3–RR performance uncovers that the optimal NH3 yield rates of CuM/OMC catalysts at −0.8 V (vs reversible hydrogen electrode (RHE)) follow this order: Cu5Fe5/OMC > Cu5Co5/OMC > Cu7Ni3/OMC > Cu/OMC > Fe/OMC > Co/OMC > Ni/OMC > OMC. The bimetallic CuM/OMC catalysts exhibit higher NH3 yield rates than the monometallic catalysts. This is attributed to strong synergistic effects between the Cu and M components. We expect that these insights can stimulate new developments of bimetallic catalysts in electrocatalysis.

Superlubricity of TiN coating using glycerol with the addition of Cu nanoparticles

Xiaojing Fu,Shuming Guo,Yong Wan,Changsheng Zheng,Qiang Li,Bingchang Liu

Superlubricity was achieved by the addition of copper nanoparticles (CuNPs) as an additive to glycerol, a sustainable lubricant, which was applied to TiN-coated steel that underwent ball-on-flat reciprocating testing at an average contact pressure of 54.6 MPa. A coefficient of friction of ∼ 0.007 and a wear rate of 2.0 × 10 –8 mm 3 /N m were achieved on the TiN coating when lubricated with glycerol + 0.1 wt% CuNPs at a sliding speed of 120 mm/s. XPS and Raman analysis suggested that a surface tribofilm containing CuNPs and a carbon-based film derived from the degradation of glycerol were deposited onto the contact area of the tribopairs, which effectively prevented the direct asperity contact between the steel ball and TiN-coated steel, enabling ultra-low friction.

Hierarchical Ag-Cu interfaces promote C-C coupling in tandem CO2 electroreduction

Zhizhou Cai,Ning Cao,Fanxing Zhang,Xiangzhou Lv,Ke Wang,Yi He,Yao Shi,Hao Bin Wu,Pengfei Xie

Electrocatalytic CO 2 reduction into ethanol driven by renewable energy represents a promising strategy for energy storage and mitigation of global warming, but it has remained challenging to gain high activity and selectivity of ethanol. Here we take advantage of atomic arrangement in immiscible Ag-Cu composite during annealing and establish hierarchical interfaces in the obtained core-shell catalyst. The atomic Ag-Cu interactions increase electrochemical surface area and expedite charge dynamics, resulting in an unprecedented electrocatalytic performance with the faradaic efficiency of C 2+ products, ethanol as 80.2 %, 52.6 % and the current density of ∼320 mA cm −2 at −1.0 V (versus reversible hydrogen electrode). Moreover, the Ag-Cu catalyst exhibits a notable stability for ∼60 h. Mechanism studies reveal that local CO intermediates preferentially accumulate on the core, then migrate to the continuous Cu surface for C-C coupling energy-favorably toward ethanol. Our work highlights a novel design principle as interface engineering for advanced tandem electrocatalysts.

Chitosan Sponge/Cu–WO3–x Composite for Photodynamic Therapy of Wound Infection

Xingrui Qi,Jiamin Gan,Zhidong Zhao,Nian Li,Yufang Chen,Tao Jin

One of the potential treatments for bacterial wound infections is photodynamic therapy. WO3–x semiconductor materials can generate reactive oxygen species when exposed to light, which can inactivate bacteria. In this work, we improved their photocatalytic performance by doping WO3–x with Cu. The wound dressing was prepared by loading Cu–WO3–x into a highly biocompatible chitosan sponge. The composite sponge dressing showed significant inactivation of Escherichia coli and Staphylococcus aureus, and in vitro toxicity assays on L929 cells demonstrated the biosafety of the dressing. Through in vivo wound healing trials, composite sponge dressings have been shown to accelerate wound healing, and this composite chitosan sponge can be possibly used for photodynamic therapy of bacterial wound infections.

Preparation and properties of CNTs-Cu hybrids/epoxy superhydrophobic and anticorrosive coatings

Zhongbo Zhu,Shumei Kang,Hua Chen,Qingping Zhao,Zhaokang Huo,Pengyu Li,Qidong Cao,Chenshuo Lu

In this work, hydrophobized copper powders combined siloxane-modified carbon nanotubes (SHMWCNTs) to obtain intertwined hybrids of carbon nanotubes and copper (CNTs-Cu hybrids), and superhydrophobic CNTs-Cu hybrids/epoxy coatings were prepared on the surface of AH36 carbon steel by drop coating. The surface morphology and wettability of coatings were changed by adjusting the ratios of SHMWCNTs to hydrophobized copper powders. The obtained coating can show a water contact angle of 167.2°, a water sliding angle of 2.9°, a plant oil contact angle of 134.3°, and self-cleaning properties. The coating maintains superhydrophobicity after 300 tape-peeling times, exhibiting excellent mechanical durability. The fouled area percentages of chlorella on the coating and a pure epoxy resin were 0.23(±0.07)% and 12.18(±1.22)%, respectively, displaying anti-biofouling resistances. The coating has excellent corrosion resistance, and its corrosion current density reached 9.55 × 10 -8 A/cm 2 .

Highly Ethylene-Selective Electroreduction CO2 Over Cu Phosphate Nanostructures with Tunable Morphology

Zhang Li,Men Yong,Wu Bin,Feng Yuanfen,Song Chao,Liu Shuang,Wang Jinguo,An Wei,Magkoev Tamerlan T.

Highly selective production of valuable ethylene from electrocatalytic CO 2 reduction reaction (ECO 2 RR) is particularly desirable yet challenging. Morphology engineering is an effective strategy for catalyst design, which can adjust the electronic structure of catalyst surface, change the adsorption behavior of critical reaction intermediates over catalyst surface, and thus regulate the activity of electrocatalytic CO 2 reduction reaction. In this work, we prepared copper phosphate catalysts with different morphologies and tested their catalytic activity for the ECO 2 RR in the flow cell. Compared with irregular flocculent aggregates, copper phosphate nanospheres exhibit a high and stable ethylene Faradaic efficiency of 47% with high current density of 350 mA·cm − 2 , which is higher than the 200 mA·cm − 2 required for industrial applications. The catalysts were extensively characterized by SEM, EDS, XRD, ICP-OES, XPS, BET and CO-TPD. Combining the characterization results and activity data, we found that the superior spherical morphology of copper phosphate can increase the electron density around Cu, stabilize the Cu + species on the surface through the electron transfer between P and Cu, and adjust the adsorption strength of CO intermediates (*CO) to enhance the productivity of C 2+ products. This work provides new insights into catalyst design for highly efficient C 2 H 4 production from the electrocatalytic CO 2 reduction reaction by tuning morphologies of Cu-based catalysts.

Synergistic trimetallic Ni–Cu–Sn catalysts for efficient selective hydrogenation of phenylacetylene

Wei Chen,Huawu Xu,Xiaoling Ma,Lin Qi,Zhiming Zhou

Selective hydrogenation of phenylacetylene is the most effective way to remove a small amount of phenylacetylene from styrene, but it is still a challenge to develop catalysts with high activity and selectivity. Herein, a series of non-precious bimetallic Ni 3 M/SiO 2 (M = Zn, Sn, Cd, Fe, Co, Cu, or Mo) and trimetallic Ni 3 Cu–Sn/SiO 2 catalysts were prepared and applied to selective hydrogenation of phenylacetylene. A trade-off between activity and selectivity was observed on Ni 3 M/SiO 2 , where Ni 3 Cu/SiO 2 showed the best hydrogenation activity because of the hydrogen spillover effect of the Ni–Cu alloy, while Ni 3 Sn/SiO 2 exhibited the highest selectivity to styrene due to the active-site isolation effect of the Ni–Sn alloy. Impressively, trimetallic Ni 3 Cu–Sn/SiO 2 offered superior catalytic performance (94 % styrene selectivity at >99 % phenylacetylene conversion) as compared to bimetallic catalysts, owing to the synergistic effect among Ni, Cu, and Sn. In the case of Cu and Sn co-doping, the hydrogen spillover on the Ni–Cu alloy was deeply suppressed by Sn, which enabled an effective modification of the geometric and electronic structures of Ni to favor styrene desorption. The hydrogenation activity of Ni 3 CuSn 0.3 /SiO 2 can be readily enhanced by increasing the metal loading and further improved by elevating the reaction temperature and pressure, but meanwhile the high selectivity is little affected. This work demonstrates a multi-metal synergistic strategy to break the activity–selectivity trade-off of Ni-based bimetallic catalysts in the selective hydrogenation of alkynes.

Photo-Tuned Cu/Cu2O/CdS/PPy Heterojunctions for Hg2+ Sensing in Seawater

Minggang Zhao,Zhensen Liang,Ming Li,Hongzhi Cui,Ye Ma