查找使用阿拉丁产品的科研文献

Efficient removal of radioactive iodide by three-dimensional Cu@Cu2O: An adsorption and electrocatalytic oxidation coupling process

Han Jiao,Yaru Li,Kaihua Gao,Jingyu Zhao,Chun Wang,Mingcheng Li,Ping Na

Electrochemical promotion technology, an environmentally friendly and facile strategy, is becoming increasingly attractive to researchers. In this work, a novel Cu@Cu 2 O foam block composite material was constructed through a one-step hydrothermal method. The product was then employed as the anode and electrified to catalyse removal of radioactive iodide ions (I − ) in the liquid phase. The removal rate of I − sharply increased to 96.65 % under electrification, which is a 4.5-fold increase over that without electrification. The current strength had an impact on this result, and the removal was still relatively high in a wide range of pH values. The composite material had good reusability and could maintain good performance after simple separation. Therefore, based on X-ray diffraction and X-ray photoelectron spectroscopy analysis, we proposed a mechanism of electrochemical oxidation and adsorption coupling for the iodine removal. As Cu@Cu 2 O adsorbed I − to form CuI, the current flow oxidised I − to I 2 , which finally was adsorbed by the formed CuI. Therefore, the current provides services of accelerating I − movement and oxidation. This coupling model of electrocatalytic oxidation and adsorption provides us with a new research method to remove iodide from water.

Monodisperse Cu/Cu2O@C core–shell nanocomposite supported on rGO layers as an efficient catalyst derived from a Cu-based MOF/GO structure

Ke Yang,Yu Yan,Haiyang Wang,Zhixuan Sun,Wen Chen,Hongtao Kang,Yi Han,Wenquan Zahng,Xiaohua Sun,Zhenxing Li

A novel copper/copper(I) oxide@carbon (Cu/Cu2O@C) core–shell nanocomposite monodispersed on the surface of reduced graphene oxide (defined as Cu/Cu2O@C-rGO) was synthesized using a one-step calcination of Cu-based metal organic frameworks (MOFs)/graphene oxide (GO) composite structure. The size of the resultant Cu/Cu2O@C core–shell nanoparticles (NPs) on the rGO layers were mainly distributed in range of about 90–100 nm with good dispersion, which was characterized using transmission electron microscopy. X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, nitrogen adsorption–desorption isotherms, X-ray photoelectron spectrometry and thermogravimetric analyses were also carried out to characterize the structure and composition of the Cu/Cu2O@C-rGO. The catalytic performance of the Cu/Cu2O@C-rGO composite was evaluated using a reduction reaction from 4-nitrophenol to 4-aminophenol. It was demonstrated that the Cu/Cu2O@C-rGO composite exhibited an excellent catalytic performance, which can reach a nearly 100% conversion rate in 90 s with 0.1 mg of catalyst. This catalyst also showed a good performance for the degradation of other organic dyes such as methylene blue, methyl orange and rhodamine B. Additionally, the core–shell structure exhibited good stability and reusability for the reduction reaction, which was because of its relatively better oxidation resistance than that of the bare Cu NPs. This research provided an efficient and stable non-noble metal-based catalyst derived from the MOF/GO structure.

Construction synergetic adsorption and activation surface via confined Cu/Cu2O and Ag nanoparticles on TiO2 for effective conversion of CO2 to CH4

Bo-hui Li,Kai-hua Zhang,Xiao-jing Wang,Yu-pei Li,Xinying Liu,Bao-Hang Han,Fa-tang Li

High-performance photocatalysts for catalytic reduction of CO 2 are largely impeded by inefficient charge separation and surface activity. Reasonable design and efficient collaboration of multiple active sites are important for attaining high reactivity and product selectivity . Herein, Cu-Cu 2 O and Ag nanoparticles are confined as dual sites for assisting CO 2 photoreduction to CH 4 on TiO 2 . The introduction of Cu-Cu 2 O leads to an all-solid-state Z-scheme heterostructure on the TiO 2 surface, which achieves efficient electron transfer to Cu 2 O and adsorption and activation of CO 2 . The confined nanometallic Ag further enhances the carrier’s separation efficiency, promoting the conversion of activated CO 2 molecules to •COOH and further conversion to CH 4 . Particularly, this strategy is highlighted on the TiO 2 system for a photocatalytic reduction reaction of CO 2 and H 2 O with a CH 4 generation rate of 62.5 μmol∙g −1 ∙h −1 and an impressive selectivity of 97.49 %. This work provides new insights into developing robust catalysts through the artful design of synergistic catalytic sites for efficient photocatalytic CO 2 conversion.

The Effect of g-C3N4 in Its Composite With Cu-Cu2O on the Catalysis of Aerobic Oxidation of Benzylic Alcohols

Yongguang Wang,Yi Pei,Siqi Hu,Chunxin Lu,Wei Zhong,Zhiyin Xiao,Junjie Wang,Xiaoming Liu

In this work, the preparation and characterization of a composite of Cu-Cu 2 O with g-C 3 N 4 and its application in the catalysis of aerobic oxidation of benzylic alcohols are reported. The composites Cu-Cu 2 O/g-C 3 N 4 were prepared starting with CuSO 4 under reduction conditions with ball milling, followed by thermal treatment. The introduction of g-C 3 N 4 into the composite can enhance the catalytic oxidation. Band structure analysis based on UPS data reveals that the enhancement can be attributed to the small work function of g-C 3 N 4 , which raises the VBM level of the chief catalyst Cu 2 O through injecting electrons into the oxide at the heterojunction due to Fermi energy alignment. Both VBM ascending and forming an internal electric field (IEF) due to the electron transfer across the interface contribute to the enhancement in the catalysis. Further, the N-rich matrix g-C 3 N 4 promotes proton transfer in the catalysis due to its basicity, which also accelerates the catalysis.

Facile synthesis of an antimony-doped Cu/Cu2O catalyst with robust CO production in a broad range of potentials for CO2 electrochemical reduction

Hongyu Chen,Zhaojie Wang,Shoufu Cao,Siyuan Liu,Xiaojing Lin,Yi Zhang,Yizhu Shang,Qiuying Zhu,Sainan Zhou,Shuxian Wei,Baojun Wei,Daofeng Sun,Xiaoqing Lu

The electrocatalytic CO2 reduction reaction (CO2RR) on copper-based catalysts is a promising method to produce valuable chemicals, but its selectivity is much lower than expected largely due to insufficient research on the structure of new materials. Herein, the antimony-doped Cu/Cu2O (Cu/Cu2O–Sb) catalyst is developed for a highly selective CO2RR to CO. The synthesized Cu/Cu2O–Sb exhibits intensive suppression of hydrogen evolution, a low overpotential and high faradaic efficiency (FE) towards CO. The CO selectivity is as high as ∼95% with a partial current density of ∼6.3 mA cm−2 at −0.9 V and maintains over 90% in a broad range of potentials. DFT calculations reveal that the doping of antimony achieves the distinct activation of CO2 and suppression of hydrogen evolution. Meanwhile, the pre-adsorbed *CO significantly promotes the desorption of the neighboring *CO, which is the key for high selectivity of CO2RR to CO. This work will provide a new consideration for the origin of high selectivity during the CO2RR and pave the way toward design of highly selective CO2 reduction catalysts.

Preparation of novel microencapsulated phase change material with Cu-Cu2O/CNTs as the shell and their dispersed slurry for direct absorption solar collectors

Bin Xu,Chenghua Chen,Jing Zhou,Zhongjin Ni,Xiaochun Ma

In this study, a novel microencapsulated phase change material paraffin@Cu-Cu 2 O/CNTs was successfully prepared by hydrothermal reduction and in situ deposition method , in which paraffin as the core, Cu, Cu 2 O and carbon nanotubes (CNTs) as the shell. SEM and TEM results proved that the microcapsules have a core-shell structure, the CNTs were irregularly wrapped on the shell, and the diameter of the microcapsules was about 600-800 nm. The melting temperature and latent heat of the paraffin@Cu-Cu 2 O/CNTs microcapsules were 61.17 °C and 81.31Jg -1 , respectively, and the encapsulation rate of the microcapsules was calculated to be 41.53% from the results of the DSC measurement. Due to the shell material, the paraffin@Cu-Cu 2 O/CNTs microcapsules displayed excellent thermal stability, its thermal decomposition temperature is increased by 97 °C compared to paraffin. Moreover, the paraffin@Cu-Cu 2 O/CNTs microcapsules were dispersed in water to form a new kind of slurry, such fluid exhibited great improvement in terms of thermal conductivity , specific heat capacity , light absorption performance and photo-thermal conversion efficiency than that of paraffin@Cu-Cu 2 O microcapsules slurry. Therefore, the high heat storage capability and excellent photo-thermal conversion performance of the paraffin@Cu-Cu 2 O/CNTs microcapsule slurry make it to be the most potential heat transfer fluid for direct absorption solar collector.

Band bending caused by forming heterojunctions in Cu-Cu2O/rGO-NH2 semiconductor materials and surface coordination of N-methylimidazole, and the intrinsic nature of synergistic effect on the catalysis of selective aerobic oxidation of alcohols

Jiamei Ma,Wei Zhong,Langlang You,Yi Pei,Chunxin Lu,Zhiyin Xiao,Zhongquan Shen,Xiujuan Jiang,Nianlong Qian,Xiaoming Liu,Shuhua Zhang

In this work, three materials of Cu-Cu 2 O/rGO-NH 2 -4.4/1, -1/1 and -1/10.4, in which the numeric suffices denote the ratio of Cu/Cu 2 O in the materials, were described and characterized using various analytical techniques including FTIR, XRD, SEM, HRTEM, XPS and Raman spectroscopy. To probe the band structures of these materials, UPS, cyclic voltammetry, and UV–vis reflection spectroscopy were also employed. The formation of heterojunctions in the ternary materials tune their band structures by raising the energy level of valence band maximums (VBMs), inducing an internal electric field (IEF) and an electron accumulation layer (EAL) within the materials. Augment of copper content in the materials can enhance the energy level rising. The coordination of N-methylimidazole (NMI) with Cu 2 O of the materials can also contribute to raising the energy level. The changes in these electronic properties bring about a synergistic effect in selective aerobic oxidation of benzylic alcohols via improving O 2 activation and facilitation of electron transfer between the catalyst and the reactants due to the rising of the energy level of VBM and the formation of IEF.

Growth of Cu particles on a Cu2O truncated octahedron: tuning of the Cu content for efficient glucose sensing

Gang Wang,Hong Sun,Lu Ding,Gang Zhou,Zhong-Sheng Wang

A simple and versatile hydrothermal method is developed to synthesize Cu–Cu2O, in which Cu particles grow on the surface of a Cu2O truncated octahedron. Through the reduction of Cu2+ by glucose in an alkaline solution, the Cu2O truncated octahedron is quickly formed via a kinetic control process, and then Cu particles selectively nucleate on the high-energy (110) facets of Cu2O, generating a heterostructure. The amount of Cu in the sample is successfully tuned by varying the reaction temperature. Compared to Cu2O, the hybrid Cu–Cu2O architecture shows superior electrocatalytic performance for glucose oxidation due to the synergistic effect between more electrocatalytic active but less conductive Cu2O and more conductive but less electrocatalytic active Cu. By tuning the content of Cu in the heterostructure, the highest electrocatalytic activity is achieved at the Cu/Cu2O molar ratio of 0.83.

Novel core–shell-like nanocomposites xCu@Cu2O/MgAlO-rGO through an in situ self-reduction strategy for highly efficient reduction of 4-nitrophenol

Liguang Dou,Yanna Wang,Yangguang Li,Hui Zhang

A series of novel hierarchical nanocomposite catalysts xCu@Cu2O/MgAlO-rGO were fabricated by calcination of CuxMg3−xAl-LDH/rGO precursors (LDH: layered double hydroxide, rGO: reduced graphene oxide, and x = 0.5, 1.0, and 1.5), obtained by a facile citric acid-assisted coprecipitation route, under a N2 flow upon in situ self-reduction of lattice atomic-dispersed Cu2+ by rGO. Systematic characterization reveals highly dispersed core–shell-like Cu@Cu2O nanoparticles near the border between vertically interconnected mixed oxide MgAlO nanoplates and rGO layers. All the obtained catalysts show extraordinary catalytic performances for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) at room temperature. The 1.0Cu@Cu2O/MgAlO-rGO shows the highest activity for complete conversion of 4-NP with an apparent rate constant (kapp) of 55.3 × 10−3 s−1, a normalized rate constant (knor) of 14 497 s−1 g−1 on an active Cu content, and an unprecedented recycling stability for 25 successive cycles, which are superior to those of the recently reported Cu- and Co-based metal nanoparticles and even compared favourably with those of the most active noble metal catalysts. The superior activity of 1.0Cu@Cu2O/MgAlO-rGO can be attributed to the highly dispersed core–shell-like Cu@Cu2O nanoparticles and the greatly enhanced four-phase synergistic effect among Cu, Cu2O, MgAlO and rGO upon calcination. Moreover, 1.0Cu@Cu2O/MgAlO-rGO shows an excellent efficiency in the fixed bed system for the treatment of simulated industrial effluents containing nitrophenols and organic dyes. The present cost-effective, highly efficient and reusable non-noble metal nanocatalyst would open a new pathway for future water remediation.

Stable Cu/Cu2O/CuN3@NC Catalysts for Aqueous Phase Reforming of Methanol

Minglei Lu,Zhuoyu Zheng,Weiwei Lu,Haiping Zhu,Junwei Liao,Yuxin Ge,Xueer Huang,Qian Zhang,Jiajin Li,Yiyuan Zhou,Xiaoping Wu,Baozhu Chen,Chunxiao Yang,Xitang Qian,Minhua Shao,Tiejun Wang

Aqueous-phase reforming of methanol represents a promising avenue for hydrogen (H2) production. However, developing highly efficient and low-cost nonprecious catalysts remains challenging. Here, we report the synthesis of Cu-based catalysts with Cu, Cu2O, and CuN3 nanoparticles anchored on the nitrogen-doped carbon, forming Cu0/Cu+/Cu-N3 active sites. This catalyst achieves a H2 production rate of 140.1 μmol/gcat/s at 210 °C, which is several times to 2 orders of magnitude higher than that of Cu-, Ni-, even Pt-based catalysts, demonstrating excellent long-term stability over 350 h at 210 °C. A mechanism investigation reveals that the Cu-N3 site facilitates water dissociation into *OH and improves *CO and *OH conversion, leading to enhanced CO conversion and H2 production kinetics.

Synthesis of hollow Cu/Cu2O/Cu2S nanotubes for enhanced electrocatalytic hydrogen evolution

Yunrui Wei,Weidong He,Pengxiao Sun,Jiangmei Yin,Xiaolong Deng,Xijin Xu

Cu/Cu 2 O/Cu 2 S nanotubes (NT) with rough-surfaces and hollow heterostructure structures have been synthesized by sulfurizing the as-prepared Cu/Cu 2 O nanowires (NWs). The Cu/Cu 2 O/Cu 2 S NT electrode exhibits excellent hydrogen evolution reaction (HER) performance with low onset overpotential of 48 mV and a Tafel slope of 107 mV dec −1 in acidic solution. Furthermore, the overpotentials are only ~86 and ~214 mV to achieve current densities of 10 and 100 mA cm −2 . The impressive catalytic performance of Cu/Cu 2 O/Cu 2 S NT toward HER can be attributed to the unique rough-surfaces, hollow structure, and the synergistic effect between multiple atoms and ions.

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

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