Facile Electrochemical Synthesis of Hexagonal Cu2O Nanotube Arrays and Their Application

Controlled Synthesis and Uniform Anchoring of Hollow CuxO Nanocubes on Carbon Nanofiber for Enhanced Se(S)-Se(S) Bond Activation

In the present study, we fabricated hollow cubic Cu_xO nanoparticles (∼23 nm) incorporated with CNF (HC-Cu_xO/CNF) through controlled thermal oxidation of solid cubic Cu₂O nanoparticles (∼21 nm) supported on carbon nanofibers (SC-Cu₂O/CNF) under airflow, exploiting the nanoscale Kirkendall effect. These hollow Cu_xO nanocubes with increased surface areas exhibited outstanding catalytic activity for unsymmetrical chalcogenide synthesis under ligand-free conditions.

Cu2O/Ti3C2Txnanocomposites for detection of triethylamine gas at room temperature

Triethylamine gas is one of the harmful volatile organic compounds for human health and the ecological environment. Therefore, in order to prevent the detrimental effects of triethylamine gas, it has greatly requirement to be accurately detected. Unfortunately, Cu₂O has a low triethylamine gas response and slow recovery. Because of this, we prepared Cu₂O/Ti₃C₂T_xnanocomposites by a facile ultrasonication technique. Cu₂O is uniformly dispersed on the surface and interlayers of multilayer Ti₃C₂T_xto form a stable hybrid heterostructure. The optimized Cu₂O/Ti₃C₂T_xnanocomposite sensor's response to 10 ppm triethylamine at room temperature is 181.6% (∣R_g-R_a∣/R_a × 100%). It is 3.5 times higher than the original Cu₂O nanospheres (52.1%). Moreover, due to the characteristics of high carrier migration rate and excellent conductivity of Ti₃C₂T_x, the response recovery rate (1062 s/74 s) of Cu₂O/Ti₃C₂T_xcomposites is greatly improved than pristine Cu₂O (3169 s/293 s). In addition, Cu₂O/Ti₃C₂T_xnanocomposites sensor also shows excellent repeatability, outstanding selectivity, and long-term stability. Thus, the Cu₂O/Ti₃C₂T_xnanocomposites sensor has broad application prospects for detecting triethylamine gas at room temperature.

Hydroxyl ions: flexible tailoring of Cu2O crystal morphology

The precise control architectures of Cu2O crystals are very crucial, which have a significant influence on their various performances. Herein, Cu2O crystals with diverse architectures were achieved via finely adjusting the concentration of NaOH. The intriguing results showed that the addition of specific amounts of OH- to the solution was crucial to tailor the morphology and size of the resulting microcrystals. We observed the evolution of the shapes of the Cu2O microcrystals, which change from a rhombic dodecahedron to spherical, octahedral-like and then to hexapod upon the increase in the NaOH concentration. Adjusting the volume of NaOH added provides a means to vary the particle size. Furthermore, density functional theory (DFT) may reveal that OH- ions serve as an efficient coordination agent selectively adsorbing onto different crystal faces of Cu2O crystals modifying the crystal energies, inducing the structure anisotropy on crystal growth. This work reveals that an effective and facile strategy has been developed for morphology-control of Cu2O crystals.

Designing bioinspired coral-like structures using a templateless electropolymerization approach with a high water content

Here, with the aim of obtaining densely packed porous nanostructures of various shape using templateless electropolymerization in organic solvent (dichloromethane), original thieno[3,4- b]thiophene-based monomers with different substituents are studied. First of all, the adding of water in solution has a huge influence on the formation of porous structures because a much higher amount of gas (O₂ and/or H₂) is released. Rigid substituents such as aromatic groups have a beneficial effect on the formation of nanotubular structures contrary to flexible ones such as alkyl chains. Special results are obtained with the pyrene substituent (Thieno-Pyr). With this monomer, coral-like structures are obtained. These structures are obtained by the formation first on long nanotubular structures and their sagging due to their weight. Then, the released gas is trapped inside these structures leading to huge craters. These exceptional surfaces could be used in the future in various potential applications such as in drug delivery, cell growth, sensors, optical devices or surface adhesion. This article is part of the theme issue 'Bioinspired materials and surfaces for green science and technology (part 2)'.

Enhancing resistive-type hydrogen gas sensing properties of cadmium oxide thin films by copper doping

The pure and Cu-doped CdO thin films with various doping concentrations (0.5 to 2 wt%) were deposited on amorphous glass substrates by a chemical spray pyrolysis technique for hydrogen gas sensor application.

Novel synthesis of a Cu2O–graphene nanoplatelet composite through a two-step electrodeposition method for selective detection of hydrogen peroxide

Optimized electrodeposition technique for the synthesis of Cu₂O–graphene composite for H₂O₂sensing.

Hollow CuxO (x = 2, 1) micro/nanostructures: synthesis, fundamental properties and applications

In this review, we comprehensively summarize the important advances in hollow Cu_xO micro/nanostructures, including the universal synthesis strategies, the interfacial Cu–O atomic structures as well as the intrinsic properties, and potential applications. Remarks on emerging issues and promising research directions are also discussed.

Organic–inorganic hybrid polyoxometalate and its graphene oxide–Fe3O4nanocomposite, synthesis, characterization and their applications as nanocatalysts for the Knoevenagel condensation and the synthesis of 2,3-dihydroquinazolin-4(1H)-ones

Organic–inorganic hybrid of H₆Cu₂[PDA]₆[SiW₉Cu₃O₃₇]·12H₂O (HybPOM), was synthesized and grafted on graphene oxide decorated with Fe₃O₄. The structures of HybPOM and GO@Fe₃O₄@HybPOM nanocomposites were characterized and their catalytic activities investigated.

Cu2O NPs decorated BiPO4 photo-catalyst for enhanced organic contaminant degradation under visible light irradiation

The surface of BiPO₄ was decorated with Cu₂O nanoparticles (NPs) (hereafter designed as Cu₂O/BiPO₄) via an interfacial self-assembly method.

Co/Cu2O assisted growth of graphene oxide on carbon nanotubes and its water splitting activities

Graphene oxide (GO) is formed in the fabrication process of CNT/Co materials from the exfoliated tube wall of CNT.

Efficient photocatalysts from polymorphic cuprous oxide/zinc oxide microstructures

Polymorphic Cu₂O/ZnO were synthesized by a mild solution method for photocatalysts, displaying enhanced photocatalytic activity. A pseudo cell was launched to demonstrate the potential charge-separation mechanism.

Novel Cu₂O quantum dots coupled flower-like BiOBr for enhanced photocatalytic degradation of organic contaminant

Here we report a highly efficient novel photocatalyst consisting of Cu2O quantum dots (QDs) incorporated into three-dimensional (3D) flower-like hierarchical BiOBr (hereafter designated QDs-Cu2O/BiOBr), which were synthesized via a simple reductive solution chemistry route and applied to decontaminate the hazardous wastewater containing phenol and organic dyes. The deposition of Cu2O QDs onto the surface of the BiOBr was confirmed by structure and composition characterizations. The QDs-Cu2O/BiOBr composites exhibited superior activity for organic contaminant degradation under visible light and 3 wt% QDs-Cu2O/BiOBr composite showed the highest degrade rate for phenol and methylene blue (MB), which was 11.8 times and 1.4 times than that of pure BiOBr, indicated the QDs-Cu2O/BiOBr composite has the great potential application in purifying hazardous organic contaminant. The incorporated Cu2O QDs played an important role in improving the photocatalytic performance, due to the enhancement of visible light absorption efficiency as well as the efficient separation of the photogenerated charge carriers originating from the intimately contacted interface and the well-aligned band-structures, which was confirmed by the results of PL, photocurrent and EIS measurements. The possible photocatalytic mechanism was proposed based on the experiments and theoretical results.

Controllable synthesis of Cu2O hierarchical nanoclusters with high photocatalytic activity

Cu₂O hierarchical nanoclusters which are made up of many 2–7 nm grains were synthesized and have high photocatalytic activity.

Optimization for visible light photocatalytic water splitting: gold-coated and surface-textured TiO2 inverse opal nano-networks

A gold nanoparticle-coated and surface-textured TiO2 inverse opal (Au/st-TIO) structure that provides a dramatic improvement of photoelectrochemical hydrogen generation has been fabricated by nano-patterning of TiO2 precursors on TiO2 inverse opal (TIO) and subsequent deposition of gold NPs. The surface-textured TiO2 inverse opal (st-TIO) maximizes the photon trapping effects triggered by the large dimensions of the structure while maintaining the adequate surface area achieved by the small dimensions of the structure. Au NPs are incorporated to further improve photoconversion efficiency in the visible region via surface plasmon resonance. st-TIO and Au/st-TIO exhibit a maximum photocurrent density of ∼0.58 mA cm(-2) and ∼0.8 mA cm(-2), which is 2.07 and 2.86 times higher than that of bare TIO, respectively, at an applied bias of +0.5 V versus an Ag/AgCl electrode under AM 1.5 G simulated sunlight illumination via a photocatalytic hydrogen generation reaction. The excellent performance of the surface plasmon-enhanced mesoporous st-TIO structure suggests that tailoring the nanostructure to proper dimensions, and thereby obtaining excellent light absorption, can maximize the efficiency of a variety of photoconversion devices.