Hydrothermal Synthesis of Three-Dimensional Hierarchical CuO Butterfly-Like Architectures

Photoelectrochemical Water-Splitting Using CuO-Based Electrodes for Hydrogen Production: A Review

The cost-effective, robust, and efficient electrocatalysts for photoelectrochemical (PEC) water-splitting has been extensively studied over the past decade to address a solution for the energy crisis. The interesting physicochemical properties of CuO have introduced this promising photocathodic material among the few photocatalysts with a narrow bandgap. This photocatalyst has a high activity for the PEC hydrogen evolution reaction (HER) under simulated sunlight irradiation. Here, the recent advancements of CuO-based photoelectrodes, including undoped CuO, doped CuO, and CuO composites, in the PEC water-splitting field, are comprehensively studied. Moreover, the synthesis methods, characterization, and fundamental factors of each classification are discussed in detail. Apart from the exclusive characteristics of CuO-based photoelectrodes, the PEC properties of CuO/2D materials, as groups of the growing nanocomposites in photocurrent-generating devices, are discussed in separate sections. Regarding the particular attention paid to the CuO heterostructure photocathodes, the PEC water splitting application is reviewed and the properties of each group such as electronic structures, defects, bandgap, and hierarchical structures are critically assessed.

Soft-template-assisted synthesis: a promising approach for the fabrication of transition metal oxides

The past few decades have witnessed transition metal oxides (TMOs) as promising candidates for a plethora of applications in numerous fields. The exceptional properties retained by these materials have rendered them of paramount emphasis as functional materials. Thus, the controlled and scalable synthesis of transition metal oxides with desired properties has received enormous attention. Out of different top-down and bottom-up approaches, template-assisted synthesis predominates as an adept approach for the facile synthesis of transition metal oxides, owing to its phenomenal ability for morphological and physicochemical tuning. This review presents a comprehensive examination of the recent advances in the soft-template-assisted synthesis of TMOs, focusing on the morphological and physicochemical tuning aided by different soft-templates. The promising applications of TMOs are explained in detail, emphasizing those with excellent performances.

N,N′-di-caboxy methyl perylene diimide (PDI) functionalized CuO nanocomposites with enhanced peroxidase-like activity and their application in visual biosensing of H2O2 and glucose

Perylene diimide functionalized CuO nanobelts were demonstrated to possess higher intrinsic peroxidase-like activity than that of pure CuO nanobelts.

3D Cathodes of Cupric Oxide Nanosheets Coated onto Macroporous Antimony-Doped Tin Oxide for Photoelectrochemical Water Splitting

Cupric oxide (CuO), a narrow-bandgap semiconductor, has a band alignment that makes it an ideal photocathode for the renewable production of solar fuels. However, the photoelectrochemical performance of CuO is limited by its poor conductivity and short electron diffusion lengths. Herein, a three-dimensional (3D) architecture consisting of CuO nanosheets supported onto transparent conducting macroporous antimony-doped tin oxide (mpATO@CuONSs) is designed as an excellent photocathode for promoting the hydrogen evolution reaction (HER). Owing to the 3D structure affording superior light-harvesting characteristics, large contact areas with the electrolyte, and highly conductive pathways for separation and transport of charge carriers, the mpATO@CuONSs photocathode produces an impressively high photocurrent density of -4.6 mA cm^-2 at 0 V versus the reversible hydrogen electrode (RHE), which is much higher than that of the CuONSs array onto planar FTO glass (-1.9 mA cm^-2 ).

Facile fabrication and enhanced sensing properties of hierarchically porous CuO architectures

Hierarchically porous CuO architectures were successfully fabricated via copper basic carbonate precursor obtained with a facile hydrothermal route. The shape of the precursor is preserved after its conversion to porous CuO architectures by calcination. The obtained CuO are systemically characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller N(2) adsorption-desorption analysis. The results reveal that hierarchical CuO microspheres are monoclinic structure and are assembled by porous single-crystal sub-microplatelets. The Brunauer-Emmett-Teller N(2) adsorption-desorption analysis indicates that the obtained CuO has a surface area of 12.0 m(2)/g with pore size of around 30 nm. The gas sensing performance of the as-prepared hierarchical CuO microspheres were investigated towards a series of typical organic solvents and fuels. They exhibit higher sensing response than that of commercial CuO powder. Their sensing properties can be further improved by loading of Ag nanoparticles on them, suggesting their potential applications in gas sensors.