Cupric Oxide Nanoleaves for the Oxidative Degradation of Methyl Orange without Heating or Light

Abstract

Low-cost 2D cupric oxide nanoleaves (CuO NLs) are straightforwardly synthesized at room temperature by precipitation varying the addition method of the alkali. No further treatments are necessary to obtain high purity NLs. The effect of the different addition methods of alkali on the morphological, structural, vibrational, and optical properties is studied by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) and ultraviolet−visible (UV−vis) spectroscopies. NLs grown by alkali addition in a dropwise manner are on average 281, 178, and 17 nm long, wide, and thick, respectively, and composed of crystallites of 14 nm corresponding to the crystallographic planes (1̅ 11)/ ( 002) and ( 111)/(200). NLs obtained by this method agglomerate forming flower-like nanostructures, exhibiting indirect band gap energy of 1.21 eV. NLs grown by alkali addition in a one-step manner are on average significantly bigger, being 602, 219, and 26 nm long, wide, and thick, respectively, composed of crystallites of 19 and 16 nm corresponding to the crystallographic planes (1̅ 11)/(002) and ( 111)/(200), respectively. These NLs agglomerate randomly with no predominant form observed, exhibiting indirect band gap energy of 1.39 eV. The addition method of alkali does not influence the average crystallite size of NLs, whereas the microstrain distribution is sensitive to the initial concentration of OH − ions. Our results suggest that an indirect electronic transition between the valence and conduction bands might be more feasible than a direct one. NLs grown by the one-step method present the highest efficiency as catalyst toward catalytic oxidative degradation of the methyl orange dye with no heating and without the influence of light. Finally, this catalyst is easily recycled several times preserving its high catalytic activity.

Practical Coprecipitation Approach for High-Aspect Ratio Cupric Oxide Nanoparticles: A Sustainable Catalytic Platform for Huisgen and Fluorogenic Click Chemistry

“…The diffraction peaks can be clearly indexed to the monoclinic phase of CuO, which is in good accordance with the JCPDS card no. 98-009-2192 (space group C 2̅ c , (a) 4.653 Å, (b) 3.410 Å, (c) 5.108 Å, α = γ = 90° and β = 99.48°). ,− The 2θ diffraction peaks at 32.88, 35.84, 39.00, 46.68, 48.94, 53.88, 58.42, 61.68, 66.44, 68.28, 72.54, and 75.22° correspond to the (110), (002), (111), (1̅12), (2̅02), (020), (202), (1̅13), (022), (220), (311), and (2̅22) lattice planes of the monoclinic phase of CuO, respectively. The monoclinic phase purity is further ascertained by the absence of the characteristic reflection peaks of Cu 2 O and Cu­(OH) 2 .…”

“…In the aforementioned context, cupric oxides in various nanodimensions have been frequently encountered as a heterogeneous catalyst for triazolylation owing to their well-understood physicochemical properties, environmentally friendly appeal, and facile recyclability. − However, controlling the size and shape is a complicated combination of various interlinking factors such as steric confinements, temperature, and electrostatic interactions. Nevertheless, different modes of preparation for CuO nanomaterials have been documented, depending on which, the morphology and size can be fine-tuned. − In terms of simplicity, chemical coprecipitation is by far the most popular method, as it does not employ any reducing agents, support materials, or immobilizing agents. − With this background coupled with our pursuit on azide–alkyne cycloaddition by CuO-based nanocatalysis, − we herein report a simple synthesis of nanorod-like cupric oxide (referred throughout as CuO NRs) by adopting the coprecipitation strategy. Compared to other established procedures, our coprecipitation strategy enables the formation of CuO nanoparticles in high aspect ratio (Table ).…”

Invoking Cathodic Photoelectrochemistry through a Spontaneously Coordinated Electron Transporter: A Proof of Concept Toward Signal Transduction for Bioanalysis

“…Preparation of the CuO Nanoleaves and Their Modification on the ITO Electrode. Based on the previous literature 20 with slight modifications, the cupric oxide (CuO) nanoleaves were synthesized. Specifically, 30 mL of 0.1 M NaOH solution was mixed with 10 mL of 0.1 M CuCl 2 solution under constant stirring in a beaker, and then the mixture was stirred at 30 °C for 5 h to obtain a black precipitate.…”

Structural Disorder of CuO, ZnO, and CuO/ZnO Nanowires and Their Effect on Thermal Conductivity

“…Most of the papers reporting on cupric oxide nanowires focus on enhanced thermal conductivity in nanofluids [4]. This property has been taken advantage of for applications in wastewater treatments [17]. Previous works have demonstrated that thermal conductivity depends on impurities, surface reconstruction, and structural disorder [18,19].…”