Characterization of Some Physical and Photocatalytic Properties of CuO Nanofilms Synthesized by a Gentle Chemical Technique

Abstract

Pure and Li-doped CuO nanofilms were synthesized on heated glass substrates using the spray-pyrolysis technique. The deposited pure CuO nanofilms were achieved at a precursor molarity of 0.2 M using a solution prepared from copper nitrate trihydrate (Cu(NO3)2·3H2O). Doped Li–CuO nanofilms were obtained using several doping concentrations (3, 6, 9, 12 and 15%) by adding a solution prepared from lithium nitrate (LiNO3). The pure and Li–CuO samples were investigated by different techniques. XRD revealed three dominant peaks (-111), (111) and (211), which are the properties of monoclinic CuO. The increase in Li-doping concentration showed the appearance of other peaks of low intensities detected at 2θ ranging from 49 to 68°. AFM images showed a textured and inhomogeneous surface composed of spherical grains whose size decreased with increasing Li doping. UV–visible spectroscopy showed that the CuO samples were of low transparency; the transmittance was less than 50%. The band-gap energy determined from Tauc’s equation plot increased from 2.157 to 3.728 eV with the increase in Li doping. These values correspond well to the band gap of semiconducting CuO. The photocatalytic properties were accelerated by Li doping, as revealed by the discoloration of aqueous methylene-blue (MB) solution under ultraviolet irradiation.

Influence of Al Doping on the Physical Properties of CuO Thin Films

“…The electrical resistivity data obtained in this study are comparable to those obtained by Ziad T. Khodair et al [20].…”

“…This can be attributed to two main factors: (i) when the Al +3 ions occupy the Cu +2 ion sites, an additional number of free electrons are created; (ii) the significant reduction in size of the grains generates a huge number of frontiers, and hence an improvement in transport time and/or electron collisions. The electrical resistivity data obtained in this study are comparable to those obtained by Ziad T. Khodair et al [20].…”

“…The CuO films, pure or Al-doped, needed for the experiments presented herein have all been grown via chemical spray pyrolysis. An eco-friendly, cost-efficient process, it is a method of thin film growth consisting of spraying a solution onto a heated surface in order for the constituents to react and create the desired chemical compound [15][16][17][18][19][20]. All the initial chemical reagents are chosen so that the products, other than the desired chemical compound, are volatile at the deposition temperature or during annealing.…”

Synthesis and Investigation of Pure and Cu-Doped NiO Nanofilms for Future Applications in Wastewater Treatment Rejected by Textile Industry

“…It is to be noted that the blue color of MB solution disappears after 300 min, especially for high Cu-doping (Figure 8). As discussed in our previous work [54,55] and reported by Khan et al [56,57], the photocatalysis carried out in atmospheric air show that the role of the nanoparticles of the films and of the oxygen O 2 is essential for the degradation of MB dye solution.…”

CuO Nanorods Immobilized Agar-Alginate Biopolymer: A Green Functional Material for Photocatalytic Degradation of Amaranth Dye

“…Thus, a blue shift was observed in CuO which suggests that CuO NPs are functionalized with the biopolymer matrix. Further, the energy band gap value is calculated by using Tauc’s plot equation given below [ 44 ]: where α is the absorption coefficient, h is Plank’s constant, v is frequency of different radiations, A is constant and n is constant (value depends on type of band transitions: ½ is direct transitions and 1 is indirect transitions). CuO has direct transition and the value of n is 1/2 [ 45 ].…”