Optimization of Facile Synthesized ZnO/CuO Nanophotocatalyst for Organic Dye Degradation by Visible Light Irradiation Using Response Surface Methodology

Abstract

In this study, we aimed to observe how different operating parameters influenced the photocatalytic degradation of rhodamine B (RhB, cationic dye) and bromophenol Blue (BPB, anionic dye) over ZnO/CuO under visible light irradiation. This further corroborated the optimization study employing the response surface methodology (RSM) based on central composite design (CCD). The synthesis of the ZnO/CuO nanocomposite was carried out using the co-precipitation method. The synthesized samples were characterized via the XRD, FT-IR, FE-SEM, Raman, and BET techniques. The characterization revealed that the nanostructured ZnO/CuO formulation showed the highest surface area (83.13 m2·g−1). Its surface area was much higher than that of pure ZnO and CuO, thereby inheriting the highest photocatalytic activity. To substantiate this photocatalytic action, the investigative analysis was carried out at room temperature, associating first-order kinetics at a rate constant of 0.0464 min−1 for BPB and 0.07091 min−1 for RhB. We examined and assessed the binary interactions of the catalyst dosage, concentration of dye, and irradiation time. The suggested equation, with a high regression R2 value of 0.99701 for BPB and 0.9977 for RhB, accurately matched the experimental results. Through ANOVA we found that the most relevant individual parameter was the irradiation time, followed by catalyst dose and dye concentration. In a validation experiment, RSM based on CCD was found to be suitable for the optimization of the photocatalytic degradation of BPB and RhB over ZnO/CuO photocatalysts, with 98% degradation efficiency.

Green Synthesis of TiO2 Nanoparticles Using Acorus calamus Leaf Extract and Evaluating Its Photocatalytic and In Vitro Antimicrobial Activity

“…The kinetic data were calculated using pseudo-first-order and pseudo-second-order model equations. The derived pseudo-first-order kinetic model for solution/solid systems has the following linear form [53,54]:…”

A comparative study of Cu-anchored 0D and 1D ZnO nanostructures for the reduction of organic pollutants in water

“…Aer the analysis of positions and comparative intensities of the diffracted peaks, the occurrence of single-phase hexagonal wurtzite of ZnO with space group P6 3 mc was established. 56 The XRD patterns of the ZnO nanostructures were similar, except for the variation in line broadening due to the change in the morphologies. The pristine ZnO nanostructures exhibit well-dened XRD peaks at 2q ¼ 31.8 , 34.5 , 36.3 , 47.6 , 56.7 , 62.9 , 66.5 , 68 , 69.2 , 72.6 , and 77 , which are corresponding to the (100), (002), ( 101), ( 102), ( 110), ( 103), ( 200), ( 112), ( 201), (004), and (202) crystal planes, respectively.…”

Impact of Diverse Parameters on the Physicochemical Characteristics of Green-Synthesized Zinc Oxide–Copper Oxide Nanocomposites Derived from an Aqueous Extract of Garcinia mangostana L. Leaf

“…In the case of hetero-structured NCs, the bands may overlap [41]. Moreover, the energy bandgap of ZnO-CuO NCs involved coupled transitions from the O 2 (2p) valance band to zinc(II) (3d 1 -4s) and copper(II) (3d 9 ) ion conduction bands [42]. Additionally, the presence of CuO, acting as an impurity, reduces the energy bandgap in ZnO-CuO NCs [6,23], and this effect became more significant with higher concentrations of mangosteen leaf aqueous extract and higher calcination temperatures, suggesting the presence of a higher amount of CuO in ZnO-CuO NCs.…”

“…The high PL indicates significant recombination of charge carriers, while low PL suggests maximum charge separation, which is beneficial for the photo-degradation of the processes [6,21,23,42]. The emission peaks of the ZnO-CuO NCs in the violet region (390-405 nm) were attributed to near-band-edge (NBE) emission caused by the defect states in ZnO and CuO [6,21,42].…”