Preparation of ZnO Photocatalyst for the Efficient and Rapid Photocatalytic Degradation of Azo Dyes

Abstract

Zinc oxide (ZnO) photocatalysts were synthesized by sol–gel method using zinc acetate as precursor for degradation of azo dyes under UV irradiation. The resultant samples were characterized by different techniques, such as XRD, SEM, and EDX. The influence of preparation conditions such as calcination temperature and composite ratio on the degradation of methyl orange (MO) was investigated. ZnO prepared with a composite ratio of 4:1 and calcination temperature of 400 °C exhibited 99.70% removal rate for MO. The effect of operation parameters on the degradation was also studied. Results showed that the removal rate of azo dyes increased with the increased dosage of catalyst and decreased initial concentration of azo dyes and the acidic condition is favorable for degradation. Furthermore, the kinetics and scavengers of the reactive species during the degradation were also investigated. It was found that the degradation of azo dyes fitted the first-order kinetics and superoxide ions were the main species. The proposed photocatalyst can efficiently and rapidly degrade azo dyes; thus, this economical and environment-friendly photocatalyst can be applied to the treatment of wastewater contaminated with synthetic dyes.

Paper-Based Nanoplatforms for Multifunctional Applications

“…ZnO and TiO 2 have been largely used in photocatalysis, in which the latter continues to be one of the most widely embraced photocatalysts nowadays [12,31,65]. ZnO and TiO 2 are wide bandgap materials, which makes them active under UV light irradiation, and thus it is expectable that both materials have higher photocatalytic activity under UV than under solar radiation [31].…”

Enhanced Red Emission in Ultrasound‐Assisted Sol‐Gel Derived ZnO/PMMA Nanocomposite

“…e presence of NH 3 (3) and ultrasound irradiation inhibited fast aggregation of neutrally charged Zn (OH) 2 into amorphous solids. Furthermore, ultrasonication induced the condensation of Zn(OH) 2 into ZnO nanocrystals according to (4). is process took part homogeneously in all the volume of reaction forming spherical ZnO NPs when the concentration of the zinc precursor was low, for example, 0.02 or 0.05 M. It was reported that the presence of Zn(OH) 2 is a key factor for the growth of ZnO nanocrystals into hexagonal nanorods by adding Zn(OH) x complexes onto positively charged, Zn-terminated (0001) planes [22][23][24].…”

“…Zinc oxide (ZnO) is a n-type semiconducting material with a great application potential as electron conduit in (opto) electronic devices [1,2], photocatalysts [3,4], and photoluminescence materials [5,6]. ere are several methods for the synthesis of ZnO nanostructures, including sol-gel method, controlled precipitation, solvothermal techniques, microemulsion, and sonochemical treatments [7].…”

Efficient photocatalytic degradation of Acid Red 57 using synthesized ZnO nanowires

“…[23] Figure 13 shows the degradation rate in the presence and absence of the scavengers. [23] Figure 13 shows the degradation rate in the presence and absence of the scavengers.…”