3-D/3-D Z-Scheme Heterojunction Composite Formed by Marimo-like Bi2WO6 and Mammillaria-like ZnO for Expeditious Sunlight Photodegradation of Dimethyl Phthalate

Abstract

In the present work, we assessed the photocatalytic performance of the new 3-D/3-D Z-scheme heterojunction composite for the degradation of dimethyl phthalate (DMP). The composite was composed by marimo-like Bi2WO6 and mammillaria-like ZnO which was named BWZ. The composite was successfully fabricated using a hydrothermal-precipitation method and analyzed via different characterization techniques. Under natural sunlight irradiation, the optimal composite with 20 wt% of Bi2WO6/ZnO (20-BWZ) exhibited a photodegradation rate constant of 0.0259 min−1, which reached 2.3 and 5.9-folds greater than those of pure ZnO (0.0112 min−1) and Bi2WO6 (0.0044 min−1), respectively. That was predominantly attributed to the formation of a Z-scheme photocatalytic system in the as-synthesized composite reduced the charge carrier recombination and accelerated the photoactivity. Transient photocurrent response and electrochemical impedance spectroscopy analyses were performed to confirm this conclusion. The reusability test indicated that the 20-BWZ had no significant deactivation after four runs, which inferred good stability of the as-prepared composite. Furthermore, the quenching test demonstrated that the photogenerated hole, superoxide anion radical and hydroxyl radical were all involved in the photodegradation of DMP, among which •OH was the principal reactive species. This work revealed that the as-prepared BWZ composites have great potential applications for the degradation of refractory pollutants in the environmental remediation field.

A Fresh Perspective on the Impact of ZnTiO3 Coupling on the Microstructure and Photocatalytic Properties of TiO2 Fabricated at Varied Temperatures

“…Remarkably, the PL spectra align with this prediction, with the principal peak of PT-470 indeed located near 400 nm. Peaks between 450-470 nm originate from the recombination of photogenerated electrons and holes due to oxygen vacancies and surface defects [43,44]. This resonance validates the theoretical projection.…”

Increasing the photocatalytic degradation rate of a rGO/PVA nanocomposite decorated with ZnO nanoparticles

“…In a nutshell, the ˙O 2 − and ˙OH species contribute to synchronous photo-decomposition of the MB dye. 42–45…”

“…In a nutshell, the O 2 À and OH species contribute to synchronous photo-decomposition of the MB dye. [42][43][44][45] Fig. 8a illustrates the removal efficiency of rGO for the MB dye versus time, as the initial MB concentration increased from 5 to 20 ppm.…”

In situ dynamic monitoring of the photodegradation process through differential absorption spectroscopy

“…To analyse the photodegradation efficiency, the reaction rate is calculated after determining the concentration changes of the contaminant. 26 However, traditional contaminant detection methods, such as absorption spectrometry 27–29 and liquid chromatography, 30 require time to make the measurement, costs associated with purchasing of equipment and a significant area of space occupied by the equipment. Furthermore, in these conventional methods, the photodegradation reaction and concentration-detection experiments are operated separately.…”