Study of Calcination Temperature Influence on Physicochemical Properties and Photodegradation Performance of Cu2O/WO3/TiO2

Photodegradation is a sustainable green technology that has been studied worldwide, especially for wastewater treatment. The calcination temperature has an important impact on the physicochemical properties of the prepared photocatalysts. In this study, a ternary photocatalyst of Cu2O/WO3/TiO2 (CWT) was successfully synthesized using an ultrasonic-assisted hydrothermal technique, and the calcination temperature was varied from 500 to 800 °C. The characterization outcomes proved that the anatase phase titanium dioxide (TiO2) in the CWT composite transformed to rutile phase TiO2 when the calcination temperature reached 700 °C and 800 °C. The surface area of the CWT composite decreased from 35.77 to 8.09 m2.g−1 and the particle size of the CWT composite increased from 39.11 to 180.25 nm with an increasing calcination temperature from 500 to 800 °C. Photoelectrochemical (PEC) studies showed the charge-transfer resistance of 208.10 Ω, electron lifetime of 32.48 ms, current density of 1.40 mA.cm−2, transient photovoltage of 0.53 V, and p-n heterojunction properties for CWT-500. Reactive Black 5 (RB5) was used as the model pollutant to examine the photodegradation performance. The photodegradation rate of CWT-500 was the highest (0.70 × 10−2 min−1) due to its large surface area, effective separation of photoexcited electron-hole pairs, and low photoexcited charge carrier recombination rate.