“…Wastewater usually contains complex organic pollutants and heavy metals, which make the treatment very difficult and time-consuming. Traditional wastewater purification methods, including the physical adsorption method, membrane filtration, the biological method, and so on, cannot solve the problem completely. − The physical adsorption method just transfers pollutants from one system to another, requiring additional treatment. − The membrane filtration method needs high costs and high energy consumption . The biological method demands suitable pH value, salt content, and temperature of wastewater and is time-consuming. , Therefore, advanced oxide techniques, such as photocatalysis, piezocatalysis, and tribocatalysis, have received increasing attention because these techniques can transform solar energy or mechanical energy into chemical energy using naturally existing clean energy. , The photocatalytic process is used to produce holes and electrons within semiconductors under light irradiation; then, these photogenerated holes and electrons are employed in catalytic reactions .…”