Remarkable Enhancementof TiO₂–NActivity under Visible Light Exposure by Codoping with Cu from ElectroplatingWastewater for Degradation of Amoxicillin Residual in Water Media

The development of photocatalysts with wastewater management has drawn the attention of many scientists. This research investigates the enhancement activity of TiO₂ photocatalyst codoped with N and Cu from urea and electroplating wastewater respectively as sources, for photodegradation of amoxicillin (AMX) residual in water media. The synthesis of codoped TiO₂ photocatalyst has been done through sol–gel process to determine the optimal concentration for each single dopant of Cu and N based on the highest band gap energy (<i>E</i>_g) narrowing and their performance in photodegradation of AMX. The synthesized photocatalysts are investigated by material characterization. The effect of the double dopants on the photocatalyst activity was examined through photodegradation of AMX. The optimum N and Cu dopant concentrations were 30 and 0.60 wt %, giving <i>E</i>_g values of 2.88 and 2.93 eV, respectively. This ratio is used to synthesize the codoping photocatalyst that significantly reduces <i>E</i>_g in 2.74 eV with AMX photodegradation reaching 95.76%. This dwindling of band gap energy in codoping photocatalyst could be widely applied in visible light exposure for the photodegradation of AMX having 20 mg/L in 50 mL over TiO₂–N,Cu (30:0.6 wt %) using 1 g/L of the photocatalyst dose, solution pH 5, and 120 min irradiation time.