Enhancing the visible-light photoactivity of silica-supported TiO2 for the photocatalytic treatment of pharmaceuticals in water

Autor(es)

de Araujo Gusmao, Carolina ^[1] ; Palharim, Priscila Hasse ^[1] ; Ramos, Bruno ^{[1, 2]} ; Teixeira, Antonio Carlos Silva Costa ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Chem Engn, Escola Politecn, Res Grp Adv Oxidat Proc AdOx, Av Prof Luciano Gualberto, Tr 3, BR-380 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Escola Politecn, Dept Met & Mat Engn, Av Prof Luciano Gualberto, Tr 3, BR-380 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Environmental Science and Pollution Research; OCT 2021.
• Citações Web of Science: 0

Resumo

Catalyst samples based on SiO2-supported TiO2 were prepared with the incorporation of Ag (metal), S (nonmetal), and ZnO@S (semiconductor and nonmetal). The materials were evaluated regarding their morphological, optical, and crystalline properties as well as their photoactivity under visible and ultraviolet light toward the degradation rate of a model emerging pollutant, acetaminophen (ACT). All modified materials exhibited improved performance over the undoped catalyst. The Ag-doped catalyst achieved the largest degradation under visible radiation (about 30% in 120 min), whereas under ultraviolet irradiation, the ZnO@S-doped sample exhibited the best performance (about 62% in 120 min). A Doehlert design was carried out to evaluate the influence of pH and temperature on the photoactivity of Ag-TiO2/SiO2. In addition, the role of each reactive species in the photodegradation reaction was investigated by radical scavenger experiments, and the superoxide radical anion O-2(center dot-) was shown to be the predominant reactive species. The stability of the Ag-TiO2/SiO2 material under ultraviolet and visible light was confirmed after five successive operation cycles, showing a reasonable (about 50%) loss of activity under visible irradiation and a slight improvement (about 13%) under UV light, as a result of the photo-reduction of Ag+. Lastly, the effect of the initial pollutant concentration showed that ACT degradation using Ag-TiO2/SiO2 follows the Langmuir-Hinshelwood kinetics, with intrinsic reaction rate k = 2.71 x 10(-4) mmol L-1 min(-1) under visible-light radiation. (AU)

• Processo FAPESP: 18/21271-6 - Degradação de poluentes de interesse emergente por luz solar: fotorreatores e tratamentos inovadores
• Beneficiário: Antonio Carlos Silva Costa Teixeira
• Modalidade de apoio: Auxílio à Pesquisa - Regular