Ag/Cr-TiO2 and Pd/Cr-TiO2 for Organic Dyes Elimination and Treatment of Polluted River Water in Presence of Visible Light

Mariana Alejandra Gil; Julie J Murcia; Mónica Hernández-Laverde; Nicola Morante; Diana Sannino; Vincenzo Vaiano

doi:10.3390/nano13162341

Ag/Cr-TiO₂ and Pd/Cr-TiO₂ for Organic Dyes Elimination and Treatment of Polluted River Water in Presence of Visible Light

Nanomaterials (Basel). 2023 Aug 15;13(16):2341. doi: 10.3390/nano13162341.

Authors

Mariana Alejandra Gil¹, Julie J Murcia¹, Mónica Hernández-Laverde^{1

2}, Nicola Morante³, Diana Sannino³, Vincenzo Vaiano³

Affiliations

¹ Grupo de Catálisis, Universidad Pedagógica y Tecnológica de Colombia UPTC, Avenida Central del Norte, Tunja 150002, Boyacá, Colombia.
² Grupo GIA UNAD, Escuela de Ciencias Básicas Tecnología e Ingeniería, Universidad Nacional Abierta y a Distancia UNAD, Sogamoso 152217, Boyacá, Colombia.
³ Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy.

Abstract

In this work, photocatalytic materials constituted by Cr-doped TiO₂ (Cr-TiO₂) decorated with noble metals show high effectiveness in the mineralization of Acid Orange 7 (AO7) and in the disinfection of real river water. The materials were firstly obtained by sol-gel method to get Cr-TiO₂ that was subsequently modified by photochemical deposition of Ag or Pd nanoparticles (Ag/Cr-TiO₂, Pd/Cr-TiO₂). Chemical-physical characterization results evidenced that the noble metals were homogeneously distributed on the Cr-TiO₂ surface. By using Pd(0.25%)/Cr-TiO₂, the AO7 discoloration efficiency was about 91.4% after only 60 min of visible irradiation, which can be due to the lowest band gap of this material. Moreover, nitrates, chlorides, total hardness, and coliform bacteria content significantly decreased after the treatment of real river water samples (that is contaminated by industrial and domestic effluents) under UV and visible light irradiation in the presence of TiCrOx decorated with noble metals. One hundred percent of elimination rate for E. coli, total coliforms, and other enterobacteriaceae (without regrowth) was achieved by using Ag/Cr-TiO₂ as photocatalyst.

Keywords: bacteria elimination; dye; noble metals decorated TiCrOx photocatalysts; visible light photocatalysts.

Grants and funding

This work was funded by the Ministerio de Ciencia, Tecnología e Innovación—Minciencias and Ministerio de Salud y Protección Social, Project 110991891727, and Universidad Pedagógica y Tecnológica de Colombia (UPTC) Project SGI 3393.