Photocatalytic removal of patent blue V dye on Au-TiO 2 and Pt-TiO 2 catalysts

Abstract

In this work it was studied the efficiency of a photocatalytic process for the removal of Patent blue V. This dye is very difficult to remove by conventional treatments such as adsorption or coagulation therefore the photocatalytic process is a very interesting alternative for the removal this dye mainly because it does not require expensive oxidants and it can be carried out at mild temperatures and pressures. In this work it was tested the efficiency of Au-TiO 2 and Pt-TiO 2 photocatalysts in the Patent blue V removal. The Au-TiO 2 catalysts were prepared by two different methods: chemical reduction and photochemical deposition; Pt-TiO 2 catalysts were obtained only by photochemical deposition. In the synthesis of the catalysts prepared by photochemical deposition, it was evaluated the influence of some parameters, such as deposition time and the intensity of the light source over the physicochemical properties and photocatalytic activity of the materials obtained. An analysis of the effect of the catalyst dosage and initial Patent blue V concentration over the dye degradation efficiency was also attempted. In general, it was observed that the presence of Au or Pt on TiO 2 enhances the Patent blue V photodegradation; it was found that noble metal particle size and distribution on TiO 2 surface are important factors influencing the dye removal. The highest dye degradation was obtained over the 2 Au-TiO 2 catalyst prepared by photochemical deposition, using high light intensity and 15 minutes of deposition time during the synthesis. A discoloration and a total organic carbon (TOC) removal of 93 and 67% respectively, were obtained over this material after 180 minutes of UV irradiation. These values are higher than that the obtained on S-TiO 2 (discoloration and TOC removal of about 25% and 3%, respectively).

Liquid-Plasma Hydrogenated Synthesis of Gray Titania with Engineered Surface Defects and Superior Photocatalytic Activity

“…and nonmental (N, S, I, etc.) doping, artificial crystal structure modification, and carbonaceous nanomaterial compositing (carbon nanotubes, graphene, and fullerenes) [4][5][6][7][8][9][10]. Nevertheless, the visible-light energy conversion remains insufficient due to little solar light absorption and many carrier-recombination centers [11,12].…”

Facile Synthesis of Cu Quantum Dots‐TiO2 Nanosheets Schottky Junction and Improved Photocatalytic Degradation Activity

“…Moreover, the high charge recombination efficiency of TiO 2 also lead to a low quantum yield and a low photocatalytic efficiency, which greatly limits the actual application . Therefore, cation doping, anion doping, semiconductor combination and noble metal modification are often used to enhance the photocatalytic activity of TiO 2 . For the former several methods, the activity enhancement still remains limited.…”

“…For the former several methods, the activity enhancement still remains limited. Noble metals such as Au, Ag and Pt can significantly improve the photocatalytic activity of titanium dioxide . However, the high cost is not suitable for wide practical application.…”

Fluorinated and Platinized Titania as Effective Materials in the Photocatalytic Treatment of Dyestuffs and Stained Wastewater Coming from Handicrafts Factories

“…Photocatalysis has been recognized as an eco-friendly, less expensive, non-selective and effective alternative in the treatment of effluents. Thus, a number of studies have demonstrated that heterogeneous photocatalysis is a promising approach of Advanced Oxidation Process in the treatment of dyestuffs in the liquid phase [2][3][4][5][6][7][8][9][10][11]. In most of these studies, lab prepared dyes solutions or synthetic wastewater are employed and only a few researchers have conducted studies by using real industrial wastewater samples [12,13].…”

“…As TiO 2 is the most recognized and employed material in photocatalysis, many efforts have been devoted to improve its effectiveness; thus, noble metal addition [11,18], non-metals doping [19,20], sulfation and fluorination [4,[21][22][23][24][25][26][27][28][29][30] among others have been reported to be suitable alternatives for titania modification. Taking into account that the practical application of TiO 2 is not in the form of dispersions, many studies in this area have been also focused on supported TiO 2 being photolyzed in the presence of a pollutant during a continuous cleaning process [14,16,28,31,32], in these processes the separation of the pollutant from the processed solution at the end of the process it is not necessary.…”