Photoelectrocatalytic Degradation of Paraquat by Pt Loaded TiO2 Nanotubes on Ti Anodes

Abstract

Nanotube structured TiO2 on Ti surface were prepared in ethylene glycol (Ti/TiO2NTEG) medium by anodic oxidation method with different times and then the plates were calcinated at different temperatures. Non-nanotube structured Ti/TiO2, prepared by thermal oxidation method, and nanotube structured TiO2 on Ti plate in hydrogen fluoride solution were also prepared for comparison. Pt loaded Ti/TiO2NTEG photoanodes were also prepared by cyclic voltammetry method with different cycles and the optimum loaded Pt amount was determined. Photoanodes were characterized by using X-ray Diffraction (XRD), Scanning Electron Microscopy-Energy-Dispersive X-ray Analysis (SEM-EDX), and photocurrent methods. XRD analyses proved that almost all TiO2 is in anatase phase. SEM analyses show that nanotubes and Pt nanoparticles on nanotube surface are dispersed quite homogeneously. The longest nanotubes were obtained in the ethylene glycol medium and the nanotube length increased by increasing applied anodic oxidation time. In addition, a linear correlation between nanotube length and XRD peak intensity was found. Moreover, SEM-EDX and XRD analyses evidence that Pt nanoparticles on nanotube surface are metallic and in cubic structure. Photoelectrocatalytic degradation of paraquat was performed using the prepared photoanodes. Moreover, electrocatalytic and photocatalytic degradations of paraquat were also investigated for comparison, however lower activities were observed. These results evidence that the photoanodes show a significant synergy for photoelectrocatalytic activity.

RETRACTED: SrFexNi1−xO3−δ Perovskites Coated on Ti Anodes and Their Electrocatalytic Properties for Cleaning Nitrogenous Wastewater

“…), limiting their application [6]. Electrocatalysis with the metal oxides anode has attracted widespread concerns in cleaning nitrogenous wastewater owing to its high efficiency, clean oxidation, and easy controllability [7,8]. For example, Okanishi et al [9] used the SnO 2 -modified Pt electrocatalyst to oxidize the ammonia and its activation energy realized 58 kJ mol −1 .…”

Selective Photocatalytic Oxidation of Glycerol and 3-Pyridinemethanol by Nanotube/Nanowire-Structured TiO2 Powders Obtained by Breakdown Anodization

“…The Ti plates were then chemically cleaned in a solution medium containing 4% HF, 31% HNO 3 , and 65% water for 30 s ( Özcan et al, 2018 ). Afterward, the Ti plates were again cleaned in an ultrasonic bath in water for 10 min and dried at room temperature to remove all contaminating ions coming from the use of HF and HNO 3 .…”

“…The two-electrode system in which the anodic oxidation process is applied to form nano-structured TiO 2 samples on the Ti plate surface is shown in Supplementary Figure S1 . The solution in which anodic oxidation will be carried out was prepared by dissolving 0.3% by mass of NH 4 F in a solution containing 2% water and 98% ethylene glycol by volume ( Özcan et al, 2018 ). Anodic oxidation was carried out in this prepared electrolyte solution by applying a definite constant voltage (50 or 60 V) to the electrodes for a certain time (3 or 5 h) and washed with pure water.…”

Special Issue: Application of Photoactive Nanomaterials in Degradation of Pollutants

“…The obtained materials were exploited in photoelectrocatalytic, electrocatalytic, and photocataytic degradation of Paraquat, one of the most widely used herbicides. The obtained results evidenced that the photoanodes show a significant synergy for photoelectrocatalytic activity [14].…”