A Facile Route to Synthesize a TiNT-RuO₂ Electrocatalyst for Electro-Generated Active Chlorine Production

Abstract

This study aimed to fabricate a novel TiNT-RuO 2 electrocatalyst to produce active chlorine with the capacity to oxidize recalcitrant organic matter. Titanium oxide nanotubes (TiNTs) were first grown via Ti foil anodization in potentiostatic mode in an ethylene glycol solution containing H 2 O and NH 4 F and then annealed at 450°C in air. RuO 2 nanoparticles were deposited on the TiNTs using a hybrid strategy that included pulsed electrodeposition of the Ru nanoparticles, followed by thermal treatment. X-ray diffraction (XRD) only revealed peaks related to metallic Ti and anatase (TiO 2 ) for the TiNTs, whereas additional peaks associated with the tetragonal RuO 2 structure were shown for TiNT-RuO 2 . Scanning electron microscopy showed a well-organized structure for the TiNTs with an average inner diameter of approximately 185 nm for the NTs, while RuO 2 nanoparticles (size <10 nm) were homogenously deposited on the walls and around the openings of the TiNTs. TiNT-RuO 2 preferred the active chlorine formation over oxygen evolution owing to the presence of the RuO 2 nanoparticles. Rapid degradation testing revealed complete elimination of picloram (PCL) in 2 h when 10 mA cm −2 was imposed on the TiNT-RuO 2 , whereas 48% of the 2,4-dichlorophenoxyacetic acid (2,4-D) was removed under the same conditions using the electro-generated active chlorine on the TiNTs.

Review on Structural Adjustment Strategies of Titanium‐Based Metal Oxide Dimensionally Stable Anodes in Electrochemical Advanced Oxidation Technology

“…[71] The combined anode of RuO 2 and carbon materials is feasible and promising for efficient electrochemical degradation of pollutants, such as RuO 2 -TiO 2 /nanographite composite anode with RuO 2 and TiO 2 nanoparticles uniformly distributed on the surface of nanographite sheet. The synergistic effect of RuO 2 , TiO 2 , and nanographite increases the specific surface area, improving the EO activity and reducing the charge [100] Copyright 2019, IOP. e) Combination structure of MAE electrode.…”

“…The initial degradation rates of PCL and 2, 4‐D were slightly related to the current density. [ 100 ] In addition, the life of a mixed metal oxide anode (Ti/TiO 2 NTAs/IrO 2 –RuO 2 –Ta 2 O 5 ) anodized for 240 min is about 20% longer than that of the anode without any anodized layer on the substrate, [ 101 ] so the TiO 2 NTAs as an interlayer can evidently improve the lifetime of the anode. It is noteworthy that the type of titanium matrix also affects the improved anode electrochemical capability.…”

“…d) Changes in 2,4-D and PCL concentrations during electrochemical degradation. Reproduced with permission [100]. Copyright 2019, IOP.…”