TiO₂ Nanotube Array Photoelectrocatalyst and Ni–Sb–SnO₂ Electrocatalyst Bifacial Electrodes: A New Type of Bifunctional Hybrid Platform for Water Treatment

Abstract

Bifunctional hybrid electrodes capable of generating various reactive oxygen species (ROS) over a wide range of potentials were developed by coupling electrocatalysts and photoelectrocatalysts. To achieve this, Ni-doped Sb-SnO2 (NSS) was deposited on one side of a titanium (Ti) foil while the other side was anodized to grow a TiO2 nanotube array (TNA) for electrochemical ozone generation and photoelectrochemical hydroxyl radical generation, respectively. Surface characterization indicated that NSS and TNA were formed and spatially separated yet electrically connected through the Ti substrate. While each catalyst possessed unique electrochemical properties, the coupling of both catalysts resulted in mixed electrochemical properties that drove electrocatalysis at high potentials and photoelectrocatalysis at low potentials. The performance of the NSS/TNA electrode for phenol decomposition was ∼3 times greater than that of single-layer catalysts and ∼1.5 times greater than the combined catalytic performances of the individual NSS and TNA catalysts. This synergistic effect was attributed partly to the simultaneous generation of hydroxyl radicals and ozone, followed by the production of other ROS. A mechanism for the generation of ROS was discussed.

High thermostable ordered mesoporous SiO2–TiO2 coated circulating-bed biofilm reactor for unpredictable photocatalytic and biocatalytic performance

“…There into, the phenolic wastewater that includes phenol and 2,4,5-Trichlorophenol (TCP) has been one of the major problems for decades. Phenolic compounds are examples of recalcitrant toxic pollutants presented in liquid waste streams from a variety of industries, such as those involved in production of steel, resins, ceramics, fiberglass, fungicides and herbicides, metals, and textiles [4][5][6]. Especially, 2,4,5-TCP tends to bioaccumulate in the environment due to its biorecalcitrance in nature and in wastewater treatment plants [7].…”

Deposition efficiency in the preparation of ozone-producing nickel and antimony doped tin oxide anodes

“…In a later publication [26] they used ethanol as solvent but kept the high dopant levels in the precursor solution. This resulted in a very low current efficiency for ozone formation of 1 %, whereas 9.3 % was reached when water was used as solvent.…”

“…This was later discussed to be a consequence of surface enrichment of Sb [9,14]. Other studies have also reported an enrichment of either Sb or Ni, or both [24][25][26]. Most authors correlate this to surface enrichment.…”

Using TiO2 Mesoflower Interlayer in Tubular Porous Titanium Membranes for Enhanced Electrocatalytic Filtration

“…physisorbed ÁOH (donated as MO x (ÁOH)), which are critical for unselective and effective degradation of organic pollutants [18,20,33]. It has been reported that O ad appears to actively participate in electrochemical reactions [34]. In contrast, TPTM/ATO with a lower O ad content tends to form weak oxidants (e.g.…”