Electrochemical degradation of refractory pollutants using TiO2 single crystals exposed by high-energy {001} facets

•{001}-facet TiO2 SCs are proposed as an efficient anode for water treatment.•{001} polar facet favors dissociative adsorption and promotes charge mobility on TiO2 anode.•Pollutants are degraded mainly via a direct anodic oxidation mechanism at the TiO2 SCs.•TiO2 SCs are a promising anodic material for water/wastewater treatment.

Anodic material plays a vital role in electrochemical water treatment. Titanium dioxide (TiO2) has been widely recognized as an excellent semiconductor photocatalyst, rather than an efficient electrocatalyst, due to its relatively low electric conductivity and poor electrochemical activity. In this work, it is found that TiO2 can actually become a superior electrocatalyst when its crystal shape and exposed facet are finely tuned. The shape-engineered TiO2 single crystals with {001} facets exhibit an excellent electro-catalytic activity and stability for degrading typical organic pollutants such as rhodamine B and bisphenol A, and treating complex landfill leachate. Its electro-catalytic superiority is mainly attributed to the single-crystalline structure and exposed polar {001} facet. Our findings could provide new possibility of utilizing TiO2 for efficient electrochemical water treatment because of its high activity, great stability, low cost and no toxicity.

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