Tribocatalytic degradation of dyes by tungsten bronze ferroelectric Ba2.5Sr2.5Nb8Ta2O30 submicron particles

Abstract

Searching for a new approach in environmental remediation in terms of dye degradation is important in industrialized society. In this work, ferroelectric Ba_2.5Sr_2.5Nb₈Ta₂O₃₀ (BSNT) submicron powders prepared by the high-temperature solid-phase method are used for dye degradation under magnetic stirring. The dye in solution can be quickly degraded by magnetically stirring BSNT submicron particles in the dark in ambient temperature conditions. More importantly, the degradation efficiency can be greatly improved through simple modification of the stirring materials from glass to polypropylene, with a degradation efficiency of rhodamine B as high as 99% in 1.5 h at a gentle stirring speed of 300 rpm. Control experiments reveal that the degradation of the dye is mainly contributed by the friction between BSNT submicron particles and PTFE stirring rods. It is proposed that the friction between ferroelectric polar BSNT particles and PTFE causes charge transfer and induces a non-zero internal electric field to drive the separation of electron–hole pairs in BSNT particles, resulting in a novel tribocatalytic degradation of the dye, which is proven by the detection of ˙OH and ˙O₂⁻ intermediate products during stirring. This work demonstrates that the friction energy of ferroelectric materials with strong polarization is an alternative approach for highly efficient dye degradation.