TiO2 with Super Narrow Bandgap Achieved in One-Step Single-Mode Magnetic Microwave Induced Plasma Treatment

TL;DR

This paper reports a novel one-step plasma treatment method to synthesize TiO2 with an ultra-narrow bandgap and stable Ti3+ surface doping, significantly enhancing visible-light photocatalytic performance.

Contribution

A new one-step magnetic microwave plasma process enables precise surface Ti3+ doping and chemical composition control in TiO2, improving its photocatalytic efficiency.

Findings

Achieved super narrow bandgap (~1.1 eV) TiO2.

Surface Ti3+ doping enhances visible-light photocatalysis.

Surface TiOx composition is precisely controlled and stable.

Abstract

TiO2 with super narrow bandgap (1.1 eV~) are successfully synthesized via a facile and novel one-step single-mode magnetic microwave induced plasma treatment. The selectively surface Ti3+-doping on obtained TiO2 as trapping centers which significantly restrain the photo-excited carrier recombination and achieve the enhancement of visible-light photocatalytic performance. In addition, the surface chemical composition of TiOx is precisely controlled in a wide region of 1.19 < x < 1.92 during one-step reaction. A detailed XPS analysis reveals that the surface formed Ti3+ shows highly thermal/chemical stability even through high-temperature treatment (~800 oC) in oxidative atmosphere and photocatalytic reaction.