Defective Black TiO₂ Nanotube Arrays for Enhanced Photocatalytic and Photoelectrochemical Applications

Abstract

Black TiO2 is of great interest for efficient solar harvest in photocatalytic and photoelectrochemical applications. In this work, we report a convenient, low-cost, and safe method for producing black TiO2 nanotube arrays (TNTAs). By a simple soaking in an ethylene glycol (EG) solution of NH4F, the as-anodic TNTAs turn black, with a substantial amount of oxygen vacancies and Ti3+ sites induced. The thus-obtained black TNTAs deliver greatly enhanced photoelectrochemical and photocatalytic performance of high stability.