Oxygen-Induced Bi5+-Self-Doped Bi4V2O11 with a p-n Homojunction Toward Promoting the Photocatalytic Performance.

Bi5+-self-doped Bi4V2O11 (Bi5+-BVO) nanotubes with p-n homojunctions are fabricated via an oxygen-induced strategy. Calcinating the as-spun fibers with abundant oxygen plays a pivotal role in achieving Bi5+ self-doping. Density functional theory calculations and experimental results indicate that Bi5+ self-doping can narrow the band gap of Bi4V2O11, which contributes to enhancing light harvesting. Moreover, Bi5+ self-doping endows Bi4V2O11 with n- and p-type semiconductor characteristics simultaneously, resulting in the construction of p-n homojunctions for retarding rapid electron-hole recombination. Benefiting from these favorable properties, Bi5+-BVO exhibits a superior photocatalytic performance in contrast to that of pristine Bi4V2O11. Furthermore, this is the first report describing the achievement of p-n homojunctions through self-doping, which gives full play to the advantages of self-doping.