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

Bi 5+ -self-doped Bi 4 V 2 O 11 (Bi 5+ -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 Bi 5+ self-doping. Density functional theory calculations and experimental results indicate that Bi 5+ self-doping can narrow the band gap of Bi 4 V 2 O 11, which contributes to enhancing light harvesting. Moreover, Bi 5+ self-doping endows Bi 4 V 2 O 11 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, Bi 5+ -BVO exhibits a superior photocatalytic performance in contrast to that of pristine Bi 4 V 2 O 11 . 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.