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.