Efficient fabrication of ZrO2-doped TiO2 hollow nanospheres with enhanced photocatalytic activity of rhodamine B degradation

► ZrO2-doped TiO2 hollow nanospheres are efficiently fabricated without any surfactant or polyelectrolyte. ► The addition of Zr4+ obviously results in change in surface structures, phase structures, and pore size distribution. ► The incorporation of Zr4+ induces an enrichment of the electron charge density around Ti4+ ions. ► Ti1−xZrxO2 hollow nanosphere-doped moderate ZrO2 exhibits the highest activity.