TiO2 as an effective photocatalyst mechanisms, applications, and dopants: a review Fahad Irfan, Muhammad Usman Tanveer, Muhammad Abdul Moiz, Syed Wilayat Husain and Muhammad Ramzan Eur. Phys. J. B, 95 11 (2022) 184 Published online: 08 November 2022 DOI: 10.1140/epjb/s10051-022-00440-8