“…For instance, TiO2/Co-g-C3N4 [16], TbxOy loaded TiO2-oriented nanosheets [17], N-doped TiO2-carbon composite fibres [18], Cu-doped TiO2 nanoparticles modified with 8-hydroxyquinoline [19], carbon nitride loaded into titanium incorporated SBA-15 mesoporous silica (Ti-SBA15-CN) [10], and CdS/TiO2 [20] have been successfully applied for simultaneous removal of metal ions and organic pollutants. For a more efficient use of visible light, various narrow-band gap semiconductor photocatalysts, such as BiVO4 [21], bismuth oxyiodide/reduced graphene oxide/bismuth sulphide (BiOI/rGO/Bi2S3) [22], PANI-sensitized g-C3N4/ZnFe2O4 heterostructure [23] 2O3 -Bi2O2CO3 composite [24], and Au-Pd nanoparticles loaded on g-C3N4/MCM-41 [25] have been investigated for this photochemical process. Nevertheless, it is well-established that some of these photocatalysts have certain disadvantages such as photo-corrosion and instability.…”