Complete hybrid Plasmonic NPs-TiO2 system with sizes at the nanoscale can be achieved. (A) Core-shell made of anisotropic plasmonic NPs coated by crystalline TiO2 layers can perform as good visible light-driven photocatalysts. Adapted with permission from Atta et al. Chem. 2018, 4, 2140–2153 Copyright 2018, Elsevier Inc. [100]. (B). Colloidal synthesis methods allow breaking the symmetry of plasmonic NPs and even obtaining anisotropic Janus-like NPs. Adapted with permission from Rodriguez-Fernandez et al. Chem. Commun. 2014, 50, 79–81 Copyright 2014, Royal Society of Chemistry [101]. (C). Non-centrosymmetric Janus Au-TiO2 NPs can be synthesized with excellent visible light photocatalytic activity. Adapted with permission from Seh et al. Adv. Mater. 2012, 24, 2310–2314 Copyright 2012, WILEY-VCH Verlag GmbH & Co. KGaA Weinheim [102].