Figure . (a) Self-assembled Au@ZnO core-shell nanoparticle films for photoelectrochemical water splitting. Reprinted with permission © 2017, American Chemical Society (b) AuCu3 nanoparticles films obtained by the Langmuir-Schaefer technique for CO2 reduction. Reprinted with permission © 2014 Nature Publishing Group (c) Inverse opal photonic crystal of TiO2 structures (black line) has significantly higher photocatalytic activity than normal TiO2 due to the slow light effect in the photonic crystal. Reprinted with permission © 2013 Royal Society of Chemistry (d) Emulsion based selfassembly of CdSe and Au nanoparticles into clusters enhance the photocatalytic H2 evolution reaction. Reprinted with permission © 2017 John Wiley & Sons. (e) Self-assembled electrode for lithium ion battery can be obtained by layer-by-layer assembly of lithium titanate nanoparticles and carbon nanotube (CNT) on Ni foil. Reprinted with permission © 2021 John Wiley & Sons. (f) Selfassembly of iron oxide nanoparticle-COOH on the APTES-ITO electrodes for the detection of ppb level Cd(II) and Pb(II) ions. © 2022 CC-BY-NC-ND 4.0.