(a) Different mechanisms of photothermal effect. Reproduced with permission from Ref. [29]. Copyright©2021, Elsevier Inc. (b) The optical path within different types of ZnO PDs and corresponding schematic drawings for the multiple reflection of light within ZnO nanoshell- and film-based devices. Reproduced with permission from Ref. [35]. Copyright©2018, WILEY-VCH. (c) Engineering the internal structure of hollow nanostructures for enhanced plasmonic properties. Reproduced with permission from Ref. [41]. Copyright©2024, American Chemical Society. (d) Several mechanisms of hollow multishelled structures reacted with photons: (i) Photons induce collective excitation of phonons and/or electrons, generating heat energy; (ii) photons are upconverted or down-converted to higher or lower energy, exhibiting photoluminescence; (iii) photons generate photo-induced carriers, and electrons travel through an external circuit, forming an electric current and producing electrical energy; (iv) photons excite electrons and holes, which participate in redox reactions, storing chemical energy. Reproduced with permission from Ref. [43]. Copyright©2019, Science China Press.