Self-Assembled PDI\nNanowires Enhanced by Plasmonic\nEffect of Gold Nanorods for Photocatalytic H<sub>2</sub>O<sub>2</sub> Production and Photoelectrochemical Cell Application

Considering the wide visible light absorption of perylene\ndiimide\n(PDI) molecules, gold nanorods (AuNRs) can be utilized by matching\ntheir transversal and longitudinal surface plasmon resonance (SPR)\nbands with the absorption wavelengths of PDI-based photocatalysts\nto achieve an efficient enhancement of the catalytic activity. Herein,\nthe composite photocatalyst of AuNRs-decorated self-assembled PDI\nnanowires (s-PDI/AuNRs) has been successfully prepared and further\napplied in the self-powered photoelectrochemical cell as the anode\nto supply H<sub>2</sub>O<sub>2</sub> fuel. The s-PDI/AuNRs-based cell\ndisplays a maximum power density of 2.36 mW cm<sup>–2</sup> in 0.1 M HCl electrolyte, which has 65.0% and 31.8% enhancement\ncompared to the pristine PDI-based cell (1.43 mW cm<sup>–2</sup>) and the s-PDI-based cell (1.79 mW cm<sup>–2</sup>), respectively.\nMoreover, the photocatalytically produced H<sub>2</sub>O<sub>2</sub> can be stored under light, which is then used as a fuel for cell\noperation in darkness. The specific capacitance can be achieved as\nhigh as 43.1 F cm<sup>–2</sup>, retaining 52.6% of its initial\nvalue after 12 h. It is verified that the enhanced photocatalytic\nperformance of s-PDI nanowires can be ascribed to the specific intermolecular\nπ-π stacking caused by the introduction of terminal carboxyl\ngroups, which results in the deepening of the valence bandwidth and\nthe enhancement of hole oxidation capacity.