Self-Assembled Perylenediimide Nanoaggregates with an Alternate Stringlike Morphology as Photoanodes to Enhance the H2O2 Photoelectrochemical Cell Performance

A self-assembled supramolecular photocatalyst of benzoic acid-substituted perylenediimide (SA-BAPDI) is successfully prepared, forming an alternate stringlike morphology driven by intermolecular hydrogen-bonding and π–π interactions. This unusual morphology induces a strong built-in electric field and an enormous π-conjugated effect, which can promote efficient separation of photogenerated carriers. Meanwhile, SA-BAPDI photocatalyst applied as the photoanode in the H₂O₂ photoelectrochemical cell for the first time can facilitate photocatalytic H₂O₂ production by water oxidation, which can be used as fuel to generate electricity through redox reactions and further to achieve solar–chemical–electrical energy conversion. The SA-BAPDI-based cell displays the maximum light power density of 1.06 mW·cm^–2 and the specific capacitance of 5025 mF·cm^–2 after 0.5 h of irradiation, which can still retain the original value of 50% in the dark for 12 h of continuous operation. This study verifies that morphology regulation of self-assembled perylenediimide supramolecular photocatalytic materials benefits the design and development of a high-performance H₂O₂ photoelectrochemical cell.