Enhancing the photothermal performance of graphene oxide by embedding perylene diimide radical anions/α-phenylethylamine hydrogen bonded complexes in graphene oxide films for solar water evaporation

Abstract

Typically, perylene diimide radical anions have broad and strong absorption in the near-infrared light region and exhibit excellent photothermal conversion performance, so they are considered as new potential organic photothermal materials. However, the stability of perylene diimide radical anions in air has always been a thorny issue. We found an effective way to improve the stability of perylene diimide radical anions through formation of low barrier hydrogen bonds between perylene diimide radicals and alkyl primary amines. In this paper, we report the synthesis of a stable perylene diimide radical anion/α-phenylethylamine hydrogen bonded complex (α-PEA⋯PDI˙⁻), and preparation of a kind of α-PEA⋯PDI˙⁻/GO (graphene oxide) film using a simple impregnation method. Compared to GO films and α-PEA⋯PDI˙⁻ powder, the film exhibited a good photothermal response with the highest photothermal conversion temperature of 82.4 °C under light, a temperature increase rate of up to 35 °C, and a photothermal conversion efficiency of 24.07%. The film is optically stable and reusable, and also exhibits superior performance compared to pure graphene oxide for solar water evaporation.