Biomass Nanomicelles Assist Conjugated Polymers/Pt Cocatalysts To Achieve High Photocatalytic Hydrogen Evolution

Abstract

Conjugated polymers are emerging as promising organic photocatalysts for photocatalytic hydrogen evolution; however, they are suffering from poor water dispersabilities. Herein, this problem is addressed in an easy and green way with the assistance of a biomass-derived material. An amphipathic xylan derivative that can be self-assembled into nanomicelles was employed as carriers to encapsulate a series of conjugated polymers to form uniform composite micelles in water. By this way, the hydrophobic conjugated polymers and their blends were successfully dispersed into water and thus enabling efficient hydrogen evolution. Moreover, the energy level offsets of these conjugated polymers enable the formation of photoinduced charge transfer (PCT) process and fluorescence resonance energy transfer (FRET) process in their composite micelles. The photocatalytic experimental results showed that in these composite micelles, conjugated polymer blends with PCT characteristic delivered much higher photocatalytic hydrogen evolution rates over that of pristine polymer, while conjugated polymer blends with FRET characteristic delivered negligible improvement. Our results demonstrated effective strategies to improve the photocatalytic activity of conjugated polymers, which could also be applied to other photocatalytic materials and systems.