Anionic donor-acceptor conjugated polymer dots/g-C3N4 nanosheets heterojunction: High efficiency and excellent stability for co-catalyst-free photocatalytic hydrogen evolution

Herein, we have assembled an anionic donor-acceptor (D-A) conjugated polyelectrolyte dots (Pdots), based on bithiophene units-containing backbone and sulfonate modified side chain (PCP-2F-Li), with porous g-C3N4 nanosheets (CNNS) into a new 0D/2D heterojunction (PCP-2F-Li Pdots/CNNS). The well-matched energy levels of PCP-2F-Li and CNNS and the strong electron-donating sulfinates in PCP-2F-Li can significantly accelerate the interfacial electron transfer in heterojunction, while the strong hydrophilicity of PCP-2F-Li can improve the interface wetting and promote the photocatalytic water-splitting. As such, PCP-2F-Li Pdots/CNNS can be used for efficient co-catalyst-free water splitting with a hydrogen evolution rate (HER) of 1932.1 mu mol.h(-1).g(-1) over 6 runs, which is 1.85 and 2.29 times of hydrophobic F8T2 Pdots/CNNS and Pt-assisted CNNS, respectively. The apparent quantum yield (AQY) of PCP-2F-Li Pdots/CNNS can reach 7.87 %, 7.73 % and 5.60 % at 420, 450 and 475 nm, respectively. The findings highlight a new type of the Pdots-assisted heterojunctions for high-efficiency and durable co-catalyst-free water splitting. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

An anionic donor-acceptor conjugated polyelectrolyte dots (PCP-2F-Li Pdots) combined with porous g-C3N4 nanosheets (CNNS) to form a 0D/2D heterojunction, showing efficient co-catalyst-free water splitting with a hydrogen evolution rate of 1932.1 mu mol.h(-1).g(-1). The well-matched energy levels and electron-donating properties of PCP-2F-Li contribute to accelerated interfacial electron transfer and improved photocatalytic performance.