Main-chain engineering of polymer photocatalysts with hydrophilic non-conjugated segments for visible-light-driven hydrogen evolution

• Published in: Nature communications Vol. 13; no. 1; pp. 5460 - 11
• Main Authors: Chang, Chih-Li, Lin, Wei-Cheng, Ting, Li-Yu, Shih, Chin-Hsuan, Chen, Shih-Yuan, Huang, Tse-Fu, Tateno, Hiroyuki, Jayakumar, Jayachandran, Jao, Wen-Yang, Tai, Chen-Wei, Chu, Che-Yi, Chen, Chin-Wen, Yu, Chi-Hua, Lu, Yu-Jung, Hu, Chi-Chang, Elewa, Ahmed M., Mochizuki, Takehisa, Chou, Ho-Hsiu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17.09.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 140/131; 147/135; 639/301/299/890; 639/4077/909/4086/4087; 639/638/224/909/4086; 639/638/455/954; 639/638/77/890; Chains (polymeric); Conjugation; Evolution; Humanities and Social Sciences; Hydrogen; Hydrogen evolution; Hydrogen-based energy; Hydrophilicity; Interfaces; Irradiation; Light irradiation; Molecular dynamics; multidisciplinary; Photocatalysis; Photocatalysts; Polymers; Science; Science (multidisciplinary); Segments; Solar energy; Solar energy conversion; Thin films; Water splitting
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-33211-1

Photocatalytic water splitting is attracting considerable interest because it enables the conversion of solar energy into hydrogen for use as a zero-emission fuel or chemical feedstock. Herein, we present a universal approach for inserting hydrophilic non-conjugated segments into the main-chain of conjugated polymers to produce a series of discontinuously conjugated polymer photocatalysts. Water can effectively be brought into the interior through these hydrophilic non-conjugated segments, resulting in effective water/polymer interfaces inside the bulk discontinuously conjugated polymers in both thin-film and solution. Discontinuously conjugated polymer with 10 mol% hexaethylene glycol-based hydrophilic segments achieves an apparent quantum yield of 17.82% under 460 nm monochromatic light irradiation in solution and a hydrogen evolution rate of 16.8 mmol m −2 h −1 in thin-film. Molecular dynamics simulations show a trend similar to that in experiments, corroborating that main-chain engineering increases the possibility of a water/polymer interaction. By introducing non-conjugated hydrophilic segments, the effective conjugation length is not altered, allowing discontinuously conjugated polymers to remain efficient photocatalysis. The introduction of hydrophilic segments into the main-chain of polymer photocatalysts allows water to efficiently enter the interior through these hydrophilic segments, and results in effective water/polymer interfaces for hydrogen evolution.