Establishing Stability in Organic Semiconductor Photocathodes for Solar Hydrogen Production

• DOI: 10.1021/jacs.0c00126
• Publication Date: 2020-04-09T12:29:58Z
• Authors: Liang Yao; Néstor Guijarro; Florent Boudoire; Yongpeng Liu; Aiman Rahmanudin; Rebekah A. Wells; Arvindh Sekar; Han-Hee Cho; Jun-Ho Yum; Florian Le Formal; Kevin Sivula
• Keywords: Organic semiconductor

As organic semiconductors attract increasing attention to application in the fields of bioelectronics and artificial photosynthesis, understanding factors that determine their robust operation direct contact with aqueous electrolytes becomes a critical task. Herein we uncover influence operational stability donor:acceptor bulk heterojunction photocathodes for solar hydrogen production significantly advance performance under conditions. First, using photoelectrochemical reduction Eu3+ impedance spectroscopy, replacing commonly used fullerene-based electron acceptor perylene diimide-based polymer drastically increases identify limiting photogenerated accumulation at organic/water interface values ca. 100 nC cm–2 is required stable (>12 h). These insights are extended solar-driven MoS3, MoP, or RuO2 water catalyst overlayers where it found morphology strongly affects due differences charge extraction. Optimized coated MoS3:MoP composite gave 1 Sun photocurrent density up 8.7 mA 0 V vs RHE (pH 1). However, increased was gained initial (>8 cm–2) deceased only 15% 33% during continuous 8 20 h, respectively, thus demonstrating unprecedented robustness without protection layer. This represents new benchmark semiconductor fuel advances criteria semiconductor/water-junction-based devices.