Shielded goethite catalyst that enables fast water dissociation in bipolar membranes
Muhammad A. Shehzad, Aqsa Yasmin, Xiaolin Ge, Zijuan Ge, Kaiyu Zhang, Xian Liang, Jianjun Zhang, Geng Li, Xinle Xiao, Bin Jiang, Liang Wu, Tongwen Xu
Abstract
Abstract Optimal pH conditions for efficient artificial photosynthesis, hydrogen/oxygen evolution reactions, and photoreduction of carbon dioxide are now successfully achievable with catalytic bipolar membranes-integrated water dissociation and in-situ acid-base generations. However, inefficiency and instability are severe issues in state-of-the-art membranes, which need to urgently resolve with systematic membrane designs and innovative, inexpensive junctional catalysts. Here we show a shielding and in-situ formation strategy of fully-interconnected earth-abundant goethite Fe +3 O(OH) catalyst, which lowers the activation energy barrier from 5.15 to 1.06 eV per HO − H bond and fabricates energy-efficient, cost-effective, and durable shielded catalytic bipolar membranes. Small water dissociation voltages at limiting current density (U LCD : 0.8 V) and 100 mA cm −2 (U 100 : 1.1 V), outstanding cyclic stability at 637 mA cm −2 , long-time electro-stability, and fast acid-base generations (H 2 SO 4 : 3.9 ± 0.19 and NaOH: 4.4 ± 0.21 M m −2 min −1 at 100 mA cm −2 ) infer confident potential use of the novel bipolar membranes in emerging sustainable technologies.