A New Phase Indium Tin Oxide (ITO) Activated Selective CO2 Reduction into Formate for Underwater Antifouling Glass

Abstract Designing unique electrocatalysts that utilizes carbon dioxide reduction reaction (CO 2 RR) for real applications is highly appreciated, yet still suffers from low selectivity, stability, and compatibility. Herein, we first report a new two‐dimensional metastable‐phase transparent conducting oxide: 1T phase indium tin oxide (m‐ITOs) with the space group of P−3m1 (164), which is totally different from that of the stable cubic phase ITO (Ia−3 (206)). The internal indium tin catalytic pairs in m‐ITOs trigger the strong electronic coupling, move up the p ‐band center, and stabilize the adsorption of HCOO* for increased formate production. In a liquid‐phase flow cell, m‐ITOs exhibit a high CO 2 RR electrocatalytic performance with the formate selectivity up to 93 ± 1.9% (83 ± 3.1% for c‐SnInO x and 74 ± 0.6% for In 2 O 3 /SnO 2 ) and remains 97% (58% for c‐SnInO x and 60% for In 2 O 3 /SnO 2 ) of catalytic activity after a 120,000 s stability test. Owing to the efficient formate formation with directly using the absorbed CO 2 in water and high transparent property, m‐ITOs exhibit excellent antifouling behavior of inhibiting Chlorella growth without reducing the transparency of itself, encouraging a promising application of observation windows in water.