CDs “inserted” abundant FeB-based electrode via “local photothermal effect” strategy toward efficient overall seawater splitting

The construction of high-efficiency long-stable catalytic electrodes for hydrogen by seawater splitting is a huge challenge in the field of green hydrogen generation. Herein, a matrix-type titanium dioxide nanorod (Ti/TiO2) is constructed on the titanium plate (Ti) by one-step oxidative etching, and a two-dimensional self-supporting electrode with good stability and “local photothermal effect” strategy is constructed as a self-supporting electrode by carbon quantum dots (CDs) “inserted” self-growing iron boron (CDs-FeBx@TiO2). Based on the microstructure regulated by CDs, the in situ growth of FeB with high conductivity and high authenticity activity, the effective separation of electron–hole pairs in the TiO2 structure is promoted, and efficient photothermal seawater electrolysis is realized. The performance of hydrogen/oxygen evolution reaction (HER/OER) and overall seawater splitting of the highly active CDs-FeBx@TiO2 electrode increased by 14.7%, 16.2% and 4.4% at 10 mA cm−2 in alkaline simulated seawater. The CDs-FeBx@TiO2 electrode remains durable for 70 days at 100 mA cm−2 and even at industrial current density, and the catalytic activity remained at 93.5%. This work provides a simple way for the preparation of catalytic electrodes with high activity and excellent stability and provides theoretical support for the practical application of high purity hydrogen from seawater.