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

Abstract

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-FeB_x@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-FeB_x@TiO₂ electrode increased by 14.7%, 16.2% and 4.4% at 10 mA cm⁻² in alkaline simulated seawater. The CDs-FeB_x@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.