Self-powered electrolysis systems for sustainable hydrogen generation from natural seawater via a Ni/V2O3 Schottky electrode

A Mg/seawater battery driven seawater electrolysis hydrogen production system based on a Ni/V 2 O 3 Schottky electrode is successfully demonstrated, achieving a total hydrogen production rate of 12.42 mL cm -2 h -1 from natural seawater with a high Mg-to-H 2 conversion efficiency up to 80.87%. • Demonstration of a self-powered system for sustainable generation of hydrogen from seawater. • The tailored Ni/V 2 O 3 Schottky electrode exhibits remarkable HER activity in seawater. • The fabricated Mg/seawater battery delivers a peak power density of 17.81 mW cm -2 . • The self-powered system yields a hydrogen production rate up to 12.42 mL cm -2 h -1 from seawater. Developing novel and efficient techniques for extracting hydrogen from natural seawater sustainably via electrolysis is highly attractive, yet remains a great challenge. Herein, a self-powered electrolysis system (SPES) driven by Mg/seawater batteries (MSBs) with a Ni/V 2 O 3 Schottky electrode is demonstrated for sustainable production of hydrogen from seawater. The Ni/V 2 O 3 Schottky electrode is constructed to serve as the hydrogen evolution reaction (HER) cathode for both the MSBs and seawater electrolysis unit in the SPES, enabling facile seawater HER with 10 and 1000 mA cm -2 at low overpotential of 176 and 649 mV respectively. The MSB with the Ni/V 2 O 3 Schottky cathode delivers a peak power density up to 17.81 mW cm -2 . Importantly, the designed SPES achieves a high hydrogen production rate up to 12.42 mL cm -2 h -1 from natural seawater with a high energy conversion efficiency of 80.87%. This work offers an intriguing technique for in-situ sustainable acquisition of hydrogen from natural seawater.