A novel 2D sulfide gallium heterojunction as a high-performance electrocatalyst for overall water splitting

It is an effective way to split water to produce high-clean hydrogen energy for solving energy crisis in the world. However, overall water splitting is still suffering from high voltage and sluggish kinetics. Herein, we firstly synthesize sulfide gallium heterojunction modified with abundant S vacancies in a one-pot hydrothermal way, showing the low OER overpotential of 345 mV with good stability as well as HER overpotential of 209 mV at 10 mA cm(-2). Furthermore, we assemble the sulfide gallium heterojunction into cathode and anode for overall water splitting, which possesses a low voltage of 1.43 V in an alkaline solution. The density functional theory calculations also reveal that the sulfide gallium heterojunction with S vacancy has narrower band energy gap in sulfide gallium. This designed heterojunction has great potential for being used as a novel electrocatalyst to replace the commercial RuO2//Pt/C system in water splitting field.

Automated summary

Splitting water to produce hydrogen energy is an effective solution to the global energy crisis. However, the process still faces challenges of high voltage and slow kinetics. In this study, a sulfide gallium heterojunction with abundant S vacancies was synthesized, exhibiting low overpotential and good stability. When applied for overall water splitting, the heterojunction achieved a low voltage in an alkaline solution. The results suggest that this designed heterojunction has great potential as a replacement for the commercial RuO2//Pt/C system in water splitting.