Towards a new avenue for rapid synthesis of electrocatalytic electrodes via laser-induced hydrothermal reaction for water splitting

Key words: 
• electrocatalytic electrode /
• laser-induced hydrothermal reaction /
• NiFe layered double hydroxides /
• hydrogen evolution reaction /
• water splitting /
• energy consumption /
• production rate

Abstract: 

Electrochemical production of hydrogen from water requires the development of electrocatalysts that are active, stable, and low-cost for water splitting. To address these challenges, researchers are increasingly exploring binder-free electrocatalytic integrated electrodes (IEs) as an alternative to conventional powder-based electrode preparation methods, for the former is highly desirable to improve the catalytic activity and long-term stability for large-scale applications of electrocatalysts. Herein, we demonstrate a laser-induced hydrothermal reaction (LIHR) technique to grow NiMoO₄ nanosheets on nickel foam, which is then calcined under H₂/Ar mixed gases to prepare the IE IE-NiMo-LR. This electrode exhibits superior hydrogen evolution reaction performance, requiring overpotentials of 59, 116 and 143 mV to achieve current densities of 100, 500 and 1000 mA·cm⁻². During the 350 h chronopotentiometry test at current densities of 100 and 500 mA·cm⁻², the overpotential remains essentially unchanged. In addition, NiFe-layered double hydroxide grown on Ni foam is also fabricated with the same LIHR method and coupled with IE-NiMo-IR to achieve water splitting. This combination exhibits excellent durability under industrial current density. The energy consumption and production efficiency of the LIHR method are systematically compared with the conventional hydrothermal method. The LIHR method significantly improves the production rate by over 19 times, while consuming only 27.78% of the total energy required by conventional hydrothermal methods to achieve the same production.