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

Abstract Electrochemical production of hydrogen from water requires the development of electrocatalysts that are active, stable, and low-cost for water splitting. In comparison with conventional powder-based electrode preparation, synthesis of binder-free electrocatalytic integrated electrodes 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 (LIHR) technique to grow NiMoO4 nanosheets on Nickel foam, which is then calcined under H2/Ar mixed gases to prepare the integrated electrode 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 remained essentially unchanged. In addition, NiFe-layered double hydroxide grown on Ni foam is fabricated with 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 LIHR method are systematically compared with conventional hydrothermal method. The LIHR method significantly improved the production rate by over 19 times, while consuming only 27.78% of the total energy required by conventional hydrothermal method to achieve the same production.