Visible Light-Induced Photocatalytic Hydrogen Generation from Seawater Using Ternary Indium Sulfide/Indium Oxide/Gold Nanocomposites Obtained via Microwave-Assisted Synthesis

Photocatalytic water splitting under visible light represents a promising pathway toward achieving future net zero-emission renewable energy. However, the development of this energy source faces a challenge owing to the scarcity of freshwater resources. The direct application of actual seawater in photocatalytic hydrogen generation is scarce. This study reports a simple and rapid microwave-assisted synthesis to fabricate a ternary indium sulfide/indium oxide/gold (In2S3/In2O3/Au) nanocomposite photocatalyst. The microwave-assisted synthesis can be performed with precise temperature control in less time. Binary In2S3/In2O3 nanosheets were first synthesized via a one-pot microwave-assisted synthesis, which exhibited an efficient spatial separation of electrons and holes than individual In2S3 or In2O3. The incorporation of Au nanoparticles onto nanosheets enhanced visible light absorption and decreased electron-hole pair recombination. In2S3/In2O3/Au nanocomposites demonstrated remarkable effectiveness in seawater splitting to generate hydrogen with a high hydrogen evolution rate (1.604 mmol h(-1) g(-1)) under low power (5 W blue light and a maximum absorption wavelength of 420 nm) visible light irradiation and low carbon emission for sustainability in water splitting materials. This work has achieved an excellent solar-to-hydrogen conversion efficiency and apparent quantum efficiency of similar to 2.11% and similar to 5.06%, respectively. The ternary nanocomposites show a high degree of reusability under repeated testing cycles, suggesting their potential and practical application for sustainable hydrogen production in the seawater environment.