Solar-driven natural seawater splitting with TiO2 coated 2D nanosheet MoS2 photocatalyst for hydrogen production

Abstract

Solar-driven seawater splitting has emerged as a sustainable approach for producing green hydrogen without relying on high-purity water driven by solar irradiation. In this study, TiO2 coated MoS2 nanocomposite photocatalyst (TiO2-MoS2) was successfully synthesized via sol-gel technique, resulting in coated 2D nanosheet MoS2 with nanoparticle TiO2, and forming a Type-II heterojunction (band gap of 3.2 eV for pure TiO2 to 2.76 eV of TiO2-MoS2). Photocatalytic performance was evaluated under simulated solar irradiation utilizing both pure water and natural seawater collected from Mediterranean, Aegean, Marmara, and Black Seas in T & uuml;rkiye. Hydrogen generation rates (HGRs) were observed as 988.9, 986.0, 966.5, and 942.1 mu mol H2.h- 1.gcat - 1 for the Aegean, Mediterranean, Marmara, and Black Seas, respectively. Compared with pure water, HGRs were approximately seven times higher in photocatalytic seawater splitting. The nanocomposite photocatalyst demonstrated long-term stability, retaining 85% of its initial activity after 11 h of continuous operation, and cycle durability, maintaining 88% of its initial performance after five consecutive cycles. These results clearly demonstrate the novelty and practical feasibility of solar-driven hydrogen generation from natural seawater, highlighting the strong potential of TiO2-MoS2 nanocomposites for scalable, sustainable hydrogen production.