Conformationally Tunable Hollow Porous g-SrTiO3/ZnS Nanofibers for Photocatalytic Production of Hydrogen

Hydrogen energy is widely recognized as the cleanest energy source with zero emissions and represents a pivotal aspect of the ambitious carbon neutralization goals. Future trends forecast a substantial transition toward employing green hydrogen from fossil energy counterparts. Therefore, there is a significant demand for developing efficient and stable semiconductor photocatalysts responsive to visible light to maximize solar utilization. The perovskite SrTiO3 (STO), a cubic chalcogenide oxide semiconductor featuring stable structure, cost-effectiveness, flexibility, light corrosion resistance, and thermal stability, has garnered extensive attention in the realm of photocatalytic applications. However, due to its intrinsic wide band gap, the limited amounts of photogenerated charge carriers result in an unsatisfactory photocatalytic efficiency. Herein, g-C3N4 was employed as the morphology manipulator on the SrTiO3 nanofibers. The ZnS nanoparticles were then grown in situ on the modified porous SrTiO3 nanofibers (g-STO) to construct g-STO/ZnS type II nanofibrous heterojunctions. Benefiting from the synergistic effects of large specific surface areas and built-in electric field, the recombination of charge carriers was significantly restrained, endowing the composite photocatalyst with excellent performance. The optimized g-STO/ZnS heterojunction with a Sr/Zn molar ratio of 1:6 displays the highest specific surface area and photocatalytic activity, yielding 1.79 mmol g–1 h–1 hydrogen production. Comparative analyses with pure STO and g-STO materials shed light on the photovoltaic properties and photocatalytic activity of g-STO/ZnS heterojunctions. This work establishes a facile routine that could allow the design of effective, high-performance photocatalyst heterojunctions for efficient sunlight-driven hydrogen production.