Extended visible light harvesting and boosted charge carrier dynamics in heterostructured zirconate–FeS₂ photocatalysts for efficient solar water splitting

Limited visible light absorption, slow charge transference, and high recombination are some of the main problems associated with low efficiency in photocatalytic processes. For these reasons, in the present work, we develope novel zirconate–FeS₂ heterostructured photocatalysts with improved visible light harvesting, effective charge separation and high photocatalytic water splitting performance. Herein, alkali and alkaline earth metal zirconates are prepared by a solid state reaction and coupled to FeS₂ through a simple wet impregnation method. The incorporation of FeS₂ particles induces visible light absorption and electron injection in zirconates, while the appropriate coupling of the semiconductors in the heterostructure allows an enhanced charge separation and suppression of the recombination. The obtained heterostructures exhibit high and stable photocatalytic activity for water splitting under visible light, showing competitive efficiencies among other reported materials. The highest hydrogen evolution rate (4490 µmol g⁻¹ h⁻¹) is shown for BaZrO₃–FeS₂ and corresponds to more than 20 times the activity of the bare BaZrO₃. In summary, this work proposes novel visible light active heterostructures for efficient visible light photocatalytic water splitting.