Mesostructured ellipsoidal capsules barium stannate based perovskite photocatalysts anchored PtO nanoparticles for hydrogen evolution

Abstract

Background: The separation and transportation of photocarriers are considered significant factors in photocatalytic H2 evolution. Method: Mesoporous BaSnO3, with superior electron mobility with a large surface area, was chosen to integrate PtO nanoparticles (NPs) to obtain a highly effective photocatalytic system. PtO NPs (5–10 nm) are uniformly hosted with high crystallinity on the mesoporous BaSnO3 networks by impregnation-calcination approach. Significant Findings: TEM images of BaSnO3 exhibited ellipsoidal capsules with lengths of 200 ± 10 nm and a diameter of 50 nm. The construction PtO/BaSnO3 heterojunction system with better electron transport ability was modulated to achieve better photocatalytic ability than BaSnO3. The H2 evolution over 1.2% PtO/BaSnO3 nanocomposite was about 21,550 μmol·g−1 after 9 h visible illumination, while bare BaSnO3 was produced only 3750 μmol·g−1. The optimal 1.2% PtO/BaSnO3 nanocomposite revealed the largest H2 evolution, and it was promoted 5.75 times larger than BaSnO3. The H2 evolution rate over-optimized 1.2% PtO/BaSnO3 photocatalyst was about 2380 μmolg−1h−1, 6 times larger than that of bare BaSnO3 (397.37 μmolg−1h−1). The obtained PtO/BaSnO3 nanocomposites could facilitate the photoinduced electrons transfer from BaSnO3 to PtO, indicating the efficient photoinduced carriers separation for the enhanced H2 evolution rate. The PtO/BaSnO3 nanocomposite displayed high photostability and recyclability even after 45 h of illumination. This work provides a novel approach for perovskites with mesoporous structures and tunable bandgap with low PtO content utilized in energy applications and photocatalytic reactions.