Perovskite BaSnO3 nanoparticles for solar-driven bi-functional photocatalytic activity: PEC water splitting and Wastewater treatment

The highly crystalline n-type BaSnO3 nanoparticles with size ∼30 nm, a larger surface area of ∼15.11 m2·g−1, and a wide optical band gap of 3.24 eV have been synthesized using a co-precipitation route for applications in photoelectrochemical water splitting and organic dye degradation. The spin-coated films of BSO nanoparticles photoanodes exhibited a photocurrent density of 20 μA·cm−2 at a forward bias potential of 0.6 V, a donor carrier density of 2.56 × 1018 cm−3 with a flat band potential of −0.82 V, and four-fold increment in the photocurrent density at a small bias voltage of 0.3 V, under AM 1.5 illumination (100 mW·cm−2). Pseudo-first-order kinetic study showed 96.49 and 95.38 % degradation performance of the Methylene Blue and Crystal Violet dyes at rate constant of 0.0128 and 0.0127 min−1, respectively, under constant irradiation for 240 min in the presence of BSO NPs, which is the highest degradation efficiency reported so far for BSO photocatalyst. The scavenger study revealed the significant role of h+ and ·OH− radicals in the degradation process. Liquid chromatography-mass spectroscopy provides intermediates obtained during the photocatalytic degradation of dyes. The present study focuses on the bifunctional photocatalytic performance of the BSO NPs as a potential candidate for PEC water splitting and wastewater treatment.