(29d) Structural Effect Study in an Assembled Nano-Heterojunction Towards Designing a Visible Light Photocatalyst for H2 Generation

Hydrogen production using photocatalytic water splitting has drawn great interest in our scientific community due to the demand for renewable energy. In photocatalytic water splitting, heterojunction formation of different functional materials in a single photocatalyst shows potential advantages over a single material photocatalyst. Advantages include extended solar light absorption from UV to visible light range, reduces photoexcited electron-hole recombination by enhancing charge separation, and increases the photo corrosion resistibility. In designing the assembled nano-heterojunction, a UV- active perovskite material (SrTiO₃) of different structures was decorated with several functional materials including visible light active (CdS), plasmonic metal (Au), and a cocatalyst. Sol gel assisted electrospinning and hydrothermal methods were used to synthesize the nano-heterojunctions. These nano-heterojunctions were characterized by field emission scanning electron microscopic with energy dispersive spectroscopic observations, X-ray diffraction patterns, N₂ gas absorption-desorption isotherm measurements, and UV-visible spectrophotometry. Structural effect of SrTiO₃ and CdS in the assembled nano-heterojunctions were investigated in terms of charge recombination and H₂ generation from photocatalytic water splitting. Charge recombination phenomena were studied by photoluminescence spectra and photocurrent measurements. High photocatalytic activities of these assembled nano-heterojunctions are expected due to multifunctional materials assembly, preferential heterostructure formation, and enhanced visible light absorption.