Photocatalytic hydrogen generation through water splitting on nano-crystalline LaFeO3 perovskite

Visible light active ABO3 type photocatalyst with LaFeO3 composition was synthesized by sol-gel method. The photocatalyst was characterized by different techniques such as X-ray diffraction, BET surface area analysis, particle size analysis, scanning electron microscopy, UVevisible diffuse reflectance spectroscopy (UVeVisible DRS), and photoluminescence spectroscopy. LaFeO3 photocatalyst exhibited an optical band gap of 2.07 eV with the absorption spectrum predominantly in visible region of the spectrum. The BET surface area of photocatalyst LaFeO3 was observed as 9.5 m2/g, with the crystallite size of 38.8 nm as calculated by the Debye-Scherer equation. The photocatalytic activity of LaFeO3 was investigated for hydrogen generation through sacrificial donor assisted photocatalytic water splitting reaction by varying conditions in feasible parametric changes using visible light source, ethanol as a sacrificial donor and Pt solution of H2PtCl6 as a co-catalyst. The rate of photocatalytic hydrogen evolution was observed to be 3315 mmol g�1 h�1 under optimized conditions and using 1 mg dose of photocatalyst with reaction time of 4 h and illumination of 400 W

Visible light induced photoreduction of water by N-doped mesoporous titania

N-doped mesoporous titania was synthesized by templating method. Three different types of photocatalysts were synthesized by varying chitosan to titania compositions and designated as N-doped mesoporous titania (1:1), (1:2) and (1:3). These synthesized photocatalysts were characterized by XRD, BET-SA, UV-DRS, SEM-EDX and XPS. This photocatalyst is active in visible range with band gap energy of 2.65 eV. Formation of TieN bond reveals the decrease in the band gap of TiO2. The synthesized photocatalysts were screened initially for their photocatalytic activity using water splitting reaction. The maximum hydrogen yield of 2654.57 mmol/h/g of photocatalyst was obtained for N-doped mesoporous titania (1:2). This yield is 16 times higher as compared to the bench mark material Degussa P-25 (161 mmol/h/g of photocatalyst). The best performing photocatalyst N-doped mesoporous titania (1:2) was investigated in detail to study the influence of various operating parameters. Reuse and recycle study results in steady hydrogen yield of 9605.56 mmoles for 30 h