Photocatalytic hydrogen production using TiO2 coated iron-oxide core shell particles

Abstract

Photocatalytic water splitting plays a challenging role as it is one of the most important reactions for solving energy, environmental problems and sustainability. Photocatalytic water splitting was improved by using a novel kind of magnetically separable core shell nano photocatalyst TiO2/Fe2O3, prepared by co-precipitation method. It was characterised for particle size (XRD), band gap (UV-DRS), morphology (SEM), particle size (HRTEM), elemental composition (EDS) and electrochemical studies. Photocatalytic splitting of water was examined in tubular reactor of 500 mL capacity with various sacrificial agents viz., methanol, ethanol, acetic acid, lactic acid, EDTA and triethanolamine. To enhance the hydrogen production, various operating parameters viz., effect of sacrificial agents, catalytic dosage, light irradiation and recycle flow rate were optimized. With the optimized operating parameters (0.2 g catalyst dosage, 60 mL/min recycle flow rate, 96 W/m2 light irradiation and EDTA as sacrificial agent) the maximum hydrogen achieved was 2700 μmol/h for the quantum yield of 3.86% at 550 nm. The reusability studies were conducted and the TiO2 coated Fe2O3 core shell particles were found to be stable than the plain TiO2 nano particles. Effective charge transfer from TiO2 to Fe2O3 and the suppression of e−/h+ pair recombination attributed significant enhancement in photoactivity, thereby increasing the hydrogen production.