Hydrogen production by photocatalytic water splitting using poly(allylamine hydrochloride)/poly(acrylic acid)/TiO2/copper chlorophyllin self-assembled thin films

The aim of this study was to fabricate and characterize self-assembled thin films (SATF) obtained by a combination of poly(allylamine hydrochloride), poly(acrylic acid), titanium dioxide (TiO2) nanoparticles and the visible light sensitizer sodium copper chlorophyllin (Cu-chln) using the layer-by-layer technique. SATF with 21, 81 and 161 layers were deposited onto glass substrates and then characterized by means of several techniques, including ultraviolet and visible spectrophotometry, scanning electron microscopy, energy dispersive spectroscopy, profilometry, and inductively coupled plasma optical emission spectrometry. Their photocatalytic activity was evaluated by quantifying the hydrogen production using gas chromatography by placing the SATF in water upon irradiation with a solar simulator. The maximum average hydrogen production rates were 0.16, 0.45 and 1.26 mu mol cm(-2) h(-1) for the SATF with 21, 81 and 161 layers, respectively. Cu-chin was shown to be effective to improve the TiO2 catalytic activity, more than doubling the hydrogen production rate compared to the SATF that were fabricated with only the polyelectrolytes and TiO2. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.