A photoelectrochemical device for water splitting using oligoaniline-crosslinked [Ru(bpy)2(bpyCONHArNH2)]+2 dye/IrO2 nanoparticle array on TiO2 photonic crystal modified electrode

• A photoelectrochemical solar cell was designed using oligoaniline crosslinked bridging units.
• The oligoaniline crosslinked bridging units enhances the photocurrent and quantum yield in visible light.
• Enhanced efficiency of oxygen/hydrogen production with this device.

This article describes the construction of photoelectrochemical cell system splitting water into hydrogen and oxygen using UV–vis light under constant applied voltage. Oligoaniline-crosslinked 2-(4-aminobenzyl)malonic acid functionalized IrO2·nH2O nanoparticles and visible light absorbing dye, [Ru(bpy)2(bpyCONHArNH2)+2] arrays on titanium dioxide (TiO2) photonic crystals modified electrodes were used as photoanode, and nanostructures based on bonding of Pt nanoparticles by using electropolymerization on poly 4-(2,5-di(thiophene-2-il)-1H-pyrrol-1-il)benzenamine P(SNS-NH2) conducting polymer modified gold electrode acted as cathode. Each component in anode and cathode of the system was characterized successfully using the methods related. Some optimization studies such as the molar concentration ratio of [Ru(bpy)2(bpyCONHArNH2)+2] dye to IrO2·nH2O nanoparticles, the optimum cycle number of each components and thickness of TiO2 film were performed in order to investigate the system performance. Furthermore, the photocurrent generation capacity of the photoanode against oxygen resulting and UV stability experiments of photoanode were also investigated. After obtained all necessary informations and improvements of the system, the cell was constructed, and corresponding hydrogen gas evolution from water splitting was calculated as 1.25 × 10−8 mol/cm2 by using a gas chromatography (GC). The cell generated a photocurrent with a quantum yield of 3.5%.