RESUMEN
BiOI is a promising material for use in photoelectrocatalytic water oxidation, renowned for its chemical inertness and safety in aqueous media. For device integration, BiOI must be fabricated into films. Considering future industrial applications, automated production is essential. However, current BiOI film production methods lack automation and efficiency. To address this, a continuous automated process is introduced in this study, named AutoDrop, for producing BiOI films. Autodrop results to be a fast and facile method for producing BiOI photoelectrodes. Nanostructured thin films of this layered material are prepared using a syringe pump to dispense the precursor solution onto a continuously spinning substrate. These films are integrated into a multilayered photoelectrode, featuring mesoporous TiO2 as an electron-transporting layer on top of FTO glass. In testing the photoelectrochemical performance of the BiOI/TiO2 photoelectrodes, the highest photocurrent (44 µA cm-2) is found for a heterojunction with a BiOI thickness of 320 nm. Additionally, a further protective TiO2 ultrathin layer in contact with BiOI, grown by atomic layer deposition, enhances the durability and efficiency of the photoanode, resulting in a more than two-fold improvement in photocurrent after 2 hours of continuous operation. This study advances the automation in the sustainable production of photoelectrode films and provides inspiration for further developments in the field.
RESUMEN
2D materials are interesting flat nanoplatforms for the implementation of different electrochemical processes, due to the high surface area and tunable electronic properties. 2D transition metal dichalcogenides (TMDs) can be produced through convenient top-down liquid-phase exfoliation (LPE) methods and present capacitive behaviour that can be exploited for energy storage applications. However, in their thermodynamically stable 2H crystalline phase, they present poor electrical conductivity, being this phase a purely semiconducting one. Combination with conducting polymers like polyaniline (PANI), into nanohybrids, can provide better properties for the scope. In this work, we report on the preparation of 2D WS2@PANI hybrid materials in which we exploit the LPE TMD nanoflakes as scaffolds, onto which induce the in-situ aniline polymerization and thus achieve porous architectures, with the help of surfactants and sodium chloride acting as templating agents. We characterize these species for their capacitive behaviour in neutral pH, achieving maximum specific capacitance of 160 F/g at a current density of 1 A/g, demonstrating the attractiveness of similar nanohybrids for future use in low-cost, easy-to-make supercapacitor devices.