Energy-efficient photoelectrochemical water splitting and degradation of organic dyes over microwave-assisted WO3 nanosheets/W foil with rapid charge transport

Microwave-assisted WO3 photoelectrodes have been rarely studied in terms of their growth mechanism and photoelectrochemical (PEC) application for energy generation and waste water organic pollutants removal. Microwave-assisted rapid synthesis technique is proposed in the current study as a means of reducing the deposition time of tungsten oxide nanosheets on tungsten foil. XRD and PEC studies indicate that WO3-NS photoanodes with an active (002) plane exhibited optimal PEC performance, whereas (020) suffered from charge carrier separation during the prolongation of microwave cycles from 1 to 5. Under 1.5 G simulated sunlight, 100 mWcm2, the optimum WO3-MW-3 cycle photoanode has a maximum photocurrent density of 1.68 mA cm2 at 1.0 V vs. Ag/AgCl compared to the transparent conducting WO3/FTO substrates. The optimum morphology and large specific surface areas of WO3-NS's lead to enhanced charge separation in WO3-MW-3 cycle photoanodes. The WO3-MW-3 cycle photoanodes demonstrated 71 and 41 μmol of H2 and O2 evolution, respectively, within 180 min, while degradation of PEC orange II dye reached 98.5%. The microwave-induced systems can be used to produce a wide variety of nanostructured photoanodes for photovoltaics and electrocatalysis. Herein, for the first time, we successfully synthesized WO3 nanosheets (WO3-NSs) on W foil within a short time period using microwave radiation and demonstrated the PEC stability for PEC water splitting and Orange II dye degradation under one-sun illumination without any surfactants. [Display omitted] •Highly stable microwave assisted WO3 nanosheets photoelectrode was synthesized.•WO3-MW-3 cycle photoanode with (002) facets exhibited a photocurrent density of 1.68 mA cm−2 at 1.0 V vs. Ag/AgCl.•The WO3-PEC system was constructed for water splitting and orange II dye degradation.•Charge transfer mechanism in morphology-controlled microwave assisted WO3 is well proposed.