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.