We report on a fully solution-processable, bias-free photoelectrochemical (PEC) cell designed for overall solar water splitting, utilizing a Cu2O photocathode and a BiVO4 photoanode. These were enhanced with catalytic multilayers (CMs) for hydrogen and oxygen evolution reactions (HER and OER) via a straightforward layer-by-layer (LBL) assembly method. The CMs, consisting of cationic polyelectrolytes and anionic molecular polyoxometalate (POM) electrocatalysts, significantly improved both photocatalytic activity and stability. PEC analysis showed that the CMs enhanced charge transport and catalytic charge transfer at the photoelectrode/electrolyte interface, while also protecting the vulnerable Cu2O photocathode by forming a protective coating. This enabled the creation of an efficient and stable PEC cell for unassisted solar water splitting without toxic chemicals or energy-intensive processes. This study offers a versatile platform for designing and fabricating environmentally friendly electrochemical PEC devices. -Journal cover design by scapiens.

https://pubs.rsc.org/en/content/articlelanding/2018/gc/c8gc00681d#!divAbstract