A step further toward the application of layered double hydroxides in Sustainable Catalysis: from artificial photosynthesis to wastewater treatment

Layered-Double Hydroxides (LDHs) are known to be versatile materials that can be potentially applied in different fields. This work is focused on their specific application in artificial photosynthesis and wastewater treatment. Indeed, their catalytic properties make them possible candidates for photoelectrodes in photo-electrochemical cells (PEC), a recent technology exploited for solar fuel production, and Dye-Sensitised Solar Cells (DSSC), also known as third generation photovoltaics. Furthermore, the possibility to directly intercalate a dye in the LDH interlayer makes these materials able to absorb even more solar light and, potentially, less sensitive to dye degradation, if the latter is adsorbed on the LDH surface. In this work, LDHs were prepared by coprecipitation method, and subsequently applied onto a conductive transparent substrate by screen-printing with suitable inks. Finally, complete PEC and DSSC prototypes were assembled and tested for solar fuels production or electricity generation. Furthermore, a first trial was made to use LDHs as catalysts for the degradation of 4-nitrophenol, a well-known organic pollutant mostly found in wastewaters. The results obtained confirmed that LDH are versatile materials that can be potentially applied in all the explored fields.