A Synthetic Hydrophyte for Sunlight-Driven Water Purification

The increased global use of pharmaceutical and personal
care products
(PPCPs) and their emissions into natural water bodies pose formidable
challenges to ecosystem health. Because aquatic plants like hydrophyte natantia can effectively remove pollutants via
photosynthesis-powered rhizoextraction and phytotransformation, they
are widely applied in outdoor water purification; however, their performance
in degrading recalcitrant PPCPs remains inefficient. Here, we develop
a synthetic hydrophyte that mimics the main features of a natural
hydrophyte: photosynthesis (leaves), pollutant degradation (stem),
and pollutant extraction (root). CoOx/Mo:BiVO4/Pd artificial leaves photosynthesize hydrogen peroxide (H2O2), which is subsequently activated in the FeOCl
artificial stem, generating powerful hydroxyl radicals (•OH) that rapidly degrade pollutants extracted by the poly(vinylidene
fluoride) artificial root. The synthetic hydrophyte demonstrates remarkable
degradation rates of 85.0–99.5% for multiple recalcitrant PPCP
pollutants within 8 h, which are typically resistant to phytoremediation.
In outdoor tests, the pollutant removal efficiency of the synthetic
hydrophyte surpassed those of Hydrocotyle verticillata and Canna indica by 8.6–16.1-fold.
Moreover, synthetic hydrophytes exhibit distinct advantages of high
versatility under various pH, temperature, and water matrix conditions.
The promising sunlight-driven water purification achieved by the synthetic
hydrophyte sheds light on a new approach for achieving both efficient
and sustainable removal of recalcitrant PPCPs that are increasingly
detected in natural waters.