Cooperative coupling of photocatalytic production of H2O2 and oxidation of organic pollutants over gadolinium ion doped WO3 nanocomposite

This work reported the lanthanide ion (Gd3+) doped tungsten trioxide (Gd-WO3) nanocrystal for remarkable promoted photocatalytic degradation of organic pollutants and simultaneous in-situ H2O2 production. With doped lanthanide ion (Gd3+), Gd-WO3 showed a much broad and enhanced solar light absorption, which not only promoted the photocatalytic degradation efficiency of organic compounds, but also provided a suitable bandgap for direct reduction of oxygen to H2O2. Additionally, the isolated Gd3+ on WO3 surface can efficiently weaken the *OOH binding energy, increasing the activity and selectivity of direct reduction of oxygen to H2O2, with a rate of 0.58 mmol L−1 g−1 h−1. The in-situ generated H2O2 can be subsequently converted to •OH based on Fenton reaction, further contributed to the overall removal of organic pollutants. Our results demonstrate a cascade photocatalytic oxidation-Fenton reaction which can efficiently utilize photo-generated electrons and holes for organic pollutants treatment.