Incorporating Bi nanodots into CuBi2O4/CuFe2O4 heterojunction for a wide spectral synchronous photoreduction of hexavalent chromium and degradation of imidacloprid

Here in, we report a, wide spectrum active, Bi nanodots incorporated CuBi2O4/Bi/CuFe2O4 (CBC) heterojunction for synchronous photodegradation of imidacloprid pesticide (ICP) and photo-reduction of Cr(VI) to Cr(III). The best performing heterojunction sample CBC-30 shows nearly 100% Cr(VI) photo reduction (in less than 45 min) along with 98.2% ICP removal in 60 min. 88.7% Cr (VI) reduction & 83.2% ICP degradation was achieved under sunlight with good activity in NIR region. Scavenging experiments reveal the synchronous role of photoreduction-oxidation with electrons as active species for chromium reduction and holes for organic pollutant degradation. This is ensured by effective Z-scheme transfer between CuBi2O4 and CuFe2O4 leading to protection of high potential conduction and valence bands with strong redox capabilities. The Bi nanodots played an important role via wide spectral response owing its surface plasmon resonance as well as photoinduced electron transfer mediation which promotes the electrons transfer efficiency and enhanced photocatalytic ability.