Facile synthesis and characterization of CeO2-Al2O3 nano-heterostructure for enhanced visible-light photocatalysis and bactericidal applications

Abstract This investigation reports the enhancement of CeO2 activity as photocatalyst and antimicrobial agent by loading Al2O3 for heterojunction formation. The characterization of CeO2/Al2O3 nanocomposites (NCs) was done using HRTEM, XRD, XPS, PL, BET, FTIR, EDAX, SAED and UV–Vis-DRS. XPS core level scan of Ce3d, Al2p and O1s was analyzed to identify chemical states. The band gap of NCs was shifted to 3.05 eV from individual Al2O3 (3.72 eV) after coupling CeO2. The photocatalytic efficiency of CeO2-Al2O3 was higher with apparent-kinetic constant of 4.4 × 10−3 min−1 which was 1.9 and 1.3 times higher than Al2O3 and CeO2 respectively. The OH· and ·O2− radicals were effectively formed during photocatalysis. NCs possessed high stability and resistant to photo-corrosion. The NCs pose high growth inhibition against E. coli, S. aureus, B. subtilis and P. aeruginosa. The potential visible-light energy usage prompted CeO2/Al2O3 NCs as noteworthy candidate for photodegradation of pollutants and for antimicrobial applications.