The production discipline and mechanism of hydroxyl radical by investigating the Ln2O3-Bi2MoO6 heterojunction photocatalysts

In order to reveal the radicals production mechanism and discipline of heterojunction photocatalysts, a series of novel Ln(2)O(3)-Bi2MoO6 (Ln = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb and Lu) were designed and successfully synthesized. The photocatalytic experiments and radical trapping experiments illustrated that all the Ln(2)O(3)-Bi2MoO6 samples efficiently enhanced the photocatalytic performance, and the samples loaded by single valence Ln(2)O(3) (Nd2O3, Gd2O3, Dy2O3, Er2O3 and Lu2O3) could only produce superoxide radicals (center dot O-2(-)), and holes (h(+)) in the photocatalytic process, and the samples loaded by multivalence Ln(2)O(3) (Ce2O3, Yb2O3, Pr2O3, Sm2O3, Eu2O3 and Tb2O3) additionally produced the powerful hydroxyl radical (center dot OH), and further enhanced the photocatalytic performance. Significantly, the Ln(2)O(3)-Bi2MoO6 could produce abundant center dot OH and show superior photocatalytic performance when both valence states of multivalence lanthanide ions are unstable 4f electronic structure (4f(2), 4f(1) in Pr3+, Pr4+ and 4f(5), 4f(6) in Sm3+, Sm2+), and the possible mechanism of radicals production in different Ln(2)O(3)-Bi(2)MoO(6 )heterojunctions system was creatively put forward. This study deeply investigated the production discipline and mechanism of hydroxyl radical in Ln(2)O(3)-Bi2MoO6 heterojunction photocatalysts, and provided a theory foundation for fabricating novel lanthanide oxide loaded photocatalysts. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study revealed that Ln(2)O(3)-Bi2MoO6 photocatalysts' performance is influenced by lanthanide oxides, with multivalence lanthanide oxide carriers producing more hydroxyl radicals and enhancing photocatalytic effects.