Visible
light response is as important as energy band potential
for photocatalytic water splitting. In this work, upconversion CeF3 nanoparticles are developed by O and N doping. The contents
and species of O and N regulated by various temperatures act on the
large-scale regulation of defects and band structures distinctly,
which can suppress the recombination of photogenerated carriers. O,N-CeF3-160 nanoparticles establish the most suitable defects and
electronic structure in all O,N-CeF3 nanoparticles. It
exhibits the optimal oxygen evolution rates up to 1277 μmol
g–1 h–1, whose apparent quantum
yield (AQY) is up to 53.09% at 550 nm. The photoluminescence (PL)
spectra and density of state (DOS) illustration elucidate the internal
reason for the distinct photocatalysis activity. Defects are just
as important as band structure in the modification of O,N-codoped
CeF3 upconversion nanoparticles. This work provides the
approach to regulate CeF3 upconversion materials to achieve
better photoactivity under visible light.