Herein,
first, we synthesize a multifunctional photocatalyst
via
metal oxides loaded (Co/Pd) on acid-treated TiO2 nanorods
(ATO) and further introduce hydrogen annealing treatment. The hydrogen
annealing treatment introduces metal oxides converted into a bimetallic
form and delays the photogenerated charge recombination process. Also,
oxygen vacancies are formed due to the partial reduction of Ti4+ to Ti3+ sites. In addition, oxygen vacancies
help to improve photocatalytic degradation and antibacterial activity.
The hydrogen-treated photocatalyst (Pd(1)Co(1)/ATO (red)) demonstrates
high degradation efficiencies of 99.63 and 99.90% (180 min) for orange
II dye and BPA degradation, respectively, and an antibacterial activity
of 97.00% (120 min) under one sun irradiation. In the photocatalytic
removal of abiotic pollutants and live bacteria, the trapping experiment
suggests that radical species (•O2
– and •OH), assisted by photoinduced
holes, are responsible for the high activities. The photoelectrochemical
performance and time-resolved PL (TRPL) study illustrate that Pd(1)Co(1)/ATO
(red) reveals superior photoelectrochemical charge separation (electron–hole),
lower resistance, and shorter lifetime (τ1 = 0.40
ns) as a photocatalyst. Finally, plausible charge transport mechanisms
are proposed for the photocatalytic degradation of organic dye and
bacterial disinfection over the Pd(1)Co(1)/ATO (red) photocatalyst.