Hydrogen-Treated TiO₂ Nanorods Decorated with Bimetallic Pd–Co Nanoparticles for Photocatalytic Degradation of Organic Pollutants and Bacterial Inactivation

Abstract

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.

Hollow TiO2–SiO2 Nanospheres for Photocatalytic Degradation of Organic Dyes

“…The morphology of the composite h-TiO 2 /SiO 2 was captured by field-emission scanning electron microscopy (SEM, Zeiss Sigma 300) at an accelerating voltage of 10 kV, and the samples were sputter-coated with a gold film before observation. The surface morphology of the photocatalysts during synthesis, including the carbon sphere templates and h-TiO 2 , was observed by transmission electron microscopy (TEM, FEI Talos F200X G2). − Functional groups in the samples were studied using a Fourier infrared spectrometer, and data were recorded in the range of 4000–400 cm –1 . Photoluminescence spectra were analyzed using an Edinburgh FLS 1000 fluorescence spectrophotometer.…”

Construction of a AgBr–Ag2MoO4 heterojunction and its photocatalytic sterilization activity

“…The used scavengers in this study are as follows: TEMPOL is for O 2 À , Cr(VI) is for electrons (e À ), sodium oxalate is for holes (h + ) and isopropanol is for OH, respectively. [38][39][40][41] As shown in Fig. 9, after adding TEMPOL and Cr(VI) to the reaction system, the antibacterial rate decreased by about half, which suggests that O 2…”

Combination of alkali treatment and Ag3PO4 loading effectively improves the photocatalytic activity of TiO2 nanoflowers

“…For example, Hwang et al loaded metal oxides on acid-treated TiO 2 nanorods and further hydrogen treated them, and the prepared photocatalysts achieved 99.63% and 99.90% degradation efficiency for orange II dye and bisphenol A, respectively. 26 This can be attributed to the oxygen vacancies and hydroxyl groups introduced by hydrogen treatment, which promote the charge transport and increase the number of active groups, thereby improving the photocatalytic performance of photocatalysts.…”