The Inhibition Effect of Tert-Butyl Alcohol on the TiO2 Nano Assays Photoelectrocatalytic Degradation of Different Organics and Its Mechanism

Abstract

The inhibition effect of tert-butyl alcohol (TBA), identified as the ^•OH radical inhibitor, on the TiO₂ nano assays (TNA) photoelectrocatalytic oxidation of different organics such as glucose and phthalate was reported. The adsorption performance of these organics on the TNA photoelectrode was investigated by using the instantaneous photocurrent value, and the degradation property was examined by using the exhausted reaction. The results showed that glucose exhibited the poor adsorption and easy degradation performance, phthalate showed the strong adsorption and hard-degradation, but TBA showed the weak adsorption and was the most difficult to be degraded. The degradation of both glucose and phthalate could be inhibited evidently by TBA. But the effect on glucose was more obvious. The different inhibition effects of TBA on different organics could be attributed to the differences in the adsorption and the degradation property. For instance, phthalate of the strong adsorption property could avoid from the capture of ^•OH radicals by TBA in TNA photoelectrocatalytic process.

Keywords: Hydroxyl radical inhibitor; Inhibition effect; Photoelectrocatalysis; Tert-butyl alcohol; TiO2 nano assays.

Fig. 1

SEM images of the TiO₂ nanotube arrays obtained from a the top view and b the cross-section. c The cyclic voltammetry performance of this thin-layer reactor. d The comparison of PEC, photocatalytic (PC), and electrocatalytic (EC) degradation of 100 mg L⁻¹ glucose

Fig. 2

The structure of the thin-layer reactor. 1—TiO₂ nanotube array electrode; 2—The saturated Ag/AgCl reference electrode; 3—The Pt counter electrode; 4—The quartz window; 5—The flow inlet; 6—The flow outlet

Fig. 3

The schematic diagram of typical response photocurrent signals in the glucose oxidation

Fig. 4

I–t curves obtained from PEC degradation of a glucose and b phthalate at different concentrations. The relationship between I ₀ value and the initial concentration of c glucose and d phthalate

Fig. 5

a I–t curves obtained from the PEC degradation of TBA at different concentrations. b The relationship between the concentration of TBA and its original photocurrent value. c The I–t curves obtained from the PEC degradation of glucose and TBA both at the concentration of 100 mg L⁻¹. d The Q _net obtained from the PEC degradation of glucose and TBA

Fig. 6

The comparison of I–t curves obtained from the PEC oxidation of organics in and out of present TBA. a Glucose b Phthalate

Fig. 7

I–t curves obtained from the PEC degradation of 100 mg L⁻¹ TBA and 100 mg L⁻¹ a glucose b phthalate containing TBA of different concentrations, respectively. c The relationship between I ₀ value and the concentration of TBA that existing in the glucose-TBA and phthalate-TBA mixtures

Fig. 8

The degradation rate of the mixture vs the different concentrations of added TBA

Fig. 9

The schematic diagram of the PEC degradation of organic-TBA mixtures on the surface of TNA electrode