The photocatalytic selectivity between molecularly imprinted TiO₂ and target contaminants

In this paper, it is proposed that the photocatalysis selectivity exists between the catalysts and the target contaminants. Therefore, the selectivity of the two catalysts, MIP-TiO₂ and NIP-TiO₂, can be distinguished by using the same test wavelength to measure the absorbance of different pollutants and different test wavelength to measure the absorbance of the pollutants. At first, MIP-TiO₂ was obtained in one step to degrade ethyl parahydroxybenzoate wastewater. Then, the effects of test wavelength and test time on the standard curve, reaction rate, selectivity coefficient, and selectivity factor, as well as the effect of the amount of molecular imprinting on photocatalytic activity and selectivity are studied through photocatalytic experiments. XRD, FT-IR, and TEM were used to characterize the catalysts. The results show that the test wavelength and reaction time have impact on the reaction rate, selectivity coefficient, while selectivity factor, and have no effect on the simulation of the standard curve. Furthermore, the selectivity factor does not change its applicability to calculate the selectivity due to the different selectivity coefficients. In addition, the degradation rate of target contaminants in 2 h by MIP-TiO₂ is 81%, while NIP-TiO₂ is only 74%. Moreover, MIP-TiO₂ has a selectivity factor of 2.680, indicating that it has a higher selectivity for target contaminants than NIP-TiO₂. This paper provides a further understanding of the photocatalytic selectivity between molecularly imprinted TiO₂ and target contaminants.