Rapid Degradation and Mineralization of Perfluorooctanoic Acid by a New Petitjeanite Bi₃O(OH)(PO₄)₂ Microparticle Ultraviolet Photocatalyst

Abstract

Water treatment techniques for destructive removal of perfluoroalkyl substances (PFAS) have only recently begun to emerge in the research literature, comprising unconventional advanced oxidation and reduction methods. Photocatalytic degradation of PFAS has not been widely pursued, which is a result of the limited ability of common semiconductor materials to induce C−F bond cleavage in aqueous systems. Herein, degradation of perfluorooctanoic acid (PFOA) by bismuth phosphate photocatalysts under ultraviolet irradiation has been investigated for the first time, including the relatively well-known monoclinic BiPO 4 wide band gap semiconductor, as well as a novel Bi 3 O(OH)(PO 4 ) 2 (BOHP) composition. Compared to BiPO 4 and a β-Ga 2 O 3 nanomaterial reference catalyst, BOHP microparticles achieved dramatically faster PFOA degradation and mineralization, despite both a smaller surface area and a lower band gap energy. The rate constant for degradation of PFOA by BOHP in a pure water solution was ∼15 times greater than those of both BiPO 4 and β-Ga 2 O 3 (∼20−30 times greater when normalized for surface area) and was on the same order of magnitude as that of phenol degradation by P25 TiO 2 in the same photoreactor. The superior performance of BOHP was primarily related to the surface charge and adsorption behavior of PFOA, in combination with the favorable redox potentials of BOHP charge carriers. The catalyst was further tested at low PFOA concentrations (i.e., microgram per liter range) in the presence of natural organic matter, and rapid degradation of PFOA was also observed, indicating the potential of BOHP to enable practical ex situ destructive treatment of PFAS-contaminated groundwater.

A BiOCl/β-FeOOH heterojunction for HER photocatalytic performance under visible-light illumination

“…For the effective potential difference of CB between BiOCl and β-FeOOH, the e − of β-FeOOH can transfer to the CB of BiOCl through the fabricated heterojunction interfaces. In this process, the transferred e − can be captured by H 2…”

“…However, while developing the industry, it also caused a lot of energy consumption. In order to be sustainable, energy crisis have attracted more and more attention . Therefore, how to solve the above problem efficiently becomes a hot topic of research.…”

“…In order to be sustainable, energy crisis have attracted more and more attention. [1][2][3][4][5] Therefore, how to solve the above problem efficiently becomes a hot topic of research.…”

Reductive Defluorination and Mechanochemical Decomposition of Per- and Polyfluoroalkyl Substances (PFASs): From Present Knowledge to Future Remediation Concepts

“…After three hours of UV treatment, 98.8% of PFOA was degraded and the defluorination rate was 31.6% under anaerobic conditions. Sahu et al used a bismuth phosphate photocatalyst (Bi 3 O(OH)(PO 4 ) 2 ) for the UV treatment of PFOA [ 95 ]. This material showed quantitative PFOA degradation after one hour and a defluorination rate of approximately 60% after two hours, which was much higher than for other catalysts (Ga 2 O 3 , BiPO 4 and TiO 2 ) in this experiment.…”

Highly Efficient Degradation of Perfluorooctanoic Acid over a MnOx‐Modified Oxygen‐Vacancy‐Rich In2O3 Photocatalyst

“…[7] Cates et al reported a Bi 3 O(OH) (PO 4 ) 2 microparticle ultraviolet photocatalyst for PFOA degradation. [8] A recent study found that PFOA molecules can bind well to the surface of commercial In 2 O 3 through their terminal carboxylate groups via a bidentate or bridging configuration. [9] Thus, upon UV irradiation, In 2 O 3 shows a significant photocatalytic degradation ability towards PFOA.…”