Synthesis of FePcS-PMA-LDH Cointercalation Composite with Enhanced Visible Light Photo-Fenton Catalytic Activity for BPA Degradation at Circumneutral pH.

Fenglian Huang,Erping Li,Shiqiang Tian,Yan Qi,Yaqun Qiu,Liangliang Zhou

doi:10.3390/ma13081951

Abstract

(1) Background: Iron tetrasulfophthalocyanine with a large nonlinear optical coefficient, good stability, and high catalytic activity has aroused the attention of researchers in the field of photo-Fenton reaction. Further improvement of the visible light photo-Fenton catalytic activity under circumneutral pH conditions for their practical application is still of great importance. (2) Methods: In this paper, iron tetrasulfophthalocyanine (FePcS) and phosphomolybdic acid (PMA) cointercalated layered double hydroxides (LDH) were synthesized by the ion-exchange method. All samples were fully characterized by various techniques and the results showed that FePcS and PMA were successfully intercalated in layered double hydroxides and the resulted compound exhibited strong absorption in the visible light region. The cointercalation compound was tested as a heterogeneous catalyst for the visible light photo-Fenton degradation of bisphenol A (BPA) at circumneutral pH. (3) Results: The results showed that the degradation and total organic carbon removal efficiencies of bisphenol A were 100% and 69.2%, respectively. (4) Conclusions: The cyclic voltammetry and electrochemical impedance spectroscopy measurements demonstrated that the main contribution of PMA to the enhanced photo-Fenton activity of FePcS–PMA–LDH comes from the acceleration of electron transfer in the reaction system. Additionally, the possible reaction mechanism in the photo-Fenton system catalyzed by FePcS–PMA–LDH was also proposed.

Highlights

In recent years, great endeavors have been made to develop efficient chelating agents for stabilizing iron and enhancing the photo-Fenton degradation of refractory organic contaminants in water under neutral pH conditions [1,2,3,4]
The above peaks can be found in the patterns of FePcS–layered double hydroxides (LDH) and FePcS–phosphomolybdic acid (PMA)–LDH, but slightly shifted to lower angles when compared with ZnAl–LDH
The value of the basal distance increased from 0.894 nm for ZnAl–LDH to 1.037 nm and 1.046 nm for FePcS–LDH and FePcS–PMA–LDH, respectively (Table 1). These results indicate the interlayer space of ZnAl–LDH is expanded after intercalated by FePcS and FePcS–PMA

Summary

Introduction

Great endeavors have been made to develop efficient chelating agents for stabilizing iron and enhancing the photo-Fenton degradation of refractory organic contaminants in water under neutral pH conditions [1,2,3,4]. A large number of Fe complexes such as Fe–ethylenediaminetetraacetic acid, Fe–oxalate, Fe–ethylenediamine–N, N0 –disuccinic acid, and iron phthalocyanine complex (FePc) have been reported as photo-Fenton catalysts [5,6,7,8], in which FePc has been found to have good response to visible light [7,9,10,11]. Effective energy transfer can occur between the excited FePc and H2 O2 , resulting in the formation of the OH radical, which can oxidize organic matter with high efficiency [12]. Previous studies have shown that POM can act as an electron acceptor and lead to the formation of reduced POM [14,15,16,17,18], which can accelerate the transfer of

Methods

Results

Discussion

Conclusion