Core/shell FeVO4@BiOCl heterojunction as a durable heterogeneous Fenton catalyst for the efficient sonophotocatalytic degradation of p-nitrophenol

Abstract

In this study, a FeVO4@BiOCl p-n heterojunction with n-type porous FeVO4 nanorods as the core and p-type flower-like BiOCl nanostructures as the shell was successfully prepared by a facile hydrothermal method. The novel heterostructure was investigated as a durable heterogeneous Fenton catalyst for ultrasonic irradiation (US), ultraviolet irradiation (UV) and coupling irradiation systems (US/UV). Characterization of FeVO4@BiOCl core shell heterojunction was conducted by XRD, SEM, EDS elemental mapping, TEM, HRTEM, SAED, FTIR, Raman, BET, PZC, XPS and DRS. Several different experimental parameters, including irradiation time, H2O2 concentration, catalyst amount, initial concentration, and pH value, were optimized. The stability and reusability of the prepared FeVO4@BiOCl core shell heterojunction were evaluated as well. Mineralization experiments were carried out using the optimized parameters. The results showed that FeVO4@BiOCl core shell heterojunction exhibits a superior sonophotocatalytic performance compared to either sonocatalysis or photocatalysis. Moreover, the formation of p-n core@shell nanostructures could significantly increase the pHpzc, and to an excellent stability for the degradation of PNP after six cycles. The remarkable enhancement of the degradation performance of FeVO4@BiOCl core shell heterojunction can be attributed to the unique structure and morphology with a matched energy band structure owing to the internal electric field induced by the p-n junction, a high transfer efficiency and the efficient separation of e -/h + pairs, resulting in a huge number of reactive species for the degradation of PNP. A plausible mechanism over FeVO4@BiOCl core shell heterojunction for the sonophotocatalytic degradation of PNP is proposed based on a special three-way, i.e. one as a photocatalyst and a two-way Fenton-like mechanism with the dissociation of H2O2. Active species trapping and calculated band gap energy were also discussed.

Highly efficient catalytic degradation of p-nitrophenol by Mn3O4.CuO nanocomposite as a heterogeneous fenton-like catalyst

“…The comparison of catalytic dosage, sonication time and removal efficiency of proposed catalyst and reported catalysts for the degradation of nitrophenol compounds was presented in Table 1. As can be seen, the proposed catalyst displayed relatively short sonication time and also considerable removal efficiency comparing with other reported catalysts [22][23][24]45,46]. The results reported in this study showed that the prepared catalyst is a potential candidate for the removal of PNP from aqueous solution.…”

Hydrogen peroxide enhanced sonophotocatalytic degradation of acid orange 7 in aqueous solution: optimization by Box–Behnken design

“…Previous studies also confirmed that ˙OH played an important role in degrading various dyes such as acid blue 113, acid blue 7 and methyl orange using US/UV/ZnO/PS, 11 US/metal–organic framework‐2/peroxydisulfate and formic acid/UV systems, respectively 41,42 . Other reactive species such as h+ and electrons (e − ) may exist in the current system, but their contributions to dye removal were reported to be small in comparison with the ˙OH 43 …”

Synthesis, Functional Modifications, and Diversified Applications of Hybrid BiOCl-Based Heterogeneous Photocatalysts: A Review

“…According to previous research, BiOCl-based photocatalysts can be divided into three main categories: metal/BiOCl, semiconductor/BiOCl, and carbon/BiOCl heterogeneous structures. − ,,,,− ...…”

“…The synthesis of type-II and Z-scheme junctions in metal oxide (sulfide)/BiOCl systems is a promising method to acquire higher photocatalytic performances, which provides a better opportunity to understand the transfer pathways of photoinduced charge carriers and further reveals the photocatalytic mechanisms. In recent years, the controllable synthesis of metal oxide (sulfide)/BiOCl and other oxysalts/BiOCl photocatalysts has been extensively reported, and the relationships between structure and property as well as performance of products have also been amply elucidated. − …”

“…Besides, other double metal oxide/BiOCl composites have also been successfully fabricated, including Bi 2 MoO 6 /BiOCl, , Bi 2 Ti 2 O 7 /BiOCl, Bi 4 Ti 3 O 12 /BiOCl, ZnFe 2 O 4 /BiOCl, , Cs x WO 3 /BiOCl, NaBiO 3 /BiOCl, LiBiO 3 /BiOCl, SrFe 12 O 19 /BiOCl, PbBiO 2 Cl/BiOCl, KCa 2 Nb 3 O 10 /BiOCl, CoWO 4 /BiOCl, FeVO 4 @BiOCl, NiCo 2 O 4 @BiOCl, and CuBi 2 O 4 /BiOCl . The corresponding synthetic methods, reactants and applications are summarized in Table .…”