Photocatalytic degradation of nitrobenzene in wastewater by persulfate integrated with Ag/Pb3O4 semiconductor under visible light irradiation

Abstract

Nitrobenzene oxidation was executed utilizing an innovative method, in which Ag/Pb 3 O 4 semiconductors irradiated by visible light were used for activation of persulfate into sulfate radicals. Batch mode experiments were accomplished to elucidate the effect of persulfate concentrations and Ag/Pb 3 O 4 dosages on the nitrobenzene oxidation behaviors. The physicochemical properties of original and reacted Ag/Pb 3 O 4 were illustrated by X-ray diffraction analyses, UV-Vis diffuse reflectance spectra, FE-SEM images, EDS analyses, photoluminescence spectra and X-ray photoelectron spectra, respectively. The main oxidant was hypothesized to be sulfate radicals, induced from persulfate caused by photocatalysis of Ag/Pb 3 O 4 . It was clearly reflected on the scavenging experiments with addition of benzene, ethanol and methanol individually. As far as degradation pathways concerned, nitrobenzene was essentially transformed into hydroxycyclohexadienyl radicals, and sequentially converted to 2-nitrophenol, 3-nitrophenol or 4-nitrophenol simultaneously. Denitration of nitrophenols gave rise to synthesis of phenol, followed with generation of hydroquinone and p -benzoquinone.

A critical review of textile industry wastewater: green technologies for the removal of indigo dyes

“…Processes based on ozone oxidation (e.g., O 3 /UV, O 3 /H 2 O 2 , O 3 /Fe 2+ , O 3 /ultrasound) (Rekhate and Srivastava 2020 ; Li et al 2021 ; Yacouba et al 2021 ) and electrooxidation through imposed an electric potential involve the hydroxyl radicals being generated on an electrode surface (Asfaha, Tekile and Zewge, 2021 ; Ding et al 2021 ; Ozyonar and Solmaz 2021 ; Song et al 2022 ). Recently, peracids such as peracetic acid, and salts, such as peroxymonosulfate and persulfate, have been proposed as new oxidants in wastewater treatment (Chen and Liu 2021 ; Chu et al 2021 ; Escobedo, Cho and Chang, 2021 ; Hao et al 2021 ; Kiejza et al 2021 ).…”

Photocatalytic Degradation of Toxic Phenolic Compound and Bacterial Inactivation by Ternary Li doped Zn0.5Ni0.5Fe2O4

“…Although the specific mechanism of the Li/ antibacterial ZNF's activity is unknown, the discussion is consistent with earlier studies. [42][43][44][45][46][47] In Table 1, the performance of Li/ZNF is compared to that of other reported doped materials. The results reveal that Li/ZNF has comparatively greater performance.…”

“…À quenching [43] or interacts with the radical to produce a weaker oxidant ( * SO 5 À ) above the optimum concentration. Based on the findings, 4 mM H 2 O 2 was used for the following studies.…”

“…When persulfate is injected into the system, photocatalysis of Li/ZNF can successfully transform part of the S 2 O 8 2À anions into * SO 4 À radicals. Also, according to prior studies, [40][41][42][43] À , which then attacks the TCP in the system. Excess K 2 S 2 O 8 causes * SO 4…”

Pb/Pb3O4 Metal–Semiconductor Nanocomposite Obtained on 4A Zeolite─Optical and Structural Properties

“…Metallic nanoalloys containing metal oxides can enhance mechanical properties, thermal stability, electrical and magnetic characteristics, and corrosion resistance when compared to individual nanomaterials or their larger-scale counterparts. , These improvements enable a wide range of specific applications, especially in solar cells, biosensors, catalysis, and nanodevices, among others. − In addition, incorporating metal oxides can provide special electrical or magnetic properties to the alloys. − Lead and its oxides are mainly used to manufacture rechargeable lead-acid batteries, corrosion-resistant surface coatings, and catalysts. − In this context, photoconductive lead oxides have gained popularity as essential semiconductor materials in various optoelectronic devices. − Among the lead oxides, minimum or red lead (Pb 3 O 4 ) is a semiconductor with a band gap around 2.1–2.2 eV. It stands out due to its excellent pyroelectric and ferroelectric properties and high electrical resistivity .…”