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[Display omitted] • Coordinative Fe-N x improved the catalytic ability of FeOCN for photo-Fenton process. • The consumption of H 2 O 2 was reduced in the photo-Fenton process over FeOCN. • FeOCN showed high catalytic performance for tetracycline degradation. • The improved charge separation favored Fe(III)/Fe(II) conversion. • FeOCN exhibited wide applicable pH range and anti-interference ability to anions. Tetracycline (TC) antibiotics have been widely used over the past decades, and their massive discharge led to serious water pollution. Photo-Fenton process has gained ever-increasing attention for its excellent oxidizing ability and friendly solar energy utilization ability in TC polluted water treatment. This work introduced coordinative Fe into oxygen-enriched graphite carbon nitride (OCN) to form FeOCN composites for efficient photo-Fenton process. Hemin was chosen as the source to provide the source of coordinative Fe-N x groups. The degradation efficiency of TC reached 82.1 % within 40 min of irradiation, and remained 76.9 % after five runs of reaction. The degradation intermediates of TC were detected and the possible degradation pathways were gained. It was found that h+, OH, and O 2 − played major roles in TC degradation. Notably, the photo-Fenton performance of FeOCN was stable in highly saline water or strong acid/base environment (pH 3.0–9.0). Besides, H 2 O 2 can be generated in-situ in this photo-Fenton process, which is favorable for practical application. It can be anticipated that the coordinative FeOCN composites will promote the application of photo-Fenton oxidation process in TC polluted water treatment. [ABSTRACT FROM AUTHOR]

The traditional homogenous and heterogenous Fenton reactions have frequently been restrained by the lower production of Fe2+ ions, which significantly obstructs the generation of hydroxyl radicals from the decomposition of H 2 O 2. Thus, we introduce novel photo-Fenton-assisted plasmonic heterojunctions by immobilizing Fe 3 O 4 and Bi nanoparticles onto 3D Sb 2 O 3 via co-precipitation and solvothermal approaches. The ternary Sb 2 O 3 /Fe 3 O 4 /Bi composites offered boosted photo-Fenton behavior with a metronidazole (MNZ) oxidation efficiency of 92% within 60 min. Among all composites, the Sb 2 O 3 /Fe 3 O 4 /Bi-5% hybrid exhibited an optimum photo-Fenton MNZ reaction constant of 0.03682 min− 1, which is 5.03 and 2.39 times higher than pure Sb 2 O 3 and Sb 2 O 3 /Fe 3 O 4 , respectively. The upgraded oxidation activity was connected to the complementary outcomes between the photo-Fenton behavior of Sb 2 O 3 /Fe 3 O 4 and the plasmonic effect of Bi NPs. The regular assembly of Fe 3 O 4 and Bi NPs enhances the surface area and stability of Sb 2 O 3 /Fe 3 O 4 /Bi. Moreover, the limited absorption spectra of Sb 2 O 3 were extended into solar radiation by the Fe3+ defect of Fe 3 O 4 NPs and the surface plasmon resonance (SPR) effect of Bi NPs. The photo-Fenton mechanism suggests that the co-existence of Fe 3 O 4 /Bi NPs acts as electron acceptor/donor, respectively, which reduces recombination losses, prolongs the lifetime of photocarriers, and produces more reactive species, stimulating the overall photo-Fenton reactions. On the other hand, the photo-Fenton activity of MNZ antibiotics was optimized under different experimental conditions, including catalyst loading, solution pH, initial MNZ concentrations, anions, and real water environments. Besides, the trapping outcomes verified the vital participation of •OH, h+, and •O 2 − in the MNZ destruction over Sb 2 O 3 /Fe 3 O 4 /Bi-5%. In summary, this work excites novel perspectives in developing boosted photosystems through integrating the photocatalysis power with both Fenton reactions and the SPR effects of plasmonic materials. • Photo-Fenton-assisted plasmonic Sb 2 O 3 /Fe 3 O 4 /Bi photocatalyst has been introduced. • Sb 2 O 3 /Fe 3 O 4 /Bi recorded 92% of MNZ removal in 60 min under simulated solar light. • The collaboration between SPR effects and photo-Fenton reactions promoted photoactivity. • Sb 2 O 3 /Fe 3 O 4 /Bi enabled the formation of h+,.•OH, and •O 2 − via the boosted photo-Fenton reaction. • The Fe3+/Fe2+ cycles of Fe 3 O 4 upgraded both light utilization and photocarrier disintegration. [ABSTRACT FROM AUTHOR]

In this study, photo-Fenton-like oxidation method was evaluated for synthetic sugar industry wastewater using visible-light driven Cu–BiOI photocatalyst. Reaction conditions including initial pH, catalyst loading, initial hydrogen peroxide (H 2 O 2) concentration, and temperature, were optimized. At these optimized conditions, the total saccharide concentration (TSC) and total organic carbon (TOC) removals were 56.20% and 30.67%, respectively whereas the maximum TSC and TOC removal reached up to 93.35% and 74.72% respectively by decreasing initial sucrose concentration. The kinetic study showed that the reaction order for sucrose and TOC oxidation was determined as 2 for pseudo-homogeneous power law models with respect to sucrose concentration and TOC, respectively.For heterogeneous models, Langmuir-Hinshelwood model based on the mechanism of adsorbed pollutant and oxidant on different catalytic sites was the best fit for oxidation of sucrose and other organic intermediates. According to the catalyst characterization studies, incorporation of copper was successful and Cu–BiOI possesses high photocatalytic activity accomplished by acid-assisted synthesis method. • A greener process was applied for treatment of sugar industry wastewater. • Highest TSC and TOC removals reached 93.35% and 74.72%, respectively. • Catalytic activity of Cu–BiOI was attributed to its unique micro-flower structure. • Oxidation reactions were represented by homogeneous and heterogeneous models. [ABSTRACT FROM AUTHOR]