Turning on Singlet Oxygen Generation by Outer-Sphere Microenvironment Modulation in Porphyrinic Covalent Organic Frameworks for Photocatalytic Oxidation.

Singlet oxygen (1 O2 ) is ubiquitously involved in various photocatalytic oxidation reactions; however, efficient and selective production of 1 O2 is still challenging. Herein, we reported the synthesis of nickel porphyrin-based covalent organic frameworks (COFs) incorporating functional groups with different electron-donating/-withdrawing features on their pore walls. These functional groups established a dedicated outer-sphere microenvironment surrounding the Ni catalytic center that tunes the activity of the COFs for 1 O2 -mediated thioether oxidation. With the increase of the electron-donating ability of functional groups, the modulated outer-sphere microenvironment turns on the catalytic activity from a yield of nearly zero by the cyano group functionalized COF to an excellent yield of 98 % by the methoxy group functionalized one. Electronic property investigation and density-functional theory (DFT) calculations suggested that the distinct excitonic behaviors attributed to the diverse band energy levels and orbital compositions are responsible for the different activities. This study represents the first regulation of generating reactive oxygen species (ROS) based on the strategy of outer-sphere microenvironment modulation in COFs.

Synergized photothermal therapy and magnetic field induced hyperthermia via bismuthene for lung cancer combinatorial treatment.

Thanks to its intrinsic properties, two-dimensional (2D) bismuth (bismuthene) can serve as a multimodal nanotherapeutic agent for lung cancer acting through multiple mechanisms, including photothermal therapy (PTT), magnetic field-induced hyperthermia (MH), immunogenic cell death (ICD), and ferroptosis. To investigate this possibility, we synthesized bismuthene from the exfoliation of 3D layered bismuth, prepared through a facile method that we developed involving surfactant-assisted chemical reduction, with a specific focus on improving its magnetic properties. The bismuthene nanosheets showed high in vitro and in vivo anti-cancer activity after simultaneous light and magnetic field exposure in lung adenocarcinoma cells. Only when light and magnetic field are applied together, we can achieve the highest anti-cancer activity compared to the single treatment groups. We have further shown that ICD-dependent mechanisms were involved during this combinatorial treatment strategy. Beyond ICD, bismuthene-based PTT and MH also resulted in an increase in ferroptosis mechanisms both in vitro and in vivo, in addition to apoptotic pathways. Finally, hemolysis in human whole blood and a wide variety of assays in human peripheral blood mononuclear cells indicated that the bismuthene nanosheets were biocompatible and did not alter immune function. These results showed that bismuthene has the potential to serve as a biocompatible platform that can arm multiple therapeutic approaches against lung cancer.

Exploring the Enhanced Catalytic Activity of Pt Nanoparticles Generated on the Red Phosphorus/Graphitic Carbon Nitride Binary Heterojunctions in the Photo-assisted Hydrolysis of Ammonia Borane.

Ammonia borane (AB) holds great promise for chemical hydrogen storage, but its slow dehydrogenation kinetics under ambient conditions requires a suitable catalyst to facilitate hydrogen production from AB. Here, we fabricated binary red phosphorus/graphitic carbon nitride (RP/g-CN) heterojunctions decorated with Pt nanoparticles (NPs, denoted Pt/RP/g-CN) with a facile ultrasound-assisted two-step protocol as a photo-assisted catalyst for the hydrolysis of AB (HAB). The heterojunction established through intimate P-O-N bonds was proven to have improved photophysical properties such as a lower electron-hole recombination and enhanced visible light utilization compared to the pristine components. With the incorporation of Pt NPs, the optical properties of RP/g-CN heterojunctions were further improved through Schottky junction formation between semiconductors and Pt NPs, enabling a superb hydrogen gas (H2) generation rate of 142 mol H2·mol Pt-1·min-1 under visible light irradiation. Even though g-CN is a well-known host material for many metal NPs, here we discovered that the interaction of Pt NPs with RP in the ternary heterojunction structure is more favorable than that of g-CN, stressing the key role of RP as a support material in the designed ternary heterostructure. The band alignment of the ternary heterojunction catalyst along with the flow of charge carriers was also studied and shown to be a type-II heterojunction structure without hole migration, namely, a complex type-II heterojunction. Several scavenger experiments were also conducted to explain the mechanism of the photo-assisted HAB. To the best of our knowledge, this is the first example of a dual mechanism proposed for the visible light-assisted HAB. While the majority of the H2 was believed to be produced on the Pt NPs surface with the traditional B-N bond dissociation mechanism, the strong oxidizing action of OH• radicals formed by the heterojunction photocatalyst was also speculated to account for the 33% increase in the activity upon visible light irradiation through another mechanism.

Boosting Tetracycline Degradation with an S-Scheme Heterojunction of N-Doped Carbon Quantum Dots-Decorated TiO2.

N-doped carbon quantum dots (N-CQDs) derived from the Rumex crispus L. plant were incorporated into TiO2 via a facile hydrothermal method. As-prepared materials were characterized and used in the photocatalytic tetracycline (TC) degradation under UVA light irradiation by examining several operational parameters involving the N-CQDs amount, initial TC concentration, pH, and photocatalytic reaction time. XRD analysis revealed the conversion of the rutile phase to the anatase phase after the incorporation of N-CQDs into the TiO2 structure. The results revealed that the N-CQDs/TiO2 photocatalysts demonstrated the highest efficiency in TC degradation compared to other processes of adsorption, photolysis (UVA), and photocatalysis with TiO2 (TiO2/UVA). Under optimized conditions, 10 mg/L TC at pH 5.15 with 0.2 g/L N-CQDs/TiO2 catalyst showed 97.7% photocatalytic degradation for 120 min under UVA irradiation. The formation of an S-scheme heterojunction between N-CQDs and TiO2 provided enhanced charge separation and strong redox capability, causing significant improvement in the photocatalytic performance of N-CQDs/TiO2. Trapping experiments showed that O2•- and h+ are the predominant reactive species for the TC elimination in an aqueous solution.

Facile preparation of N-tert-butyl amides under heat-, metal- and acid-free conditions by using tert-butyl nitrite (TBN) as a practical carbon source.

tert-Butyl nitrite (TBN) is a nontoxic substance that has frequently been used as a source of nitrogen, oxygen, or nitric oxide (NO), but not as a carbon source in chemical transformations. Here, for the first time to the best of our knowledge, we introduced TBN as a source of carbon (tert-butyl group) for the synthesis of highly valuable N-tert-butyl amides from nitriles and water under very mild conditions.

A facile tert-butyl nitrite-assisted preparation of deamino graphitic carbon nitride (DA-gCN) as a photocatalyst for the C-H arylation of heteroarenes using anilines as radical source.

In pristine graphitic carbon nitride (g-CN), amino groups often function as structural defects that trap photogenerated charges, resulting in low photocatalytic activity as well as reaction with nitrite, aldehyde, etc., ensuing in poor product yield. Without significantly altering the optical characteristics, the removal of amino groups is necessary to increase the photocatalytic activity and structural stability of pristine g-CN. The deamino graphitic carbon nitride (DA-gCN-5) was prepared by tert-butyl nitrite (TBN)-treatment, characterized and used as a photocatalyst for the radical C-H arylation of heteroarenes using anilines as radical source. Indeed, the photophysical characteristics of DA-gCN-5 and those of pristine g-CN are very comparable, except that DA-gCN-5 has a fewer residual amino groups, higher crystallinity, and compressed structure with a different morphology. Moreover, DA-gCN-5-catalyzed C-H arylation reaction offers greater product yield in a shorter reaction time compared to that of pristine g-CN in the coupling between heteroarenes and the in situ generated aryl diazonium salts from anilines under visible light irradiation. The amino groups in pristine g-CN absorbed the TBN that was added to convert aniline into the appropriate diazonium ions during the reaction. As a result, deamino graphitic carbon nitride produced by chemical treatment has better photophysical properties and catalytic activity than pristine g-CN. Additionally, this is the first method that uses diazotization reaction for the preparation of deamino graphitic carbon nitride, as far as we are aware.

One-pot synthesis of graphene hydrogel/M (M: Cu, Co, Ni) nanocomposites as cathodes for electrochemical removal of rifampicin from polluted water.

Nowadays, the removal of pharmaceutical contaminants from water resources and wastewater is of great importance due to environmental and health issues. Over the decades, various methods have been reported to remove pollutants from wastewater. Among the developed methods, advanced oxidation processes (AOPs) have received significant attention from researchers. In this study, we report the one-pot synthesis of graphene hydrogel-metal (GH-M, M: Co, Ni, Cu) nanocomposites via the combination of polyol and hydrothermal methods. The structure of the resulting nanocomposites was examined by transmission electron microscopy (TEM), inductively coupled plasma-mass spectroscopy (ICP-MS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and Raman spectroscopy methods. Afterward, as-prepared GH-Cu, GH-Co, and GH-Ni nanocomposites were used to prepare cathodes for the electro-Fenton (EF) process to remove rifampicin (RIF) from polluted water. The effect of operational parameters, including current density (mA/cm2), initial pH, initial RIF concentration (mg/L), and process time (min) was investigated via response surface methodology (RSM). The optimal values for current density, pH, initial RIF concentration, and process time using GH-Ni as cathode were 30 mA/cm2, 5, 30 mg/L, and 90 min, respectively. The results at optimal values showed that the maximum RIF removal efficiency for GH-Cu, GH-Co, and GH-Ni cathodes was 90.47, 92.60, and 93.69%, respectively. Brunauer Emmett Teller (BET), atomic force microscopy (AFM), energy-dispersive X-ray (EDX), and cyclic voltammetry (CV) analyses were performed to investigate the performance of the cathodes for the RIF removal. Finally, total organic carbon (TOC), gas chromatography-mass spectrometry (GC-MS), and atomic absorption spectroscopy (AAS) analyses were performed for further investigation of the RIF removal from polluted water. The results claimed that one-pot synthesized GH-M cathodes can effectively remove RIF from polluted water through EF process.

Optimizing Pt Electronic States through Formation of a Schottky Junction on Non-reducible Metal-Organic Frameworks for Enhanced Photocatalysis.

Charge transfer between metal sites and supports is crucial for catalysis. Redox-inert supports are usually unfavorable due to their less electronic interaction with metal sites, which, we demonstrate, is not always correct. Herein, three metal-organic frameworks (MOFs) are chosen to mimic inert or active supports for Pt nanoparticles (NPs) and the photocatalysis is studied. Results demonstrate the formation of a Schottky junction between Pt and the MOFs, leading to the electron-donation effect of the MOFs. Under light irradiation, both the MOF electron-donation effect and Pt interband excitation dominate the Pt electron density. Compared with the "active" UiO-66 and MIL-125 supports, Pt NPs on the "inert" ZIF-8 exhibit higher electron density due to the higher Schottky barrier, resulting in superior photocatalytic activity. This work optimizes metal catalysts with non-reducible supports, and promotes the understanding of the relationship between the metal-support interaction and photocatalysis.

Magnetically recoverable nickel-palladium alloy nanocatalysts for direct C-H arylation reactions.

Novel magnetically recoverable nanocatalyst comprising nickel-palladium (NiPd) alloy nanoparticles (NPs) supported on reduced graphene oxide (rGO) modified with cobalt ferrite (CoFe2O4) NPs was fabricated for the direct C-H arylation of imidazopyridine, imidazole, indolizine and furan with aryl halides. To prepare the presented catalyst, rGO nanosheets were first modified with as-synthesized CoFe2O4 NPs and then the obtained CoFe2O4-rGO nanocomposites served as a support material for the synthesis of bimetallic NiPd alloy NPs at various compositions. The obtained CoFe2O4-rGO/NiPd nanocatalysts were characterized by many advanced analytical techniques including TEM, STEM-EDS, XRD, XPS, and ICP-MS. Next, to optimize the reaction conditions, CoFe2O4-rGO/NiPd nanocatalysts with different alloy compositions and their monometallic counterparts (CoFe2O4-rGO/Ni and CoFe2O4-rGO/Pd) were initially tested in the direct C-H arylation of imidazopyridine with bromobenzene. Among all tested nanocatalysts under the optimum reaction conditions, CoFe2O4-rGO/Ni20Pd80 showed the best catalytic activity in terms of the isolated product yields. The C-H arylation reactions were studied over a broad substrate scope (35 examples from 36 substrates) and gave the related biaryl products in good to excellent yields. Besides a broad substrate scope, the late-stage C-H arylation of zolimidine, a gastroprotective drug, was realized under the optimized reaction conditions. Moreover, the CoFe2O4-rGO/Ni20Pd80 nanocatalysts were recovered from the reaction medium using a simple magnet and reused in the C-H arylation reactions up to five consecutive runs without a significant drop in the product yield. This study shows that magnetically recoverable Pd nanoalloys are promising heterogeneous catalysts to be used in sustainable C-H functionalization reactions.

Exfoliated black phosphorous-mediated CuAAC chemistry for organic and macromolecular synthesis under white LED and near-IR irradiation.

The development of long-wavelength photoinduced copper-catalyzed azide-alkyne click (CuAAC) reaction routes is attractive for organic and polymer chemistry. In this study, we present a novel synthetic methodology for the photoinduced CuAAC reaction utilizing exfoliated two-dimensional (2D) few-layer black phosphorus nanosheets (BPNs) as photocatalysts under white LED and near-IR (NIR) light irradiation. Upon irradiation, BPNs generated excited electrons and holes on its conduction (CB) and valence band (VB), respectively. The excited electrons thus formed were then transferred to the CuII ions to produce active CuI catalysts. The ability of BPNs to initiate the CuAAC reaction was investigated by studying the reaction between various low molar mass alkyne and azide derivatives under both white LED and NIR light irradiation. Due to its deeper penetration of NIR light, the possibility of synthesizing different macromolecular structures such as functional polymers, cross-linked networks and block copolymer has also been demonstrated. The structural and molecular properties of the intermediates and final products were evaluated by spectral and chromatographic analyses.

Unveiling the catalytic nature of palladium-N-heterocyclic carbene catalysts in the α-alkylation of ketones with primary alcohols.

We report herein the synthesis of four new Pd-PEPPSI complexes with backbone-modified N-heterocyclic carbene (NHC) ligands and their application as catalysts in the α-alkylation of ketones with primary alcohols using a borrowing hydrogen process and tandem Suzuki-Miyaura coupling/α-alkylation reactions. Among the synthesized Pd-PEPPSI complexes, complex 2c having 4-methoxyphenyl groups at the 4,5-positions and 4-methoxybenzyl substituents on the N-atoms of imidazole exhibited the highest catalytic activity in the α-alkylation of ketones with primary alcohols (18 examples) with yields reaching up to 95%. Additionally, complex 2c was demonstrated to be an effective catalyst for the tandem Suzuki-Miyaura-coupling/α-alkylation of ketones to give biaryl ketones with high yields. The heterogeneous nature of the present catalytic system was verified by mercury poisoning and hot filtration experiments. Moreover, the formation of NHC-stabilized Pd(0) nanoparticles during the α-alkylation reactions was identified by advanced analytical techniques.

Expanding the Scope of 2D Black Phosphorus Catalysis to the Near-Infrared Light Initiated Free Radical Photopolymerization.

In the drive toward the development of efficient and stable inorganic semiconductor materials with broadband solar absorption ability to induce various photochemical processes is a highly attractive research field. In this study, two-dimensional (2D) few-layer black phosphorus (BP) exfoliated in a solvent is utilized as photocatalyst to initiate the polymerization of various monomers under visible and near-IR (NIR) light irradiation. Upon the light exposure, few-layer BP generates excited electrons and holes, which undergo electron transfer reactions with the onium salts to form free radicals capable of initiating free radical polymerization. Among the onium salts tested, aryldiazonium salt was found to be the most efficient in the photopolymerization process owing to its favorable reduction potential with the conduction edge potential of BP. The presented strategy also provides the possibility for the in situ preparation of BP-polymer composite materials.

One-pot synthesis of graphene hydrogel-anchored cobalt-copper nanoparticles and their catalysis in hydrogen generation from ammonia borane.

We reported a facile one-pot synthesis of bimetallic CoCu nanoparticles (NPs) anchored on graphene hydrogel (GH-CoCu) as catalysts in hydrogen generation from the hydrolysis of ammonia borane (HAB). The presented novel one-pot method composed of the reduction of the mixture of graphene oxide, cobalt(II), and copper(II) acetate tetrahydrates by aqueous ethylene glycol solution in a teflon-coated stainless-steel reactor at 180 °C. The structure of the yielded GH-CoCu nanocatalysts was characterized by TEM, SEM, XRD, XPS, and ICP-MS. This is the first example of both the synthesis of bimetallic CoCu NPs anchored on GH and the testing of a hydrothermally prepared noble metal-free GH-bimetallic nanocomposites as catalysts for the HAB. The presented in situ synthesis protocol allowed us to prepare different metal compositions and investigating their catalysis in the AB hydrolysis, where the best catalytic activity was accomplished by the GH-Co33Cu67 nanocatalysts. The obtained GH-CoCu nanocatalysts exhibited a remarkable catalytic performance in the HAB by providing the highest hydrogen generation rate of 1015.809 ml H2 gcatalyst-1 min-1 at room temperature. This study has a potential to pave a way for the development of other GH-based bimetallic nanocatalysts that could be used in different applications.

Photothermal Antibacterial and Antibiofilm Activity of Black Phosphorus/Gold Nanocomposites against Pathogenic Bacteria.

Black phosphorus (BP) as a layered two-dimensional (2D) semiconductor material with a tunable band gap has attracted growing attention for promising applications in diverse fields including biotechnology owing to its excellent physical and chemical properties. In this study, BP crystals were synthesized using a chemical vapor transport method and exfoliated into BP nanosheets in deoxygenated water or hexane. Next, monodisperse Au nanoparticles that were synthesized using a surfactant-assisted chemical reduction method were assembled on exfoliated BP nanosheets hexane to yield BP/Au nanocomposites. The photothermal antibacterial and antibiofilm activities of BP nanosheets and BP/Au nanocomposites were investigated against Enterococcus faecalis, a pathogenic biofilm-forming bacterium, by studying the photothermal effect and bacterial growth curve and using colony counting and live/dead fluorescence staining methods under near-infrared (NIR) light irradiation. Thanks to the higher photothermal conversion efficiency of BP/Au nanocomposites than that of bare BP nanosheets under NIR light irradiation, they destructed the bacterial cell membrane more efficiently than bare BP with the biofilm inhibition rate of 58%. It should be noted that this is the first study on the antibacterial and antibiofilm activity of BP/Au nanocomposites via a photothermal process under NIR light irradiation. This work shows the potential of BP/Au nanocomposites in fighting against pathogenic bacteria and paves the way for the exploration of antibacterial platforms based on the biocompatible 2D semiconductor BP.

Black phosphorus as a metal-free, visible-light-active heterogeneous photoredox catalyst for the direct C-H arylation of heteroarenes.

Black phosphorus (BP) is for the first time employed as a metal-free, heterogeneous photoredox catalyst for the direct C-H arylation of heteroarenes with aryl diazonium salts. The arylated heteroarenes are obtained in moderate to good yields under visible-light illumination, and the protocol is shown to be applicable for the scale-up synthesis.

Mesoporous Graphitic Carbon Nitride/Black Phosphorus/AgPd Alloy Nanoparticles Ternary Nanocomposite: A Highly Efficient Catalyst for the Methanolysis of Ammonia Borane.

A novel ternary nanocomposite, mesoporous graphitic carbon nitride/black phosphorus-AgPd (denoted mpg-CN/BP-AgPd), was successfully fabricated by assembling the as-prepared AgPd alloy nanoparticles (NPs) on mesoporous graphitic carbon nitride/black phosphorus (mpg-CN/BP) binary composites. This novel nanocomposite comprises a heterojunction support material formed by two distinct nonmetallic semiconductors (mpg-CN and BP) with adaptable band gaps and edge voltages, providing enhanced catalytic activity to AgPd alloy NPs in hydrogen generation from the methanolysis of ammonia borane (AB) compared to its single components under the blue light-emitting diode (LED) light illumination. The yielded mpg-CN/BP-AgPd ternary nanocomposites were characterized by many advanced analytical techniques (transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL), time-resolved spectroscopy, inductively coupled plasma-mass spectroscopy (ICP-MS), and fourier transform infrared (FTIR), and then they were tested as catalysts in hydrogen generation from the methanolysis of AB at room temperature. Several parameters such as the effect of mpg-CN/BP ratio, alloy composition, and type of the light source were studied to optimize the catalytic activity of the mpg-CN/BP-AgPd nanocomposites in the methanolysis of AB. The best catalytic activity of mpg-CN/BP-AgPd nanocomposites was obtained using an mpg-CN/BP ratio of 5/1 (wt/wt) and Ag50Pd50 alloy composition under the blue LED illumination at room temperature. The activity of the ternary nanocomposites was further enhanced by the acetic acid treatment, and a high initial turnover frequency of 43.7 mol(H2) mol(catalyst)-1 min-1 was reported. Besides their high catalytic activity, the mpg-CN/BP-AgPd nanocomposites were reusable catalysts in the methanolysis of AB. This study also included detailed kinetics of AB methanolysis catalyzed by mpg-CN/BP-AgPd nanocomposites.

Photocatalytically Active Graphitic Carbon Nitride as an Effective and Safe 2D Material for In Vitro and In Vivo Photodynamic Therapy.

Thanks to its photocatalytic property, graphitic carbon nitride (g-C3 N4 ) is a promising candidate in various applications including nanomedicine. However, studies focusing on the suitability of g-C3 N4 for cancer therapy are very limited and possible underlying molecular mechanisms are unknown. Here, it is demonstrated that photoexcitation of g-C3 N4 can be used effectively in photodynamic therapy, without using any other carrier or additional photosensitizer. Upon light exposure, g-C3 N4 treatment kills cancer cells, without the need of any other nanosystem or chemotherapeutic drug. The material is efficiently taken up by tumor cells in vitro. The transcriptome and proteome of g-C3 N4 and light treated cells show activation in pathways related to both oxidative stress, cell death, and apoptosis which strongly suggests that only when combined with light exposure, g-C3 N4 is able to kill cancer cells. Systemic administration of the mesoporous form results in elimination from urinary bladder without any systemic toxicity. Administration of the material significantly decreases tumor volume when combined with local light treatment. This study paves the way for the future use of not only g-C3 N4 but also other 2D nanomaterials in cancer therapy.

Sonocatalytic removal of methylene blue from water solution by cobalt ferrite/mesoporous graphitic carbon nitride (CoFe2O4/mpg-C3N4) nanocomposites: response surface methodology approach.

In this study, cobalt ferrite/mesoporous graphitic carbon nitride (CoFe2O4/mpg-C3N4) nanocomposites were successfully synthesized by using a two-step protocol. Firstly, monodispersed CoFe2O4 nanoparticles (NPs) were synthesized via thermal decomposition of metal precursors in a hot surfactant solution and then they were assembled on mpg-C3N4 via a liquid phase self-assembly method. The sonocatalytic performance of as-synthesized CoFe2O4/mpg-C3N4 nanocomposites was evaluated on the methylene blue (MB) removal from water under ultrasonic irradiation. For this purpose, response surface methodology (RSM) based on central composite design (CCD) model was successfully utilized to optimize the MB removal over CoFe2O4/mpg-C3N4 nanocomposites. Analysis of variance (ANOVA) was applied to investigate the significance of the model. The results predicted by the model were obtained to be in reasonable agreement with the experimental data (R2 = 0.969, adjusted R2 = 0.942). Pareto analysis demonstrated that pH of the solution was the most effective parameter on the sonocatalytic removal of MB by CoFe2O4/mpg-C3N4 nanocomposites. The optimum catalyst dose, initial dye concentration, pH, and sonication time were set as 0.25 g L-1, 8 mg L-1, 8, and 45 min, respectively. The high removal efficiency of MB dye (92.81%) was obtained under optimal conditions. The trapping experiments were done by using edetate disodium, tert-butyl alcohol, and benzoquinone. Among the reactive radicals, •OH played a more important role than h+ and [Formula: see text] in the MB dye removal process. Moreover, a proposed mechanism was also presented for the removal of MB in the presence of CoFe2O4/mpg-C3N4 nanocomposites under the optimized sonocatalytic conditions. Finally, a reusability test of the nanocomposites revealed a just 9.6% decrease in their removal efficiency after five consecutive runs.

Heterogeneous sono-Fenton-like process using magnetic cobalt ferrite-reduced graphene oxide (CoFe2O4-rGO) nanocomposite for the removal of organic dyes from aqueous solution.

We report herein the synthesis of monodisperse cobalt ferrite (CoFe2O4) nanoparticles (NPs) via a surfactant-assisted high temperature thermal decomposition method and then their assembly on reduced graphene oxide (rGO) to yield CoFe2O4-rGO nanocomposites, which displayed outstanding sonocatalytic activity for the removal of organic dyes from aqueous solutions under ultrasonic irradiation. As-prepared CoFe2O4-rGO nanocomposites were characterized by using transmission electron microscopy (TEM), high-resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Micro-Raman spectroscopy, Vibrating sample magnetometer (VSM) and inductively couple plasma mass spectrometer (ICP-MS). To evaluate the sonocatalytic activity of the CoFe2O4-rGO nanocomposites, the sonocatalytic removal of several organic dyes (AO7, AR17, BR46 and BY28) was studied. The reaction conditions were optimized by studying the effects of various key operating parameters such as pH, catalyst dosage, H2O2 initial concentration, initial dye concentration, ultrasonic power and reaction time on the removal of AO7 dye. The maximum removal efficiency of 90.5% was achieved at pH 3 using 0.08gL-1 catalyst, 3mM H2O2 and 10mgL-1 AO7 dye under 350W ultrasonic power in 120min of reaction time span. Experimental results revealed that the kinetic of the removal process could be described using Langmuir-Hinshelwood (L-H) kinetic model. The trapping experiments showed that O2·- radicals constitute the major reactive oxygen species (ROS) in the AO7 dye removal process. The reusability of the nanocomposites revealed about 22% drop in the removal efficiency within five consecutive runs. A possible sonocatalytic mechanism for the removal of organic dyes was also proposed. The intermediate by-products of the dye formed in the removal process were characterized by using the GC-MS technique.