Photodegradation Of Rhodamine Research Articles

N-doped titania nanoparticles containing Mo6 bromide and iodide clusters: Activity in photodegradation of rhodamine B and tetracycline

Contamination of water sources is a major environmental problem with far-reaching consequences for humanity. Organic substances are among the most widespread and persistent pollutants. Advanced oxidation processes, especially photocatalysis, have been considered as one of the most promising technologies for organic pollution control. In this study, hybrid photocatalysts based on N-doped TiO2, which exhibits activity in the visible region of the spectrum, and different content of octahedral Mo6 bromide and iodide cluster complexes were synthesized to achieve the highest efficiency of the formed S-scheme photocatalytic system under white light irradiation. According to the data obtained, the resulting materials are nanoparticles with a diameter of ∼10 nm exhibiting absorption up to ∼550 nm. Photocatalytic studies were performed using model organic molecules – the more colored rhodamine B (RhB) and the less colored antibiotic tetracycline (TET). The most active samples showed high efficiencies against both pollutants with keff ∼0.3–0.4 and 0.4–0.5 min−1, respectively, while the activity of iodide complexes was ∼1.3 times higher than that of bromide complexes. The stability of the catalysts is preserved for up to 5 cycles of TET photodegradation.

Synthesis of corn straw based carbon doped Nb2O5 as photocatalysts for Rhodamine B degradation under visible light illumination

Developing efficient visible light photocatalytic materials has always been a challenge for researchers. We have successfully prepared a series of corn straw based carbon doped Nb2O5 with excellent photocatalytic performance under visible light. A series of characterizations were carried out on the synthesized materials, including power X-Ray diffraction (XRD), scan electron microscopy (SEM), nitrogen adsorption, UV–vis diffuse reflectance spectra, X-ray photoelectron spectroscopy (XPS). The photocatalytic performance of the synthesized samples was investigated under visible light irradiation using Rhodamine B as the degradation target. Under visible light irradiation for 30 min, C/Nb2O5 can decompose Rhodamine B by 97.1 %, and the photocatalytic performance remains unchanged after 5 cycles. In the article, the contributions of three active substances involved in the photodegradation of Rhodamine B were studied through scavenger study, and the mechanism of C/Nb2O5 photodegradation of Rhodamine B was analyzed. This research is of great significance for the application of biomass materials and the improvement of environmental quality, and also provides new ideas for designing and synthesizing new composite functional materials.

Green synthesized metal nanoparticle incorporated titania silica and its application in the photodegradation of Rhodamine B

Photocatalytic activity of Titania has a very intriguing mechanism with numerous potential uses such as air and water cleaning. The inclusion of silica improves its catalytic capabilities. The use of titania silica nanoparticles for photocatalytic activity in environmental applications is limited due to their activity in the UV region rather than the visible range. Titania silica nanoparticles were synthesised using the sol-gel method. Metal nanoparticles of vanadium, manganese and silver were synthesised and integrated into the titania silica using a green method. To clarify the structure property correlations for titania silica materials, several characterisation techniques such as SEM-EDAX, IR analysis, UV-Visible spectroscopy and XRD were applied. The photocatalytic activities of titania alone, titania silica and titania silica including the various metals were studied.

Helical Ni‐Cluster Organic Framework Constructed from Enantiopure Lactate Derivative: Synthesis, Structure and Properties

AbstractUnder hydrothermal condition, lactate derivative (R)‐4‐(1‐ carboxyethoxy)‐2‐methylbenzoic acid ((R)‐H2cma) as chiral synthon assembled with 4,4′‐di(1H‐imidazol‐1‐yl)‐1,1′‐biphenyl (4,4’‐dib) and Ni(II) ions to obtain complex {[Ni2((R)‐cma)2(4,4’‐dib)2(H2O)] ⋅ 2H2O}n (HU20‐R). In complex HU20‐R, carboxyl group from lactate unit of (R)‐cma2− anion and coordinating H2O molecule adopt a μ2‐coordination mode to obtain dinuclear [Ni2(CO2)2(H2O)]2+ cluster. (R)‐cma2− anions and Ni(II) ions build single left‐handed (R)‐cma‐Ni‐chain, while 4,4’‐dib ligands are bridged by different Ni(II) centers to form double left‐handed 4,4’‐dib‐Ni‐chain. These helical secondary structures are further connected together to result in an 8‐connected 3D framework. PXRD tests indicated that complex HU20‐R has well hydro‐stability. UV‐vis absorption experiment confirmed that HU20‐R is a semi‐conducting material with strong absorption capacity for ultraviolet‐visible (UV‐vis) light. Additionally, electrochemical experiment revealed that HU20‐R has low impedance and high charge transport capacity. Further test results confirm that HU20‐R has noticeable photo‐catalytic effect in photodegradation of Rhodamine B (RhB) and antiferromagnetic property.

Optical, dielectric and photoelectrochemical performances of the CeO2/silicon nanowire system: Studying the silicon nanowire length effect on the photodegradation of rhodamine B

Optical, dielectric and photoelectrochemical performances of the CeO2/silicon nanowire system: Studying the silicon nanowire length effect on the photodegradation of rhodamine B

Synthesis of heterojunction BiVO4/MnO2 graphene ternary nanocomposites with enhanced photocatalytic activities through degradation of rhodamine B and tetracycline hydrochloride

Our research has resulted in synthesizing highly efficient BiVO4/MnO2 graphene ternary heterostructures prepared with a simple hydrothermal technique. These structures demonstrate exceptional performance in the photodegradation of rhodamine B (RhB) dye and tetracycline hydrochloride (TC). Adding MnO2 and graphene oxide significantly enhanced the absorption of visible light, photocatalytic activity, and surface area of the nanocatalyst. The prepared materials were characterized by XRD, SEM, BET, DRS, and PL spectroscopy. The PL spectra of G/MnBV-4 show less intensity and lower recombination rate, which is beneficial for photocatalytic activity. The as-synthesized G/MnBV-4 material exhibits outstanding photocatalytic activities toward the TC and RhB dye degradation under visible light irradiation. The reaction rate constant of G/MnBV-4 was estimated in the case of RhB and TC as 0.094 min−1 and 0.021 min−1 respectively, showcasing the material's high efficiency. The optimized material (BiVO4/MnO2 graphene) is stable and reusable, with only a 10 % reduction in removal efficiency after five consecutive cycles. Furthermore, the OH− and O2− are active species for removing organic pollutants. In contrast, holes are attributed to a lower effect. This study describes a photocatalytic approach to effectively removing the TC from waste bodies. The enhanced degradation efficiencies were ascribed to developing heterostructures and fast electron transfer between interfaces. Moreover, graphene increased photogenerated charge carriers' surface adsorption properties and charge separation efficiency. Hence, graphene works as an electron trapper and tuning bandgap energy, which plays a significant role in addition to photocatalytic activity.

Two Novel Visible‐Light‐Active Borate Composites Photocatalysts: 2 %Pt/Gd0.85Ce0.15B5O9 and 2.5 %CuO/Gd0.90Ce0.10B5O9

AbstractOne of the important research components of photocatalytic research is the development of new photocatalysts, and recent studies have shown the rise of borate‐type photocatalysts. This paper focuses on the photoreduction of potassium dichromate and the photodegradation of rhodamine B by two borate composites under simulated sunlight. A coral‐like borate was obtained by sol‐gel preparation and then assembled by photodeposition with Pt nanoparticles dots or CuO particles to obtain the new composites with excellent performance. The kinetic constants of photocatalytic properties of 2 %Pt/Gd0.85Ce0.15B5O9 and 2.5 %CuO/Gd0.90Ce0.10B5O9 samples in the reduction and degradation reactions are 0.0050 min−1 and 0.0150 min−1, which are 25 and 4.2 times of the intrinsic GdB5O9 sample respectively. The results of the study indicate the research promise of developing new visible photocatalysts based on borates, especially for photocatalytic applications for pollutant removal.

Screening and optimization of the most influencing factors during the photodegradation of Rhodamine B by zinc oxide photocatalyst: application of Plackett–Burman and central composite designs

Screening and optimization of the most influencing factors during the photodegradation of Rhodamine B by zinc oxide photocatalyst: application of Plackett–Burman and central composite designs

Magnetic separation, sunlight-driven photocatalytic activity, and antibacterial studies of Sm-doped Co0.33Mg0.33Ni0.33Fe2O4 nanoparticles.

Magnetic nanoparticles have emerged as a promising tool for wastewater treatment due to their unique properties. In this regard, Co0.33Mg0.33Ni0.33SmxFe2-xO4 (0.00 x 0.08) nanoparticles were prepared to examine their magnetic separation efficiency (MSE), photocatalytic, antibacterial, and antibiofilm performances. Pure nanoparticles, having the highest saturation magnetization (Ms = 31.87emu/g), exhibit the highest MSE, where 95.6% of nanoparticles were separated after 20min of applying a magnetic field of 150 mT. The catalytic performance of the prepared samples is examined by the photodegradation of rhodamine B (RhB) dye exposed to direct sunlight radiation. Improved photocatalytic activity is exhibited by Co0.33Mg0.33Ni0.33Sm0.04Fe1.96O4 nanoparticles, labeled as Sm0.04, where the rate of the degradation reaction is enhanced by 4.1 times compared to pure nanoparticles. Rising the pH and reaction temperature improves the rate of the photodegradation reaction of RhB. The incorporation of 15 wt% reduced graphene oxide (rGO) with Sm0.04 enhanced the rate of the reaction by 1.7 and 2.4 times compared with pure Sm0.04 sample and rGO, respectively. The antibacterial and antibiofilm activities against Escherichia coli, Leclercia adecarboxylata, Staphylococcus aureus, and Enterococcus faecium are assessed by the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) broth microdilution, the agar well diffusion, the time-kill assays, the biofilm formation, and destruction assays. The bacteria used in these assessments are isolated from wastewater. The nanoparticles exhibit a bacteriostatic activity, with a better effect against the Gram-positive isolates. Co0.33Mg0.33Ni0.33SmxFe2O4 (x = 0.00) nanoparticles have the best effect. The effect is exerted after 2-3h of incubation. Gram-positive biofilms are more sensitive to nanoparticles.

Optimization of preparation conditions of Bi-doped TiO2/montmorillonite composites and its photodegradation of Rhodamine B

In order to improve the photocatalytic degradation performance of titanium intercalated montmorillonite composites, the sol-gel method was used to intercalate bismuth/titanium polymerized hydroxyl cations into the interlayer of sodium-based montmorillonite (Na-MMT). The optimum synthesis conditions of Bi-doped TiO2/montmorillonite composite photocatalytic material (Bi/Ti-MMT) were investigated. Powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM) and UV–vis diffusion reflectance spectrum (UV-Vis DRS) had been used to study the formation of Bi/Ti-MMT. Under the conditions of Bi/Ti molar ratio of 7 %, montmorillonite suspension mass fraction of 2 %, calcination temperature of 600 ℃ and calcination time of 3 h, the Bi/Ti-MMT had the highest photocatalytic activity, the degradation rate of Rhodamine B (RhB) was 88.16 %. In Bi/Ti-MMT composites, TiO2 existed in anatase phase. Bi3+ replaced Ti4+ and was doped into the TiO2 lattice, which can inhibit the growth of TiO2 crystals and reduce the band gap. The photoresponse range of the composite material was broadened to visible light, which improved the utilization of light.

Charge-Selective Photocatalytic Degradation of Organic Dyes Driven by Naturally Occurring Halloysite Nanotubes

This study explores the use of Halloysite NanoTubes (HNTs) as photocatalysts capable of decomposing organic dyes under exposure to visible or ultraviolet light. Through a systematic series of photocatalytic experiments, we unveil that the photodegradation of Rhodamine B, used as a model cationic dye, is significantly accelerated in the presence of HNTs. We observe that the extent of RhB photocatalytic degradation in 100 min in the presence of the HNTs is ~four times higher compared to that of bare RhB. Moreover, under optimized conditions, the as-extracted photodegradation rate of RhB (~0.0022 min−1) is comparable to that of the previously reported work on the photodegradation of RhB in the presence of tubular nanostructures. A parallel effect is observed for anionic Coumarin photodegradation, albeit less efficiently. Our analysis attributes this discrepancy to the distinct charge states of the two dyes, influencing their attachment sites on HNTs. Cationic Rhodamine B molecules preferentially attach to the outer surface of HNTs, while anionic Coumarin molecules tend to attach to the inner surface. By leveraging the unique properties of HNTs, a family of naturally occurring nanotube structures, this research offers valuable insights for optimizing photocatalytic systems in the pursuit of effective and eco-friendly solutions for environmental remediation.

Photocatalytic Performances of ZnS/g-C3N4 Nanocomposites with Different Mass Ratios

In this study, we prepared a series of ZnS/graphitic-C3N4 nanocomposites in various mass percentages and morphological properties of all the nanocomposites were examined by utilizing SEM/EDX technique. The photocatalytic performances of ZnS/graphitic-C3N4 nanocomposites were evaluated by degradation of Rhodamine B molecules under visible light. The photocatalytic performances of all nanocomposites under various photocatalyst dosages and initial Rhodamine B concentrations were further investigated for determination of optimal conditions.the obtained results indicated that ZnS/graphitic-C3N4 nanocomposites show almost 2 times higher photocatalaytic performances than pure graphitic-C3N4 and ZnS nanoparticles. The scavenger studies showed that the superoxide radicals had a major role in the photodegradation and the photodegradation of Rhodamine B follows the pseudo-first-order kinetic.

Effect of acidic and basic leachants on the synthesis of ZnO nanoparticles from Egyptian zinc ore, their optical/surface characteristics and photocatalytic performance

It is of pivotal significance to optimize the parameters affecting the extraction of metals from natural ores to convert them to value-added products. Owing to their semiconducting nature, most metal oxides, including ZnO, have various electronic, optical, and photocatalytic applications. Hence, we are investigating the leaching of Zn from Smithsonite (an Egyptian ore) using acidic/basic leaching agents (leachants). The leached salts were employed in a co-precipitation method followed by calcination to obtain crystalline ZnO nanoparticles. Both photocatalytic performance of the ZnO nanoparticles obtained from acid leaching and basic leaching were investigated toward the photodegradation of Rhodamine B dye. The ZnO(A) prepared using the acid leaching route has achieved about 5.6-fold enhancement in the dye photodegradation% and 5.3-fold enhancement in the observed rate constant compared to ZnO(B) prepared from basic leaching. Finally, the superior photocatalytic activity of the ZnO(A) is attributed to the smaller particle size, larger surface area, and existence of some defects that enhanced the photocatalytic performance.

Investigation of the Photocatalytic Performance, Mechanism, and Degradation Pathways of Rhodamine B with Bi2O3 Microrods under Visible-Light Irradiation.

In the present work, the photodegradation of Rhodamine B with different pH values by using Bi2O3 microrods under visible-light irradiation was studied in terms of the dye degradation efficiency, active species, degradation mechanism, and degradation pathway. X-ray diffractometry, polarized optical microscopy, scanning electron microscopy, fluorescence spectrophotometry, diffuse reflectance spectra, Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, UV-visible spectrophotometry, total organic carbon, and liquid chromatography-mass spectroscopy analysis techniques were used to analyze the crystal structure, morphology, surface structures, band gap values, catalytic performance, and mechanistic pathway. The photoluminescence spectra and diffuse reflectance spectrum (the band gap values of the Bi2O3 microrods are 2.79 eV) reveals that the absorption spectrum extended to the visible region, which resulted in a high separation and low recombination rate of electron-hole pairs. The photodegradation results of Bi2O3 clearly indicated that Rhodamine B dye had removal efficiencies of about 97.2%, 90.6%, and 50.2% within 120 min at the pH values of 3.0, 5.0, and 7.0, respectively. In addition, the mineralization of RhB was evaluated by measuring the effect of Bi2O3 on chemical oxygen demand and total organic carbon at the pH value of 3.0. At the same time, quenching experiments were carried out to understand the core reaction species involved in the photodegradation of Rhodamine B solution at different pH values. The results of X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and X-ray diffractometer analysis of pre- and post-Bi2O3 degradation showed that BiOCl was formed on the surface of Bi2O3, and a BiOCl/Bi2O3 heterojunction was formed after acid photocatalytic degradation. Furthermore, the catalytic degradation of active substances and the possible mechanism of the photocatalytic degradation of Rhodamine B over Bi2O3 at different pH values were analyzed based on the results of X-ray diffractometry, radical capture, Fourier-transform infrared spectroscopy, total organic carbon analysis, and X-ray photoelectron spectroscopy. The degradation intermediates of Rhodamine B with the Bi2O3 photocatalyst in visible light were also identified with the assistance of liquid chromatography-mass spectroscopy.

Enhanced photocatalytic activity of SnO2/g-C3N4 nanocomposite synthesized using sonochemistry method

The SnO2/g-C3N4 nanocomposite materials were successfully synthesized via the solid reaction and sonochemistry methods. The properties of the obtained product were investigated using several methods: X-ray diffraction, UV-vis diffuse reflectance spectroscopy, and Scanning electron microscope. The photocatalytic properties of the samples were evaluated through the photodegradation of Rhodamine B solution. The results demonstrate that the SnO2/g-C3N4 prepared by the sonochemistry method exhibits higher photocatalytic activity than that prepared by the solid reaction method. This enhanced photocatalytic activity is attributed to the formation of heterostructures between SnO2 and g-C3N4 materials, resulting in the efficient separation of photo-generated electron-hole pairs. Furthermore, the nanocomposite exhibits a larger specific surface area compared to the product obtained through the solid reaction method.

Facile preparation and characterization of Zn2Ti3O8/g-C3N4 nanocomposites for degradation of rhodamine B under simulated sunlight

Zinc titanate (Zn2Ti3O8, ZTO) was initially synthesized using a straightforward and inexpensive Pechini approach, and subsequently Zn2Ti3O8/g-C3N4 (ZTO/CN) nanocomposites with varied contents were created using an ultrasonic-assisted co-precipitation process. Based on the appropriate bandgaps (2.0 eV and 2.7 eV), the photodegradation of rhodamine B (RhB) was studied. This is the first time that ZTO/CN nanocomposites are studied for the degradation of organic pollutants. The results showed that the best performance belonged to the sample with a mass ratio of 0.25 to 1 among different ZTO/CN nanocomposites. Therefore, 50 mg of ZTO/CN (0.25:1) degraded 89.0 % of 10 ppm RhB. Scavenger testing revealed that superoxide radicals and holes played significant parts in photodegradation processes.

Post-Synthetic Modifications of Ti(IV)-Based Metal-Organic Frameworks for Enhanced Photocatalysis and Conductivity

Metal-Organic Frameworks (MOFs) are coordination networks with organic ligands containing potential voids, ideal for guest-host interactions. These unique characteristics make them interesting materials for several different applications, including catalysis. Unfortunately, most MOFs feature metal oxide nodes that are insulting by nature, which limits their potential in electro- and photochemical catalysts. To combat these issues, post-synthetic modifications (PSM) can be used to tune MOF properties. This research reports on different PSMs incorporated into the Ti(IV)-based MOFs MIL-125(Ti) and MIL-125(Ti)-NH2. PSMs that introduce intentional defect states and dopant metal ions, such as Ce(IV), were explored to determine their influence on the photo-degradation of Rhodamine B in aqueous solution. Post-Synthetic Metal Exchange (PSME) was used to incorporate Ce(IV) at the Ti(IV) sites in MIL-125(Ti) and MIL-125(Ti)-NH2, and intentional defect states were introduced using formic acid during MOF synthesis. In addition, conductive organic polymers were utilized to make novel polymer-MOF hybrid composites that showed enhanced charge transport properties compared to pristine MOF. Ultimately, these results show how PSMs can be used to impart conductivity and enhance photocatalysis in the MOFs MIL-125(Ti) and MIL-125(Ti)-NH2.

Efficient utilization of ceramic waste (cyclone dust waste) for enhancing the photocatalytic performance of TiO2 nanoparticles toward Rhodamine B photodegradation

Owing to the increase in the world's population, industrial demands are significantly increasing, and air/water pollution has become a global threat that severely affects human health. Many pollutants are discharged into the ecosystem, ceramic dust/wastes cause air pollution and textile dyes are among the recalcitrant organic water pollutants. This requires efficient waste management and waste remediation. Photocatalysis is one of the most efficient technologies for treating organic pollutants, where TiO2 nanoparticles are the most widely used photocatalysts. However, the wide bandgap and rapid e-h recombination rates of TiO2 nanoparticles impede their practical applications. Herein, we are hitting “two birds with one stone” by utilizing ceramic waste powder in the fabrication of photocatalysts to degrade organic pollutants. The employed ceramic waste “cyclone dust waste (CDW)” was used as filler materials during the sol-gel synthesis of TiO2 photocatalyst. The synthesis method is a facile and cost-effective route because CDW was employed as obtained from the production line without any further processing. Different loading percentages of CDW were in-situ added to the TiO2 during the synthesis. x%CDW-TiO2 samples were investigated toward the photodegradation of Rhodamine B dye as a primary pollutant model, where 30%CDW-TiO2 nanocomposite was the optimum sample that achieved 2.6-fold enhancement in the RB photodegradation% compared to the bare TiO2. The physicochemical properties of the as-fabricated samples were investigated using different techniques, including XRD, HR-TEM, FE-SEM, DRS, and PL. It was found that the as-prepared CDW extended the light absorption capability of the 30%CDW-TiO2 nanocomposite toward the visible light. The PL results showed the reduction of e-h recombination rate in 30%CDW-TiO2 nanocomposite owing to the constructed Type-II/Z-scheme heterojunction. This work will open the door to the investigation of different wastes to be used as filler materials to be incorporated in the synthesis of value-added compounds.

Microwave assisted eco-benign synthesis of novel palladium nanoparticles (ACPs-PdNPs): A new insight into photocatalytic and biomedical applications

The increasing bacterial infections and water contamination are the most critical global challenge. To address these challenges, innovative approaches are required to generate safe and effective nanoscale materials that inhibit the growth of microbes and remove hazardous contaminants from water. In this study, we described for the first time the eco-benign synthesis of acid protease mediated palladium nanoparticles (ACPs-PdNPs) using Melilotus indicus leaf extract. A series of physicochemical characterizations were applied to evaluate the size, shape and crystalline structure of ACPs-PdNPs. The surface Plasmon resonance (SPR) peak at 343 nm examined in the U.V spectra and the FTIR peaks at 591 cm¯1 confirmed the formation of as prepared NPs. Moreover, the ACPs-PdNPs possessed an extremely small particle size (5–30 nm), brown in color with spherical morphology. The as-synthesized nanoparticles were screened for their biological activities and photocatalytic applications. The catalytic efficiency of ACPs-PdNPs were inquired by the photodegradation of Rhodamine B (Rh. B) dye. Based on the findings, only 20 min of irradiation were enough to degrade 99 % of Rh. B. The ACPs-PdNPs demonstrated exceptional antibacterial activity against Escherichia coli (E. coli) bacteria in both light and dark environments, with inhibition zones of 33 mm and 27 mm, respectively. In addition, 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenger potential of these nanoparticles was quite strong by scavenging 88 % of the DPPH radicals. Furthermore, the Michigan Cancer Foundation (MCF-7) women's breast cancer cell lines were strongly inhibited by the acid protease mediated ACPs-PdNPs with the IC50 value of 66.37 µg/mL. Due to their trivial size and substantial surface area, ACPs-PdNPs exhibited exceptional photocatalytic and biomedical applications.

Simple and fast synthesis of BiOBr/[Bi6O5(OH)3](NO3)5·3H2O composites for efficient photocatalytic degradation of RhB under visible light

In this study, a heterostructure photocatalyst consisting of Bi6O5(OH)3](NO3)5·3H2O (was denoted as BiOOHN) and BiOBr was fabricated via a simple and economic co-precipitation method. In this method, the amount of Br in the composition was controlled by changing the volume of hydrobromic acid (HBr) during the manufacturing process. The photocatalytic performance of the prepared samples by photodegradation of rhodamine B (RhB) solution under visible light radiation was investigated and the optimum amount of HBr was obtained. The results showed that BiOBr/BiOOHN composite has higher photocatalytic efficiency compared to pure BiOOHN and BiOBr, so that almost 100 % of RhB solution was degraded in the presence of BiOBr/BiOOHN composite photocatalyst during 100 min, while this value was equal to 0 % and 21 % for pure BiOOHN and BiOBr, respectively. Results indicated that the BiOOHN band gap is in the ultraviolet region (3.45 eV) and not possible to activate this sample to generate electron-hole pairs under visible radiation. While the energy gap of the samples synthesized in the presence of HBr was around 2.90 eV, which enables the activation of these compounds under visible radiation to generate electron-hole pairs for photocatalytic reactions. Therefore, the weak BiOOHN photocatalytic performance is attributed to the its wide band gap energy in comparison with other samples. Also, the better performance of composite samples compared to pure BiOBr is owing to the formation of a heterostructure between BiOOHN and BiOBr. It leads to better separation of electron-hole pairs at the interface of two semiconductors and hinders their recombination, which improves photocatalytic performance. Also, a mechanism for the photocatalytic reactions of RhB degradation was proposed based on experimental data and the experiment of trapping active species. According to this mechanism, the holes and free hydroxyl radicals (•OH) play a key role in the photocatalytic degradation reactions of RhB.