Efficient Photocatalytic Degradation Of Rhodamine Research Articles

Efficient photocatalytic degradation of Rhodamine B dye by undoped and zinc doped zirconium dioxide NPs

Undoped and Zinc-doped Zirconium Dioxide (ZrO2) nanoparticles (NPs) were synthesized via the co-precipitation method, employing Zirconium (IV) Oxynitrate hydrate (ZrO2N2·xH2O), Zinc Sulfate (ZnSO4·7H2O), and ammonia solution as precursor materials at room temperature. A comprehensive characterization of the structural, morphological, optical, and catalytic properties of the prepared samples was conducted using various techniques. Powder X-ray diffraction (PXRD) analysis revealed that the synthesized NPs exhibited a tetragonal phase structure, with crystallite sizes decreasing as doping concentration increased. Scanning electron microscopy (SEM) images confirmed the spherical shape of the NPs. Energy-dispersive X-ray spectroscopy (EDX) verified the presence of Zr, O, and Zn elements with high purity. Raman spectroscopy corroborated the tetragonal structure of the synthesized ZrO2 NPs. Ultraviolet–visible (UV–Vis) spectroscopy studies determined the cutoff wavelengths, while Tauc plot enabled the calculation of band gap energies. Fourier transform infrared spectroscopy (FTIR) confirmed the functional groups present in the synthesized samples. Photoluminescence spectroscopy provided evidence of defects and charge carrier recombination processes. The catalytic efficacy of the synthesized ZrO2 NPs was demonstrated through the degradation of Rhodamine B dye under visible and UV light.

Eco-friendly synthesis of CuO/Bi2O3 nanocomposite for efficient photocatalytic degradation of rhodamine B dye.

Plant-mediated synthesized materials are receiving more attention than conventional ones due to their wide availability, ease of access, simple preparation methods, environmental benign, and possess superior physicochemical properties. In this work, plant extract-mediated CuO, Bi2O3, and CuO/Bi2O3 nanocomposite samples were successfully synthesized using bamboo leaves extract as a capping agent. These materials were utilized for the photodegradation of Rhodamine B (RhB) dye, which served as a model organic dye pollutant. The physicochemical characterization techniques such as XRD, SEM-EDS, FTIR, and DRS-UV-vis spectrophotometry provide insight into the crystal structure, morphology, surface functional groups, and optical properties. These analyses confirm the effective formation of CuO, Bi2O3, and CuO/Bi2O3 materials. Surprisingly, upon calcination at 450°C for 4h, the color of the nanocomposite changed from pale green to gray greenish, providing evidence for the formation of the CuO in CuO/Bi2O3 nanocomposite. The photocatalytic optimization parameters such as pH (4), catalyst load (35mg), irradiation time (180min) and concentration of RhB (10 mg L-1) dye were investigated. By coupling CuO with Bi2O3 nanoparticles resulted in an improved photocatalytic property for the degradation of RhB dye under optimal conditions. As a result, CuO/Bi2O3 nanocomposite exhibited a significantly boosted photocatalytic degradation efficiency (95.6%) compared to pure CuO (40.2%) and Bi2O3 (80.5%) photocatalysts, with good reusability. For comparison purpose, the photocatalytic degradation of RhB dye using selected photocatalyst was evaluated under dark and sunlight systems. This eco-friendly approach holds great potential for synthesis new nanocomposite with modified properties, thereby enabling the practical application of high-efficiency photocatalysts. The plausible mechanism of the electrons and holes transfer was proposed.

Highly efficient photocatalytic degradation of rhodamine B by immobilizing CdS quantum dots on ZnCr-layered double hydroxide nanosheets

The removal of Rhodamine B (RhB), a commonly encountered cationic dye in heavily contaminated wastewater streams, from wastewater effluents presents a significant challenge. Herein, we focus on developing an innovative ternary nanocomposite of zinc oxide nanoparticles, quantum dots of cadmium sulfide (CdS QDs), and zinc-chromium carbonate layered double hydroxide nanosheets (ZnCr–CO3-LDH NSs) via a sonochemical synthesis route. The synthesized ternary nanocomposite, CdS QDs@ZnO/ZnCr–CO3-LDH referred to as CZC-LDH, exhibits remarkable photodegradation performance of rhodamine B (RhB) dye under UV-A radiation. A comprehensive investigation into the photocatalytic efficiency and characteristics of CZC-LDH was conducted using various analytical techniques, including XRD, FESEM, DRS, XPS, HR-TEM, PL, and BET (surface area analysis). Results indicate that CZC-LDH demonstrates superior photocatalytic efficiency, achieving 98.26 % degradation of RhB within 3-h only. Moreover, the influence of different scavengers on CZC-LDH photocatalytic efficiency was evaluated to elucidate the plausible RhB photocatalytic degradation pathway. The as-prepared CZC-LDH exhibits exceptional photocatalytic performance, stability, and reusability, positioning it as a promising candidate to previously reported photocatalysts in literature.

Anthraquinone and its Derivatives as a Recyclable Photocatalyst for Efficient Photocatalytic Degradation of Rhodamine B in Water under Visible Light

AbstractThis study presents findings that suggest it is possible to fine‐tune and enhance the optical properties of anthraquinone (AQ) and its photocatalytic performance in the degradation of rhodamine B (RhB) at the molecular level through varying its keleton substituents. Specifically, the electron‐withdrawing substituent demonstrates a more pronounced improvement effect compared to the electron‐donating substituent. Out of the several compounds, 2‐carboxyanthraquinone (AQ−COOH) exhibits the highest photocatalytic activity. This is due to its ionization in water, generating H+ ions that enhance the destruction of RhB through photodegradation. After 30 min of exposure to visible light, the degradation rate of RhB reaches an impressive 99.9 %. It is noteworthy that a hydrochloric acid solution with a concentration of 0.5 mmol ⋅ L−1 has a considerable promoting impact on the photodegradation of RhB catalyzed by AQ−COOH, and that the total degradation of RhB can be accomplished in 15 min. In addition, AQ−COOH also has good applicability for the degradation of tetracycline, methylene blue, and methyl orange. As a recyclable solid catalyst, the catalytic activity of AQ−COOH remained mostly unchanged after being used five times. Additionally, AQ−COOH did not undergo degradation when exposed to visible light, indicating its excellent stability in the process of catalyzing RhB degradation. According to quenching experiments and EPR spectrum characterizations, the photo‐generated active species oxygen vacancies (h+), photogenerated electrons (e−), superoxide free radicals (O2⋅−), singlet oxygen (1O2) and hydroxyl radical (•OH) are involved in the hypothesized photo‐catalytic degradation mechanism.

Sn-MOF and Sn-MOF@Fe3O4 composites for highly efficient photocatalytic degradation of rhodamine B

In this paper, 5,10,15,20-tetrakis-(4-carboxyphenyl)porphyrin (TCPP) was used as the ligand, and metal Sn and Fe were used as the nodes to construct metal–organic framework (MOF) materials Sn-MOF and Sn-MOF@Fe3O4 with a three-dimensional structure. Both Sn-MOF and Sn-MOF@Fe3O4 were utilized for photocatalytic degradation of rhodamine B (Rh B) dye. The effects of catalyst dosage, initial pH of the reaction solution and H2O2 on the degradation of Rh B in water under different environments were investigated. The main active species during the photocatalytic reaction were identified by capture experiments. The results showed that Sn-MOF@Fe3O4 could effectively inhibit the complexation of electrons and holes, and exhibited high catalytic activity for Rh B at a catalyst concentration of 0.25 g/L and pH 3. The degradation efficiency reached 100 % after UV–Vis irradiation for 20 min and the performance of Sn-MOF@Fe3O4 for photocatalytic degradation of Rh B was superior to other photocatalysts.

Green synthesis and studies on citrus medica leaf extract-mediated Au–ZnO nanocomposites: A sustainable approach for efficient photocatalytic degradation of rhodamine B dye in aqueous media

Abstract Incorporating narrow band gap oxide semiconductors and metals into zinc oxide (ZnO) nanostructures broadens the range of light sensitivity to include visible wavelengths. In this study, the photocatalytic degradation of rhodamine B (RhB) dye was studied as a model for environmental pollution in aqueous media. This study describes the use of photodegradation catalysts, including gold (Au), ZnO, and Au–ZnO nanocomposites (prepared in ratios of 90:10 and 95:5) using the extract of Citrus medica leaves. X-ray diffraction (XRD) findings have shown that ZnO nanoparticles (NPs) have a hexagonal wurtzite structure. Field emission-scanning electron microscopy findings have depicted that ZnO NPs have diverse shapes, including spherical, quasi-spherical, hexagonal, and anisotropic, with some clumping. Au exhibits consistent spherical shapes and sizes with even distribution. Au–ZnO (90:10) shows quasi-spherical NPs with interconnected spherical Au, forming a porous and uneven surface. Au–ZnO (95:5) has spherical gold nanoparticles (Au NPs) dispersed on a textured ZnO surface, with some clustering and size variation as evident from the transmission electron microscopy, atomic force microscopy, and diffuse reflectance UV-visible spectroscopy analysis. The characterization results have demonstrated the uniform distribution of Au across the ZnO lattice. Additionally, the XRD patterns confirmed the hexagonal wurtzite structure of ZnO. Furthermore, energy-dispersive analysis of X-ray (EDX)-mapping verified the inclusion of zinc, oxygen, and Au in the hybrid Au–ZnO nanocomposites and their effective distribution. The topological analysis revealed a rough surface for the generated nanostructures. By comparing the results of various techniques, EDX analysis using atomic and weight ratios confirmed the presence of oxygen and Au in the nanocomposite. Additionally, the surface area analysis (BET) test has reported that the adsorption and desorption of nitrogen follow a Type III isotherm. The presence of an H3-type hysteresis loop further confirms the mesoporous nature of the composites, which reports the presence of wedge-shaped pores. The Au–ZnO (90:10) nanocomposite exhibits a higher surface roughness compared to other composites. In addition, this UV-visible diffuse reflectance spectroscopy has enumerated the band gaps of various nanomaterials using UV-visible spectroscopy. Moreover, the analysis has unveiled that combining ZnO with Au NPs (doping) improved the photocatalytic performance of ZnO. This improvement is attributed to the formation of additional energy levels within the ZnO band gap due to the presence of Au ions. Experimental investigation of the breakdown of RhB dye under visible light irradiation revealed superior photocatalytic activity for the Au–ZnO (90:10) nanocomposite compared to both Au–ZnO (95:5) and pure ZnO and Au counterparts. Multiple experiments confirmed the effective photodegradation and removal of RhB dye from the aqueous medium using the nanocatalyst under visible light irradiation. Under optimal conditions (1.0 g·L−1 photocatalyst, 10 ppm RhB, and pH 10), 99% photodegradation efficiency was reached within 50 min of irradiation. Investigation of reactive species revealed that the increased effectiveness of photodegradation in Au–ZnO (90:10) stems from the presence of photogenerated holes and hydroxyl radicals. The study also analyzed the reaction kinetics and order, and the reusability of the best photocatalyst Au–ZnO (90:10)) was confirmed through five consecutive cycles, demonstrating its sustained effectiveness in photodegradation. These findings highlight the potential of Au–ZnO (90:10) nanocomposite as a promising material for photocatalytic degradation of organic dyes.

Boosting the recyclability of flame-made Bi2O3 via insitu immobilization in cellulose acetate nanofibers for efficient photocatalytic degradation of rhodamine B dye

Flame spray pyrolysis is a novel fast-process for producing functional metal oxides. However, these functional nanomaterials are challenged with poor recyclability in water treatment from pollutants such as dyes. Herein, Bi2O3 nanoparticles were produced by flame spray pyrolysis and spun together with eco-friendly cellulose acetate polymer into nanofiber membrane via electrospinning technique. The results reveal that cellulose acetate (CA) has good interaction with the particles, leading to reduced band gap, retardation of fast recombination of carriers and good electron transportation on the surface of the nanofiber membrane. The Bi2O3/CA nanofiber membrane records similar photocatalytic performance to that of flame-made Bi2O3 nanoparticles, that is about 95% dye degradation at 90 min, which was far better than CA and Bi2O3/polyacrylonitrile nanofiber membranes. The electron spin resonance test and free radical scavenger test reveal that abundant hydroxyl radicals serve as the most active species that enhance photocatalytic degradation of dye on Bi2O3/CA nanofiber membrane. The flexible Bi2O3/CA nanofiber membrane also demonstrates easy recyclability after several runs with no significant decline in performance. This study pins the effectiveness of using eco-friendly cellulose acetate in obtaining inorganic-organic composite to concurrently achieve good photocatalytic performance and recyclability.

Efficient photocatalytic degradation of rhodamine B using Ag-doped TiO2-loaded groundnut shell activated carbon under solar light

Efficient photocatalytic degradation of rhodamine B using Ag-doped TiO2-loaded groundnut shell activated carbon under solar light

Activation of peroxymonosulfate by halloysite nanotube-supported TiO2 composite for efficient photocatalytic degradation of Rhodamine B

In this study, to enhance the peroxymonosulfate (PMS)-assisted photocatalytic degradation of Rhodamine B (RhB) under visible light over TiO2, a novel halloysite nanotube (HNTs) supported TiO2 composite photocatalyst was prepared by the sol-gel method. The crystal structure and bonding information of samples were investigated by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible diffuse reflection spectroscopy (DRS), photoluminescence (PL) and electrochemical impedance spectroscopy (EIS) were used to characterize the morphology, optical properties and energy band structure of the samples. The composite with weight ratio of 1:5 (HNTs/TiO2) (named HT-20) exhibited apparently enhanced PMS-assisted photocatalytic RhB degradation efficiency and can degrade approximately 95.31 % of RhB in 30 min, and the first-order rate constants (k) of HT-20-PMS system is about 54.5 times higher than that of B–TiO2. In addition, the possible mechanism of enhanced PMS-assisted photocatalytic activity of HT-20 was proposed. The improvement of photocatalytic activity in the composite photocatalyst can be ascribed to the large surface area and strong adsorption capacity of HNTs.

Synthesis of Phosphotungstic acid/S-doped g-C3N4 Photocatalyst and Its Photocatalytic Degradation of Organic Pollutants in Aqueous Solutions

The S-doped g-C3N4 (SCN) was prepared by thermal condensation method using thiourea as a precursor, and then the phosphotungstic acid (PTA)/SCN composite photocatalytic material was prepared by reflux adsorption method. The photocatalytic degradation experiments of Rhodamine B showed that SCN20 had the highest photocatalytic degradation rate (74 %), which was 1.9 times and 3.5 times higher than that of PTA (39 %) and SCN (21 %), respectively. The photocatalytic degradation rate of SCN20 was increased by 5 times compared to that of SCN, indicating that the photocatalytic degradation performance of the composite material was significantly improved. The photocatalytic degradation mechanism study revealed that O2- was the main active species in the photocatalytic degradation of Rhodamine B, and the addition of PTA helped the effective separation of electrons-hole and improved the photocatalytic degradation rate. Our PTA/SCN is proposed as an environmental safety tool due to several advantages, such as low cost, convenient preparation, and efficient photocatalytic degradation of Rhodamine B.

Synthesis of visible light responsive Ce0.2Co0.8Fe2O4/g-C3N4 composites for efficient photocatalytic degradation of rhodamine B

Synthesis of visible light responsive Ce0.2Co0.8Fe2O4/g-C3N4 composites for efficient photocatalytic degradation of rhodamine B

Direct Z-scheme heterojunction of BiVO4microsphere/g-C3N4nanosheets for the efficient photocatalytic degradation of Rhodamine B

Optimizing content of BiVO4 in heterostructure drives maximum efficiency for RhB photodegradation, about 12.5 and 2.4 times higher than pure BiVO4and g-C3N4. ˙O2−and ˙OH are principal active species for ameliorating photocatalytic RhB degradation.

Mesoporous graphitic carbon nitride/hydroxyapatite (g-C3N4/HAp) nanocomposites for highly efficient photocatalytic degradation of rhodamine B dye

Recently, there is a rise in demand for low-cost natural source-derived photocatalysts for the degradation of harmful dyes. Here, we report new mesoporous g-C 3 N 4 /HAp nanocomposites prepared by a simple hydrothermal method for efficient photocatalytic degradation of rhodamine B (RhB) dye. Ultrafine g-C 3 N 4 nanosheets were synthesized from the polymerization of melamine and exfoliation of bulk g-C 3 N 4 . HAp nanoparticles were obtained by mixing mussel shell powder with Na 2 HPO 4 and microwave irradiation of the mixture. The g-C 3 N 4 (1-3 wt. %)/HAp was produced from hydrothermally reacting g-C 3 N 4 and HAp. XRD analysis of g-C 3 N 4 /HAp confirms the presence of g-C 3 N 4 and HAp phases. From FT-IR, Raman, NMR, and XPS spectra, the chemical bonds of g-C 3 N 4 /HAp were confirmed. The microscopic (SEM, TEM, and AFM) images illustrate the fine fusion of g-C 3 N 4 and HAp. BET and TG/DTA studies reveal that the g-C 3 N 4 /HAp is mesoporous in nature and is thermally stable. Optoelectronic properties indicate that g-C 3 N 4 /HAp’s luminescence changes with the g-C 3 N 4 concentration. In addition, g-C 3 N 4 /HAp showed high photocatalytic efficiency for RhB degradation (99%) in comparision to g-C 3 N 4 and HAp. The g-C 3 N 4 /HAp is recyclable and possesses good photochemical stability. Superoxide and hydroxyl radicals play a key role in the photodegradation of RhB. A reaction mechanism involving charge (electrons, holes) transfer at Z-scheme heterojunction of g-C 3 N 4 /HAp is proposed. This ‘green’ method, of g-C 3 N 4 /HAp synthesis from g-C 3 N 4 and biowaste-derived HAp, can potentially be applied for catalytic removal of pollutants from industrial effluents.

Facile Synthesis and Characterizations of Mixed Metal Oxide Nanoparticles for the Efficient Photocatalytic Degradation of Rhodamine B and Congo Red Dyes.

Photocatalytic degradation has been suggested to be a cheap and efficient way to dispose of organic pollutants, such as dyes. Therefore, our research team strives to produce nanophotocatalysts in a simple and inexpensive way. In this work, the Pechini sol-gel technique was employed for the facile synthesis of Mn0.5Zn0.5Fe2O4/Fe2O3 and Fe0.5Mn0.5Co2O4/Fe2O3 as mixed metal oxide nanoparticles for the efficient photocatalytic degradation of Rhodamine B and Congo Red dyes. XRD, FT-IR, a N2 adsorption/desorption analyzer, EDS, FE-SEM, and an UV-Vis diffuse reflectance spectrophotometer were used to characterize the produced samples. The XRD patterns revealed that the average crystallite size of the Fe0.5Mn0.5Co2O4/Fe2O3 and Mn0.5Zn0.5Fe2O4/Fe2O3 samples is 90.25 and 80.62 nm, respectively. The FE-SEM images revealed that the Fe0.5Mn0.5Co2O4/Fe2O3 sample consists of cubic and irregular shapes with an average diameter of 1.71 µm. Additionally, the Mn0.5Zn0.5Fe2O4/Fe2O3 sample consists of spherical shapes with an average diameter of 0.26 µm. The energy gaps of the Fe0.5Mn0.5Co2O4/Fe2O3 and Mn0.5Zn0.5Fe2O4/Fe2O3 samples are 3.50 and 4.3 eV and 3.52 and 4.20 eV, respectively. In the presence of hydrogen peroxide, the complete degradation of 100 mL of 20 mg/L of Rhodamine B and Congo Red dyes occurred at pH = 8 and 3, respectively, within 50 min, using 0.1 g of the synthesized samples.

Microinjection titration synthesis of CdS nano-particles with S-type interface-phase junctions for efficient photocatalytic degradation of rhodamine B

Currently, water scarcity caused by pollution is a serious threat to human survival and development. To address this problem, impurity energy levels of -NH2 groups using CS2-storage material (CS2SM) as an S source were introduced in this study, and CdS nano-particles (NPs) with enhanced sulfur vacancies (Vs-CdS NPs) and S-type interface-phase junctions were synthesized through a simple microinjection titration strategy. Moreover, rhodamine B (Rh B) with a volume of 100 mL and a concentration of 100 mg/L could be 99.7% degraded over 60 min using 20 mg of CdS NPs at pH = 6.0, T = 28 °C, and 300 W xenon lamp (optical power of 150 mW) irradiation. The high photocatalytic activity of the as-synthesized CdS NPs is owing to the intrinsic electric field, energy band bending, and Coulomb forces that occur between the hexagonal and cubic phases. In addition, the presence of Vs-CdS NPs can easily capture the photogenerated carriers of CdS NPs during recombination. Moreover, the photogenerated carriers are affected by the high and low energies between the Vs-CdS NPs, resulting in the transfer of the photogenerated carriers between the Vs-CdS NPs, which ultimately prolongs the lifetime of photogenerated carriers in the CdS NPs. Subsequently, a photocatalytic mechanism of S-type interface-phase junctions was proposed to explain the highly efficient photocatalytic activity and excellent optoelectronic properties of CdS NPs.

Singlet oxygen mediated efficient photocatalytic degradation of rhodamine B and disinfection by ZnO@PDA/Ag-Ag2O nanocomposite under LED light

Herein, a core-shell ZnO@PDA/Ag-Ag2O nanocomposite with high photocatalytic efficiency was synthesized via a solvothermal method. Due to polydopamine (PDA) coating and Ag-Ag2O doping, ZnO@PDA/Ag-Ag2O nanocomposite yielded a high amount of singlet oxygen (1O2) upon visible light irradiation, compared with unmodified ZnO and ZnO@PDA nanosheets. Under LED irradiation, ZnO@PDA/Ag-Ag2O nanocomposite with a p-n heterojunction exhibited remarkable photocatalytic efficiency for removing rhodamine B and eliminating Escherichia coli and Staphylococcus aureus. Furthermore, ZnO@PDA/Ag-Ag2O nanocomposite demonstrated high stability and photocatalytic activity after five consecutive cycles. It also effectively eliminated established biofilms and inhibited the generation of new biofilms. Wound-healing infected by S. aureus in vivo indicated that ZnO@PDA/Ag-Ag2O nanocomposite with LED irradiation inhibited microbial infection of wound and promoted wound healing. Therefore, 1O2-mediated ZnO@PDA/Ag-Ag2O nanocomposite is expected to be a promising photocatalyst in the fields of sewage treatment, antibacterial agents, and nanomedicines.

Efficient photocatalytic degradation of Rhodamine B dye using solar light-driven La-Mn co-doped Fe2O3 nanoparticles.

This work aims to develop a highly efficient solar light-induced photocatalyst based on La-Mn co-doped Fe2O3 nanoparticles. Pure Fe2O3 and La-Mn co-doped Fe2O3 nanoparticles were fabricated by a simple co-precipitation method. The photocatalysts were analyzed for their morphological, structural, and magnetic characteristics. Scanning electron microscopy analysis demonstrated the formation of semi-spherical nanoparticles along with small aggregations. The size of nanoparticles was measured using a transmission electron microscope and found in the range of 42-49nm. The crystalline nature and geometry of synthesized nanoparticles were investigated using X-ray diffraction analysis. Due to the incorporation of La-Mn, the saturation magnetization and remanent magnetization of the nanoparticles decreased from 6.17 to 2.89emu/g and 1.15 to 0.52emu/g, respectively, while the coercivity was reduced from 756.72 to 756.67 Oe. The surface area of nanoparticles was increased from 77.93 to 87.45 m2/g as a result of La-Mn co-doping. The photocatalytic performance of the Fe2O3, La0.1Mn0.3Fe1.6O3, and La0.2Mn0.2Fe1.6O3 catalysts was assessed by their capability to degrade Rhodamine B (RhB) under solar light illumination. La0.2Mn0.2Fe1.6O3 displayed exceptional degradation performance, degrading RhB to 91.78% in 240min, in comparison to La0.1Mn0.3Fe1.6O3 (71.09%) and pristine Fe2O3 (58.21%) under specified reaction conditions ((RhB) = 50ppm; (catalyst) = 40mg/L; pH = 7; T = 25°C)). RhB degradation was affected by changing pH, catalytic dosage, dye concentration, and temperature. The degradation of RhB was found to be pseudo-1st order kinetics. The exceptional photocatalytic performance of La0.2Mn0.2Fe1.6O3 catalysts showed that the synthesized nanoparticles could be effectively utilized to remove organic pollutants from industrial wastewater.

Sp2 carbon-conjugated covalent organic frameworks for efficient photocatalytic degradation and visualized pH detection

The design and fabrication of versatile covalent organic frameworks (COFs) with multiple properties for diverse applications is highly desirable. Here, the difunctional COFs material g–C18N3–COF was prepared and modified to be applied for efficient photocatalytic degradation of Rhodamine B (RhB) and pH detection, respectively. Owing to the triazine unit which was suitable for photocatalyst construction, g–C18N3–COF was sensitive to visible light and exhibited excellent photocatalysis capability toward RhB. Specially, the photocatalytic degradation of RhB with a high concentration of 300 ppm using g–C18N3–COF reached equilibrium within 6 h. Moreover, g–C18N3–COF was further grown in-situ onto the filter paper to generate a novel composite material g–C18N3–COF@Paper with bright yellow fluorescence. g–C18N3–COF@Paper could visualize the pH detection by remarkable changes in its fluorescent intensity and color in the range of pH value from 1 to 5, on account of the protonation of the nitrogen atoms from the triazine ring in g–C18N3–COF. The triazine-based sp2 carbon-conjugated g–C18N3–COF, respectively, used as photocatalyst and sensor in this work offers a new strategy to construct the versatile COFs material, facilitating the application of functional COFs in the environmental protection field.

Molybdenum oxide nanorods decorated with molybdenum phosphide quantum dots for efficient photocatalytic degradation of rhodamine B and norfloxacin

Molybdenum oxide nanorods decorated with molybdenum phosphide quantum dots for efficient photocatalytic degradation of rhodamine B and norfloxacin

ZIF‐8 Derived ZnO Decorated with Polydopamine and Au Nanoparticles for Efficient Photocatalytic Degradation of Rhodamine B

AbstractThe drawbacks of low utilization efficiency of solar energy and high recombination rate of photogenerated charge carriers limit the application of ZnO in photocatalytic reaction. In this study, a novel photocatalyst of ZnO decorated with polydopamine (PDA) and Au nanoparticles was successfully fabricated, using zeolite imidazolate frameworks (ZIF‐8) as ZnO precursor, followed by decorating with PDA and Au nanoparticles. The photocatalytic performance in degradation of rhodamine B (RhB) demonstrated that ZnO@PDA‐Au‐3 exhibited the most excellent photocatalytic activity. It could degrade 99 % of RhB in 24 min under UV‐vis light irradiation, in contrast with the degradation rate of 40 % and 16 % on ZnO@PDA and ZnO, respectively. The excellent catalytic activity was attributed to the contribution of PDA and Au. Particularly, Au not only promoted the absorption of visible light through localized surface plasmonic resonance (LSPR) effect, but also effectively facilitated the separation of photogenerated charge carriers though the Schottky barrier.