Efficient Photocatalyst For Photocatalytic Degradation Research Articles

Niobium pentaoxide (Nb2O5) as an efficient photocatalyst for photocatalytic degradation of rhodamine-B

Abstract One of the most important problems that the world is currently facing in terms of its impact on the environment is figuring out how to properly manage textile effluents. Photocatalysis has been shown to be successful in the removal of intractable chemicals and is regarded as a viable wastewater treatment technology. This work focused on the photocatalytic degradation of rhodamine-B (RB) in an aqueous solution, as well as the photocatalytic behavior of niobium pentaoxide (Nb2O5) as a photocatalyst was tested. It is important to note that good photocatalytic efficiency is highly dependent on the operating conditions. There are several process parameters that influence RB photocatalytic degradation, including the amount of photocatalyst (Nb2O5) used, the concentration of RB at the start of the reaction, and the pH of the solution optimized under visible-light irradiation. According to the findings, the conditions in which the greatest amount of RB was degraded were those in which the concentration of the catalyst was 10 mg/l, the dosage of the catalyst was 1 mg/l, and the pH was 11. The results also revealed that after utilizing the catalyst three times in a row, catalyst efficiency was maintained, and the degradation rate was maintained at a greater level.

Room-temperature MXene-derived Ti3+ and rich oxygen vacancies in carbon-doped amorphous TiOx nanosheets for enhanced photocatalytic activity

Exploring efficient photocatalysts for photocatalytic degradation is of considerable importance for the long-term mitigation of environmental stress. Although defect engineering is an effective strategy to alter the electronic transport properties and light absorption capacity of TiO2, the synthesis of TiO2 rich in oxygen vacancies (OVs) via a green process at room temperature and with low energy consumption remains a challenge. Herein, amorphous TiO2 nanosheets rich in OVs were prepared by H2O2-assisted room-temperature oxidation of Ti3C2Tx MXene via a bottom-up approach. Notably, small amounts of C and Ti3+ were introduced during the preparation of carbon-doped TiO2 (C-TiOx), which was shown to possess abundant surface functional groups (e.g., –OH, –O, and –F) and two intermediate levels in its bandgap. Comparative experiments demonstrated that OVs play a key role in suppressing the recombination of photogenerated carriers and expanding the light absorption range of the photocatalyst. The unique quasi-two-dimensional structure of C-TiOx features a large number of exposed active sites, which are beneficial for improving its catalytic performance. Tetracycline (TC) was removed from the aqueous solution by the prepared photocatalysts C-TiOx and annealed-TiO2, and the former adsorbed 41.1% of TC. The TC removal efficiency of C-TiOx was 76%, which was higher than that of annealed-TiO2. This approach embodies a new strategy for introducing defects and doping in TiO2. Moreover, it is also thought that C-TiOx possesses promising characteristics suitable for a wide range of potential future applications.

Cobalt aluminate/carbon nanocomposite via an auto-combustion method: an efficient photocatalyst for photocatalytic degradation of organic dyes from aqueous media

ABSTRACT Cobalt aluminate/carbon composite nanoparticles have been synthesised by utilising an auto-combustion method using glycine as an inexpensive fuel. The products were analysed by various techniques such as powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), thermal analysis (TG), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectrum (DRS), energy-dispersive X-ray spectroscopy (EDS). The results exhibited that the average crystallite size of the as-prepared CoAl2O4/C nanocomposite was ca. 26 nm. The photocatalytic activity of the as-prepared catalyst was evaluated through the degradation of methylene blue (MB) dye under different conditions, and the photocatalytic degradation mechanism was proposed. The results indicated that CoAl2O4/C nanocomposite has a high catalytic performance for the photocatalytic degradation of MB dye under UV illumination in the presence of H2O2. The degradation efficiency reached 98.5% in 90 min with a degradation rate constant of 0.046 min−1.

Synthesis of Ce-doped NiAl LDH/RGO composite as an efficient photocatalyst for photocatalytic degradation of ciprofloxacin

The Ce-doped NiAl layered double hydroxide/reduced graphene oxide (NiAlCe LDH/RGO) composite was synthesized by a facile one-step hydrothermal method. The structure and morphology of the composite were investigated. NiAlCe LDH/RGO has large specific surface area and uniform dispersion. The presence of Ce and RGO accelerate separation of photo-generated charges, leading to an outstanding photocatalytic performance for the degradation of ciprofloxacin (CIP). As a result, the NiAlCe LDH/RGO exhibits a high photocatalytic degradation efficiency of 94% under visible light irradiation, which is much higher than that of pristine NiAl LDH (36%). Moreover, the NiAlCe LDH/RGO possesses excellent cycling stability of 84% efficiency retention after five consecutive tests. In addition, the reaction mechanism of photocatalyst was investigated by ESR and radical scavenger experiments.

Facile construction of an Ag0-doped Ag(i)-based coordination polymer via a self-photoreduction strategy for enhanced visible light driven photocatalysis

A series of Ag0-doped Ag(i)-based coordination polymers have been prepared via a facile self-photoreduction strategy, and can be utilized as efficient photocatalysts for photocatalytic degradation of methylene blue.

Microwave-assisted fabrication of copper nanoparticles utilizing different counter ions: An efficient photocatalyst for photocatalytic degradation of safranin dye from aqueous media

We herein have developed a facile, cost-effective, microwave method for the synthesis of copper nanoparticles using different counter ions: sulfate, chloride, acetate, and nitrate. The preparation was performed using ethylene glycol and sodium hypophosphite as a reaction medium and reducing agent, respectively. FT-IR, XRD, FE-SEM, EDS, XPS, DRS, and TEM techniques were used for characterization of the products. The results exhibited that the counter ions have a significant influence on the products. Copper sulfate and copper chloride salts produced the purest copper nanoparticles with 45 and 48 nm average particle size, respectively. All copper nanostructures showed high photocatalytic activity (95.0–98.0 %) for the degradation of safranin (Saf) dye under UV irradiation in 70 min. The apparent first-order rate constant (kapp) was 0.0446 min−1 for the Cu nanoparticles prepared using copper sulfate (CuSNPS). The copper product showed good reusability, stability, and applicability for the removal of Saf dye from aqueous solutions.

Detection of several quinolone antibiotic residues in water based on Ag-TiO2 SERS strategy

Herein, a surface-enhanced Raman scattering (SERS) strategy based on semiconducting substrate was exploited for detection of several antibiotic residues both in ultrapure water system and in actual water system. The as-prepared Ag-TiO2 (Ag synchronously deposited and doped TiO2) nanoparticle SERS-active substrate can achieve high sensitive SERS detection for difloxacin hydrochloride, ciprofloxacin, enrofloxacin, danofloxacin and enoxacin (five widely used quinolone antibiotics) in actual water samples, and the detection limits are as low as 4.36 × 10−12, 7.08 × 10−11, 3.94 × 10−11, 3.16 × 10−11 and 3.15 × 10−10 mol/L, respectively. These detection limits are far below the maximum of residue limit (3.01 × 10−7 mol/L) stipulated by the European Union. And, the desirable quantitative relationships can be obtained in a wide concentration range. The recoveries of five antibiotic residues from spiked actual water samples are found to be more than 80.8% with the relative standard deviations between 2.1% and 4.7%. Even, the proposed SERS method can accurately distinguish every antibiotic species from a mixed antibiotic residue sample with multiple antibiotics. And, Ag-TiO2 nanoparticles can also serve as an efficient photocatalyst for photocatalytic degradation of these antibiotic residues, which provides a multi-functional platform for synchronous determination and degradation of antibiotic residues in real environment.

Photocatalytic performance of BiFeO3 based on MOFs precursor

BiFeO3 (BFO) is considered to be a potential visible light photocatalytic material for organic degradation due to its narrow band gap. In this work, the BFO with smaller band gap and better photocatalytic performance was prepared by thermal decomposition of we prepared smaller band gap and better photocatalytic performance BFO by thermal decomposition of MOFs precursor Bi[Fe (CN)6]·5H2O. Among them, BFO‐0.5 has the best photocatalytic activity, which the photocatalytic degradation rate of methyl orange (MO) aqueous solution is 98.1% within 60 minutes. The photocatalytic activity is almost unchanged after four cycles of use. The enhanced photocatalytic activity of BFO could be attributed to the enhanced optical absorption and smaller particles. It may be conducive to design more efficient photocatalysts for photocatalytic degradation of organic dyes.

Ultrasmall Plasmonic Nanoparticles Decorated Hierarchical Mesoporous TiO2 as an Efficient Photocatalyst for Photocatalytic Degradation of Textile Dyes.

Hierarchical mesoporous TiO2 was synthesized via a solvothermal technique. The sonochemical method was adopted to decorate plasmonic nanoparticles (NPs) (Ag, Au) on the pores of mesoporous TiO2. The crystallinity, structure, and morphology were determined to understand the physicochemical nature of the nanocomposites. The catalytic efficiency of the plasmonic nanocatalysts was tested for the azo dyes (congo red, methyl orange, acid orange 10, and remazol red) under solar and visible light irradiations. The generation of hydroxyl radicals was also studied using terephthalic acid as a probe molecule. An attempt was made to understand the influence of size, work function and Fermi level of the metal NPs toward the efficiency of the photocatalyst. The efficiency of the nanocomposites was found to be in the order of P25 < mesoporous TiO2 < mesoporous Ag–TiO2 < mesoporous Au–TiO2 nanospheres under both direct solar light and visible light irradiation. The results indicated that the adsorption of dye, anatase phase, and surface plasmon resonance of NPs favored the effective degradation of dyes in aqueous solution. Further, the efficiency of the catalyst was also tested for xanthene (rose bengal), rhodamine (rhodamine B, rhodamine 6G), and thiazine (methylene blue) dyes. Both TiO2 and NPs (Ag & Au) possess a huge potential as an eco-friendly photocatalyst for wastewater treatment.

Silk fibroin linked Zn/Cd-doped SnO2 nanoparticles to purify the organically polluted water

Photocatalytic degradation of toxic organic pollutant is a challenging tasks for environmental protection. Recently most of the researchers are focusing on metal oxide semiconductors, such as TiO2, ZnO, and SnO2 as efficient photocatalysts for photocatalytic degradation of organic pollutant. In this regard, we are eager to increase the photocatalytic activity with the help of organic molecule (Silk Fibroin (SF)). Metal oxides are attached on the surface of SF with the help of polyvinyl alcohol (PVA). In this present work, pure SnO2, (Cd/Zn) doped SnO2 and SF linked nanoparticles have been successfully synthesized by microwave technique. The synthesized samples were investigated by XRD, FTIR and UV-DRS techniques. The surface morphology of all the samples were investigated by FESEM analysis. Photocatalytic activities of Cd doped SnO2 nanoparticles and SF attached Cd/Zn doped SnO2 nanoparticles were studied on methylene blue (MB) dye under UV–vis light illumination.

Preparation, Characterization and Photocatalytic Property of Cubic α-Fe2O3 Nanoparticles

Abstract A simple hydrothermal synthesis method has been designed for the controllable synthesis of cubic α-Fe2O3 nanoparticles. Structural and morphological characterizations of the synthesized products were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The size range of the cubic α-Fe2O3 particles is 130–150 nm. Results indicate that the α-Fe2O3 nanoparticles can be used as an efficient photocatalysts for photocatalytic degradation of Rhodamine B in the presence of hydrogen peroxide, which may provide the design and development of high-efficiency visible-light photocatalysts for removing toxic dyes from industrial wastewater with a new way and basis.

Visible-light-driven photocatalytic and chemical sensing properties of SnS2 nanoflakes

This work demonstrated the successful and facile large-scale synthesis and characterizations of SnS2 nanoflakes. The detailed morphological studies revealed that the synthesized products were nanoflakes and were grown in large quantity. The XRD pattern and detailed compositional studies confirmed that the synthesized SnS2 nanoflakes were well-crystalline and possessing hexagonal SnS2 phase. The synthesized SnS2 nanoflakes were used as efficient photocatalysts for photocatalytic degradation and effective electron mediators for the fabrication of chemical sensor. The photocatalytic properties of SnS2 nanoflakes towards the photocatalytic degradation of Rhodamine B dye under visible light irradiation showed reasonably good degradation of ∼61%. Moreover, the as-synthesized SnS2 nanoflakes were used as efficient electron mediators for the fabrication of nitroaniline chemical sensor by simple I-V technique. Very high-sensitivity of ∼ 505.82±0.02mAcm−2.(mole/L)−1 and experimental detection limit of ∼15×10−6 (mole/L) in a short response time of ∼10.0s with LDR in the range of 15.6×10−6–0.5×10−3moleL−1 were observed for the fabricated nitroaniline chemical sensor. The observed results indicated that the SnS2 nanoflakes can efficiently be used as visible-light-driven photocatalysts and the fabrication of ultra-high sensitive chemical sensors.

Sonochemical and visible light induced photochemical and sonophotochemical degradation of dyes catalyzed by recoverable vanadium-containing polyphosphomolybdate immobilized on TiO2 nanoparticles

Na5PV2Mo10O40 supported on nanoporous anatase TiO2 particles, TiO2–PVMo, was used as an efficient photocatalyst for photocatalytic degradation of different dyes by visible light using oxygen as oxidant. This catalyst showed a good catalytic activity in the sonocatalytic and sonophotocatalytic decomposition of different dyes in aqueous solutions. The TiO2–PVMo composite showed higher photocatalytic and sonocatalytic activity than pure polyoxometalate or pure TiO2.