Photocatalytic Dye Degradation Efficiency Research Articles

Designing an eco-friendly Co/MnS/S-g-C3N4 nanocomposites: revolutionizing photocatalytic dye degradation and antibacterial efficiency

Designing an eco-friendly Co/MnS/S-g-C3N4 nanocomposites: revolutionizing photocatalytic dye degradation and antibacterial efficiency

Molten-salt-chemistry-assisted synthesis of heterostructured g-C3N4/BiOI nanocomposites with enhanced sunlight absorption properties for efficient solar-to-chemical energy conversion

The g-C3N4 nanosheets coupled BiOI (g-C3N4/BiOI) nanocomposites with unique heterojunction structure and excellent wide-spectrum sunlight absorption properties have been developed via molten-salt-chemistry-assisted strategy. The heterostructured g-C3N4/BiOI shows enhanced solar to the thermal effect, improved electron mobility and carrier lifetime for efficient photocatalytic dye degradation. The engineered g-C3N4/BiOI catalyst exhibits outstanding photocatalytic activity for methyl orange (MO) removal with 100 % degradation conversion and excellent stability under solar light irradiation, which is respectively 2.69 and 1.27 times higher than those of g-C3N4 and BiOI counterparts. The broad scope toward other dyes degraded by g-C3N4/BiOI and the generality of the molten-salt-chemistry-assisted strategy for synthesizing g-C3N4/BiOCl and g-C3N4/BiOBr with considerable photodegradation efficiency are proved. The analysis of kinetic behaviors, electron spin resonance, and nanosecond transient absorption spectra for structure-activity relationship, key intermediate of •O2− species, and excited state lifetime of g-C3N4/BiOI heterojunction material in the photocatalytic MO degradation processes are also demonstrated.

Enhancing photocatalytic dye degradation efficiency through the utilization of shock wave effects on neodymium oxide (Nd2O3)

This article delves into the impact of shockwaves on neodymium oxide (Nd2O3) nanoparticles, aiming to evaluate their physical and chemical stability. Nd2O3 nanoparticles were subjected to varying sets of shock pulses (100, 200, and 300) in photocatalytic dye degradation. The nanoparticles crystallinity and unit cell volume after shockwave exposure were examined using powder X-ray diffraction (PXRD) analysis with unit-cell software. PXRD data revealed no alterations in the crystalline structure, lattice parameter and unit cell volume. Comparisons between pre- and post-shockwave field emission scanning electron microscopy (FE-SEM) portraying data demonstrate that repeated shockwave application causes a decrease in particle size. Raman spectroscopy, under ambient conditions, shows a high intensity after shock conditions intensity will decrease. Furthermore, FTIR spectroscopy revealed the characteristic strong and broad absorption band associated with metal-oxygen (Nd-O) groups in the Nd2O3 nanoparticles. UV–Vis diffuse reflectance spectroscopy (DRS) was used to investigate the bandgap of the Nd2O3 nanoparticles. Initially, the bandgap was measured at 5.96 eV under ambient conditions, but following the shockwave exposure, it was decreased to approximately 5.91 eV. Interestingly, the surface area of the shockwave-treated Nd2O3 nanoparticles is increased and exhibited an increased efficiency in photocatalytic dye degradation. This finding holds promising implications for environmental remediation applications.

Photocatalytic degradation of Rhodamine B dye via Bi2O3 embedded BaO-P2O5-TeO2 glass nanocomposites: An ab initio study of structural, optical, and electrical transport properties

Bismuth incorporated glassy systems with composition xBi2O3-(1-x) [0.3BaO-0.3P2O5-0.4TeO2] (where x = 0.10, 0.15, 0.20, and 0.25) are synthesized by melt quenching technique. The glassy systems are examined for their structural, and surface morphological properties using XRD, SEM, and EDX analysis. A study of photocatalytic activity for the degradation of common organic dyes like Rhodamine B (RhB) dye under visible light is also carried out. From UV-vis absorbance data, the calculated optical band gap energy values declined from (2.99-2.56) eV, whereas the Urbach energy and refractive index values increased from (0.35 -0.52) eV, and (2.39 - 2.52), respectively with the rise of Bi2O3 content(x). Additionally, the fundamental processes of electrical conductivity have been studied within the framework of Jonscher's universal power law and the Almond-West formalism. The Mott and Greaves model asserts that the small polaron hopping model underlies DC conductivity; as Bi2O3 content increases, DC conductivity rises, but hopping distance (Rhop) and hopping energy (Whop) drop dramatically. The electrical conductivity study reveals the semi-conducting nature of the as-prepared samples. In our present study, we are focusing on the structural, optical, and electrical transportation properties, additionally, we investigated this class of glassy materials as a promising candidate for photocatalytic dye degradation. Our study reveals that RhB dye can degrade up to 75% within 340 min of visible light illumination. Moreover, the test demonstrates the production of superoxide radicals by the CB-electrons and hydroxyl radicals by the VB holes enables efficient photocatalytic dye degradation.

Multifunctional Pr-V2O5/rGO hybrid nanomaterial for sensitive heavy metal ion detection and efficient photocatalytic dye degradation

Multifunctional Pr-V2O5/rGO hybrid nanomaterial for sensitive heavy metal ion detection and efficient photocatalytic dye degradation

Synthesis of sustainable silver nanoparticles using plant extract and their antimicrobial, anticancer, and photocatalytic dye degradation efficiency analysis

The green synthesis of noble metal nanoparticles has gained a lot of interest in the area of nanotechnology, because of its high therapeutic properties. The present study focussed on the synthesis of the silver nanoparticles (Ag-NPs) using Ceropegia debilis leaf extract and characterized by various physio-chemical techniques and surface morphological studies. The prepared Ag-NPs exhibit a face-centred cubic structure, spherical morphology, and high purity as shown by XRD, SEM, and EDS analyses. The average size of the Ag-NPs was confirmed by TEM study as 18.6 ± 7.5 nm. The synthesized Ag-NPs show remarkable antioxidant activity of 72.1% compared to standard BHT 86.9%. Furthermore, Ag-NPs show remarkable cytotoxic properties against MCF 7 and A 549 cell line of 37.19% and 33.33%, respectively at 250 µg/mL. The antibacterial activity of Ag-NPs was investigated against the human pathogen and intestinal pathogen Staphylococcus aureus and Escherichia coli by agar disc diffusion method. Moreover, the synthesised Ag-NPs exhibit good antifungal properties against the fungal specimen Trichoderma viride assessed by well diffusion technique. In addition, Ag-NPs serve as an excellent nanocatalyst in the removal of toxic methylene blue dye (93.2%) from industrial wastewater under sunlight irradiation.

Facile synthesis of nickel doped ZnO and CeO2 nanocomposite for efficient photocatalytic dye degradation, catalytic reduction and antimicrobial studies

The current research work reports on binary Nickel oxide-Zinc oxide (NiO-ZnO) and Nickel oxide-Cerium oxide (NiO-CeO2) nanocomposites synthesis by facile single step in-situ thermal decomposition method and its applications. The structural and morphological studies were examined using various characterization techniques like IR, UV-DRS, XRD and SEM with EDAX studies. The IR bands at 545-533 cm−1 corresponds to M-O stretching vibration. The XRD studies confirms the structural pattern of NiO-ZnO and NiO-CeO2 nanocomposites. SEM with EDAX results reveal the structure, composition and purity of synthesized nanocomposites. The nanocomposites were employed as photocatalyst for degradation of methylene blue and methyl orange dyes and as a catalyst toward 4-nitrophenol reduction. Antibacterial studies against E. coli (Gram-negative) and S. aureus (Gram-positive) bacterial pathogens were carried out using the nanocomposites. The outcomes show 97% efficiency in forty minutes for catalysis and 120 min for dye degradation and a better zone of inhibition in antibacterial studies for NiO-ZnO nanocomposite. The comparative result for both the nanocomposites discloses that the photocatalytic degradation, catalytic and antimicrobial efficiency of NiO-ZnO nanocomposite is more efficient than NiO-CeO2 nanocomposite. The results reveal the outstanding catalytic and dye degradation and antibacterial activity of NiO-ZnO than NiO-CeO2.

Enhanced photocatalytic activity of FeSO4 in a ZnO photocatalyst with H2O2 for dye degradation

In this study, the photocatalytic degradation efficiency of ZnO synthesized by a hydrothermal method and iron-supported ZnO catalysts by an impregnation method, dried (D) and calcined (C), was evaluated, through the degradation of methylene blue (MB) and methyl orange (MO) molecules under UV irradiation. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N2 adsorption-desorption, and UVvisible diffuse reflectance spectroscopy (DRS). XRD showed that FeSO4 is supported on ZnO, and the XPS study revealed higher concentrations of hydroxyl groups and Fe3+ for the dried catalyst. The bandgap energies were 3.24, 3.23, and 3.19 eV for ZnO, Fe/ZnO D and Fe/ZnO C, respectively. The results revealed that Fe/ZnO D with H2O2 exhibited a higher photocatalytic degradation efficiency than ZnO, achieving 97% and 99% degradation for MB and MO at 10 min, which implies that the integrated iron in ZnO serves as an electron-hole separator. In addition, the catalyst has a larger BET specific area, the presence of hydroxyl groups and sulfate ions on the surface of the catalyst with holes forms hydroxyl radicals (•OH), and the presence of Fe3+ on the surface catalyst with H2O2 produces more •OH radicals. •OH radicals are the major oxidation species in this process, which promotes the degradation of dyes. The photocatalytic dye degradation efficiency was also evaluated for various catalyst doses, dye concentrations and solution pH values. Moreover, the stability of the catalyst over repeated cycles of dye treatment was demonstrated.

Facile fabrication of MoS2 and MoSe2 layered structures on Mo foil for the efficient photocatalytic dye degradation and electrocatalytic hydrogen evolution reaction

The rapidly growing necessity for sustainable materials in fields such as energy, environmental science, and medicine, two dimensional-based photo- and electro-catalysts has obtained mounting consideration. A simple methodology was employed to fabricate MoSe2 and MoS2 layered structures on flexible Mo foil as heterogeneous catalysts for the electrocatalytic hydrogen evolution reaction (HER) and the photocatalytic decolorization of chromic red (CR) and methylene blue (MB) dyes. The structural characteristics confirm the formation of the multi-layer thick MoSe2 and MoS2 nanofilms. The toxic MB and CR dyes were rapidly and effectively decolorized in polluted water by the photocatalysts within 30 min of UV-light irradiation. The fabricated layered structures exhibited favorable HER electrocatalytic activities along with low overpotentials, small Tafel slopes, and excellent 24-h stability performances. The strong catalytic behavior of these structures fabricated on Mo foil in relation to the HER reaction and the dye decolorization process make them suitable candidates for the catalyst industry.

Aspects of superior photocatalytic dye degradation and adsorption efficiency of reduced graphene oxide multiwalled carbon nanotubes with modified ZnO-Al2O3 nanocomposites

Due to the poor effectiveness of nanomaterials, the elimination of hazardous textile dyes from wastewater is quite challenging. A wide range of low-cost, hybrid, and highly effective nanomaterials have attracted much research for their potential in wastewater treatment. Herein, ZnO-Al2O3 nanoparticles were successfully grafted on reduced graphene oxide/multiwalled carbon nanotubes (ZnO-Al2O3-rGO/MWCNT) via the hydrothermal process. This nanohybrid material has been characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Brunner Emmet Teller (BET) analysis. ZnO-Al2O3-rGO/MWCNT has degraded 30 ppm Congo red dye to 90% within 1 h, while 20 ppm rose Bengal dye to 80% within 1.5 h. The kinetics of degradation for both these dyes is followed well by the pseudo-first-order model. Furthermore, ZnO-Al2O3-rGO/MWCNT was explored for the adsorption of Sudan III and displayed an outstanding removal capacity (220 mg g−1) compared with bare catalyst ZnO−Al2O3 (72 mg g−1). The sorption of Sudan III dye onto the adsorbent is spontaneous endothermic and follows pseudo−second−order kinetics and Langmuir isotherm models. Experiments using radical trapping have shown that hydroxyl radicals are the principal reactive intermediates in the photoexcitation process. The desorption and regeneration of as−prepared nanocomposite are also assessed.

CuAs2O4: Design, Hydrothermal Synthesis, Crystal Structure, Photocatalytic Dye Degradation, Hydrogen Evolution Reaction, Knoevenagel Condensation Reaction, and Thermal Studies.

CuAs2O4 has been explored as a heterogeneous catalyst in the fields of photocatalysis, electrocatalysis, and solvent-free organic transformation reactions. The homogeneity has been successfully attained for the first time by designing a pH-assisted hydrothermal synthesis technique. Single-crystal X-ray diffraction studies reveal that no phase transition has been observed by lowering the temperature up to 103 K with no existence of satellite reflections. The crystal structure exhibits tetragonal symmetry with space group P42/mbc and consists of [CuO6] octahedra and [AsO3E] tetrahedra (E represents the stereochemically active lone pair). Structural investigation shows a cylindrical void inside the structure, which could lead to interesting physical and chemical properties. The photocatalytic dye degradation efficiency with methylene blue (MB) showed ∼100% degradation, though the degradation efficiency increased by 2-fold with the addition of 6% H2O2. The reusability of the catalyst up to the 10th cycle with ∼35% MB dye degradation has been established. It can exhibit HER activity with a low overpotential of 165 mV with respect to RHE to attain the current density of j = 10 mA cm-2. SEM and TEM revealed rod-shaped particles, which supported the large number of catalytic active sites. The structural consistency of the catalyst after photodegradation and HER studies is confirmed by the PXRD pattern. XPS confirms the oxidation state of Cu and As in the compound. The catalytic activity toward the Knoevenagel condensation reaction at moderate temperature under solvent-free condition is also studied. TG-DTA shows an endothermic minimum (Tmin) at 436 °C due to the mass loss of As2O3.

Combination of ensemble machine learning models in photocatalytic studies using nano TiO2 - Lignin based biochar

Synergizing photocatalytic reactions with machine learning methods can effectively optimize and automate the remediation of pollutants. In this work, commercial Degussa TiO2 nanoparticles and lignin based biochar (LB) where used to prepare TiO2: lignin based biochar (TLB) composites using ultrasound-assisted co-precipitation method. The photocatalytic property of the TLB composites where studied by conducting the photocatalytic degradation of a Basic blue 41 (BB41) dye. The influence of calcination temperature, T:LB compositions, catalyst dosage, initial dye pH, initial dye concentration, and illumination time on photocatalytic dye degradation were experimentally studied. The degradation efficiency of 96.72 % was obtained under optimized conditions for the photocatalyst calcined at 500 °C containing a 1:1 wt percentage of TiO2 and LB. The experimental data was further used to predict the photocatalytic degradation efficiency using Gradient Tree Boosting (GTB) and Extra Trees (ET) models. The GTB model gave the highest prediction accuracy of 94 %. The permutation variable importance revealed catalyst dosage and dye concentration as the most influential parameters in the prediction of the photocatalytic dye degradation efficiency.

Unveiling efficient S-scheme charge carrier transfer in hierarchical BiOBr/TiO2 heterojunction photocatalysts.

The construction of a potential heterojunction catalyst with proper interface alignment has become a hot topic in the scientific community to effectively utilize solar energy. In this work, a one-dimensional TiO2 nanofiber/BiOBr S-scheme heterojunction was synthesized, and charge carrier dynamics within the interface channel were explored. In addition, we incorporated mixed phase TiO2 with point defects and oxygen vacancies, which greatly promoted the initial band edge shift from the UV region. Upon the addition of BiOBr, absorption in the visible light region of the electromagnetic (EM) spectrum was observed with a decrease in the optical band gap value. The optimized BiOBr heterojunction (BTNF1.5) revealed a higher photocatalytic RhB dye degradation efficiency due to the efficient generation and separation of charge carriers upon light irradiation. The optimum sample BTNF1.5 showed a high degradation efficiency of 98.4% with a rate constant of 47.1 min-1 at 8 min of visible light irradiation, which is double than that of the pure TiO2. Electrochemical analysis, time-resolved photoluminescence and Kelvin probe measurement revealed an S-scheme charge-transfer mechanism within the BiOBr/TiO2 system. This work provides a strategy for the facile synthesis of heterojunction photocatalysts exhibiting exceptional catalytic performance.

Effect of Co2+ doping on structural, optical and photocatalytic properties of La2CuO4 perovskite

In this article, structural, optical and photocatalytic properties of a series of Co2+ doped La2CuO4 perovskites, synthesized via sol–gel auto-combustion method, have been investigated for the first time. Structural and Fourier-transform infrared (FTIR) studies revealed pure orthorhombic phase formation with smaller crystallite sizes at higher Co2+ concentrations. Elemental composition was confirmed by energy-dispersive X-ray (EDX) analysis, and X-ray photoelectron spectroscopy (XPS) studies indicated the possible oxidation states of the constituent elements. The optical energy band gaps were estimated to be 1.31–1.04 eV, indicating the semiconducting nature and proper bandgap tuning with increased Co2+ content of the prepared perovskites. The highest photocatalytic methylene blue dye degradation efficiency, about 90%, was achieved for the 15% Co2+ doped La2CuO4 perovskite, indicating its potential use as a photocatalyst for environmental remediation.

Biocatalyst coupling with Mo-doped SnO2 nanoparticles for efficient photocatalytic dye degradation: An eco-friendly approach for environmental remediation

Specifically, biocatalyst coupled semiconductor photocatalysts have great potential towards the eco-friendly decomposition of toxic organic dyes that contaminate water bodies. This study reports the synthesis of vermiwash activated molybdenum doped tin oxide (Mo:SnO2) nanomaterial, for the photocatalytic degradation of a representative cationic dye - methylene blue (MB). The photocatalytic performance of the synthesized nanoparticles was evaluated using UV-visible (UV-vis) spectroscopy and the degrading efficiency of MB dye was quantified. The addition of vermiwash resulted in a marked improvement in the photocatalytic activity of Mo:SnO2 nanoparticles, with a degradation efficiency of 96% achieved after 75 min of irradiation. The nanoparticles were characterized using XRD, SEM-EDX, TEM, FTIR, XPS and UV-vis to confirm the crystal structure, morphology, functional groups, elemental analysis and bandgap energy by using Tauc’s plot. The study demonstrates the potential of vermiwash as a green and efficient bio co-catalyst for improving the photocatalytic activity of Mo:SnO2 nanoparticles regarding the degradation of textile effluents. Thus, this study paves a way for new eco-friendly approach for the synthesis of cost-effective, biocatalyst coupled semiconductor photocatalyst.

Antibacterial Nanocellulose-TiO2/Polyester Fabric for the Recyclable Photocatalytic Degradation of Dyes.

In this paper, we report an antibacterial, recyclable nanocellulose-titanium dioxide/polyester nonwoven fabric (NC-TiO2/PET) composite for the highly efficient photocatalytic degradation of dyes. The NC-TiO2 was loaded onto the surface of flexible PET nonwoven fabric through a simple swelling and dipping method. The NC-TiO2 in the particle size range of ~10 nm were uniformly attached to the surface of the PET fibers. The NC-TiO2/PET composite has the ability to achieve the stable photocatalytic degradation of dyes and presents antibacterial properties. The degradation rates to methylene blue (MB) and acid red (AR) of the NC-TiO2/PET composite reached 90.02% and 91.14%, respectively, and the inhibition rate of Escherichia coli was >95%. After several rounds of cyclic testing, the photocatalytic performance, antibacterial performance, and mechanical stability of the NC-TiO2/PET composite remained robust.

Angle-free random laser enabled efficient photocatalytic degradation of Rhodamine 6G molecules

Efficient photocatalytic dye degradation has been realized based on the first attempt of using a random laser. In previous studies, most photocatalytic dye degradation was conducted by using broad-angular emission lamps, light-emitting diodes, and conventional lasers. However, these types of light sources could be restricted by some disadvantages, such as weak intensity or high directionality. Unlike traditional lasers, random lasers obviate the need for the cavity. The advantage of broad-angular emission lights and the feature of laser-level intensity make random lasers a promising light source for many potential applications. In this study, an ultraviolet random laser (UVRL) derived from zinc oxide (ZnO) was used in the photocatalytic dye degradation experiment. It is found that the degradation efficiency of the UVRL is much better than that of conventional lasers and ultraviolet light-emitting diodes. The success of applying random laser systems in the photocatalytic reaction is expected to expand the applications of random lasers.

6-connected Zn(II)-MOF: Efficient photocatalytic dye degradation and remarkable luminescent detection of biomolecules and hazardous ions

{[Zn(Bimb)3]·2ClO4}n (KA@MOF_VS) coordination polymer have been synthesized at room temperature, using Bis(2-Carboxyethyl)isocyanurate and1,4-bis [(1H-imidazol-1-yl)methyl]benzene (Bimb) and characterised by FT-IR spectra analysis, Powder X-ray diffraction, and thermal analysis. Single crystal X-ray analysis reveals that KA@MOF_VS is having 6-connected net and giving a standard 412⋯63pcu topology with multi-functional luminescence sensing for Acetone, NB, 2A-5NP, NFT, Fe+3, Cr2O72− in general and sucrose 150 mg/dl with high sensitivity in particular. Photocatalytic degradation of series of toxic organic dyes has also been tested with KA@MOF_VS. The main finding of this work is a very first study of sucrose sensing in presence of anti-interfering analyte like creatine and creatinine which could be helpful in designing of materials for sucrose detection in diabetic patient in case of creatine and creatinine anomaly if present in blood.

Direct fabrication of metal-free graphene nanohairs/polyimide heterojunction for the highly efficient photocatalytic degradation of industrial dyes

A single-step three-dimensional graphene nanohairs/polyimide heterojunction (GPH) is fabricated using a CO2 laser-assisted method. An optimization process has been systematically carried out to obtain high-quality graphene nanohairs on polyimide. The obtained GPH was characterized by X-Ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. Using the fabricated GPH as a photocatalyst, the photocatalytic degradation of three industrial dyes namely, methyl orange (MO), methylene blue (MB), and Rhodamine B (RhB), was studied under UV irradiation. The decolorization of the samples was studied by UV–vis absorbance spectrometer. Starting from 5 ppm dye solutions with GPH, the degradation efficiencies of 97 % for MO in 60 min, 98 % for RhB in 90 min, and 88 % for MB in 170 min, were achieved. Furthermore, the stability of GPH was evaluated and after five runs, the degradation efficiency of MO, RhB and MB is decreased to 85 %, 91 % and 75 % from 98 %, 97 %, and 88 %, respectively. The mechanism for the degradation of dyes using GPH was proposed. The simple and feasible fabrication of GPH with excellent photocatalytic dye degradation efficiency would create the new insight into the flexible heterostructures for degrading the industrial wastewater treatment process.

Photocatalytic dye degradation efficiency and reusability of potassium polyacrylate hydrogel loaded Ag@ZnO nanocomposite

Photocatalytic dye degradation efficiency and reusability of potassium polyacrylate hydrogel loaded Ag@ZnO nanocomposite