Orange Dye Degradation Research Articles

Influence of Pd, Pt and Au nanoparticles in the photocatalytic performance of N-TiO2 support under visible light.

In this article, we report the modification and photocatalytic evaluation of commercial TiO2-P25 under visible light for methyl orange (MO) dye degradation under visible light. The activity of materials doped with N, Pd, Pt and Au on to the TiO2-P25 was evaluated, with optimal photocatalytic performance achieved using Au nanoparticles doped on an N-functionalized titania surface. X-ray diffraction (XRD), physical nitrogen adsorption/desorption isotherm curves, transmission electron microscopy (TEM), diffuse reflectance spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to study the structural and textural properties of the samples. The chemical species present in the bulk and surface of the catalysts were identified using X-ray photoelectron spectroscopy (XPS) and microwave plasma-atomic emission spectroscopy. The results show that Au/N-TiO2 photocatalyst presents a remarkable enhanced activity for MO dye degradation, under visible light illumination, reaching 100% after 4 h. The enhanced photocatalytic activity using this composite is attributable to the well-dispersed and small size of Au nanoparticles, large surface area, reduction of band-gap energy and the interaction between nitrogen and Au which promoted a synergistic effect. This article is part of the discussion meeting issue 'Green carbon for the chemical industry of the future'.

Catalytic properties of Fe-based amorphous alloys based on LPBF

Laser Powder Bed Fusion (LPBF) additive manufacturing technology has the advantages of high forming accuracy and rapid cooling. It is expected to overcome the limitations of forming difficulties in amorphous alloys and provide a new opportunity for the production of amorphous alloy structural parts. In this paper, FeSiBCrC amorphous alloy powder was used to prepare Fe-based amorphous alloy samples by LPBF technology. In view of the excellent properties of Fe-based amorphous alloy, the catalytic degradation performance of Fe-based amorphous alloy samples prepared by LPBF was systematically investigated. The catalytic degradation performance of the Fe-based amorphous alloy was optimised by changing the reaction conditions. In the methyl orange (MO) dye degradation experiment, the degradation rate reached 90.99 % within 10 min. Increasing the sample dosage and reaction temperature can improve the degradation efficiency, but excessive addition of H2O2, raising the pH and the initial dye concentration will reduce the degradation efficiency. In addition, in the cyclic catalytic experiment, it was found that it has self-renewing performance, and the degradation efficiency was still higher than 95 % within 35 min after repeated degradation 12 times. Fe-based amorphous alloy catalysts prepared on the basis of LPBF have good catalytic activity and will provide economical and effective technical support for wastewater treatment.

Optimizing photocatalytic performance with Ag-doped ZnO nanoparticles: Synthesis and characterization

The development of nanotechnology has significantly impacted the improvement of photocatalytic performance of ZnO NPs. In this study synthesis of pure ZnO and Ag–ZnO nanoparticles via a co-precipitation method at varying Ag concentrations (1 %, 2 %, 3 %, 4 % and 6 %) to enhance their photo catalytic efficacy. X-ray diffraction (XRD) analysis estimates crystallite size which decreased by increasing Ag concentration, ranging from 30.6 nm (Pure ZnO) to 22.5 nm 6 % Ag-doped ZnO. Scanning electron microscopy (SEM) revealed decrease in particle size with increasing Ag content. UV–Vis spectroscopy indicating a narrowed band gap of optimal sample. Photocatalytic activity of the synthesized nanoparticles was evaluated using methylene orange (MO) dye degradation under light irradiation. The MO concentration exhibited a decrease with increasing irradiation time in the presence of photocatalysts. Recombination rate of NPs decreases by increasing the concentration of Ag i.e. 4%Ag dope ZnO NPs have lowest recombination rate and maximum degradation efficiency. FTIR analysis confirms the preparation of Ag-doped ZnO NPs. This improvement can be credited to the synergistic effect of Ag doping, leading to a narrowed band gap and potentially maximum degradation of MO by using Ag-doped ZnO NPs.

Green synthesis of silver nanoparticles from waste leaves of tea (Camellia sinensis) and their catalytic potential for degradation of azo dyes

Tea leaves are discarded after use as waste material. An attempt was made to explore the potential of tea waste as an alternative source of extensive reducing agent for green and biocompatible synthesis of silver nanoparticles (WT-AgNPs) from silver nitrate salt, and prospective utilization for degradation of toxic azo dyes such as methyl orange and Congo red occurring in effluents. Green tea extract was also used as reducing agent to synthesize AgNPs (GT-AgNPs) to compare their physicochemical properties and efficiency vis-à-vis WT-AgNPs. Both WT-AgNPs and GT-AgNPs were characterized by Ultraviolet-Visible (UV) and Fourier Transform Infrared (FTIR) Spectroscopy, particles size and zeta potential measured by Dynamic Light Scattering (DLS), surface morphology and elemental composition determined by Field Emission Scanning Electron Microscopy (FESEM). The average particle size, zeta potential and surface plasmon resonance (SPR) were 74.85 nm, -22.62 mV, 422 nm and 69.53 nm, -21.28 mV, 420 nm for WT-AgNPs and GT-AgNPs, respectively. Catalytic degradation reaction of methyl orange and Congo red using the biogenic AgNPs followed the pseudo-first order kinetics in both cases. The rate constants of methyl orange dye (100 ppm) degradation using the catalysts (WT-AgNPs and GT-AgNPs) were 0.087 s−1(R2=0.922) and 0.099 s−1 (R2=0.963) respectively, showing 93 % and 95.5 % degradation of dye in 40 min in presence of NaBH4. For Congo red (100 ppm) degradation, the rate constants were 0.112 s−1 (R2=0.917) and 0.113 s−1(R2=0.943). Both WT-AgNPs and GT-AgNPs exhibited bacteriostatic effect inhibiting growth of E. coli. The study offers potential use of waste tea leaves as an effective reducing agent for large-scale green synthesis of silver nanoparticles having multifarious environmental applications in general, dye degradation and antibacterial action in particular.

Utilizing <i>Chlorophytum comosum</i> Leaf Extract for Eco-friendly Synthesis of Iron-Based Nanoparticles: Assessing Their Efficacy in Methyl Orange Dye Degradation and Antimicrobial Activities

Utilizing <i>Chlorophytum comosum</i> Leaf Extract for Eco-friendly Synthesis of Iron-Based Nanoparticles: Assessing Their Efficacy in Methyl Orange Dye Degradation and Antimicrobial Activities

Halogen-doped 2D reduced graphene oxide with TiO2 nanocomposite for water remediation application

Water contamination by organic and inorganic pollutants has been a challenging problem impacting living organisms. The current study explores the photocatalytic property of nanocomposite based on iodine-doped reduced graphene oxide with titanium dioxide nanoparticles (TNPs) for methyl orange (MO) dye degradation. A nanocomposite of TNPs with iodine-doped reduced graphene oxide (TIR) is prepared using the hydrothermal technique. The physicochemical properties of nanocomposite were explored by various techniques such as an X-diffractometer (XRD), Raman spectroscopy, Fourier transforms the infrared spectrum, energy-dispersive X-ray spectroscopy spectrum (EDX), and high-resolution transmission electron microscopy (HRTEM). The XRD reveals the crystalline structure of the TIR nanocomposite. The anatase TNPs with an average particle size of 9.68 ± 2.1 nm are confirmed by HRTEM. The Raman spectrum confirms the presence of iodine molecules with a peak at 101 cm−1, and the EDX spectrum confirms the presence of iodine molecules with 15.31 % elements in the TIR nanocomposite. The MO dye degradation efficiency of 96.12 % with 120 min UV exposure for TIR suggests that the iodine-doped nanocomposite is a promising photocatalyst for water remediation.

Antibacterial potential and dye decolorization with graphitic carbon nitride and eudragit doped CdTe nanostructures evidential molecular docking analysis

Co-precipitation procedure was employed to prepare efficient ternary system-based catalysts composed of various concentrations (2 and 4 wt.%) of graphitic carbon nitride (g-C3N4) and fixed amount (3 wt.%) of eudragit (Eud)-doped cadmium telluride (CdTe) nanostructures (NSs). The main objective of this study was to explore and enhance the dye degradation potential by changing the recombination rate of CdTe with doping and improving their multifunctional efficacy as catalysts and antibacterial agents. The dopants have altered the particle size, dispersal and optical properties of CdTe. The different concentrations of g-C3N4 and fixed amount of Eud, reaction temperature, and duration influence these characteristic properties of CdTe. g-C3N4 /Eud-doped CdTe with porous structure showed excellent methyl orange (MO) dye degradation efficiency (98.0 %) in neutral medium. Furthermore, 4 wt.% of g-C3N4 doped NSs exhibited significant inhibition zone as 9.35 ± 0.08 mm against MDR S. aureus bacteria. The molecular docking studies were conducted to elucidate the mechanistic interactions between g-C3N4/Eud-doped CdTe nanostructures and the target enzymes DNA gyrase S. aureus and D alanine-D-alanine ligase (ddlB)S. aureus, in order to justify their microbicidal efficacy.

Enhanced Photocatalytic Degradation of Methyl Orange Using Nitrogen‐Functionalized MesoporousTiO2 Decorated with Au9 Nanoclusters

A novel catalyst for dye degradation is fabricated through attaching Au9 nanoclusters (Au9 NCs) to N functionalized mesoporous TiO2 (NMTiO2). The NMTiO2 is created through chitosan‐assisted soft templating resulting in an N terminated surface preventing the agglomeration of the Au9 NCs adsorbed surface and enhancing the overall loading with Au9. The calcination atmosphere influenced the surface properties of the NMTiO2 and its capability to adsorb the Au9 NCs. The photocatalytic effectiveness of these materials was probed through methyl orange (MO) dye degradation. The black coloured Au9/NMTiO2 catalyst is highly effective to completely degrade MO dyes within 20 min due to its large reaction constant (0.176 min−1). Parameter interactions for the dye degradation process were explored using response surface methodology (RSM) and the dependency of MO degradation on the affecting parameters was evaluated based on the statistical analysis and 3D plots.

Au9 clusters deposited as co-catalysts on S-modified mesoporous TiO2 for photocatalytic degradation of methyl orange

Au9 nanoclusters (Au9 NCs) were deposited onto S-functionalized mesoporous TiO2 (SMTiO2) to produce efficient photocatalysts for Methyl Orange (MO) dye degradation with UV light. The morphology, the surface composition and the size of the deposited Au9 NCs of the catalyst was analysed. SMTiO2 could adsorb more clusters with lesser Au9 cluster agglomeration than unmodified MTiO2. This finding is attributed to the capability of the thiol groups to form strong bonds with the Au9 clusters. To study Au9 NCs effect on dye degradation activity, the MO degradation reaction constants under UV-light irradiation for SMTiO2 nanoparticles (NPs) and Au9 NCs decorated SMTiO2 photocatalysts were studied, which were 0.07 min−1 and 0.149 min−1, respectively. Hence, it takes almost half the time to completely degrade MO using Au9 NCs decorated SMTiO2 photocatalysts compared to SMTiO2 substrate. Results were analysed using the response surface methodology (RSM) to study the interaction between the reaction parameters.

Constructing of GQDs/ZnO S-scheme heterojunction as efficient piezocatalyst for environmental remediation and understanding the charge transfer mechanism

Highly efficient catalysts are challenging in the fields of environmental remediation. In this work, for the first time, we combined graphene quantum dots (GQDs) and piezocatalytic materials (ZnO) to construct a novel S-scheme GQDs/ZnO heterojunction via facile method. The obtained GQDs/ZnO heterojunction presented excellent piezocatalytic activity such as higher reaction kinetic rate constant (0.051 min−1) and degradation efficiency (96.1 % within 60 min) as well as superior stability toward methyl orange (MO) dye degradation, far exceeding those of pure ZnO and most reported other typical piezocatalysts. This superior piezocatalytic performance of GQDs/ZnO could be ascribed to S-scheme heterojunction facilitating charge carrier transfer and separation, and enhancing the redox ability as well as the formation atomic-level interfacial bridge of Zn–C–O bond at GQDs/ZnO interface. Furthermore, density functional theory (DFT) calculations demonstrated the charge transfer path of GQDs/ZnO S-scheme heterojunction and provided a novel understanding for S-scheme heterojunction mechanism in piezocatalytic field, which supports the experimental evidences of S-scheme heterojunction. This research provides an effective strategy to modulate charge transfer from the atomic level, highlighting an innovative insight for the practical application of highly efficient piezocatalysts in environmental remediation.

Magnetically recyclable ZnO coated Fe3O4 nanocomposite for MO dye degradation under UV-light irradiation

We describe the synthesis of zinc oxide (ZnO) coated magnetite (Fe3O4) [ZnO/Fe3O4] nanocomposite and its photocatalytic application towards the methyl orange (MO) dye degradation. ZnO/Fe3O4 nanocomposite was prepared by opting the ex-situ mechanical stirring process of ZnO powder and solvothermally prepared Fe3O4 nanoparticles. The photocatalytic properties of the ZnO/Fe3O4 nanocomposite were investigated, and the degradation of methyl orange (MO) dye was found to be 84% in 120 min under UV light. The electron transfer mechanism might explain the still debatable MO dye degradation mechanism in the present case. The photogenerated electrons transfer to the conduction band (CB) of Fe3O4 from the CB of ZnO under UV light exposure. This results in the creation of defect levels (i.e., Fe2+ or Fe3+) in ZnO, lowering the CB of ZnO. The reusability and efficient magnetic separability of ZnO/Fe3O4 photocatalyst was established by 60% degradation after four cycles under UV light irradiation. The nanocomposite's XRD pattern before and after photocatalytic degradation exhibited no structural change, demonstrating the photocatalyst's outstanding stability. Our investigations demonstrated the potential for MO dye degradation by ZnO/Fe3O4 nanocomposite under UV light irradiation.

Functionalization of Fluorine on the Surface of SnO2-Mg Nanocomposite as an Efficient Photocatalyst for Toxic Dye Degradation.

This work reports on the photocatalytic activity of tin oxide (SnO2)-doped magnesium (Mg) and fluorine (F) nanoparticles for methyl orange and safranin dye degradation under sunlight irradiation. Nanocatalysis-induced dye degradation was examined using UV-visible spectroscopy and a pseudo-first-order kinetics model. The results indicate that the prepared nanoparticles exhibit superior photocatalytic activity, and the degradation of methyl orange (MO) dye is approximately 82%. In contrast, the degradation of safranin dye is 96% in the same time interval of 105 min. The calculated crystallite size of the SnO2-Mg-F nanocomposite is 29.5 nm, which respects the particle size found in the DLS analysis with a tetragonal structure and spherical morphology affirmed. The optical characteristics were assessed, and their respective bandgap energies were determined to be 3.6 eV. The influence of F in Mg and SnO2 is recognized with the XRD and FT-IR spectra of the prepared particles.

Biosynthesis of Al-doped ZnO nanoparticles with different Al doping ratio for methylene orange dye degradation activity

Al-doped ZnO nanoparticles were synthesized using the green method for dye degradation activity for the first time. The Allium Calocephalum Wendelbow (ACW) plant leaf extract has been employed in the biosynthesis of the aluminum (Al) doped and undoped (pure) zinc oxide (ZnO) nanoparticles (NPs) for the applicability of dye degradation capability. In order to investigate the dye degradation behavior process, methylene orange (MO) is being used. For produced Al-doped and undoped ZnO NPs, the efficiency and sustainability of the (ACW) leaf plant for the dye decomposition process has been examined. The produced Al-doped and pure ZnO NPs have been studied for their quality and structure using a variety of characterization technique. For the first time, the green synthesis process was applied in order to thoroughly examine the impact of the various Al-doped green ZnO nanoparticle ratios on the average size, shape, distribution, crystal structure, functional group, optical capabilities, chemical compositions, and energy band-gap. The ratio of Al-doped ZnO NPs consisted of 0% (pure), 0.025%, 0.050%, 0.075%, 0.10%, and 0.20%. The results demonstrate that the characteristics of the doped and pure green ZnO NPs are significantly affected by the varied Al-doped ZnO ratio. ACW plant leaf extract was examined using FTIR and UV–Visible spectroscopy, and the results suggested that this extract might be a promising alternative for the environmentally friendly synthesizing of both doped and undoped ZnO NPs. At ambient temperature, the UV–Visible spectra of leaf extract displayed two separate absorption peaks roughly at 262 nm and 350 nm. As additional proof of the ACW plant's use of the green method in this research, the examination of the MO dye degrading activity by Al-doped and pure ZnO NPs was conducted utilizing the newly produced Al-doped and pure ZnO NPs made to utilize the green technology. The Al-doped ZnO NPs produced at a ratio of 0.075% displayed a significant degradation rate percentage when dye degradation ability was measured with UV light. Also, the average dye degradation percentage of 90.5% for 80 min of the fabricated Al-doped green ZnO NPs displayed a quicker than average dye degradation percentage of 74% for 140 min of the fabricated pure green ZnO NPs.

Microwave assisted zirconium oxide based catalytic activation of persulfate for methyl orange dye degradation

In this investigation, zirconium oxide (ZrO2) based activation of persulfate (PS) under microwave (MW) irradiation for methyl orange (MO) dye degradation was studied. ZrO2 was synthesized using facile hydrothermal method and it was characterized via XRD, FTIR, SEM, and TGA techniques. Subsequently, MW/ZrO2/PS experiments were conducted to explore the effect of ZrO2 dosage (0–1.5 g/L), initial MO concentration (15–250 mg/L), MW reactor temperature (60–90 ℃), MW power (240–700 W), PS dosage (50–250 mg/L), and presence of NaCl (0–5000 mg/L) on MO removal at pH ~ 7. Under the optimal conditions (ZrO2 ~ 0.5 g/L, MO concentration ~ 25 mg/L, MW temperature ~ 90 ℃, MW power ~ 560 W, and PS dose~250 mg/L), 99 % of MO removal and 85.9 % of TOC removal were observed. Moreover, the toxicity of the initial sample was reduced by 72.9 %. Interestingly, the catalytic oxidation of MO was not affected due to the presence of NaCl. Radical studies confirmed that SO4−⦁ radical was the major active species responsible for MO degradation. Subsequently, the central composite design (CCD) approach was used to find out the interaction effects between MO concentration (10–250 mg/L), PS dosage (50–500 mg/L), and MW treatment time (5–20 min) on MO removal. The CCD based response surface model was found to be significant and reliable (p < 0.0001). Moreover, the chemical cost and energy cost for MW/ZrO2/PS experiments under optimized condition was estimated as $22.5 and $30.3 per kg of MO removal. Overall, transition metal-based PS activation under MW irradiation could be one of the potential alternatives for dye wastewater treatment.

Design of ternary CeO2/Fe2O3/reduced graphene oxide-based hybrid nanocomposite for superior photocatalytic degradation material for organic dyes

Green energy and environmental preservation are becoming two foremost concerns in the human society. A successful strategy for addressing the issue of environmental pollution the photocatalytic application was helped to breakdown the harmful substances and sterilization of microorganisms in the presence of catalyst and sunlight. Herein, we introduced a serious of ternary CeO2/Fe2O3/r-GO based hybrid nanocomposite as an efficient catalyst for dye-degradation process. The effective catalyst was prepared via simple hydrothermal method assisted with annealing route. The hybrid catalyst was subjected to the XRD, FTIR, SEM and UV-DRS to estimate the structural and optical properties. Based on the study, the hybrid CeO2/Fe2O3/r-GO nanocomposite was exposed the brilliant absorption characteristics phenomena, and photocatalytic activities with remarkable stability. The methylene blue and methylene orange dye degradation activities were estimated using with the prepared hybrid nanocomposite. Fascinatingly, the hybrid CeO2/Fe2O3/r-GO catalyst was delivered the 90% and 86% dye-degradation result in the methylene blue and orange dyes under the UV light irradiation. Additionally, CeO2/Fe2O3/r-GO composite was gratefully recycled for five photodegradation sequences without experiencing any substantial changes to its activity or crystalline characteristics. The improved photocatalytic activity of the CeO2/Fe2O3/r-GO catalyst was mainly permitted to the synergic effects of the heterojunctions in the interface. The study's goal is to provide a good understanding for designing a suitable visible-light-driven photocatalyst with acceptable environmental remediation.

Enhanced photocatalytic activity of Cu and Ni-doped ZnO nanostructures: A comparative study of methyl orange dye degradation in aqueous solution

Heterogeneous photocatalysis has been considered one of the most effective and efficient techniques to remove organic contaminants from wastewater. The present work was designed to examine the photocatalytic performance of metal (Cu and Ni) doped ZnO nanocomposites in methyl orange (MO) dye degradation under UV light illumination. The wurtzite hexagonal structure was observed for both undoped/doped ZnO and a crystalline size ranging between 8.84 ± 0.71 to 12.91 ± 0.84 nm by X-ray diffraction (XRD) analysis. The scanning electron microscope (SEM) and energy dispersive X-ray (EDX) revealed the irregular spherical shape with particle diameter (34.43 ± 6.03 to 26.43 ± 4.14 nm) and ensured the purity of the individual elemental composition respectively. The chemical bonds (O–H group) and binding energy (1021.8 eV) were identified by Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) results respectively. The bandgap energy was decreased from 3.44 to 3.16 eV when Ni dopant was added to the ZnO lattice. The comparative photocatalytic activity was observed in undoped and doped nanocomposites and found to be 76.31%, 81.95%, 89.30%, and 83.39% for ZnO, Cu/ZnO, Ni/ZnO, and Cu/Ni/ZnO photocatalysts, respectively, for a particular dose (0.210 g) and dye concentration (10 mg L−1) after 180 min illumination of UV light. The photocatalytic performance was increased up to 94.40% with the increase of pH (12.0) whereas reduced (35.12%) with an increase in initial dye concentration (40 mg L−1) using Ni/ZnO nanocomposite. The Ni/ZnO nanocomposite showed excellent reusability and was found 81% after four consecutive cycles. The best-fitted reaction kinetics was followed by pseudo-first-order and found reaction rate constant (0.0117 min−1) using Ni/ZnO nanocomposite. The enhanced photodegradation efficiency was observed due to decreases in bandgap energy and the crystalline size of the photocatalyst. Therefore, Ni/ZnO nanocomposite could be used as an emerging photocatalyst to degrade bio-persistent organic dye compounds from textile wastewater.

Methyl orange dye adsorption and degradation at low temperature using iron oxide-incorporated biochar derived from industrial by-products

Sustainable waste management enhances national development and benefits society and the environment. Pyrolysis has the potential to contribute to this growth by converting waste into energy and other useful by-products. This study aimed to eliminate methyl orange (MO) dye from dye-contaminated water using industrial by-products to synthesize iron-oxide-incorporated biochar (Fe2O3/Fe3O4/BC). Biomass, biochar (BC), and Fe2O3/Fe3O4/BC were characterized by proximate, ultimate, elemental, XRD, and Brunauer–Emmett–Teller surface area analyses. Minitab 19 statistical analysis was used to optimize biochar output and MO dye removal. The heating rate and residence period of 5.9 °C/min and 186.7 min, respectively, were the optimal conditions for producing biochar with a maximum fixed carbon concentration of 55.48. At pH 3, 4 g/l biochar with 3 % iron oxide, and 317 K, MO dye removal was 100 %. MO dye was eliminated by bond breaking of the azo group and adsorption onto the active sites of biochar containing iron oxide.

In English

Zinc oxide nanostructures (NS) were grown on thin discontinuous films of noble metals of silver and gold in order to study their structure, optical properties as well as photocatalytic and antiviral activity. The paper presents the results of X-ray diffraction study, scanning electron microscopy study, photoluminescence and Raman measurements. X-ray diffraction experiments demonstrate similar patterns for all grown ZnO nanostructures. The SEM images of ZnO NS grown on Ag/Si and Au/Si wafers demonstrate more dense surface microstructure compared to ZnO NS grown on bare Si wafers. The most intensive ultraviolet and deep level emissions are observed for ZnO NS grown on Ag/Si wafers. Increase in thicknesses of Ag island film from 5 nm to 10 nm gives significant increase in intensity of ultraviolet and deep level emissions. Photocatalysis of grown ZnO nanostructures was studied by methyl orange dye degradation. Superior photocatalytic results are demonstrated by ZnO nanostructures grown on Ag/Si wafers, for which constants of dye degradation were twice higher than for ZnO nanostructures grown on Si and Au/Si substrates. The photocatalytic results correlates with photoluminescence spectra: more intensive photoluminescence in ultraviolet and visible ranges of optical spectrum leads to better photocatalytic performance. The cytotoxic effect of ZnO nanostructures was studied without photoactivation by the help of cell cultures MDCK and Hep-2 while the virucidal effect of ZnO nanostructures was studied by the help of Influenza A virus (H1N1) (strain FM / 1/47) and human adenovirus serotype 2 (HAdV2). ZnO nanostructures in a 1:10 dilution were not toxic to Hep-2 and MDCK cells. Most of the tested ZnO nanostructures exhibited no virucidal activity against human adenovirus serotype 2 (HAdV2) and influenza A virus (H1N1) (strain FM / 1/47) in the absence of photoexcitation.

Enhancement of bifunctional photocatalytic activity of boron-doped g-C3N4/SnO2 heterojunction driven by plasmonic Ag quantum dots

Enhancement of photocatalytic charge transfer with reduced electron–hole (e− + h+) recombination toward the targeted chemical reaction is a challenging task. In this study, we utilized boron (B) dopant as impurity levels, and the plasmonic Ag quantum dots (QDs), and g-C3N4/SnO2 heterojunction nanocomposite under visible light (λ = 385–740 nm) as a nanocomposite photocatalytic system for energy and environmental applications. The introduction of B dopant with optimal level (BCN1.0) of 1 wt% resulted in the fast migration of photoexcited electrons from valence band to the conduction band of g-C3N4 and reduced the migration distance of the electrons from valence band to the conduction band and improved surface redox reactions. The heterojunction formed with SnO2 nanorods and nanoparticles enhanced the electron–hole transfer rate across the interface of the heterojunction (BCNS15) with 15 wt% and improved the photocatalytic activity during redox reactions. The introduction of plasmonic Ag QDs (1 wt%) as a co-catalyst improved the H2 generation efficiency (BCNS–Ag1.0). Ultraviolet photoelectron spectroscopy results confirmed that the charge transfer process was initiated via the Z-scheme mechanism. Photoluminescence spectra identified the reduction of electron–hole recombination that was responsible for improved catalytic efficiency in the optimized heterojunction nanocomposite. The synergetic effect of B dopant, the visible light sensitization effect and the co-catalytic effect of the Ag QDs, the formation of a heterojunction of the B-g-C3N4/SnO2/Ag (BCNS–Ag1.0) nanocomposite resulted in 2.5 times higher methyl orange dye degradation efficiency which is 65.6% compared to pristine g-C3N4 (CN) 25.9%. Further, the photocatalysts were tested for photocatalytic H2 generation, the optimized BCNS–Ag1.0 nanocomposite heterojunction showed 3.2 times higher H2 generation activity (10.2 mmol/h/gcat) than pristine CN(3.1 mmol/h/gcat) through Z-scheme mechanism. Finally, the BCNS–Ag1.0 nanocomposite demonstrated excellent stability toward methyl orange degradation as well as H2 generation for at least 4 cycles. Therefore, the BCNS–Ag1.0 nanocomposite is a promising photocatalytic system for scale-up synthesis.

Elemental semiconductor red phosphorus/ZnO nanohybrids as high performance photocatalysts

The solar energy conversion through the photocatalyst for the pollutant degradation is important effort for development of the visible light photocatalysts for the practical application in various filed. In this work, elemental semiconductor red phosphorus/ZnO nanohybrid (Z-Rp) through simple, cost-effective, and sustainable ball milling approach and further studied its visible light driven-photocatalytic activity towards the pollutant degradation under visible irradiation. The prepared Z-Rp were characterized by the various stereoscopic and microscopic technique which shows improvement of the structural, optical, and physical properties of the zinc oxide after addition of the elemental red phosphorous. The Diffuse reflectance spectroscopy and valence band spectra shows the shifting of the energy band towards the visible light region after incorporating of the red phosphorus which are father supported by the visible light degradation process. The optimized Z-Rp nanohybrids displayed the excellent visible light driven photocatalytic activity toward the methyl orange dye degradation as compared to the bare materials, which further prove the optimal reaction parameter could effectively enhanced visible light photocatalytic activity. This easy fabrication process and inexpensive earth abundant Rp compared to the silver and gold-based plasmonic metal, which are also used to enhance the photocatalytic performance of the metal oxide nanoparticles, can be a good and sustainable approach for the solar energy conversion for various application.