S. K. Jesudoss

Studies on the efficient dual performance of Mn1–xNixFe2O4 spinel nanoparticles in photodegradation and antibacterial activity

The present work describes the successful synthesize of spinel magnetic ferrite Mn1-xNixFe2O4 (x=0.0, 0.1, 0.2, 0.3, 0.4 & 0.5) nanoparticles via a simple microwave combustion method which was then evaluated for its photocatalytic activity in the degradation of indigo carmine (IC) synthetic dye, a major water pollutant. Our results reveal that the synthesized of Ni2+ doped MnFe2O4 nanoparticles possess well-crystalline pure cubic spinel phase, exhibit excellent optical and magnetic properties. Further, the photocatalytic performance of the synthesized nanoparticles at different concentration ratios of Ni2+ ions was monitored by photocatalytic degradation of indigo carmine synthetic dye under UV (λ=365nm) light irradiation. In order to get maximum photocatalytic degradation (PCD) efficiency, we have optimized various parameters, which include catalyst dosage, initial dye concentration, pH and Ni2+ dopant content. It was found that the reaction was facilitated with optimum catalyst dose of 50mg/100mL, high dye concentrations of 150mg/L and acidic pH and among all the synthesized samples, Mn0·5Ni0.5Fe2O4 exhibit superior performance of photocatalytic activity on the degradation of indigo carmine synthetic dye. These results highlighted the potential use of effective, low-cost and easily available photocatalysts for the promotion of wastewater treatment and environmental remediation. In addition, the antibacterial activity of spinel magnetic Mn1-xNixFe2O4 nanoparticles against two Gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two Gram negative bacteria (Pseudomonas aeruginosa and Escherichia coli) was also examined. Our antibacterial activity results are comparable with the results obtained using the antibiotic, streptomycin.

Effects of Ba doping on structural, morphological, optical, and photocatalytic properties of self-assembled ZnO nanospheres

A simple low-temperature co-precipitation method was employed to synthesize pure and Ba-doped self-assembled ZnO nanospheres. The presence of self-assembled nanosphere-like morphology, high crystallinity, uniform size distribution, and more defects were confirmed by X-ray diffraction, high-resolution scanning electron microscopy, high-resolution transmission electron microscopy, diffuse reflectance spectroscopy, and photoluminescence spectroscopy. Photocatalytic degradation of 2,4,6-trichlorophenol, a potent endocrine-disrupting chemical in aqueous medium was investigated. The effects of Ba doping on the structure, morphology, absorption, emission, and photocatalytic activity of ZnO nanospheres were investigated systematically. Furthermore, the effects of different photocatalytic degradation reaction parameters were investigated. The resulting photocatalytic degradation activity of Ba-doped ZnO nanospheres shows superior efficiency compared to pure ZnO and commercial TiO2 (Degussa P-25).Graphical AbstractA simple co-precipitation method was developed to synthesize pure and Ba-doped ZnO self-assembled nanospheres. The prepared photocatalyst shows a novel morphology, high crystallinity, uniform size distribution, and more defects. Effect of Ba doping on the structural, optical and photocatalytic properties of ZnO nanospheres were investigated systematically.

Anti-cancer activity of hierarchical ZSM-5 zeolites synthesized from rice-based waste materials

Herein, organic template-free MFI-type ZSM-5 zeolites were successfully synthesized by the hydrothermal method using waste materials such as rice husk ash (RHA), rice hull ash (RHuA), and rice straw ash (RSA). The waste materials were locally obtained, precleaned, and properly heat-treated to produce a high-purity crystalline SiO2 that was used in the synthesis of ZSM-5 zeolites under autogenous pressure in a short reaction time (5 days). The mineralogical phases, morphology, textural and thermal properties of the synthesized products were investigated by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Raman spectroscopy, high-resolution scanning electron microscopy (HR-SEM), N2 adsorption/desorption isotherms (BET), temperature-programmed desorption (NH3-TPD), and thermogravimetric analysis (TGA/DTA). The as-synthesized ZSM-5 zeolites showed good crystallinity, and no amorphous material existed in the framework of the ZSM-5 zeolites after calcination and ammonium exchange processes. The characterization results prove that the high crystallinity of RHA as compared to that of the other materials (RHuA and RSA) is due to the high silica content in RHA. The transformation occurs from high-crystallinity RHA into ZSM-5 zeolite and also increases the crystallinity of zeolites. In addition, we have investigated hierarchical ZSM-5 zeolites at various concentrations for their potential cytotoxicity effect against the human lung epithelial cancer A549 cells.

Hierarchical ZSM-5 Zeolite Nanosurfaces with High Porosity—Structural, Morphological and Textural Investigations

The present paper describes the successful synthesis of hierarchical ZSM-5 zeolite nanosurfaces with high porosity from the rice straw ash (RSA) by means of the hydrothermal method at varying time intervals in the presence of small amount of tetrapropylammonium bromide as a single template. The synthesized samples were characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), high resolution scanning electron microscopy (HR-SEM), and nitrogen adsorption–desorption analysis (BET). The XRD pattern confirms the formation of pure ZSM‐5 zeolite crystalline phase without any impurity phases. The IR spectrum shows a vibration band at 548 cm−1, which is assigned to the double 5-rings of MFI-type zeolites. The surface area results reveal the formation of additional mesoporosity without destroying the intensive microporosity in a hierarchical ZSM-5 zeolite, which is due to the addition of TPABr during the synthesis. The characterization results conclude that the long time process of hierarchical ZSM-5 zeolite nanosurfaces with high porosity have produced high crystallinity.

Correction to ‘Investigation on preferably oriented abnormal growth of CdSe nanorods along (0002) plane synthesized by henna leaf extract-mediated green synthesis’

[This corrects the article DOI: 10.1098/rsos.171430.].

In-vitro anti-cancer activity of organic template-free hierarchical M (Cu, Ni)-modified ZSM-5 zeolites synthesized using silica source waste material

The present paper is focused on a simple and economical route to synthesize the organic template-free hierarchical pure and M (Cu, Ni)-modified ZSM-5 zeolites (1%, 3% and 5%) using hydrothermal treatment in the presence of silica rich rice husk ash and its application studies through the evaluation of their anti-cancer activity on A459 human lung epithelial cancer cell lines. The physical properties of the samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, high resolution scanning electron microscopy, high resolution transmission electron microscopy, N2 adsorption/desorption techniques and thermogravimetric analysis respectively. These metals modified hierarchical ZSM-5 zeolites showed considerable in-vitro anticancer efficiency towards human lung cancer (A549) cell lines through (3-(4, 5-dimethyl thiazolyl)-2, 5-diphenyl tetrazolium bromide) MTT assay. Among the all M (Cu, Ni)-modified ZSM-5 zeolites, 5% Cu-ZSM-5 zeolites showed higher potential cytotoxicity against A459 cell lines. The possible mechanism was explored from the fundamental signaling pathways of cell death by hierarchical metal modified ZSM-5 zeolites in A459 human lung epithelial cancer cell lines. Finally, our experimental results revealed that the organic template-free hierarchical pure and M (Cu, Ni)-modified ZSM-5 zeolites have significant anti-cancer mediating action by inducing oxidative stress to intercede DNA damage and can be considered as a potential applicant in the biomedical field.

Liquid Phase Catalytic Oxidation of Toluene Over Rich Silica and Alumina Composition of Hierarchical Ordered ZSM-5 Zeolites Prepared Without Organic Templates

Hierarchical ordered ZSM-5 zeolites were successfully synthesized by a template-free hydrothermal treatment using rice joints ash as the source of silica. The formation of hierarchical ordered ZSM-5 zeolites and its physicochemical properties were investigated systematically. The mineralogical phases, morphology, surface area and porosity, acidity and thermal stability of the synthesized hierarchical materials were investigated using XRD, FT-IR, HR-SEM, N2 adsorption-desorption (BET) analysis, NH3-TPD and TGA/DTA analysis. The excellent catalytic activity of hierarchical ordered ZSM-5 zeolites (150 °C) was revealed in the selective oxidation of toluene to the corresponding benzaldehyde with 82% conversion and 94% selectivity. The material was evaluated for the oxidation of toluene in the presence of H2O2 as the oxidizing agent and 1,4-dioxane solvent. The obtained results noted that the material was highly active, stable and can be recycled at least four times without a loss of catalytic efficiency. The crystallization was carried out in an autoclave for 5 days maintained at a temperature of 150 °C for the transformation of RJA into hierarchical ZSM-5 zeolite structure as well as to achieve high crystallinity.