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The co-precipitation approach has been used in the current research work to synthesize cobalt-doped zinc oxide nanoparticles (ZnO NPs) employing zinc and cobalt nitrate hexahydrate as precursor salts. Ultraviolet-visible spectra and Fourier transform infrared were used to confirm that the manufacturing procedure was efficient and that the synthesized sample contained a range of unique binding sites. The catalytic efficacy of the prepared nanoparticles for the reduction of Methylene blue dye in the presence of NaBH4 as a reducing agent has been investigated. The concentration of methylene blue, the catalyst dose, and the concentration of sodium borohydride all play significant roles in the catalytic reduction of methylene blue (MB). The best result for the complete reduction of methylene blue was obtained in 14 min of reaction time. Catalytic reduction of methylene blue in the involvement of synthesized nanoparticles was found to be followed by the Langmuir-Hinshelwood mechanism. Concerning this process, the reduction reaction is affected by the quantity of methylene blue, catalyst, and sodium borohydride. This effective catalytic activity of Co-doped ZnO nanoparticles suggests that these NPs can work wonders as nano-catalysts for the reduction of hazardous dyes. [ABSTRACT FROM AUTHOR]

In this study, a facile green synthesis method was adopted for the fabrication of magnesium oxide nanoparticles (MgO-NPs) from Calotropis gigantea (Aak plant) root extract which acted as a capping and reducing agent. The fabricated MgO-NPs were characterized by UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR) and high resolution-scanning electron microscopy to determine optical, morphological and biological characteristics. UV-Vis spectra results showed an absorption peak at 317 nm whereas scanning electron microscopy showed spherical morphology of the synthesized MgO-NPs. FTIR spectra of the root extract confirmed the presence of phytochemicals, that is, amines, phenols, amides and ketones. Methylene blue (MB) dye was used as model contaminant to assess catalytic reduction potential of the synthesized MgO-NPs. Results obtained showed that biogenic MgO-NPs are suitable for catalytic reduction of MB dye and, when assembled in a sustainable manner, MgO-NPs have the potential to be used for the removal of toxic organic pollutants from industrial effluents. [ABSTRACT FROM AUTHOR]

This study reports a novel, facile and eco-friendly approach for the reduction of CuSO4 ·5H2 O into stable and well-dispersed copper nanoparticles (Cu NPs) using aqueous leaf extract of Syzygium cumini. The reduction was affirmed by UV-Visible spectrophotometer maximum absorbance at 535 nm. The effect of various parameters including temperature, pH, precursor salt concentration and incubation time on particle size of Cu NPs has been evaluated. Fourier-transform infrared spectroscopy showed a strong band at 3,307 cm–1 indicating the O–H groups of alcohols and phenols. Scanning electron microscopy analysis showed spherical morphology of Cu NPs with particle size of 19 nm. The prepared nanoparticles showed excellent catalytic performance for the removal of methylene blue (MB) from the aqueous medium using sodium borohydride (NaBH4 ) as a reducing agent. The kinetic studies showed that Cu NPs followed pseudo-first-order for catalytic reduction of MB. [ABSTRACT FROM AUTHOR]

Abstract In this study, stable copper oxide nanoparticles (CuO-NPs) were biogenically prepared using a bulb of Allium sativum extract (as reducing and capping agents) in a surfactant-free environment. A successful synthesis of CuO-NPs and factors affecting chemical reaction at a specific time, temperature, pH, and salt concentration was monitored by the UV-VIS technique. The characterization analysis like UV-VIS and FTIR suggested CuO-NPs were monodispersed, pure, and highly stable. CuO-NPs displayed outstanding photocatalytic results (95% within 50 min) for decolorization of methylene blue dye. [ABSTRACT FROM AUTHOR]

Copper and copper oxide nanoparticles (Co/CoO NPs) were synthesized by a green approach using Syzygium cumini leaf extract. The formation of synthesized Co/CoO NPs was monitored by using UV–Visible spectroscopy which shows surface plasmon resonance (SPR) at 380 nm. The parameters affecting the particle size or yield of Co/CoO NPs including pH, temperature, reaction time, and concentration of salt also has been studied. The performance or efficiency of catalysts has been investigated by the degradation of 4-nitrophenol (4-NP) and methylene blue (MB) in the presence of sodium borohydride. The kinetic studies displayed that Co/CoO NPs obeyed pseudo-first-order for catalysis of selected contaminants. [ABSTRACT FROM AUTHOR]

In this study, zinc ferrite nanoparticles (ZF-NPs) were synthesized using aqueous seed extract of Piper nigrum as a bio-reducing and stabilizing agent. FTIR, SEM, FE-SEM, XRD, and TGA have been used for characterizing ZF-NPs. The results showed that Piper nigrum stabilized ZF-NPs have high purity and size range of 60–80 nm. The performance of the ZF-NPs has been investigated by photocatalytic reduction of methylene blue (MB) in the presence of sunlight. The factors responsible for affecting the degradation values of the reaction were also explored for developing a better understanding of the phenomenon. [ABSTRACT FROM AUTHOR]

A novel and facile green approach was adopted for carrying out the large scale synthesis of the nickel (Ni) and nickel oxide (NiO) nanoparticles (NPs). The seeds extract of Hordeum vulgare plant which is rich in phenolic content and antioxidants was utilized for reducing the precursor metal salt into NPs. The results of UV/Vis spectroscopy revealed that the synthesized nanoparticles were monodispersed in nature and plant extract controlled the particle size effectively. FTIR spectrum revealed that amines and phenolic groups of the plant were responsible for the formation and stabilization of Ni nanoparticles. The best yield of nanoparticles was obtained at pH 12 using 1 M salt solution, temperature of 60 °C and heating time of 60 minutes. The catalytic activity of synthesized nanoparticles was checked by degradation of methylene blue dye and it was found that degradation of the dye followed first order kinetics. [ABSTRACT FROM AUTHOR]

• Poly-(N-isopropylmethacrylamide-co-methacrylic acid) microgel was prepared. • Prepared microgel was fabricated with copper oxide nanoparticle. • CuO based hybrid microgel was used for catalytic reduction of Methylene blue dye. • The hybrid microgel was stable and can be reused for four consecutive cycles. The present study involves the synthesis of poly-(N-isopropylmethacrylamide-co-methacrylic acid) [p(NiPmA-mAc)] microgels for the stabilization of copper oxide nanoparticles (CuO NPs) via free radical precipitation approach and synthesized material as a catalyst for catalytic degradation of methylene blue (MB) dye. Results clearly indicate that p(NiPmA-mAc) microgel not only serves as an excellent micro-reactor but also works as an effective stabilizing / fabricating medium for the successful synthesis of CuO NPs. UV–Vis spectra of CuO-[p(NiPmA-mAc)] showed the maximum peak was observed at 400 nm. Scanning electron microscopic (SEM) and X-ray diffraction (XRD) analysis showed spherical morphology of in-situ synthesized CuO NPs with crystalline size of 20 ± 4 nm. Different parameters which affect catalytic reduction reactions such as pollutant/catalyst dose, reductant concentration and effect of time were investigated. Results showed that the apparent rate constant for catalytic reduction of MB was 0.5307 min−1. The application of the CuO NPs loaded p(NiPmA-mAc) microgel catalyst for catalytic degradation of MB has shown excellent results with complete degradation (100%) within 15 min. Further, the recyclability of the CuO-[p(NiPmA-mAc)] catalyst has shown promising results during four consecutive cycles thus, confirming its stability. [ABSTRACT FROM AUTHOR]

Methylene blue (MB) is a carcinogenic pollutant widely known for its hazardous impacts on humans and marine life. Recently, the photocatalysis mediated degradation of MB has been widely reported as an advanced approach for the removal of this harmful dye from the aqueous mediums. Numerous scientists have documented the use of nanomaterials (NMs) based photocatalytic assemblies for the degradation of MB. This study highlights the fundamentals and factors involved in the degradation reaction of MB. Furthermore, the detailed kinetics and mechanistic description are also presented for providing essential insights into the light mediated reaction of MB. The vast academic literature is organized by classifying the NMs based photocatalysts based on the utilized stabilization mediums and the advantages/disadvantages of the peculiar stabilization mediums are also discussed for presenting the comparative analysis of the reported stabilization mediums for the preparation of photocatalysts. Future prospects are also discussed for further extending the advancement of scientific research in this field. [Display omitted] [ABSTRACT FROM AUTHOR]

Zn 4 O(BO 2) 6 based on the [B 24 O 48 ] sodalite-cage structure fixed by the inside [Zn 4 O 13 ] clusters is expected to be a new class of solid-state lighting material with perfect thermal and mechanical stabilit y. Herein, in the current work, we have respectively introduced non-equivalent rare-earth cations Eu3+ and Pr3+ into Zn 4 O(BO 2) 6 host to design white and green emission materials by a novel solid-phase sintering method at lower temperatures. Zn 2 B 6 O 11 replacing B 2 O 3 or H 3 BO 3 as raw materials can effectively avoid the impure products caused by the uncontrollable volatilization of B 2 O 3 or H 3 BO 3. The newly designed light-emitting materials of Zn 4(1- x) O(BO 2) 6 : x Re3 + (Re Eu or Pr), including Zn 4 O(BO 2) 6 host, have good absorption capacity in the ultraviolet region. Under ultraviolet irradiation, Zn 4 O(BO 2) 6 , Zn 4(1- x) O(BO 2) 6 : x Eu3+and Zn 4(1- x) O(BO 2) 6 : x Pr3+ emit the blue, white and green lights, respectively. In addition, all these materials can effectively degrade methylene blue, in which Zn 4(1- x) O(BO 2) 6 : x Pr3+ has the highest efficiency. The luminescence and degradation mechanisms of Zn 4 O(BO 2) 6 , Zn 4(1- x) O(BO 2) 6 : x Eu3+and Zn 4(1- x) O(BO 2) 6 : x Pr3+ have been adequately explained by their electronic structures based on the first principle calculations. The current study confirms that the doping of Eu3+/Pr3+ in Zn 4 O(BO 2) 6 can broaden its applications as photoluminescent and photocatalytic materials. [ABSTRACT FROM AUTHOR]

In present investigation, gCN supported carbon coated Lanthanum doped tungsten oxide (C@LWO/gCN) composite were synthesized via hydrothermal approach. The photodegradation of different cationic dyes like malachite green (MG), crystal violet (CV) and methylene blue (MB) has been carried out under prepared C@LWO/gCN composite. Furthermore, the comparative photodegradation was also performed using pristine LWO and C@LWO nanowires. The synthesized samples were characterized via physiochemical techniques such as XRD, FESEM, EDX, FTIR, BET and UV/Vis spectroscopy. The results proved incorporation of La ions into WO 3 lattice and reduced band gap of doped sample which significantly boost up the capability of the material towards photodegradation. The maximum degradation was found out at pH = 6, 5 mg catalyst dose, 5 ppm dye concentration and 35 °C temperature. The achieved results proved that the trapping agents compete with prepared composite specie for the h+, e−, HO● and O 2 ●- radicals. The obtained experimental records of photodegradation of cationic dyes using C@LWO/gCN composite has correlation with pseudo first order kinetics, Langmuir-Hinshelwood model and t 1/2. The simplest facile synthetic approach, remarkable photodegradation performance against colored and colorless effluents suggest that C@LWO/gCN composite exhibit great potential for large-scale wastewater treatment. [Display omitted] [ABSTRACT FROM AUTHOR]