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Nanoscience in Biotechnology
Published in Khalid Rehman Hakeem, Majid Kamli, Jamal S. M. Sabir, Hesham F. Alharby, Diverse Applications of Nanotechnology in the Biological Sciences, 2022
Charu Gupta, Mir Sajad Rabani, Mahendra K Gupta, Shivani Tripathi, Anjali Pathak
Chemical reduction method is the most frequently used approach for synthesizing NPs. The reducing agents such as alcohol, poly(N-vinylpyr-rolidone) (PVP) (Kim, 2007), ascorbic acid, sodium citrate, or sodium boro-hydride (Cao and Hu, 2009), tetra-n-tetra-fltetra-009e (TFATFB), CTAB (Hanauer et al., 2007), and N,N-dimethylformamide (DMF) (Pastoriza-Santos and Liz-Marzan, 2000) facilitate the reduction of metal particles into NPs. Electrochemical method of synthesizing NPs stimulates chemical reactions with the help of an applied voltage in an electrolyte solution (Sau and Rogach, 2010). In the photochemical synthesis method, silver (Ag) salt can be photoreduced with citrate or a polymer, irradiated by various sources of light, for instance, ultraviolet radiation (Sato-Berru et al., 2009). Further, traces of these toxic chemicals such as sodium borohydride or hydrazine are highly sensitive, nonbiodegradable and cause a hazardous effect on the environment.
Removal of Pharmaceuticals From Wastewater Using Nanomaterials
Published in Maulin P. Shah, Removal of Refractory Pollutants from Wastewater Treatment Plants, 2021
Employing the use of biogenic nanomaterials is advantageous over conventional methods. Conventional wastewater treatment methods are, to a certain extent, detrimental to the environment due to their inability to degrade the pollutants into environmental-friendly end products and passing them off from one phase to another. Apart from this, they require large areas to function, high capital, and maintenance costs. Nanotechnology is therefore used as an alternative technique in the form of nano-based adsorbents, catalysts, and membranes (Diallo and Brinker, 2011). They are mass produced using physicochemical methods; however, toxic waste gets introduced into the environment which affects human health and the environment. For instance, sodium borohydride generates hydrogen diborane which is a highly toxic by-product (Li et al., 2006). Biogenic nanoparticles synthesized from bacteria, algae, fungus, and plants are a new alternative. Their attributes makes them suitable for pharmaceutical waste removal from wastewater, including low cost of production, no toxic waste production, greater surface area, stability due to lipid bilayer structure in some, better physiological solubility and manipulation of size and shape by altering pH, contact time, and substrate availability (Li et al., 2011) (see Figure 1.2).
Alkenes and Alkynes: Structure, Nomenclature, and Reactions
Published in Michael B. Smith, A Q&A Approach to Organic Chemistry, 2020
Sodium borohydride, NaBH4, also known as sodium tetrahydridoborate, is an inorganic compound, a white solid, and it is a reducing agent used in organic chemistry primarily for the reduction of ketones and aldehydes to alcohols (see Section 14.3). What is the product when mercuric acetate reacts with 3-methyl-pent-1-ene in the presence of water and then subsequent reaction with sodium borohydride? Is that product the result of a rearrangement? Why or why not?
Green synthesis of copper oxide and manganese oxide nanoparticles from watermelon seed shell extract for enhanced photocatalytic reduction of methylene blue
Published in International Journal of Phytoremediation, 2023
Arzu Ekinci, Sinan Kutluay, Ömer Şahin, Orhan Baytar
To the knowledge of the literature, no known synthesis of CuO and MnO NPs by the green method using watermelon seed shell extract, and its use as a catalyst in the photocatalytic reduction of methylene blue. This represents an innovation aspect of our proposed study. For this purpose, within the scope of the study, CuO and MnO NPs were synthesized through a simple, cost-efficient, and green method using watermelon seed shell extract as a stabilizing and reducing agent. The synthesized CuO and MnO NPs were characterized by using scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and Ultraviolet spectroscopy (UV). The photocatalytic performance of the CuO and MnO NPs used as catalysts were investigated for the reduction of methylene blue in an aqueous solution. In the photocatalytic reduction of methylene blue, sodium borohydride (NaBH4) was used as the reducing agent. Besides, the kinetics of the photocatalytic reaction was investigated by a pseudo-first order model.
Anionic hydrogel fabricated with metal nanoparticles: highly efficient and easily recyclable catalysts
Published in Soft Materials, 2021
Hina Naeem, Muhammad Ajmal, Saba Zamurad Khan, Muhammad Naeem Ashiq, Muhammad Siddiq
Methacrylic acid (MAAc, 99%, monomer), N, N-methylenebisacrylamide (MBA 99%, crosslinking agent), ammonium persulfate (APS 98% as initiator) was purchased from Sigma-Aldrich. N, N, N, N -tetramethylethylenediamine (TEMED, 98%, an accelerator) was purchased from Merck. Metal-ion sources used were cobalt chloride hexahydrate (CoCl2. 6H2O 99% from Merck) and silver nitrate (AgNO3 98% from Dae-Jung). Sodium borohydride (NaBH4, 98% Dae-Jung) was employed as a reducing agent for metal NPs formation. All the aromatic nitro compounds, i.e. 4-Nitrophenol (4-NP, 99%), 2-Nitroaniline (2-NA, 99%), and organic dyes (Methyl Orange MO, 99% and Eosin Y EY, 99%) used were purchased from Sigma Aldrich. Deionized water (DI) was used as a medium throughout the synthesis.
Granular-carbon supported nano noble-metal (Au, Pd, Au-Pd): new dual-functional adsorbent/catalysts for effective removal of toluene at low-temperature and humid condition
Published in Environmental Technology, 2021
Bien Cong Trung, Le Nguyen Quang Tu, Nguyen Tran Minh Tri, Ngo Thanh An, Nguyen Quang Long
In recent years, scientists have focused on developing efficient catalysts for the purpose of reducing the temperature for the oxidation of VOCs and they are categorized into three major types: noble metals catalysts, non-metal oxide catalysts, and mixed-metal catalysts [2–4]. Metal oxide catalysts are cheaper, but they are less durable and less efficient than noble metal catalysts supported in the oxidation of VOCs [2,3]. Au catalyst, especially its nanoparticle morphology, has prominent advantages compared with other noble metals catalysts (Pt, Pd, etc.) used for the catalytic oxidation of VOCs at the low temperatures [2,13] due to its electronic configuration [11,12]. Nano Au catalysts can be synthesized by various methods. The chemical reduction method or metal-sol method is an effective method of synthesizing metallic nanoparticles. The basic principle of this method is to reduce metal ions by chemical reducing agents, in other words, the transfer of an electron from the donor to the recipient. Basically, there are three components used in this method: (1) metal ions, (2) reducing agent and (3) molecular stabilizer. Sodium borohydride (NaBH4) is the most commonly used reducing agent for this method due to its strong reducing properties [14–18]. This is a simple method of synthesizing nanoparticles (NPs) without requiring special equipment and it has high economic efficiency. In addition, the NPs size can be adjusted by varying the concentration of the reactants and/or the stabilizers [16,19,20].