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Type II Heterojunction Photocatalysts for Environmental Applications
Published in A. Pandikumar, K. Jothivenkatachalam, S. Moscow, Heterojunction Photocatalytic Materials, 2022
K. S. Rajni, T. Raguram, Vengudusamy Renganathan, Shen-Ming Chen
Enhanced photocatalytic activity of CdS/H2Ti5O11 ultrathin nanobelt (NB) nanocomposite (CdTi) was reported by Xiong et al. [40]. They are prepared by a two-step synthesis process. Under visible light irradiation, the photocatalytic activity of as-prepared CdTi-5 with an optimal loading of 81.3% CdS converts 4-nitroaniline to p-phenylenediamine (PPD) with 98% yield in 3 min. It is found to be much higher than that of the bare CdS and P25/CdS composition. The formation of heterojunction between titanate, nanobelt, and CdS is responsible for the smooth transfer of photogenerated electron and promotes the separation of photoinduced carriers. From XRD, it is noted that CdTi nanocomposite (CdTi-1) exhibits the characteristic diffraction peak of hexagonal CdS and H2Ti5O11 simultaneously (Fig. 3.2a,b). When the CdS content is increased in the composite, only the CdTi-5 diffraction patterns of hexagonal CdS are observed as H2Ti5O11 is covered.
Applications of Liquid Marbles
Published in Andrew Terhemen Tyowua, Liquid Marbles, 2018
Liquid marbles have also been used as microreactors for the miniaturized synthesis of nanocomposite. A schematic illustration for such a process is shown in Figure 5.5 for the synthesis of graphene/Ag nanocomposite. Thermally robust liquid marbles, prepared by encapsulating ~5 µL of a mixture of 7–20 mg AgNO3 and 14–21 mg ascorbic acid dissolved in 1 mL of graphite oxide (GO) with superhydrophobic Fe3O4/carbon microsheets, were used for the experiment (Chu et al. 2014). The liquid marbles were placed on a water bath (80°C) for 50 mins, where the mixture was reduced to graphene/Ag nanocomposite, followed by transferring to water at room temperature, where the superhydrophobic particles desorbed from the nanocomposite surfaces. The superhydrophobic Fe3O4/carbon microsheets were removed using a magnet, leaving the spherical graphene/Ag nanocomposite. Lastly, the nanocomposite was dialyzed in deionized water for 72 h to remove residual ascorbic acid. The graphene/Ag nanocomposite obtained exhibited one of the best catalytic characteristics for 4-nitroaniline reduction into p-phenylenediamine compared with other reported catalysts (Chu et al. 2014).
Physical Properties of Individual Groundwater Chemicals
Published in John H. Montgomery, Thomas Roy Crompton, Environmental Chemicals Desk Reference, 2017
John H. Montgomery, Thomas Roy Crompton
Biological. A bacterial culture isolated from the Oconee River in North Georgia degraded 3-nitroaniline to the intermediate 4-nitrocatechol (Paris and Wolfe, 1987). A Pseudomonas sp. strain P6, isolated from a Matapeake silt loam, did not grow on 3-nitroaniline as the sole source of carbon. However, in the presence of 4-nitroaniline, all of the applied 3-nitroaniline metabolized completely to carbon dioxide (Zeyer and Kearney, 1983). In the presence of suspended natural populations from unpolluted aquatic systems, the second-order microbial transformation rate constant determined in the laboratory was reported to be 4.6 ± 0.1 × 10−13 L/organism ⋅ h (Steen, 1991).
Facile synthesis of silver nanoparticles in a crosslinked polymeric system by in situ reduction method for catalytic reduction of 4-nitroaniline
Published in Environmental Technology, 2019
Zahoor H. Farooqi, Rida Khalid, Robina Begum, Umar Farooq, Qingshi Wu, Weitai Wu, Muhammad Ajmal, Ahmad Irfan, Khalida Naseem
Catalytic performance of Ag-PNiM hybrid microgels was tested using selective reduction of 4-nitroaniline into p-phenylenediamine as a model reaction in the presence of an excess of NaBH4. The progress of catalytic conversion of 4-NA into a single product (i.e. p-phenylenediamine) can be easily monitored by UV-Visible spectrophotometry by measuring a decrease in absorbance with the passage of time at a wavelength of 380 nm, which is the λmax of 4-nitroaniline. The catalytic reduction of 4-nitroaniline is of great importance because 4-nitroaniline is highly toxic, while its reduction product (i.e. p-phenylenediamine) is an important industrial reagent. It has been already reported in the literature that 4-nitroaniline can be completely converted into p-phenylenediamine on the surface of metal nanoparticles successfully [33].
Ultrasonic assisted synthesis of Zn(II) 2D coordination polymer and 4-nitroaniline photoluminescence sensing manifestation through DFT studies
Published in Journal of Coordination Chemistry, 2022
Madiha Riasat, Shahzad Sharif, Shazia Khurshid, Sidra Farid, Rehana Bano, Mazhar Amjad Gilani, Onur Şahin, Fouzia Perveen
The developing interest in using sonochemical synthesis refers to its ease of use, cost effectiveness, speedy reaction time, excellent yields, and purity of products [24]. Previously, zinc(II) 2 D polymer has been synthesized by hydrothermal method and published as a structural report [25]. Moreover, micro-sized or nano-sized coordination polymers/powders were obtained while using sonochemical technique by complexation of zinc with other than pyridine-3,5-dicarboxylic acid [26–29]. In this study, we report the synthesis of crystalline product by utilizing sonochemical method. 4-Nitroaniline is a common chemical intermediate of pesticide, dyes, explosives, pharmaceutical and rubber industry [30]. It is highly soluble in water and commonly found in industrial waste. Owing to its poor biodegradability and chemical persistence, environmental protection agencies in many countries have ranked 4-nitroaniline as a potent pollutant. It is highly poisonous, carcinogenic and a prospective mutagen [31]. It is not only lethal for aquatic life but also causes respiratory disorders, skin eczema, anemia, diarrhea and methemoglobinemia in humans. Therefore, a facile, rapid, sensitive and selective method is required for the efficient determination of 4-nitroaniline. Currently numerous spectroscopic, chromatographic, electrochemical and colorimetric methods are used for the determination of 4-nitroaniline, but all these methods have their own limitations. Complex sample matrix, low concentration of analyte, costly instrumentation and laborious sample preparation are just only a few shortcomings. Coordination polymer based luminescence sensors are the ideal candidates for the determination of nitroaromatics as these methods offer additional benefits of structural tailorability, short response time, low detection limit and easy to operate [32]. Here, we report sonochemical synthesis, structural discussion and selective luminescence quenching of 1 against 4-nitroaniline. The structural and luminescence properties are in agreement with theoretical DFT calculations.