Plasmonic photocatalysts based on silver nanoparticles – layered double hydroxides for efficient removal of toxic compounds using solar light

2018 ◽  
Vol 444 ◽  
pp. 407-413 ◽  
Author(s):  
Diana Gilea ◽  
Teodora Radu ◽  
Mihaela Muresanu ◽  
Gabriela Carja
Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 454 ◽  
Author(s):  
Esthela Ramos-Ramírez ◽  
Francisco Tzompantzi-Morales ◽  
Norma Gutiérrez-Ortega ◽  
Héctor G. Mojica-Calvillo ◽  
Julio Castillo-Rodríguez

In recent years, the search for solutions for the treatment of water pollution by toxic compounds such as phenols and chlorophenols has been increasing. Phenols and their derivatives are widely used in the manufacture of pesticides, insecticides, paper, and wood preservers, among other things. Chlorophenols are partially biodegradable but not directly photodegradable by sunlight and are extremely toxic—especially 2,4,6-trichlorophenol, which is considered to be potentially carcinogenic. As a viable proposal to be applied in the treatment of water contaminated with 2,4,6-trichlorophenol, this paper presents an application study of the thermally activated Mg/Fe layered double hydroxides as photocatalysts for the mineralization of this contaminant. Activated Mg/Fe layered double hydroxides were characterized by X-ray diffraction, thermal analysis, N2 physisorption, and scanning electron microscopy with X-ray dispersive energy. The results of the photocatalytic degradation of 2,4,6-trichlorophenol in aqueous solution showed good photocatalytic activity, with an efficiency of degradation of up to 93% and mineralization of 82%; degradation values which are higher than that of TiO2-P25, which only reached 18% degradation. The degradation capacity is attributed to the structure of the MgO–MgFe2O4 oxides derived from double laminate hydroxide Mg/Fe. A path of degradation based on a mechanism of superoxide and hollow radicals is proposed.


2021 ◽  
Author(s):  
Yuying Hu ◽  
Susu Liu ◽  
Min Qiu ◽  
Xiaohuan Zheng ◽  
Xiaoming Peng ◽  
...  

Abstract Ly @ FeZn layered double hydroxides (LDHs) controllable fabrication based on Box-Behnken Design (BBD) model was fabricated, and presented stable and efficient removal performance for Ciprofloxacin (CIP), Norfloxacin (NOR) and Ofloxacin (OFL) removal. It should be noted that Ly @ FeZn had different adsorption behavior towards CIP, NOR and OFL. Furthermore, the Ly @ FeZn was characterized by SEM, XRD, FT-IR and XPS. Results revealed the optimized fabrication condition (temperature of 60 °C, Fe / Zn molar ratio of 0.5 and the lysine dosage of 5.8 mmol) for the removing efficient. The highest adsorption capacity of CIP, NOR and OFL were 193.83, 190.20 and 62.12 mg/g, respectively. Adsorption kinetics of both CIP and NOR were well simulated with the pseudo-first-order kinetic model, while that of OFL was well-described by the pseudo-second-order. Moreover, the adsorption thermodynamics of CIP and NOR on Ly @ FeZn indicated that the adsorption processes were exothermal, feasible and spontaneous. It was worth noting that the adsorption mechanism of Ly @ FeZn for CIP and NOR were the synergistic reaction of electrostatic attraction, chemical bonding and flocculation. On the other side, the adsorption behavior of OFL was relatively low, and the adsorption mechanism was only electrostatic attraction.


2021 ◽  
pp. 127613
Author(s):  
Jiahui Ge ◽  
Lili Lian ◽  
Xiyue Wang ◽  
Xueling Cao ◽  
Wenxiu Gao ◽  
...  

2016 ◽  
Vol 123 ◽  
pp. 134-140 ◽  
Author(s):  
Facui Yang ◽  
Shiqi Sun ◽  
Xiaoqi Chen ◽  
Yue Chang ◽  
Fei Zha ◽  
...  

2016 ◽  
Vol 199 ◽  
pp. 260-271 ◽  
Author(s):  
Gaku Mikami ◽  
Florentina Grosu ◽  
Shogo Kawamura ◽  
Yusuke Yoshida ◽  
Gabriela Carja ◽  
...  

Soil Systems ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 37
Author(s):  
Massimo Pigna ◽  
Antonio Violante ◽  
Antonio Giandonato Caporale

The need for cost-effective adsorbents of inorganic arsenic (As(III) and As(V)) stimulates the academia to synthesize and test novel materials that can be profitably applied at large-scale in most affected areas worldwide. In this study, four different layered double hydroxides (Cu-Al-, Mg-Al-, Mg-Fe- and Zn-Al-LDH), previously synthesized and studied for As(III) removal capacity, were evaluated as potential adsorbents of As(V) from contaminated systems, in absence or presence of common inorganic anions (Cl−, F−, SO42−, HCO3− and H2PO4−). The As(V) desorption by H2PO4− was also assessed. Lastly, the As(V) adsorption capacities of the four layered double hydroxides (LDHs) were compared with those observed with As(III) in a complementary paper. All the LDHs adsorbed higher amounts of As(V) than As(III). Fe-Mg-LDH and Cu-Al-LDH showed higher adsorption capacities in comparison to Mg-Al-LDH and Zn-Al-LDH. The presence of competing anions inhibited the adsorption of two toxic anions according to the sequence: Cl− < F− < SO42− < HCO3− < < H2PO4−, in particular on Mg-Al-LDH and Zn-Al-LDH. The kinetics of As(V) desorption by H2PO4− indicated a higher occurrence of more easily desorbable As(V) on Zn-Al-LDH vs. Cu-Al-LDH. In conclusion, synthetic Cu- and Fe-based LDHs can be good candidates for an efficient removal of inorganic As, however, further studies are necessary to prove their real feasibility and safety.


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