scholarly journals Probing the surface reactivity of nanocrystals by the catalytic degradation of organic dyes: the effect of size, surface chemistry and composition

2017 ◽  
Vol 5 (23) ◽  
pp. 11917-11929 ◽  
Author(s):  
Jordi Piella ◽  
Florind Merkoçi ◽  
Aziz Genç ◽  
Jordi Arbiol ◽  
Neus G. Bastús ◽  
...  

We herein present a comprehensive study on how the catalytic performance and reusability of Au nanocrystals (NCs) are affected by systematic variations of crystal size, surface coating and composition.

2012 ◽  
Vol 18 (S2) ◽  
pp. 1548-1549 ◽  
Author(s):  
V. Mochalin ◽  
Y. Gogotsi ◽  
S. Osswald

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2288
Author(s):  
Ruirui Han ◽  
Yingsen Fang ◽  
Ping Sun ◽  
Kai Xie ◽  
Zhicai Zhai ◽  
...  

In this paper, using rice straw as a raw material and urea as a nitrogen precursor, a composite catalyst (a nitrogen-doped rice straw biochar at the pyrolysis temperature of 800 °C, recorded as NRSBC800) was synthesized by one-step pyrolysis. NRSBC800 was then characterized using XPS, BET, TEM and other technologies, and its catalytic performance as an activator for permonosulfate (PMS) to degrade acid orange 7 (AO7) was studied. The results show that the introduction of N-doping significantly improved the catalytic performance of NRSBC800. The NRSBC800/PMS oxidation system could fully degrade AO7 within 30 min, with the reaction rate constant (2.1 × 10 −1 min−1) being 38 times that of RSBC800 (5.5 × 10−3 min−1). Moreover, NRSBC800 not only had better catalytic performance than traditional metal oxides (Co3O4 and Fe3O4) and carbon nanomaterial (CNT) but also received less impact from environmental water factors (such as anions and humic acids) during the catalytic degradation process. In addition, a quenching test and electron paramagnetic resonance (EPR) research both indicated that AO7 degradation relied mainly on non-free radical oxidation (primarily singlet oxygen (1O2)). A recycling experiment further demonstrated NRSBC800’s high stability after recycling three times.


2021 ◽  
Author(s):  
Yu Liu ◽  
Yan Wang ◽  
Xiao-Sa Zhang ◽  
Wen-Ze Li ◽  
Ai-Ai Yang ◽  
...  

Abstract 3D metal-organic frameworks (MOFs) can be appropriate templates for the fabrication of nanomaterials due to they have active sites exposed on the channel or surface, which thus provide them with improved catalytic performance. In this study, a 3D cobalt-based MOF [Co(H2bpta)]n (Co-MOF), where H4bpta denotes 2,2′,4,4′-biphenyltetracarboxylic acid, has been constructed with the use of a ligand with a high carbon content. On this basis, a 2D magnetic carbon-coated cobalt nanoparticle composite (C@Co) was prepared by using the title MOF. Magnetic C@Co can readily absorb dye from the solution and can thus act as an inexpensive and fast-acting adsorbent. Moreover, we have explored the adsorption isotherms, kinetics and thermodynamics of the anion dyes in detail. The adsorption capacity of the C@Co for investigated methyl orange (MO) and congo red (CR) dyes were 773.48 and 495.66 mg g− 1, respectively. It is noteworthy that MO adsorption is higher in existing materials. Thermodynamic studies suggest that the adsorption processes are spontaneous and exothermic. This study opens a new insight into the synthesis and application of carbon-based materials that enable the selective removal of organic dyes.


Author(s):  
Youlin Li ◽  
Yu Hu ◽  
Wenqiao You ◽  
Guangming Zhou ◽  
Guilong Peng

Abstract Activated carbon/CuO (AC/CuO) composites was prepared through a facile one-step hydrothermal method and used as a bifunctional material for adsorption and catalysis degradation of bisphenol A (BPA). The composite was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray powder diffraction (XRD). The obtained AC/CuO exhibited excellent adsorption and catalytic performance. The maximum adsorption capacity of BPA on the AC/CuO was 319.03 mg/g according to the Langmuir fitting. At an initial BPA concentration of 20 mg/L, the BPA degradation efficiencies were maintained above 96% for 15 min by using 20 mg/L AC/CuO and 2 mM peroxymonosulfate (PMS). Moreover, the relationship between adsorption and catalytic degradation was also investigated. The results indicated that the pre-adsorption disfavored the degradation reaction. This work not only provides a novel preparation method for AC/CuO catalyst, but also gives a deeper insight into the mechanisms between adsorption and catalytic degradation.


2020 ◽  
Vol 1218 ◽  
pp. 128488 ◽  
Author(s):  
Elmira Kalantari ◽  
Mohammad A. Khalilzadeh ◽  
Daryoush Zareyee ◽  
Mohammadreza Shokouhimehr

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