scholarly journals A Facile Co-Deposition Approach to Construct Functionalized Graphene Quantum Dots Self-Cleaning Nanofiltration Membranes

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
Tong Yu ◽  
Chenpu Wu ◽  
Zhongyan Chen ◽  
Mingen Zhang ◽  
Zhuan Hong ◽  
...  

In this study, a novel photocatalytic self-cleaning nanofiltration (NF) membrane was fabricated by constructing aspartic acid-functionalized graphene quantum dots (AGQDs) into the polydopamine/polyethyleneimine (PDA/PEI) selective layer via the co-deposition method. The chemical composition, microstructure, and hydrophilicity of the prepared membranes were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflection (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and water contact angle (WCA). Meanwhile, the effects of PEI molecular weight and AGQDs concentration on NF membrane structures and separation performance were systematically investigated. The photocatalytic self-cleaning performance of the PDA/PEI/AGQDs membrane was evaluated in terms of flux recovery rate. For constructing high-performance NF membranes, it is found that the optimal molecular weight of PEI is 10,000 Da, and the optimal concentration of AGQDs is 2000 ppm. The introduction of hydrophilic AGQDs formed a more hydrophilic and dense selective layer during the co-deposition process. Compared with the PDA/PEI membrane, the engineered PDA/PEI/AGQDs NF membrane has enhanced water flux (55.5 LMH·bar−1) and higher rejection (99.7 ± 0.3% for MB). In addition, the PDA/PEI/AGQDs membrane exhibits better photocatalytic self-cleaning performance over the PDA/PEI membrane (83% vs. 69%). Therefore, this study provides a facile approach to construct a self-cleaning NF membrane.

2021 ◽  
Author(s):  
Xu Dan ◽  
Ruiyi Li ◽  
Qinsheng Wang ◽  
Yongqiang Yang ◽  
Haiyan Zhu ◽  
...  

The paper reports the synthesis of nickel-silver-graphene quantum dot-graphene hybrid. Histidine-functionalized graphene quantum dots (His-GQDs) were bonded to graphene oxide (GO) and then combined with Ni2+ and Ag+ to form...


2017 ◽  
Vol 28 (10) ◽  
pp. 2608-2619 ◽  
Author(s):  
Chenjie Yao ◽  
Yusong Tu ◽  
Lin Ding ◽  
Chenchen Li ◽  
Jiao Wang ◽  
...  

2021 ◽  
Author(s):  
Md. Farhan Naseh ◽  
Neelam Singh ◽  
Jamilur R. Ansari ◽  
Ashavani Kumar ◽  
Tapan Sarkar ◽  
...  

Abstract Here, we report functionalized graphene quantum dots (GQDs) for the optical detection of arsenic at room temperature. GQDs with the fluorescence of three fundamental colors (red, green, and blue) were synthesized and functionally capped with L-cysteine (L-cys) to impart selectively towards As (III) by exploiting the affinity of L-cys towards arsenite. The optical characterization of GQDs was carried out using UV-Vis absorption spectroscopy, Fourier transform infrared spectroscopy, and fluorescence spectrometry and the structural characterizations were performed using transmission electron microscopy. The fluorescence results showed instantaneous quenching in intensity when the GQDs came in contact with As (III) for all test concentrations over a range from 0.025 ppb to 25 ppb, which covers the permissible limit of arsenic in drinking water. The experimental results suggested excellent sensitivity and selectivity towards As (III).


2017 ◽  
Vol 43 (12) ◽  
pp. 7457-7470 ◽  
Author(s):  
Mohammad Hassan Amini ◽  
Farnoush Faridbod ◽  
Mohammad Reza Ganjali ◽  
Parviz Norouzi

Optik ◽  
2019 ◽  
Vol 178 ◽  
pp. 802-812 ◽  
Author(s):  
Nur Syahira Md Ramdzan ◽  
Yap Wing Fen ◽  
Nur Alia Sheh Omar ◽  
Nur Ain Asyiqin Anas ◽  
Wan Mohd Ebtisyam Mustaqim Mohd Daniyal ◽  
...  

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