scholarly journals Metal oxide QD based ultrasensitive microsphere fluorescent sensor for copper, chromium and iron ions in water

RSC Advances ◽  
2020 ◽  
Vol 10 (16) ◽  
pp. 9512-9524 ◽  
Author(s):  
Md. Motiar R. Khan ◽  
Tapas Mitra ◽  
Dibakar Sahoo

Herein we developed a rapid, cheap, and water-soluble ultra-sensitive ZnO quantum dot (QD) based metal sensor for detecting different hazardous metal ions up to the picomolar range in water.

2018 ◽  
Vol 96 (4) ◽  
pp. 363-370 ◽  
Author(s):  
You-Ming Zhang ◽  
Xiao-Peng Chen ◽  
Guo-Yan Liang ◽  
Kai-Peng Zhong ◽  
Hong Yao ◽  
...  

The selective recognition of target ions in water is very important and the development of novel water-soluble chemosensor is still an intriguing challenge. Herein, a novel water-soluble fluorescent sensor based on aspartic acid (Asp) functionalized 1,8-naphthalimide derivative (Asp-NI) has been designed and synthesized. The sensor Asp-NI could dissolve in water and successively detect Fe3+ and H2PO4− in water solution with high selectivity and sensitivity. The detection limits are 4.97 × 10−7 mol/L for Fe3+ and 5.27 × 10−6 mol/L for H2PO4−. Other coexistent competitive metal ions (Hg2+, Ag+, Ca2+, Cu2+, Co2+, Ni2+, Cd2+, Pb2+, Zn2+, Cr3+, and Mg2+) showed no interference in the Fe3+ detection process. The sensor Asp-NI could act as a Fe3+ and H2PO4− controlled “On–Off–On” fluorescent switch. More interestingly, the Fe3+ induced fluorescence quenching process could be totally reversed by the addition of H2PO4−, this “On–Off–On” switching process could be repeated several times with little fluorescence loss. Notably, the actual usage of sensor Asp-NI was further demonstrated by test kits.


2015 ◽  
Vol 165 ◽  
pp. 46-55 ◽  
Author(s):  
Nidhi Singla ◽  
Ashish Tripathi ◽  
Meenakshi Rana ◽  
Sudipta Kishore Goswami ◽  
Anirban Pathak ◽  
...  

1991 ◽  
Vol 23 (1-3) ◽  
pp. 399-404 ◽  
Author(s):  
Y. Tamaura ◽  
P. Q. Tu ◽  
S. Rojarayanont ◽  
H. Abe

Stabilization of the hazardous materials by the Fe3O4-coating method was studied. In the ferrite-formation reaction in the aqueous solution, the adsorption of the metal ions and the oxidation of the adsorbed Fe(II) ions are repeated on the surface of the ferrite particles. This reaction was adopted to the coating of the hazardous materials with the Fe3O4(or ferrite). By repeating the two steps of l)the addition of the Fe(II) aqueous solution into the suspension of the hazardous materials, and 2)the oxidation by passing air through the reaction suspension, with the Fe3O4 layer, we could coat the surfaces of the hazardous materials, such as the heavy metal sludge from the neutralization-precipitation process, the CaF2 precipitates in the treatment of the waste waters containing fluoride ion along with hazardous metal ions, and the soils containing Cd(II) ion. These Fe3O4-coated hazardous materials are very stable and no heavy metal ions are leached under the normal environmental conditions. The ferrite sludges formed in the “Ferrite Process” were highly stabilized by the present method, and by the heat-treatment.


2021 ◽  
Author(s):  
Lamiaa Reda Ahmed ◽  
Ahmed F. M. EL-Mahdy ◽  
Cheng-Tang Pan ◽  
Shiao-Wei Kuo

In this paper, we describe the construction of a new fluorescent hydroxyl- and hydrazone-based covalent organic framework (TFPB-DHTH COF) through the one-pot polycondensation of 1,3,5-tris(4-formylphenyl)benzene (TFPB) and 2,5-dihydroxyterephthalohydrazide (DHTH) under...


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Anh Thi Le ◽  
Swee-Yong Pung

Purpose This paper aims to investigate the reusability of metal/metal oxide-coupled ZnO nanorods (ZnO NRs) to degrade rhodamine B (RhB). Design/methodology/approach ZnO NRs particles were synthesized by precipitation method and used to remove various types of metal ions such as Cu2+, Ag+, Mn2+, Ni2+, Pb2+, Cd2+ and Cr2+ ions under UV illumination. The metal/metal oxide-coupled ZnO NRs were characterized by scanning electron microscope, X-ray diffraction and UV-Vis diffuse reflectance. The photodegradation of RhB dye by these metal/metal oxide-coupled ZnO NRs under UV exposure was assessed. Findings The metal/metal oxide-coupled ZnO NRs were successfully reused to remove RhB dye in which more than >90% of RhB dye was degraded under UV exposure. Furthermore, the coupling of Ag, CuO, MnO2, Cd and Ni particles onto the surface of ZnO NRs even enhanced the degradation of dye. The dominant reactive species involved in the degradation of RhB dye were •OH- and •O2−-free radicals. Research limitations/implications The coupling of metal/metal oxide onto the surface of ZnO NRs after metal ions removal could affect the photocatalytic performance of ZnO NRs in the degradation of organic pollutants in subsequent stage. Practical implications A good reusability performance of metal/metal oxide-coupled ZnO NRs make ZnO NRs become a desirable photocatalyst material for the treatment of wastewater, which consists of both heavy metal ions and organic dyes. Originality/value Metal/metal oxide coupling onto the surface of ZnO NRs particles improved subsequent UV-assisted photocatalytic degradation of RhB dye.


2019 ◽  
Vol 7 (32) ◽  
pp. 10082-10091 ◽  
Author(s):  
Yujin Lee ◽  
Hyo-Min Kim ◽  
Jeonggi Kim ◽  
Jin Jang

We demonstrated the remarkable improvement of efficiency roll-off and operational lifetime in red quantum dot light emitting diodes (R-QLEDs) by incorporating rubidium carbonate (Rb2CO3) in Mg doped ZnO (MZO) electron transporting layer (ETL).


2013 ◽  
Vol 17 (01n02) ◽  
pp. 99-103 ◽  
Author(s):  
Hui He ◽  
Jian-Yong Liu ◽  
Dennis K.P. Ng

This paper describes the preparation and spectral properties of a near-infrared fluorophore in which two bis(2-picolyl)amino moieties are axially linked to a silicon(IV) phthalocyanine core. The effects of various metal ions on its absorption and fluorescence spectra have been examined. The results indicate that this compound shows a high sensitivity and moderate selectivity toward Zn2+ ion.


2014 ◽  
Vol 56 ◽  
pp. 58-63 ◽  
Author(s):  
Jian Xu ◽  
Qian Li ◽  
Ying Yue ◽  
Yong Guo ◽  
Shijun Shao

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