UV light exposure of aqueous graphene oxide suspensions to promote their direct reduction, formation of graphene–metal nanoparticle hybrids and dye degradation

Carbon ◽  
2012 ◽  
Vol 50 (3) ◽  
pp. 1014-1024 ◽  
Author(s):  
L. Guardia ◽  
S. Villar-Rodil ◽  
J.I. Paredes ◽  
R. Rozada ◽  
A. Martínez-Alonso ◽  
...  
2016 ◽  
Vol 855 ◽  
pp. 156-167
Author(s):  
Susmita Das ◽  
Vimal Chandra Srivastava

Microfluidic technology has been increasingly applied in field of photo catalytic reactor because of the large surface to volume ratio, shorter diffusion distance of the reactant solution, higher mixing efficiency and lower cost. This article reviews the detail progress in fabrication of micro-reactor for degradation of dye in waste water. Importantly, dye degradation required uniform UV light exposure which could be resolved by carrying out degradation in a micro-reactor. This paper discussed several of potential and commercial photocatalytic micro-reactor fabrication and configurations, in particular, the polydimethyl siloxane (PDMS) photocatalytic reactors.


2022 ◽  
Vol 34 (2) ◽  
pp. 395-401
Author(s):  
B.H. Azam ◽  
M.A.F. Md Fauzi ◽  
M.H. Razali

The aim of this research is to improve the photocatalytic efficiency by implementation of titanium dioxide nanowires/reduced graphene oxide (TiO2NWs/RGO) hybrid photocatalyst for dye degradation. The hybrid photocatalyst TiO2NWs/RGO was prepared using fabrication method. The physico-chemical properties of the photocatalyst was investigated by FTIR, XRD, SEM TGA, BET and their photocatalytic efficiency was evaluated for methyl orange degradation. Almost 100% of methyl orange was degraded by TiO2NWs/RGO hybrid photocatalyst under UV light within 210 min using 1.0 g at initial concentration of methyl orange were 10 and 20 ppm. This is due to the 1D/2D heterostructures of TiO2NWs/RGO hybrid photocatalyst that leads to the larger surface area, unique morphological and crystallinity properties, as well as excellent mobility of charge carriers and thermally stable structure


Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 654 ◽  
Author(s):  
Xiaoya Yuan ◽  
Dong Peng ◽  
Qiuye Jing ◽  
Jiawei Niu ◽  
Xin Cheng ◽  
...  

The potential extensive application of graphene oxide (GO) in various fields results in the possibility of its release into the natural environment with negative impacts on humans and the ecosystem. The UV-induced removal behavior of aqueous GO was evaluated in this study, and the effect of various parameters (including initial GO concentration, initial solution pH and co-existing ions) on removal rate of GO were investigated in detail. The results showed that UV-light induced a maximum removal rate of GO of 99.1% after 32 h irradiation without any additives, and that the photo-induced removal process in all cases fitted well with pseudo-first-order kinetics. Under optimal conditions, GO was completely removed, with initial GO concentrations of 10 mg/L while adjusting solution pH to 3 or adding Ca2+-containing salt. The GO and photoreduced graphene oxide (prGO) were characterized using High-resolution Transmission Microscopy (HRTEM), X-ray Photoelectron Spectroscopy (XPS), and Fourier-transform Infrared Spectroscopy (FT-IR). The radical species trapping experiments and Electron Spin Resonance (ESR) tests indicated that self-reduction of GO upon UV-light exposure could be achieved via photogenerated electrons from a GO semiconductor. Further mechanism study showed that the high efficiency of UV-induced GO removal came from UV-induced photoreduction, and pH-induced or cation-induced coagulation. This study provided a green and effective method to remove GO from aqueous solutions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sean Swetledge ◽  
Renee Carter ◽  
Rhett Stout ◽  
Carlos E. Astete ◽  
Jangwook P. Jung ◽  
...  

AbstractPolymeric nanoparticles have been investigated as potential delivery systems for therapeutic compounds to address many ailments including eye disease. The stability and spatiotemporal distribution of polymeric nanoparticles in the eye are important regarding the practical applicability and efficacy of the delivery system in treating eye disease. We selected poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with lutein, a carotenoid antioxidant associated with eye health, as our model ophthalmic nanodelivery system and evaluated its stability when suspended in various conditions involving temperature and light exposure. We also assessed the ocular biodistribution of the fluorescently labeled nanoparticle vehicle when administered topically. Lutein-loaded nanoparticles were stable in suspension when stored at 4 °C with only 26% lutein release and no significant lutein decay or changes in nanoparticle morphology. When stored at 25 °C and 37 °C, these NPs showed signs of bulk degradation, had significant lutein decay compared to 4 °C, and released over 40% lutein after 5 weeks in suspension. Lutein-loaded nanoparticles were also more resistant to photodegradation compared to free lutein when exposed to ultraviolet (UV) light, decaying approximately 5 times slower. When applied topically in vivo, Cy5-labled nanoparticles showed high uptake in exterior eye tissues including the cornea, episcleral tissue, and sclera. The choroid was the only inner eye tissue that was significantly higher than the control group. Decreased fluorescence in all exterior eye tissues and the choroid at 1 h compared to 30 min indicated rapid elimination of nanoparticles from the eye.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Fei Yuan ◽  
Haixia Ma ◽  
Chumei Yuan ◽  
Chun-Sheng Zhou ◽  
Huai-Ming Hu ◽  
...  

Three new Ln(III)-based metal-organic frameworks (MOFs), having general formula [Ln2(L)2(ox)(H2O)2]n (Ln = Nd (1), Sm (2) and Eu (3)) have been synthesized using multifunctional triazole-carboxylate linker 5-(1H-1,2,4-triazol-1-yl)-1,3-benzenedicarboxylic acid (H2L) and...


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A843-A843
Author(s):  
Michael Wagner ◽  
Megan Othus ◽  
Sandip Patel ◽  
Christopher Ryan ◽  
Ashish Sangal ◽  
...  

BackgroundAngiosarcoma is a rare cancer of endothelial cells that can be aggressive and carries a high mortality. A subset of angiosarcomas are characterized by high tumor mutational burden (TMB) and UV light exposure DNA mutational signature. Isolated case reports have suggested clinical efficacy of immune checkpoint blockade in angiosarcoma; no prospective studies of immune checkpoint inhibition in angiosarcoma have been reported. We report efficacy analysis results for patients with advanced or unresectable angiosarcoma treated with ipilimumab and nivolumab as a cohort of an ongoing phase II study for rare cancers (NCT02834013).MethodsThis is a prospective, open-label, multicenter phase II clinical trial of ipilimumab (1mg/kg IV q6weeks) plus nivolumab (240mg IV q2weeks) for patients with metastatic or unresectable angiosarcoma. Primary endpoint is objective response rate as assessed by RECIST v1.1, including measurable cutaneous disease that can be followed by photography. Secondary endpoints include PFS, OS, stable disease at six months, and toxicity. A two-stage design is used with six patients in the first stage and an additional ten patients in the second stage.ResultsAt data cutoff, 16 patients with angiosarcoma were enrolled. Median age was 68 years (25-81 years). Median number of prior lines of therapy was 2 (0-5). 9 patients had cutaneous primary tumors of any cutaneous site, 7 had non-cutaneous primary tumors. ORR for all patients was 25% (4/16, table 1, figure 1). Subgroup analysis revealed that 60% (3/5) of patients with primary cutaneous tumors of the scalp or face had a confirmed objective response. 6-month PFS was 38%. 75% of patients experienced an adverse event (AE), and 25% experienced a grade 3-4 AE. 68.8% experienced an immune related AE (irAE), and 2 (12.5%) developed grade 3 or 4 irAEs. Grade 3-4 irAEs were ALT and AST increase and diarrhea. There were no grade 5 toxicities.ConclusionsThe combination of ipilimumab and nivolumab was well tolerated and had an ORR of 25% in angiosarcoma regardless of primary site, with 3 of 5 patients with cutaneous tumors of the scalp or face responding. Ipilimumab and nivolumab warrant further investigation in angiosarcoma.AcknowledgementsFunding: National Institutes of Health/National Cancer Institute grant awards CA180888, CA180819, CA180868; and in part by Bristol-Myers Squibb CompanyTrial RegistrationNCT02834013Ethics ApprovalThis study was approved by the NCI CIRB.


2020 ◽  
Vol 44 (19) ◽  
pp. 7749-7757 ◽  
Author(s):  
Wen Jia ◽  
Dong Peng ◽  
Zijuan Feng ◽  
Xue Wu ◽  
Yi Liu ◽  
...  

Concomitant formation of metallic Bi nanoparticles and oxygen vacancies was successfully achieved within Bi/BiOBr/RGO composites by green UV-light exposure.


2018 ◽  
Vol 156 ◽  
pp. 08003 ◽  
Author(s):  
Tutuk Djoko Kusworo ◽  
Danny Soetrisnanto ◽  
Cynthia Santoso ◽  
Tyas Dwi Payanti ◽  
Dani Puji Utomo

Produced water is a wastewater generated from petroleum industry with high concentration of pollutants such as Total Dissolved Solid, Organic content, and Oil and grease. Membrane technology has been currently applied for produced water treatment due to its efficiency, compact, mild and clean process. The main problem of produced water using membrane is fouling on the membrane surface which causes on low permeate productivity. This paper is majority focused on the improvement of anti-fouling performance through several modifications to increase CA membrane hydrophilicity. The membrane was prepared by formulating the dope solution consists of 18 wt-% CA polymer, acetone, and PEG additive (3 wt-%, 5 wt-%, and 7 wt-%). The membranes are casted using NIPS method and being irradiated under UV light exposure. The SEM images show that parepared membrane has asymmetric structure consist of dense layer, intermediete layer, and finger-like support layer. The filtration test shows that PEG addition increase the membrane hydrophilicity and the permeate flux increases. UV light exposure on the membrane improves the membrane stability and hydrophilicity. The imrpovement of membrane anti-fouling performance is essential to achieve the higher productivity without lowering its pollutants rejection.


Sign in / Sign up

Export Citation Format

Share Document