scholarly journals In-Situ Synthesis of TiO2@GO Nanosheets for Polymers Degradation in a Natural Environment

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2158
Author(s):  
Yueqin Shi ◽  
Zhanyang Yu ◽  
Zhengjun Li ◽  
Xiaodong Zhao ◽  
Yongjun Yuan

Plastic photodegradation naturally takes 300–500 years, and their chemical degradation typically needs additional energy or causes secondary pollution. The main components of global plastic are polymers. Hence, new technologies are urgently required for the effective decomposition of the polymers in natural environments, which lays the foundation for this study on future plastic degradation. This study synthesizes the in-situ growth of TiO2 at graphene oxide (GO) matrix to form the TiO2@GO photocatalyst, and studies its application in conjugated polymers’ photodegradation. The photodegradation process could be probed by UV-vis absorption originating from the conjugated backbone of polymers. We have found that the complete decomposition of various polymers in a natural environment by employing the photocatalyst TiO2@GO within 12 days. It is obvious that the TiO2@GO shows a higher photocatalyst activity than the TiO2, due to the higher crystallinity morphology and smaller size of TiO2, and the faster transmission of photogenerated electrons from TiO2 to GO. The stronger fluorescence (FL) intensity of TiO2@GO compared to TiO2 at the terephthalic acid aqueous solution indicates that more hydroxyl radicals (•OH) are produced for TiO2@GO. This further confirms that the GO could effectively decrease the generation of recombination centers, enhance the separation efficiency of photoinduced electrons and holes, and increase the photocatalytic activity of TiO2@GO. This work establishes the underlying basic mechanism of polymers photodegradation, which might open new avenues for simultaneously addressing the white pollution crisis in a natural environment.

2020 ◽  
Vol 6 (39) ◽  
pp. eabb9823
Author(s):  
Huabin Zhang ◽  
Shouwei Zuo ◽  
Mei Qiu ◽  
Sibo Wang ◽  
Yongfan Zhang ◽  
...  

A cocatalyst is necessary for boosting the electron-hole separation efficiency and accelerating the reaction kinetics of semiconductors. As a result, it is of critical importance to in situ track the structural evolution of the cocatalyst during the photocatalytic process, but it remains very challenging. Here, atomically dispersed Ru atoms are decorated over multi-edged TiO2 spheres for photocatalytic hydrogen evolution. Experimental results not only demonstrate that the photogenerated electrons can be effectively transferred to the isolated Ru atoms for hydrogen evolution but also imply that the TiO2 architecture with multi-edges might facilitate the charge separation and transport. The change in valence and the evolution of electronic structure of Ru sites are well probed during the photocatalytic process. Specifically, the optimized catalyst produces the hydrogen evolution rate of 7.2 mmol g−1 hour−1, which is much higher than that of Pt-based cocatalyst systems and among the highest reported values.


2013 ◽  
Vol 58 (1) ◽  
pp. 283-290 ◽  
Author(s):  
Y. Nishizaki ◽  
H. Miyamae ◽  
S. Ichikawa ◽  
K. Izumiya ◽  
T. Takano ◽  
...  

Our effort for decontamination of radioactive cesium scattered widely by nuclear accident in March 2011 in Fukushima, Japan has been described. Radioactive cesium scattered widely in Japan has been accumulating in arc or plasma molten-solidified ash in waste incinerating facilities up to 90,000 Bq/kg of the radioactive waste. Water rinsing of the ash resulted in dissolution of cesium ions together with high concentrations of potassium and sodium ions. Although potassium inhibits the adsorption of cesium on zeolite, we succeeded to precipitate cesium by in-situ formation of ferric ferrocyanide and iron rust in the radioactive filtrate after rinsing of the radioactive ash with water. Because the regulation of no preservation of any kind of cyanide substances, cesium was separated from the precipitate consisting of cesium-captured ferric ferrocyanide and ferric hydroxide in diluted NaOH solution and subsequent filtration gave rise to the potassium-free radioactive filtrate. Cesium was captured by zeolite from the potassium-free radioactive filtrate. The amount of this final radioactive waste of zeolite was significantly lower than that of the arc-molten-solidified ash.


2012 ◽  
Vol 19 (3) ◽  
pp. 583-592 ◽  
Author(s):  
Yinke Dou ◽  
Xiaomin Chang

Abstract Ice thickness is one of the most critical physical indicators in the ice science and engineering. It is therefore very necessary to develop in-situ automatic observation technologies of ice thickness. This paper proposes the principle of three new technologies of in-situ automatic observations of sea ice thickness and provides the findings of laboratory applications. The results show that the in-situ observation accuracy of the monitor apparatus based on the Magnetostrictive Delay Line (MDL) principle can reach ±2 mm, which has solved the “bottleneck” problem of restricting the fine development of a sea ice thermodynamic model, and the resistance accuracy of monitor apparatus with temperature gradient can reach the centimeter level and research the ice and snow substance balance by automatically measuring the glacier surface ice and snow change. The measurement accuracy of the capacitive sensor for ice thickness can also reach ±4 mm and the capacitive sensor is of the potential for automatic monitoring the water level under the ice and the ice formation and development process in water. Such three new technologies can meet different needs of fixed-point ice thickness observation and realize the simultaneous measurement in order to accurately judge the ice thickness.


2013 ◽  
Vol 16 (1) ◽  
pp. 59-67

<p>The Soil Science Institute of Thessaloniki produces new digitized Soil Maps that provide a useful electronic database for the spatial representation of the soil variation within a region, based on in situ soil sampling, laboratory analyses, GIS techniques and plant nutrition mathematical models, coupled with the local land cadastre. The novelty of these studies is that local agronomists have immediate access to a wide range of soil information by clicking on a field parcel shown in this digital interface and, therefore, can suggest an appropriate treatment (e.g. liming, manure incorporation, desalination, application of proper type and quantity of fertilizer) depending on the field conditions and cultivated crops. A specific case study is presented in the current work with regards to the construction of the digitized Soil Map of the regional unit of Kastoria. The potential of this map can easily be realized by the fact that the mapping of the physicochemical properties of the soils in this region provided delineation zones for differential fertilization management. An experiment was also conducted using remote sensing techniques for the enhancement of the fertilization advisory software database, which is a component of the digitized map, and the optimization of nitrogen management in agricultural areas.</p>


2020 ◽  
Vol 10 (9) ◽  
pp. 3238
Author(s):  
Min Liu ◽  
Guangxin Wang ◽  
Panpan Xu ◽  
Yanfeng Zhu ◽  
Wuhui Li

In this study, the Ag3PO4/SnO2 heterojunction on carbon cloth (Ag3PO4/SnO2/CC) was successfully fabricated via a facile two-step process. The results showed that the Ag3PO4/SnO2/CC heterojunction exhibited a remarkable photocatalytic performance for the degradation of Rhodamine B (RhB) and methylene blue (MB), under visible light irradiation. The calculated k values for the degradation of RhB and MB over Ag3PO4/SnO2/CC are 0.04716 min−1 and 0.04916 min−1, which are higher than those calculated for the reactions over Ag3PO4/SnO2, Ag3PO4/CC and SnO2/CC, respectively. The enhanced photocatalytic activity could mainly be attributed to the improved separation efficiency of photogenerated electron-hole pairs, after the formation of the Ag3PO4/SnO2/CC heterojunction. Moreover, carbon cloth with a large specific surface area and excellent conductivity was used as the substrate, which helped to increase the contact area of dye solution with photocatalysts and the rapid transfer of photogenerated electrons. Notably, when compared with the powder catalyst, the catalysts supported on carbon cloth are easier to quickly recycle from the pollutant solution, thereby reducing the probability of recontamination.


2016 ◽  
Vol 52 (30) ◽  
pp. 5316-5319 ◽  
Author(s):  
Wenjie Fan ◽  
Haibo Li ◽  
Fengyi Zhao ◽  
Xujing Xiao ◽  
Yongchao Huang ◽  
...  

BiOI nanosheets with highly exposed (001) and surface disorders are used for efficient photocatalytic HCHO oxidation under visible light irradiation.


2005 ◽  
Vol 5 (7) ◽  
pp. 1963-1974 ◽  
Author(s):  
A. C. Lewis ◽  
J. R. Hopkins ◽  
L. J. Carpenter ◽  
J. Stanton ◽  
K. A. Read ◽  
...  

Abstract. Measurements of acetone, methanol, acetaldehyde and a range of non-methane hydrocarbons have been made in North Atlantic marine air at the Mace Head observatory. Under maritime conditions the combination of OVOCs (acetone, methanol and acetaldehyde) contributed up to 85% of the total mass of measured non methane organics in air and up to 80% of the OH radical organic sink, when compared with the sum of all other organic compounds including non-methane hydrocarbons, DMS and OH-reactive halocarbons (trichloromethane and tetrachloroethylene). The observations showed anomalies in the variance and abundance of acetaldehyde and acetone over that expected for species with a remote terrestrial emission source and OH controlled chemical lifetime. A detailed model incorporating an explicit chemical degradation mechanism indicated in situ formation during air mass transport was on timescales longer than the atmospheric lifetime of precursor hydrocarbons or primary emission. The period over which this process was significant was similar to that of airmass motion on intercontinental scales, and formation via this route may reproduce that of a widespread diffuse source. The model indicates that continued short chain OVOC formation occurs many days from the point of emission, via longer lived intermediates of oxidation such as organic peroxides and long chain alcohols.


Nafta-Gaz ◽  
2021 ◽  
Vol 77 (3) ◽  
pp. 208-214
Author(s):  
Michał Pajda ◽  
◽  
Wojciech Mazela ◽  

The aim of the work was to present the issue of eco-efficiency, based on the PN-EN ISO 14045:2012 standard in relation to the production of fatty acid methyl esters (FAME). The ecoefficiency analysis takes into account economic and environmental aspects in the improvement of products and processes / technologies. Eco-efficiency considers the product and technology throughout the life cycle, from the construction phase, through use to decommissioning. The impact on the natural environment is assessed on the basis of: consumption of energy, materials, dust and gas emissions, waste and sewage. Total costs include: production costs, raw material costs, costs during the use phase including maintenance, repair and operating costs, product disposal or recycling. The eco-efficiency analysis is helpful in making decisions regarding the selection of a new product or designing a new technology, and enables the selection of the variant that is the most economical and has the least possible impact on the natural environment. These issues are particularly important in the case of biofuels. The rapid growth of their production and the European Union’s policy, which aims to increase the share of energy from renewable sources, cause concerns of many experts regarding the threats related to the production of biofuels, both for the environment and food security. In particular, efforts are made to minimize the amount of waste and residues by implementing the idea of a circular economy. This approach promotes the development of new technologies that are more environmentally friendly. Due to the regulations set out in the RED and RED II Directives, there is a chance that the biofuels will have a less negative impact on the environment. This results from the obligation to certify compliance with the sustainability criteria, which is carried out by voluntary systems recognized by the European Commission, such as the KZR INiG System.


2021 ◽  
Vol 237 ◽  
pp. 04034
Author(s):  
Xinying Zhang ◽  
Wenjie Chen

As the natural environment becomes growingly deteriorated, environmental protection becomes a global common concern. Landscape architecture (LA) is concerned about the relationship among humans, the built, and natural environments, so it is of special significance to study corporate social responsibilities (CSR) of LA firms. This paper studied CSR of LA firms from the perspective of landscape architects, i.e., this paper explored LA design based on corporate social responsibilities. CSR of LA firms was classified into economic responsibilities and green responsibilities, so this paper studied LA design based on economic responsibilities and green responsibilities respectively. This paper contributes to the existing study of LA design by innovatively adding corporate social responsibilities into the LA design philosophies.


2020 ◽  
pp. 63-66
Author(s):  
Marina Anatolevna Sinovats

Teaching a foreign language includes two main components: to impart and to receive information. In practice, the teacher tries his best to convey the knowledge that he has. The use of innovative methods in educational institutions expands the rights and opportunities of both students and teachers. Innovative technologies contribute to the development of the country's human potential. With a number of educational opportunities available to students of the modern generation, new trends that have completely changed the face of the traditional education system have emerged. Recent trends in the methodology reflect the vitally important role of the education sector as a whole, with its internalization of the educational process, emphasis on quality, and increased use of new technologies. Theory and methods are constantly being developed in the field of ELT. The article presents well-known trends in ELT that have been practically used all over the world recently. New trends in foreign language teaching are becoming known as GTM, a communicative method.


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