scholarly journals Photocatalytic Performance Evaluation of Titanium Dioxide Nanotube-Reinforced Cement Paste

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5423
Author(s):  
Junxing Liu ◽  
Hyeonseok Jee ◽  
Myungkwan Lim ◽  
Joo Kim ◽  
Seung Kwon ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Cement Paste ◽  
Photocatalytic Performance ◽  
Construction Material ◽  
Cementitious Materials ◽  
Research Field ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Widespread Application ◽  
Reinforced Cement

Considering the increase in research regarding environmental pollution reduction, the utilization of cementitious material, a commonly used construction material, in photocatalysts has become a desirable research field for the widespread application of photocatalytic degradation technology. Nano-reinforcement technology for cementitious materials has been extensively researched and developed. In this work, as a new and promising reinforcing agent for cementitious materials, the photocatalytic performance of titanium dioxide nanotube (TNT) was investigated. The degradation of methylene blue was used to evaluate the photocatalytic performance of the TNT-reinforced cement paste. In addition, cement paste containing micro-TiO2 (m-TiO2) and nano-TiO2 (n-TiO2) particles were used for comparison. Moreover, the effect of these TiO2-based photocatalytic materials on the cement hydration products was monitored via X-ray diffraction (XRD) and thermogravimetric analysis (TG). The results indicated that all the TiO2 based materials promoted the formation of hydration products. After 28 days of curing, the TNT-reinforced cement paste contained the maximum amount of hydration products (Ca(OH)2). Furthermore, the cement paste containing TNT exhibited better photocatalytic effects than that containing n-TiO2, but worse than that containing m-TiO2.

Early Stage Development of Cement Paste Microstructure

2017 ◽  
Vol 1144 ◽  
pp. 14-21
Author(s):  
Vladimír Hrbek ◽  
Veronika Petranova ◽  
Jiří Němeček
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Cement Paste ◽  
Early Stage ◽  
Cementitious Materials ◽  
Hydration Products ◽  
Crucial Aspect ◽  
Micromechanical Properties ◽  
Stage Development ◽  
Overall Performance

The early stage development of the cement microstructure is a crucial aspect affecting the overall performance of cementitious materials. The formation of hydration products depends on the presence of water and carbon dioxide, as well as on the distribution and re-crystallization of the cement particles. In this paper we evaluate the micromechanical properties evolution of cement phases over first 28 days after casting by the electron microscopy and static areal indentation.

The Study of Alkaline-Activated Magnesium Slag Cementitious Material

2012 ◽  
Vol 517 ◽  
pp. 363-366 ◽  
Author(s):  
Li Guang Xiao ◽  
Feng Luo ◽  
Rui Bo Li ◽  
Chang Yu Liu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Property ◽  
Interaction Mechanism ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Furnace Slag ◽  
Scanning Electron

Magnesium slag cementitious material was prepared successfully using the magnesium slag-furnace slag-clinker system and different activators in this paper. The effect of activator on the mechanical property of the material was studied. The hydration and microstructure of this composite cement were analyzed by X-ray diffraction and scanning electron microscopy and the interaction mechanism was researched. The results show that the activity of magnesium slag was enhanced significantly by adding a small amount of activator. Combined activators have the best effect. The hydration products of magnesium slag cementitious materials mortar were C-S-H, Aft and Ca (OH)2 and so on.

scholarly journals Application of Supported TiO2 in Carbonated Binding Material and Its Photocatalytic Performance

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1336
Author(s):  
Heyang Si ◽  
Yongle Fang ◽  
Lu Yang
Keyword(s):  
Quartz Sand ◽  
Photocatalytic Performance ◽  
Construction Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Water Washing ◽  
Binding Material ◽  
Matrix Surface ◽  
Supported Tio2 ◽  
Photocatalytic Concrete

Although photocatalytic concrete can significantly contribute to the degradation of air pollutants and improving the sustainability levels, the complexity of ordinary cement system often caused the uncertain performance of mixed photocatalysts, which limited the real application of photocatalysts. Since the rapid carbonization hardening and relatively simple composition, γ-C2S carbonated binding material has gained considerable attention for its application in construction material. In this work, quartz sand-supported TiO2-C2S(γ) composites (TQSC) were prepared by mixing photocatalytic quartz sand with γ-C2S and mounting in γ-C2S matrix surface methods. The TiO2-coated quartz sand (TQS) was characterized by X-ray diffraction (XRD), quantitative X-ray fluorescence (XRF) and scanning electron microscopy (SEM). The photocatalytic performance and durability (washing resistance) of TQSC were also investigated by the degradation ability of NOx and rhodamine B (RhB). The results show that a uniform TiO2 layer on quartz sand was prepared, and the photocatalytic De-NOx (degradation of NOx) performance increased with increasing the mounted amounts of TiO2/quartz sand in γ-C2S carbonated matrix surface, but would decrease the photocatalytic durability. After water-washing, the De-NOx efficiencies of TQSC specimens decreased quickly at the beginning, which were adhering to the mounted amounts of TiO2/quartz sand, but would become stable after water-washing for 3600 s for all samples. The relatively high De-NOx stability and good self-cleaning effect of the water-washed TQSC-60% specimen can be considered a promising photocatalytic product for real applications.

scholarly journals Hydraulic binder obtained from recycled cement and sand powder

2018 ◽  
Vol 11 (6) ◽  
pp. 1178-1185 ◽  
Author(s):  
R. M. R. O. MENEZES ◽  
R. M. DA SILVA ◽  
E. P. FIGUEIREDO ◽  
A. C. DA SILVA BEZERRA ◽  
M. T. P. AGUILAR ◽  
...  
Keyword(s):  
Cement Paste ◽  
Quartz Sand ◽  
Construction Material ◽  
Relevant Literature ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
Cement Pastes ◽  
Supplementary Cementitious Material ◽  
Hydrated Calcium Silicate ◽  
Hydraulic Binder

Abstract Environmentally eco-efficient concrete is currently a popular choice of construction material. Reviewing relevant literature indicates that heating of cement paste can remove hydrating water, and that quartz sand of appropriate granulometry can act as a supplementary cementitious material; however, there have been virtually no reports on the reuse of these materials as alternative binders. This work evaluates the phases present in cementitious compounds produced with binders obtained by thermomechanically treating cement pastes with and without a 15% substitution of quartz sand powder (specific surface area 37.4 m²/g), referred to as RCQ and recycled cement RC, respectively. Testing included thermogravimetric analysis (performed with stripped gases), X-ray diffraction, and scanning electron microscopy with phase identification. The obtained data indicated RC cement paste possesses a predominantly ettringite microstructure, whereas the presence of calcium hydroxide and hydrated calcium silicate predominates in RCQ paste.

scholarly journals Effects of Adding Neutralized Red Mud on the Hydration Properties of Cement Paste

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4107
Author(s):  
Sukpyo Kang ◽  
Hyeju Kang ◽  
Byoungky Lee
Keyword(s):  
Compressive Strength ◽  
Cement Paste ◽  
Red Mud ◽  
Aluminum Industry ◽  
Construction Material ◽  
Calorific Value ◽  
Cementitious Materials ◽  
Heat Of Hydration ◽  
Hydration Properties ◽  
The Aluminum Industry

Red mud is a highly alkaline waste by-product of the aluminum industry. Although recycling of red mud is being actively researched, a feasible technological solution has not been found yet. In this study, we propose that neutralization of red mud alkalinity could assist in its use as a construction material. Neutralized red mud (LRM + S; pH 6–8) was prepared by adding sulfuric acid to liquefied red mud (LRM; pH 10–12). After adding LRM and LRM + S to cement paste, the heat of hydration, compressive strength, and hydration products were examined. The experiments revealed that the calorific value of the cement paste with LRM was low, and its peak was delayed, when compared with that of plain cement paste (referred to as Plain), whereas the calorific value of the cement paste with LRM + S was similar to that of Plain. At the age of 28 d, the compressive strength of the cement paste with 10% LRM + S was 99% whereas that with 20% LRM was only 55% of the strength of Plain. Thus, our results help to resolve the issue of strength degradation of cementitious materials observed upon the addition of red mud and enable its reuse as a construction material.

Preparation of graphene-TiO2 nanocomposite films and its photocatalytic performances on degradation of Rhodamine B

2018 ◽  
Vol 47 (1) ◽  
pp. 79-85
Author(s):  
Pei Qin ◽  
Guobin Yi ◽  
Xihong Zu ◽  
Huan Wang ◽  
Hongsheng Luo ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Performance ◽  
Separation Efficiency ◽  
Diffuse Reflectance Spectrum ◽  
Photogenerated Electron ◽  
Nanocomposite Films ◽  
Nanorod Arrays ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Content Type

Purpose The aim of this paper is to synthesize graphene-modified titanium dioxide (GR-TiO2) nanorod arrays nanocomposite films, so that these can enhance the photocatalytic properties of titanium dioxide and overcome the problem of difficult separation and recovery of photocatalysts. Design/methodology/approach The GR-TiO2 nanocomposite films were synthesized via hydrothermal method and spin-coating. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), ultraviolet–visible (UV-Vis) diffuse reflectance spectrum and Raman spectrum. The photocatalytic performance of the GR-TiO2 nanocomposite films for degrading Rhodamin B under ultraviolet (UV) was studied by a UV-Vis spectrophotometer. The photocatalytic enhancement mechanism of graphene was studied by photoelectrochemical analysis. Findings The introduction of graphene expanded the range of the optical response of TiO2 nanorod arrays, improving the separation efficiency of the photogenerated electron-hole pairs, and thus dramatically increasing its photocatalytic performance. Research limitations/implications A simple and novel way for synthesizing GR-TiO2 nanocomposite films has enhanced the photocatalytic performance of TiO2. Originality/value The photocatalyst synthesized is easy to separate and recycle in the process of photocatalytic reaction, so it is possible to achieve industrialization.

Study on the Synthesis and Photocatalytic Perfomance of Tube shaped Activated Carbon -TiO2 Composite Materials

2020 ◽  
Vol 2 (7) ◽  
pp. 143-150
Author(s):  
Zhifu Wu
Keyword(s):  
Titanium Dioxide ◽  
Activated Carbon ◽  
Rhodamine B ◽  
Photocatalytic Performance ◽  
Raw Materials ◽  
Phase Particle ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Photocatalytic Material

Titanium dioxide semiconductor material is one of the earliest photocatalysts with stable and reliable properties, but its quantum efficiency is relatively low. In order to improve the photocatalytic performance of titanium dioxide, the activated carbon tubular-titanium dioxide composite photocatalytic material was synthesized by sol-gel method with n-butyl titanate and activated carbon as main raw materials in the system of isopropyl alcohol and glacial acetic acid. X-ray diffraction (XRD), scanning electron microscope (SEM) and nitrogen adsorption were used to characterize the phase, particle size and adsorption performance of the photocatalyst. The photocatalytic performance of the synthesized material was tested by using rhodamine B, a simulated pollutant. The results show that rhodamine B decomposition rate can reach 100% under UV irradiation for 140 minutes. The conclusion is that the photocatalytic performance of the activated carbon tube interspersed with titanium dioxide composite was significantly improved.

Enhanced photoluminescence and photocatalytic performance of TiO2-ZnWO4 nanocomposite induced by oxygen vacancies

CrystEngComm ◽  
2021 ◽  
Author(s):  
Hainan Liu ◽  
Xiaoru Zhao ◽  
Hao SHEN ◽  
Shenglan HAO ◽  
Xianwu JIANG
Keyword(s):  
Titanium Dioxide ◽  
Diffraction Pattern ◽  
Oxygen Vacancies ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Nanocomposite Powder ◽  
X Ray ◽  
Enhanced Photoluminescence ◽  
Zinc Tungstate

Titanium dioxide (TiO2)-zinc tungstate (ZnWO4) nanocomposite powder was prepared by a sol-gel procedure. X-ray diffraction pattern (XRD) of the nanocomposite indicates that crystallinity of TiO2 is restrained by coupling with...

Simplistic Synthesis and Enhanced Photocatalytic Performance of Spherical ZnO Nanoparticles Prepared from Arabinose Solution

2019 ◽  
Vol 74 (10) ◽  
pp. 937-944 ◽  
Author(s):  
Babiker Y. Abdulkhair ◽  
Mutaz E. Salih ◽  
Nuha Y. Elamin ◽  
A. MA. Fatima ◽  
A. Modwi
Keyword(s):  
Zno Nanoparticles ◽  
Photocatalytic Performance ◽  
Hexagonal Wurtzite Structure ◽  
Zinc Nitrate ◽  
Wurtzite Structure ◽  
Sugar Solution ◽  
X Ray Diffraction ◽  
Pollutant Degradation ◽  
X Ray ◽  
Good Crystallinity

AbstractStrenuous efforts have been employed to prepare zinc oxide (ZnO) with eco-friendly methods; however, few studies have reported the fabrication of ZnO using a sustainable procedure. In this study, spherical ZnO nanoparticles were successfully fabricated for photocatalysis applications using a simple and eco-friendly method using an arabinose sugar solution. The ZnO nanoparticles with a wurtzite structure were obtained by combining zinc nitrate and arabinose in water, followed by heating, evaporation, and calcinations at different annealing temperatures. The annealed ZnO photocatalysts were characterised via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The findings revealed a hexagonal wurtzite structure and good crystallinity with crystallite size increasing from 18 to 31 nm by means of an increase in the annealing temperature. The photocatalytic performance was examined to determine the degradation of mix dye waste. The spherical ZnO nanoparticles showed mix pollutant degradation of 84 % in 25 min at 400 °C.

scholarly journals The study of rod-shaped TiO2 composite material in the protection of stone cultural relics

2020 ◽  
Vol 9 (1) ◽  
pp. 359-365
Author(s):  
Hui Shu ◽  
Yujian Song ◽  
Qiang Liu ◽  
Maobin Luo
Keyword(s):  
Photocatalytic Performance ◽  
Acid Resistance ◽  
Uv Resistance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Excellent Photocatalytic Activity ◽  
Stone Culture ◽  
Weather Resistance ◽  
Cultural Relics

AbstractTiO2 has many advantages, such as UV resistance, thermal stability, and antibacterial; the attention toward TiO2 composite materials (TCMs) is rapidly increasing in the protection of stone culture relics. An innovative rod-shaped TCM was synthesized in this study. The structure and morphology of TCM were studied by X-ray diffraction and scanning electron microscopy. The acid resistance, weather resistance, hydrophilicity, and photocatalytic performance of TCM had been investigated. The experimental results indicated that TCM has good protection effects. The stone sample treated with TCM has stronger acid resistance and weather resistance, better hydrophilicity, and more excellent photocatalytic activity compared with the untreated stone. More importantly, the stone treated with TCM has better acid resistance and weather resistance than that treated with normal shaped TiO2 materials of the previous study. This work describes an effective way to protect stone cultural relics.

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