Journal of Cleaner Production
·
2020
·
IF 7.246
Chun Pei,Ji-Hua Zhu,Feng Xing
Titanium dioxide (TiO 2 ) photocatalyst coatings on cement material surfaces of buildings or structures that require high mechanical integrity, such as tunnel walls and pedestrian roads, can directly utilize solar energy for self-cleaning surfaces and removing air pollutants in the environment. However, TiO 2 can utilize only ultraviolet (UV) light, which accounts for only 5% of sunlight. To improve photocatalytic efficiency, graphene/TiO 2 nanocomposites are prepared by a sol-gel assisted electrospray method and characterized by various instrumental analysis methods. Photocatalytic cement mortars are prepared by incorporating the as-prepared nanocomposites and commercial TiO 2 into cement mortar. The self-cleaning and air purifying properties of the cement mortars are evaluated by the discoloration of rhodamine B (RhB) and the removal of nitric oxide (NO). As desired, cement mortar coated with graphene/TiO 2 nanocomposites expresses high photocatalytic effectiveness on both RhB and NO. In addition, the regeneration of graphene/TiO 2 nanocomposite photocatalysts has also been studied. The results show that the photocatalytic activity can be effectively regenerated by UV irradiation, with good repeatability and stability. Therefore, graphene/TiO 2 -coated cement mortar is a potential candidate for effective building self-cleaning and air purification through the use of solar irradiation .
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
FIBERS AND POLYMERS
·
2024
·Vol. 25
·期 7
·2443-2456
·
IF 2.2
Li Keyu,Liang Miaoqing,Zhang Mei,Nie Jinmei,Bao Lihong
In this study, a dye-sensitizing graphene/TiO 2 (DTG) based photocatalytic composite film (TPU-DTG) was developed to address the challenging recovery of graphene photocatalyst powder from treated sewage. The composite film was created by incorporating self-made dye-sensitizing graphene/TiO 2 onto an electrospun polyurethane film using electrostatic spraying technology. The structure and morphology of the composite film were analyzed using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and X-ray diffraction (XRD). Additionally, the tensile properties and thermal stability of the composite film were examined. X-ray diffraction (XRD) analysis indicated the presence of the diffraction peak of the DTG 101 crystal plane. SEM observation of TPU-4%DTG showed that the photocatalytic nanoparticles were evenly dispersed on the fiber membrane without visible agglomeration. TPU-4%DTG presented a maximum fracture stress of 17.2128 N and an elongation at a break of 335.43%. The photocatalytic performance study revealed that TPU-4%DTG was capable of eliminating over 99% of methylene blue (MB) within 10 h, and even after five cycles of photocatalytic experiments, the removal rate of MB remained above 90%.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Xiangyu Wang,Anqi Wang,Mengyang Lu,Jun Ma
Novel ternary nanocomposite based on nano zero-valent iron (nZVI) and graphene-TiO 2 nanowires (Fe@GNW) was successfully synthesized for both reduction and photocatalytic oxidation of metronidazole (MNZ). Fe@GNW exhibits synergetic effects and significant properties, such as facilitating the photogenerated charges separation, enhancing the surface activity of nZVI, improving the adsorbent ability of catalyst, possessing the magnetic property for facile recycling. Due to the formation of micro-graphene-nZVI batteries and heterogeneous photo-Fenton system, Fe@GNW showed a superior activity in removal of MNZ (99.3%) compared with TiO 2 nanowires (43.0%) and graphene-TiO 2 nanowires (67.6%). Moreover, Fe@GNW retained excellent stability without apparent loss in catalytic activity after five cycles. MNZ removal by Fe@GNW experienced a two-stage process of reduction-adsorption and photocatalytic oxidation, which could be well-described by a revised pseudo-first order kinetics. The decomposition pathways of MNZ were proposed based on the analysis of intermediates. The quenching tests demonstrated that h + and OH are responsible for MNZ decomposition. New insights into the mechanism of the enhanced reduction and photodegradation of MNZ were proposed.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Feng Sun,Dabing Ge,Guojing Fan
Heavy metal ions in environmental water have posed a significant risk to human health due to their biodegradability and potential accumulation in aquatic organisms. This study proposed the synthesis of a TiO 2 -graphene nanocomposite for the detection of cadmium ions via an electrochemical route. Then, different methods were used to characterize and analyse the features and morphology of the obtained TiO 2 -graphene nanocomposite. Based on the optimization of the electrochemical detection conditions, this nanocomposite material was applied to the detection of Cd(II) in real water specimens from a tourism area. The electrochemical sensor for Cd(II) detection was proved applicable to protect the environment of this tourism area.
研究领域:
环境科学
·
材料科学
·
分析化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Juan Yang,Zhihui Wen,Xiaoxiao Shen,Jun Dai,Yao Li,Yingjie Li
A series of graphene-TiO 2 nanocomposites (GR-TiO 2 ) with different TiO 2 dimensionalities (including TiO 2 nanoparticles, nanotubes and nanosheets) and GR weight ratios have been prepared via the analogous in-situ synthesis approach. For the first time, a systematic comparison among GR-TiO 2 NP, GR-TiO 2 NT and GR-TiO 2 NS composite photocatalysts toward ultraviolet-driven CO 2 reduction and visible-light-induced benzylamine oxidation has been carried out based on a reasonable benchmark framework. The influences of TiO 2 dimensionalities and GR weight ratios on photocatalytic redox reactions are systematically investigated. Moreover, direct comparisons among GR-TiO 2 NP, GR-TiO 2 NT and GR-TiO 2 NS composites are also conducted in terms of reactive species generation, transient photocurrent response and interfacial charge-transfer kinetics. Due to intimate interfacial contact between graphene and two-dimensional (2D) TiO 2 nanosheets, 2D-2D GR-TiO 2 NS nanocomposites possess superior electronic coupling compared to 2D-0D GR-TiO 2 NP and 2D-1D GR-TiO 2 NT samples, which results in rapid photoinduced charge-transfer and remarkably improved photocatalytic activity for CO 2 reduction under ultraviolet irradiation. On the other hand, because of large BET surface area, GR-TiO 2 NT composites possess stronger adsorption for benzylamine and the resulting visible-light absorption, leading to greater photocatalytic activity toward selective oxidation of benzylamine under visible light illumination. Overall, the results suggest that TiO 2 nanomaterial dimensionality plays the key role in determining the interfacial charge-transfer and reaction specificity of GR-TiO 2 composite photocatalysts.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Muhan Cao,Peifang Wang,Yanhui Ao,Chao Wang,Jun Hou,Jin Qian
A magnetically separable graphene–TiO 2 (MG–TiO 2 ) hybrid photocatalyst was successfully prepared by a one step method. Namely, simultaneous reduction of graphene oxide and deposition of TiO 2 on the graphene was occurred in one single process. The as-prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL) analysis, X-ray photoelectron spectroscopy (XPS) and The Brunauer–Emmett–Teller (BET) analysis. The photocatalytic activity of the obtained samples was measured by the decomposition of methylene blue (MB) and tetrabromobisphenol A (TBBPA, a brominated flame retardant) under UV light irradiation. The results showed that MG–TiO 2 exhibited much higher photocatalytic performance than that of bare TiO 2 . The enhanced activity can be ascribed to the incorporation of graphene. In addition, the MG–TiO 2 with MG content of 3% exhibited the highest activity towards MB and TBBPA degradation. The intermediates of TBBPA in the photocatalytic degradation process were analyzed by LC–MS. On the basis of the identified intermediates, the photocatalytic degradation pathway of TBBPA was proposed. Furthermore, the recyclable ability of the samples was also studied and the results showed that the samples exhibited high stability.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Membranes
·
2019
·Vol. 9
·期 1
·16
·
IF 0
Tao Wu,Zongman Zhang,Ding Zhai,Yang Liu,Qingguo Liu,Lixin Xue,Congjie Gao
A ternary nanocomposite consisting of N-doped graphene (NGR)/TiO2/activated carbon (NGRT@AC) was prepared, and the components’ synergetic effect on dye degradation was investigated after deposition on the surface of a polysulfone membrane (PSF). As far as we know, this ternary composite catalyst has never previously been used to degrade dyes nor been used as a functional layer for separation membranes. The surface morphology and structure of the as-prepared membranes were analyzed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The NGRT@AC-modified PSF membrane (NGRT@AC-PSF) presents excellent photodegradation efficiency to methyl orange (MO) under both UV (95.2%) and sunlight (78.1%) irradiation, much higher than those values of PSF, TiO2- modified PSF (TiO2-PSF), and N-doped graphene/TiO2(NGRT)-modified PSF membranes (NGRT-PSF) under the same conditions. The high flux recovery ratio (95.5%) demonstrates that the NGRT@AC-PSF membrane shows improved antifouling performance. The photocatalytic results prove that surface deposition method (95.2%) was better than the blending method (31.1%) for forming high-performance membranes. Therefore, the NGRT@AC-PSF membrane has the potential for broad applications in dye degradation to treat waste water from textile industries.Keywords:N-doped graphene/TiO2/activated carbon nanocomposite;methyl orange;photocatalytic;antifouling performance;membrane
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
He Guo,Nan Jiang,Huijuan Wang,Kefeng Shang,Na Lu,Jie Li,Yan Wu
A hybrid graphene-TiO 2 nanocomposites have been prepared by a facile hydrothermal method to improve the photocatalytic performance and applied for synergetic degradation of fluoroquinolone antibiotic in pulsed discharge plasma (PDP) system. The characterizations of the structure and morphology, chemical bonding state, optical property and electrochemical property show that the graphene-TiO 2 nanocomposites can be hybridized successfully. Compared to the pure TiO 2 , the light absorption range can extend to visible light (<505 nm) and the recombination rate of electron–hole pairs declines apparently in the graphene-TiO 2 samples. The degradation performance experiment manifests a significant enhancement of the removal efficiency of flumequine (FLU) when the graphene-TiO 2 samples are added in the PDP system. The highest removal efficiency can reach 99.4% in PDP/graphene-TiO 2 system with 5% graphene content, which is 23.7% and 34.6% higher than that in PDP/TiO 2 system and sole PDP system, respectively. Correspondingly, the kinetic constant is 3.5 and 4.6 times higher than that in PDP/TiO 2 system and sole PDP system, respectively. The radical species trapping test suggests that OH, h + and O 2 − play the critical role for FLU degradation in PDP/graphene-TiO 2 system. The graphene-TiO 2 samples can further decompose the O 3 and improve the generation of OH and H 2 O 2 . The degradation intermediates are determined by LC–MS and IC. The toxicity evolution of FLU reaction solutions is evaluated based on inhibition of photobacterium V. fischeri . Finally, the FLU degradation mechanism in the PDP/graphene-TiO 2 system is proposed. This research would provide a novel insight into the application of graphene-based nanocomposites in PDP system as a promising remediation methodology for organic contaminants in water.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）