scispace - formally typeset
Journal ArticleDOI: 10.1016/J.JHAZMAT.2020.124204

Enhanced visible-light photocatalysis of clofibric acid using graphitic carbon nitride modified by cerium oxide nanoparticles.

05 Mar 2021-Journal of Hazardous Materials (Elsevier)-Vol. 405, pp 124204-124204
Abstract: Recently, the emerging pharmaceutical micropollutants have become an environmental concern. Herein, we report an efficient elimination of clofibric acid (CA) using visible light-driven g-C3N4/CeO2 prepared by hydrothermal method. Among the catalysts with different compound ratios, g-C3N4/CeO2-3 (1.2 g g-C3N4 with 3 mmol Ce(NO3)3∙6H2O) exhibited the best photocatalytic performance. The effect of catalyst dosage was investigated and the optimal value was determined as 0.5 g L–1. The effect of initial pH (pH0) showed CA elimination decreased with increasing pH0. The underlying mechanism for CA oxidation was proposed based on synthetical analysis of photoluminescence emission spectra, transient photocurrent responses, electron paramagnetic resonance, chemical quenching experiments and band edge potential of g-C3N4 and CeO2. Photogenerated hole was primarily responsible for CA elimination while singlet oxygen played an auxiliary role. The products of CA oxidation were detected using liquid chromatography mass spectrometry (LC-MS) method and a possible pathway was put forward. Various organics were used as target contaminants to assess photocatalytic performance of g-C3N4/CeO2 heterojunction under acidic and alkaline pH conditions. The analysis of relationship between the oxidation peak potential (EOP) and the reaction rate constant indicated that photocatalysis using as prepared g-C3N4/CeO2-3 heterojunction is apt to oxidize contaminants with electron withdrawing group under acid condition.

... read more

Topics: Photocatalysis (56%), Graphitic carbon nitride (53%), Clofibric acid (51%) ... show more
Citations
  More

7 results found


Open accessJournal ArticleDOI: 10.1038/S41378-021-00250-5
Tong Wu1, Hui Zheng1, Yichuan Kou1, Xinyue Su1  +6 moreInstitutions (3)
Abstract: Ternary noble metal-semiconductor nanocomposites (NCs) with core-shell-satellite nanostructures have received widespread attention due to their outstanding performance in detecting pollutants through surface-enhanced Raman scattering (SERS) and photodegradation of organic pollutants. In this work, ternary Au@Cu2O-Ag NCs were designed and prepared by a galvanic replacement method. The effect of different amounts of Ag nanocrystals adsorbed on the surfaces of Au@Cu2O on the SERS activity was investigated based on the SERS detection of 4-mercaptobenzoic acid (4-MBA) reporter molecules. Based on electromagnetic field simulations and photoluminescence (PL) results, a possible SERS enhancement mechanism was proposed and discussed. Moreover, Au@Cu2O-Ag NCs served as SERS substrates, and highly sensitive SERS detection of malachite green (MG) with a detection limit as low as 10-9 M was achieved. In addition, Au@Cu2O-Ag NCs were recycled due to their superior self-cleaning ability and could catalyze the degradation of MG driven by visible light. This work demonstrates a wide range of possibilities for the integration of recyclable SERS detection and photodegradation of organic dyes and promotes the development of green testing techniques.

... read more

12 Citations


Journal ArticleDOI: 10.1016/J.CHEMOSPHERE.2021.131651
A. A. Fauzi1, Aishah Abdul Jalil1, Aishah Abdul Jalil2, N.S. Hassan1  +5 moreInstitutions (3)
01 Jan 2022-Chemosphere
Abstract: Nanostructured photocatalysts commonly offered opportunities to solve issues scrutinized with the environmental challenges caused by steep population growth and rapid urbanization. This photocatalyst is a controllable characteristic, which can provide humans with a clean and sustainable ecosystem. Over the last decades, one of the current thriving research focuses on visible-light-driven CeO2-based photocatalysts due to their superior characteristics, including unique fluorite-type structure, rigid framework, and facile reducing oxidizing properties of cerium's tetravalent (Ce4+) and trivalent (Ce3+) valence states. Notwithstanding, owing to its inherent wide energy gap, the solar energy utilization efficiency is low, which limits its application in wastewater treatment. Numerous modifications of CeO2 have been employed to enhance photodegradation performances, such as metals and non-metals doping, adding support materials, and coupling with another semiconductor. Besides, all these doping will form a different heterojunction and show a different way of electron-hole migration. Compared to conventional heterojunction, advanced heterojunction types such as p-n heterojunction, Z-scheme, Schottky junction, and surface plasmon resonance effect exhibit superior performance for degradation owing to their excellent charge carrier separation, and the reaction occurs at a relatively higher redox potential. This review attends to providing deep insights on heterojunction mechanisms and the latest progress on photodegradation of various contaminants in wastewater using CeO2-based photocatalysts. Hence, making the CeO2 photocatalyst more foresee and promising to further development and research.

... read more

3 Citations


Journal ArticleDOI: 10.1016/J.CCLET.2021.06.035
Decai Yang1, Yachao Xu1, Kai Pan1, Chuanxin Yu1  +6 moreInstitutions (2)
Abstract: Surface oxygen vacancy defects of mesoporous CeO2 nanosheets assembled microspheres (D-CeO2) are engineered by polymer precipitation, hydrothermal and surface hydrogenation strategies. The resultant D-CeO2 with a main pore diameter of 9.3 nm has a large specific surface area (~102.3 m2/g) and high thermal stability. The mesoporous nanosheets assembled microsphere structure prevents the nanosheets from aggregation, which is beneficial to effective mass transfer and shortens the migration distance of charge carriers. After surface hydrogenation, the photoresponse extends to long wavelength region, combing with the band gap from 2.63 eV reduced to 2.39 eV. Under AM 1.5 G radiation, the photocatalytic degradation rate of tetracycline (TC) can be up to 99.99%, which is three times as high as that of pristine CeO2 microspheres. The excellent solar-driven photocatalytic performance can be attributed to the efficient surface oxygen vacancy engineering and the mesoporous nanosheets assembled microsphere structure, which narrows the band gap, shortens the migration distance of carriers, promotes the spatial separation of photogenerated electron-hole pairs and favors mass transfer. The strategy provides new insights for fabricating other high-efficient oxide photocatalysts .

... read more

2 Citations


Open accessJournal ArticleDOI: 10.1016/J.JELECHEM.2021.115475
Abstract: With the aim of bringing the heterogeneous electro-Fenton (EF) treatment one step closer to a more realistic operation, the scaling-up of that technology was evaluated. Assays were performed firstly at lab scale in a stirred-tank reactor and then at bench scale in a flow setup including a jet aerator and a microfluidic flow-through electrochemical cell. A fluidized-bed reactor was added to the bench-scale installation in order to retain the solid catalyst, iron-containing alginate beads. To the best of the authors’ knowledge, there are no precedent studies reporting a heterogeneous EF treatment in a similar bench scale-configuration. Hydrogen peroxide generation and clofibric acid removal were assessed at both scales at current intensities of 0.12 and 0.25 A. Results showed that the scaled-up treatment was more efficient and cost-effective: at bench scale 18 times more volume was treated, the mass production of hydrogen peroxide was 28 higher and the specific cost for the removal of clofibric acid was cut by more than half. The most efficient treatment turned out to be the EF performed at 0.12 A at bench scale. Those results highlighted the importance of the reactor design in the scaling-up process. Additionally, aromatic intermediates were detected by liquid chromatography-mass spectrometry (LC-MS) and a degradation route was suggested. Carboxylic acids were also measured by HPLC confirming that the pollutant is mineralizing.

... read more

2 Citations


Journal ArticleDOI: 10.1039/D1NJ03467G
Abstract: Rapid detection of hypoxanthine (Hx), an important freshness indicator of aquatic products, is still urgent and challenging. In the present study, a colorimetric method for the rapid detection of Hx in aquatic products was established based on the peroxidase-like activity of cobalt-doped graphite phase carbon nitride (Co-doped-g-C3N4). After calcination of the mixture of melamine, cobalt chloride, potassium chloride and sodium chloride, Co-doped-g-C3N4 was obtained with strong peroxidase-like activity and good dispersity. Through the decomposition of Hx by xanthine oxidase, the generated hydrogen peroxide (H2O2) was detected based on the oxidation reaction of H2O2 and 3,3′,5,5′-tetramethylbenzidine catalyzed by Co-doped-g-C3N4. The content of Hx could be directly measured by monitoring the spectral absorbance at 652 nm with a linear range of 2.50–153.1 mg kg−1 and a detection limit of 1.84 mg kg−1 calculated based on 3σ/K (n = 9). The established method was applied for the detection of Hx content in various aquatic products at different storage times after execution, and the data were validated by the HPLC method. The results showed that the Hx measurement by the established method was sensitive, accurate and reliable, and could be used for the rapid determination of the freshness of aquatic products at an early stage.

... read more

Topics: Detection limit (51%)

References
  More

84 results found


Open accessJournal ArticleDOI: 10.1016/J.SCITOTENV.2013.12.065
Yunlong Luo1, Wenshan Guo1, Huu Hao Ngo1, Long D. Nghiem2  +4 moreInstitutions (4)
Abstract: Micropollutants are emerging as a new challenge to the scientific community. This review provides a summary of the recent occurrence of micropollutants in the aquatic environment including sewage, surface water, groundwater and drinking water. The discharge of treated effluent from WWTPs is a major pathway for the introduction of micropollutants to surface water. WWTPs act as primary barriers against the spread of micropollutants. WWTP removal efficiency of the selected micropollutants in 14 countries/regions depicts compound-specific variation in removal, ranging from 12.5 to 100%. Advanced treatment processes, such as activated carbon adsorption, advanced oxidation processes, nanofiltration, reverse osmosis, and membrane bioreactors can achieve higher and more consistent micropollutant removal. However, regardless of what technology is employed, the removal of micropollutants depends on physico-chemical properties of micropollutants and treatment conditions. The evaluation of micropollutant removal from municipal wastewater should cover a series of aspects from sources to end uses. After the release of micropollutants, a better understanding and modeling of their fate in surface water is essential for effectively predicting their impacts on the receiving environment.

... read more

2,291 Citations


Journal ArticleDOI: 10.1002/ADMA.201500033
Shaowen Cao1, Jingxiang Low1, Jiaguo Yu2, Jiaguo Yu1  +1 moreInstitutions (3)
01 Apr 2015-Advanced Materials
Abstract: Semiconductor-based photocatalysis is considered to be an attractive way for solving the worldwide energy shortage and environmental pollution issues. Since the pioneering work in 2009 on graphitic carbon nitride (g-C3N4) for visible-light photocatalytic water splitting, g-C3N4 -based photocatalysis has become a very hot research topic. This review summarizes the recent progress regarding the design and preparation of g-C3N4 -based photocatalysts, including the fabrication and nanostructure design of pristine g-C3N4 , bandgap engineering through atomic-level doping and molecular-level modification, and the preparation of g-C3N4 -based semiconductor composites. Also, the photo-catalytic applications of g-C3N4 -based photocatalysts in the fields of water splitting, CO2 reduction, pollutant degradation, organic syntheses, and bacterial disinfection are reviewed, with emphasis on photocatalysis promoted by carbon materials, non-noble-metal cocatalysts, and Z-scheme heterojunctions. Finally, the concluding remarks are presented and some perspectives regarding the future development of g-C3N4 -based photocatalysts are highlighted.

... read more

2,206 Citations


Journal ArticleDOI: 10.1021/ACS.CHEMREV.7B00161
Yoshio Nosaka1, Atsuko Y. Nosaka1Institutions (1)
04 Aug 2017-Chemical Reviews
Abstract: The detection methods and generation mechanisms of the intrinsic reactive oxygen species (ROS), i.e., superoxide anion radical (•O2–), hydrogen peroxide (H2O2), singlet oxygen (1O2), and hydroxyl radical (•OH) in photocatalysis, were surveyed comprehensively. Consequently, the major photocatalyst used in heterogeneous photocatalytic systems was found to be TiO2. However, besides TiO2 some representative photocatalysts were also involved in the discussion. Among the various issues we focused on the detection methods and generation reactions of ROS in the aqueous suspensions of photocatalysts. On the careful account of the experimental results presented so far, we proposed the following apprehension: adsorbed •OH could be regarded as trapped holes, which are involved in a rapid adsorption–desorption equilibrium at the TiO2–solution interface. Because the equilibrium shifts to the adsorption side, trapped holes must be actually the dominant oxidation species whereas •OH in solution would exert the reactivity...

... read more

Topics: Hydroxyl radical (54%), Singlet oxygen (54%), Photocatalysis (52%) ... show more

1,207 Citations


Journal ArticleDOI: 10.1002/ADMA.200802627
Xinchen Wang1, Xiufang Chen2, Arne Thomas1, Xianzhi Fu2  +1 moreInstitutions (2)
27 Apr 2009-Advanced Materials
Abstract: [*] Prof. X. C. Wang, X. F. Chen, Prof. X. Z. Fu Research Institute of Photocatalysis State Key Laboratory Breeding Base of Photocatalysis Fuzhou University, Fuzhou 350002 (PR China) E-mail: xcwang@fzu.edu.cn; xzfu@fzu.edu.cn Prof. X. C. Wang, Dr. A. Thomas, Prof. M. Antonietti Department of Colloid Chemistry Max-Planck Institute of Colloids and Interfaces Research Campus Golm, 14476 Potsdam (Germany)

... read more

Topics: Carbon nitride (69%), Nitride (64%), Hybrid material (58%)

948 Citations


Journal ArticleDOI: 10.1039/C3CP53131G
Jiaguo Yu1, Shuhan Wang1, Jingxiang Low1, Wei Xiao2Institutions (2)
Abstract: Formaldehyde (HCHO) is a major indoor pollutant and long-term exposure to HCHO may cause health problems such as nasal tumors and skin irritation. Photocatalytic oxidation is considered as the most promising strategy for the decomposition of HCHO. Herein, for the first time, a direct g-C3N4–TiO2 Z-scheme photocatalyst without an electron mediator was prepared by a facile calcination route utilizing affordable P25 and urea as the feedstocks. Photocatalytic activities of the as-prepared samples were evaluated by the photocatalytic oxidation decomposition of HCHO in air. It was shown that the photocatalytic activity of the prepared Z-scheme photocatalysts was highly dependent on the g-C3N4 content. At the optimal g-C3N4 content (sample U100 in this study), the apparent reaction rate constant was 7.36 × 10−2 min−1 for HCHO decomposition, which exceeded that of pure P25 (3.53 × 10−2 min−1) by a factor of 2.1. The enhanced photocatalytic activity could be ascribed to the formation of a g-C3N4–TiO2 Z-scheme photocatalyst, which results in the efficient space separation of photo-induced charge carriers. Considering the ease of the preparation method, this work will provide new insights into the design of high-performance Z-scheme photocatalysts for indoor air purification.

... read more

Topics: Photocatalysis (51%)

887 Citations