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采用一步水热法合成石墨烯复合花状钨酸铋高效可见光光催化剂。降解甲基橙的性能实验结果表明, 与单纯的Bi2WO6相比, 所有Bi2WO6-rGO复合光催化剂表现出更高的光催化性能。其中, Bi2WO6-rGO (0.5wt%)具有最高的光催化活性, 其速率常数达到5.0×10-2 /min, 是纯Bi2WO6的1.7倍。增强光催化性能的原因归结为以下两方面的协同作用: 还原石墨烯在复合光催化剂中起到了电子快速传输作用; 石墨烯提供了有利于吸附有机污染物的大比表面积。本研究可以为设计与合成高性能石墨烯基光催化剂提供新的思路。 相似文献
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Yi Tian Francisco Pelayo García de Arquer Cao‐Thang Dinh Gael Favraud Marcella Bonifazi Jun Li Min Liu Xixiang Zhang Xueli Zheng Md. Golam Kibria Sjoerd Hoogland David Sinton Edward H. Sargent Andrea Fratalocchi 《Advanced materials (Deerfield Beach, Fla.)》2017,29(27)
The direct conversion of solar energy into fuels or feedstock is an attractive approach to address increasing demand of renewable energy sources. Photocatalytic systems relying on the direct photoexcitation of metals have been explored to this end, a strategy that exploits the decay of plasmonic resonances into hot carriers. An efficient hot carrier generation and collection requires, ideally, their generation to be enclosed within few tens of nanometers at the metal interface, but it is challenging to achieve this across the broadband solar spectrum. Here the authors demonstrate a new photocatalyst for hydrogen evolution based on metal epsilon‐near‐zero metamaterials. The authors have designed these to achieve broadband strong light confinement at the metal interface across the entire solar spectrum. Using electron energy loss spectroscopy, the authors prove that hot carriers are generated in a broadband fashion within 10 nm in this system. The resulting photocatalyst achieves a hydrogen production rate of 9.5 µmol h?1 cm?2 that exceeds, by a factor of 3.2, that of the best previously reported plasmonic‐based photocatalysts for the dissociation of H2 with 50 h stable operation. 相似文献
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Photocatalysts: Enhanced Solar‐to‐Hydrogen Generation with Broadband Epsilon‐Near‐Zero Nanostructured Photocatalysts (Adv. Mater. 27/2017) 
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下载免费PDF全文 Yi Tian Francisco Pelayo García de Arquer Cao‐Thang Dinh Gael Favraud Marcella Bonifazi Jun Li Min Liu Xixiang Zhang Xueli Zheng Md. Golam Kibria Sjoerd Hoogland David Sinton Edward H. Sargent Andrea Fratalocchi 《Advanced materials (Deerfield Beach, Fla.)》2017,29(27)
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采用乳液插层水解法成功制备了一种层状磁响应性光催化纳米复合材料.首先通过水热法制备磁性Fe3O4纳米粒子,将其超声分散在溶有钛酸丁酯的无水乙醇中,形成钛酸丁酯包裹Fe3O4纳米粒子的微乳液,然后将该微乳液插层于石墨烯中,利用石墨烯的层状结构作为载体形成一种稳定体系,通过控制水解,使TiO2纳米粒子与磁性Fe3O4纳米粒子共同镶嵌于石墨烯层间,形成一种新型的磁响应TiO2/石墨烯纳米复合材料.通过扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、震动样品磁强计(VSM)等手段对该复合材料进行表征,并通过模拟太阳光下降解亚甲基蓝(MB)评价复合材料的光催化性能.该复合材料通过磁分离可反复使用,重复使用7次后,对亚甲基蓝的降解率仍大于90％. 相似文献
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采用溶胶-凝胶法制备了稀土Yb掺杂纳米TiO2光催化剂(Yb-TiO2),采用XRD、UV-Vis、FT-IR等方法对其进行表征和分析,并以亚甲基蓝(MB)作为目标降解物,考察了热处理温度以及Yb掺杂量对样品性能的影响。实验结果表明,Yb掺杂样品均为金红石相和锐钛矿相的混晶相,Yb的掺入拓展了TiO2对可见光的吸收范围,有效地抑制了光生电子-空穴对的复合,提高了TiO2的光催化活性。当pH值=2.5、n(Yb)∶n(Ti)=0.005、热处理温度为650℃时,制备的样品其光催化活性明显优于Degussa P25。 相似文献
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Miquel Ortiz;Elvira Gómez;Albert Serrà; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(46):2405204
Recent trends in addressing the impending water crisis focus on the development of innovative water treatment methods. This work utilizes pollen as a core template to synthesize highly efficient onion-like photocatalysts for pollutant mineralization. The study showcases a novel electrochemical synthesis method that maintains the structural integrity of pollen, resulting in increased surface area and enhanced photocatalytic activity. After 90-min of visible light irradiation, over 99% mineralization is achieved. These hybrid photocatalysts demonstrate exceptional stability and efficacy in degrading pollutants. The used photocatalysts can be recycled into biopellets with an ash content of less than 7% (weight), moisture content of less than 8% (weight), and a calorific value of ≈22.1 ± 0.3 MJ kg−1. Additionally, the resulting ashes serve as effective peroxymonosulphate activators for pollutant mineralization. This process offers sustainable waste management while minimizing waste production, providing a practical solution for water purification. The efficacy of this approach in pollutant removal is underscored by mineralization rates exceeding 99%. 相似文献
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采用铸造工艺制备了石墨烯纳米片(GNPs)增强的AZ91镁基复合材料,测试了复合材料的力学性能,并利用光学显微镜、X射线衍射仪、透射电子显微镜、扫描电子显微镜和能谱仪对复合材料的微观组织、界面结合和断口形貌进行了表征和分析,讨论了复合材料的强化机理。结果表明:石墨烯纳米片可有效细化镁基体的晶粒组织,在添加少量石墨烯纳米片时(0.1%),复合材料的屈服强度、延伸率和显微硬度分别为(164±5)MPa、(7.7±0.1)%和(74.2±2)HV,比基体分别提高了37.8%、13.2%和24.7%。GNPs与镁基体形成了强界面结合,这更有利于发挥应力转移强化、细晶强化等作用,提高镁合金强度、塑性等力学性能。 相似文献
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Artificial Photosynthesis: Ni‐Nanocluster Modified Black TiO2 with Dual Active Sites for Selective Photocatalytic CO2 Reduction (Small 2/2018) 下载免费PDF全文
下载免费PDF全文 Tadesse Billo Fang‐Yu Fu Putikam Raghunath Indrajit Shown Wei‐Fu Chen Hsiang‐Ting Lien Tzu‐Hsien Shen Jyh‐Fu Lee Ting‐Shan Chan Kuo‐You Huang Chih‐I Wu M. C. Lin Jih‐Shang Hwang Chih‐Hao Lee Li‐Chyong Chen Kuei‐Hsien Chen 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(2)
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Tadesse Billo Fang‐Yu Fu Putikam Raghunath Indrajit Shown Wei‐Fu Chen Hsiang‐Ting Lien Tzu‐Hsien Shen Jyh‐Fu Lee Ting‐Shan Chan Kuo‐You Huang Chih‐I Wu M. C. Lin Jih‐Shang Hwang Chih‐Hao Lee Li‐Chyong Chen Kuei‐Hsien Chen 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(2)
One of the key challenges in artificial photosynthesis is to design a photocatalyst that can bind and activate the CO2 molecule with the smallest possible activation energy and produce selective hydrocarbon products. In this contribution, a combined experimental and computational study on Ni‐nanocluster loaded black TiO2 (Ni/TiO2[Vo]) with built‐in dual active sites for selective photocatalytic CO2 conversion is reported. The findings reveal that the synergistic effects of deliberately induced Ni nanoclusters and oxygen vacancies provide (1) energetically stable CO2 binding sites with the lowest activation energy (0.08 eV), (2) highly reactive sites, (3) a fast electron transfer pathway, and (4) enhanced light harvesting by lowering the bandgap. The Ni/TiO2[Vo] photocatalyst has demonstrated highly selective and enhanced photocatalytic activity of more than 18 times higher solar fuel production than the commercial TiO2 (P‐25). An insight into the mechanisms of interfacial charge transfer and product formation is explored. 相似文献
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Mohammad Rahman Kenneth Davey Shi‐Zhang Qiao 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(23)
Blueshift of optical absorption and corresponding widening of the bandgap is a fundamental problem with 2D carbon nitride nanosheets (CNNS). An additional problem is low quantum yields (<9%) due to higher loss of absorbed photons. These problems impose a significant restriction to photocatalytic performance of CNNS. Therefore, the synthesis of narrow bandgap CNNS with high quantum efficiency is of pressing research importance. This contribution reports melem‐derived narrow bandgap CNNS with a record‐low bandgap of 2.45 eV. The narrowing in bandgap comes with improved optical absorption and use of visible‐light photons together with excellent charge transport dynamics. This is demonstrated by a record high hydrogen evolution rate of 863 µmol h?1 with apparent quantum efficiency of 16% at 420 nm. 相似文献
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纳米TiO2光催化材料的研究进展 总被引：8，自引：0，他引：8
根据近年来TiO2光催化技术的研究成果,对TiO2光催化剂的制备尤其是室温制备进行了详细地综述,并从粉体纳米化、可见光敏化及光催化性能的提高三个方面探讨了TiO2材料的研究发展趋势.最后对TiO2作为光触媒的发展及应用进行了展望. 相似文献
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Ming Li Ying Chen Wei Li Xiang Li He Tian Xiao Wei Zhaohui Ren Gaorong Han 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(16)
An ethanol solvothermal route has been developed to prepare ultrathin anatase TiO2 nanosheets with dominant {001} facets (≈97%), a thickness of ≈2.5 nm, and a side length of ≈200 nm. The introduction of ethanol solvent significantly enhances the content of surface chemisorbed F? on the TiO2 nanosheet, which has a higher stability and further lowers the surface energy of {001} facets, giving rise to the large percentage of active {001} facets. Adopting well‐defined morphology, such nanosheets loaded with 1 wt% Pt exhibit an H2 evolution rate as high as 17.86 mmol h?1 g?1, and the corresponding apparent quantum efficiency has been determined to be 34.2%. 相似文献
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Ning Liu Mengqi Tang Jinxing Wu Liang Tang Wenyuan Huang Qiutao Li Jianqiu Lei Xiaodong Zhang Liang Wang 《Advanced Materials Interfaces》2020,7(17)
Herein, a one‐step solvothermal method that shows incorporation of the graphene quantum dots (GQDs) on Fe‐based metal organic frameworks (MOFs) [MIL‐101(Fe)] to form GQD/MIL‐101(Fe) (G/M101) composites is reported. MIL‐101(Fe) with the sensitization of GQDs could significantly improve the photocatalytic reduction efficiency of CO2 to generate CO. The prepared composites exhibit excellent optical properties and the photocatalytic activity of G/M101 composites is relevant to GQDs ratio. The CO production rate over G/M101‐5% (224.71 µmol h−1 g−1) is 5 times higher than that of MIL‐101(Fe) (46.20 µmol h−1 g−1). The promising photocatalytic activity of G/M101‐5% strongly depends on the beneficial separation and transfer of photoinduced carriers via a charge migration between GQDs and MIL‐101(Fe). The microstructures and interfacial structures of the G/M101‐5% composite demonstrate that GQDs are closely loaded on the surface of MIL‐101 (Fe), and thus favors to the photoreduction according to their sp2 bonding. This work may figure a new way for the synthesis of photocatalysts for the application on carbon stabilization. 相似文献
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为探索超声辅助下利用紫外光及耦合热还原工艺制备RGO/纳米TiO_2复合材料的方法,并对其在缺氧水体中的光催化还原特性进行研究,首先,以鳞片石墨为原料,采用改进的Hummers法制备了氧化石墨烯(GO),进而通过超声/紫外光还原工艺制备了还原氧化石墨烯(RGO);然后,以钛酸丁脂和RGO为前驱物,采用溶胶-凝胶法并在氮气保护下高温加热制备了RGO/纳米TiO_2复合光催化材料;接着,利用FTIR、XRD、BET及紫外-可见光谱等对RGO/纳米TiO_2复合材料进行了结构性能表征;最后,以2,4-二氯苯氧乙酸(2,4-D)为探针物,研究了RGO/纳米TiO_2在缺氧水体中的光催化特性与2,4-D降解机制。结果表明:采用低温氧化Hummers法制备的GO六碳环上生成的活性基团较少,采用超声/紫外光还原工艺及耦合高温热还原工艺可使环状结构得到良好的修复;所制备的RGO/纳米TiO_2复合材料具有良好的2,4-D降解能力,在缺氧状态下,2,4-D主要发生光催化还原反应,脱除苯环上的氯,产生氯酚、邻苯三酚及间苯三酚等中间产物,部分2,4-D被氧化降解生成CO_2和H_2O。制备的RGO/纳米TiO_2复合材料具有良好的光催化还原性能。 相似文献
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用两步水热法合成了BiOCl-RGO复合材料。先在乙二醇和去离子水的混合溶液中合成直径约为400 nm、由纳米片构成的微球状单一BiOCl样品,在此基础上引入RGO载体制备出BiOCl-RGO纳米复合材料。使用Raman光谱、XRD、XPS等手段表征样品的物相构成,用SEM和TEM观测其微观形貌,通过降解甲基橙评定样品的光催化性能。结果表明,水热温度显著影响复合材料的光催化性能,在140℃制备的BiOCl和石墨烯结合的样品具有最高的光催化性能。 相似文献