共查询到19条相似文献,搜索用时 125 毫秒
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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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以氧化石墨烯(GO)和钛酸四丁酯(Ti(OBu)4)作为初始反应物,采用乙醇溶剂热法合成了石墨烯/纳米TiO2复合材料,并利用XRD、FE-SEM、TEM、RAMAN和XPS等手段对石墨烯/纳米TiO2复合材料的晶体结构、形貌及元素形态等性质进行了表征,同时将复合材料应用于光催化降解甲基橙溶液,进行光催化性能评价。结果表明:Ti(OBu)4在乙醇溶剂中通过化学静电引力吸附到GO表面,经过溶剂热反应,GO被还原成石墨烯的同时,石墨烯的表面负载生长锐钛矿TiO2颗粒。随着溶剂热反应时间的延长,GO表面的活性基团减少,还原更加彻底,同时TiO2晶粒有一定的增大趋势;与纯TiO2相比,石墨烯/纳米TiO2复合材料光催化活性明显提高,石墨烯含量对复合材料的光催化活性有直接的影响。 相似文献
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近年来,石墨烯以其独特的结构和优异的性能成为材料科学领域备受关注的研究前沿和热点。由于石墨烯具有超高的载流子迁移率以及超大的比表面积,将石墨烯与传统的光催化材料复合可显著提高复合材料的光催化性能。综述了石墨烯/TiO2纳米复合材料的研究进展,重点阐述了石墨烯/TiO2纳米复合材料的制备方法及其在光催化领域中的应用,并指出石墨烯/TiO2纳米复合材料的光催化机理是今后研究的重点方向。 相似文献
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以氧化石墨烯(GO)、1, 12-二氨基十二烷(C12H28N2)、TiO2溶胶为原料,通过预插层-离子交换-煅烧法制备TiO2/石墨烯夹层结构纳米复合材料。采用XRD、Raman、FTIR、TEM、TG、UV-Vis和PL对TiO2/石墨烯夹层结构纳米复合材料进行表征,并研究不同TiO2含量的TiO2/石墨烯纳米复合材料对环丙沙星(CIP)的光催化降解性能。在煅烧过程中,TiO2的晶化和GO的还原同时进行。根据XRD和FTIR结果推断,TiO2纳米颗粒在石墨烯层间原位生成,并通过化学键固定在石墨烯上,形成了石墨烯/TiO2/石墨烯夹层结构。当TiO2的质量分数为65.5wt%时,TiO2/石墨烯复合材料表现出对环丙沙星最佳的光催化活性,150 min光照后降解率为90%高于纯TiO2 相似文献
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水热法一步合成ZnS/还原氧化石墨烯(ZnS/RGO)复合材料,通过XRD、FTIR、Raman、SEM分析溶剂(乙醇、水)对ZnS/RGO复合材料形貌和结构的影响。结果表明,以乙醇为溶剂制备的ZnS颗粒尺寸小、均匀分散在石墨烯片层上,在形成ZnS纳米颗粒的同时将氧化石墨烯(GO)还原成石墨烯。对亚甲基蓝(MB)的光催化结果显示,ZnS/RGO复合材料具有优异的光催化性能,其光催化速率是纯ZnS颗粒的3.7倍,石墨烯作为优良光生电子的传输通道和收集体能够降低光生电子-空穴对的重新结合率,极大提高了ZnS/RGO复合材料的光催化性能。 相似文献
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Rui-tang Guo Juan Wang Zhe-xu Bi Xin Chen Xing Hu Wei-guo Pan 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(9):2206314
Photocatalytic CO2 conversion into solar fuels is a promising technology to alleviate CO2 emissions and energy crises. The development of core-shell structured photocatalysts brings many benefits to the photocatalytic CO2 reduction process, such as high conversion efficiency, sufficient product selectivity, and endurable catalyst stability. Core-shell nanostructured materials with excellent physicochemical features take an irreplaceable position in the field of photocatalytic CO2 reduction. In this review, the recent development of core-shell materials applied for photocatalytic reduction of CO2 is introduced. First, the basic principle of photocatalytic CO2 reduction is introduced. In detail, the classification and synthesis techniques of core-shell catalysts are discussed. Furthermore, it is also emphasized that the excellent properties of the core-shell structure can greatly improve the activity, selectivity, and stability in the process of photocatalytic CO2 reduction. Hopefully, this paper can provide a favorable reference for the preparation of efficient photocatalysts for CO2 reduction. 相似文献
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TiO2/石墨烯复合材料的制备及其光催化性能 总被引:1,自引:0,他引:1
本文以氧化石墨烯和钛酸丁酯为原料,利用水热法一步制备了TiO2/石墨烯复合光催化材料,研究了氧化石墨烯用量、反应温度、反应时间对TiO2/石墨烯复合材料光催化活性的影响。采用XRD,SEM,TEM和氮气吸附-脱附实验(BET)对复合光催化材料的物相、颗粒粒径、形貌及比表面积进行了表征。结果表明,本实验最佳条件是:氧化石墨烯1mg,制备温度为180℃,反应时间为16 h。产物中的TiO2为锐钛矿晶型,其平均粒径约为18 nm。复合材料的比表面积为170m2/g,平均孔径为12.45 nm。在可见光照射(λ>420nm)下以TiO2/石墨烯为光催化剂对有机染料罗丹明B(Rhodamine B,RhB)进行光催化降解,其光催化活性明显高于相同条件下制备的TiO2。 相似文献
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Rui Zhai Lihui Zhang Mengyue Gu Xuewen Zhao Bo Zhang Yonghong Cheng Jinying Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(19):2207840
Effective photocatalytic carbon dioxide (CO2) reduction into high-value-added chemicals is promising to mitigate current energy crisis and global warming issues. Finding effective photocatalysts is crucial for photocatalytic CO2 reduction. Currently, metal-based semiconductors for photocatalytic CO2 reduction have been well reviewed, while review of nonmetal-based semiconductors is almost limited to carbon nitrides. Phosphorus is a promising nonmetal photocatalysts with various allotropes and tunable band gaps, which has been demonstrated to be promising non-metallic photocatalysts. However, no systematic review about phosphorus structures for photocatalytic CO2 reduction reactions has been reported. Herein, the progresses of phosphorus structures as photocatalysts for CO2 reduction are reviewed. The fundamentals of photocatalytic CO2 reduction, corresponding properties of phosphorus allotropes, photocatalysts with phosphorus doping or phosphorus-containing ligands, research progress of phosphorus allotropes as photocatalysts for CO2 reduction have been reviewed in this paper. The future research and perspective of phosphorus structures for photocatalytic CO2 reduction are also presented. 相似文献
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二氧化钛基纳米材料及其在清洁能源技术中的研究进展 总被引:2,自引:0,他引:2
二氧化钛纳米材料是当前纳米科技的研究热点,其在太阳能光催化分解水制氢、二氧化碳的光催化还原、染料敏化太阳能电池等清洁能源技术方面均显示了重大的应用前景.本文主要综述了近年来二氧化钛基纳米材料的研究趋势、存在的主要问题,以及这些材料在上述清洁能源利用中的最新进展.对备受关注的非金属掺杂、高能面暴露的二氧化钛、染料敏化太阳能电池阳极致密层等热点问题进行了评述和展望. 相似文献
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Tao Liu Anping Gu Tao Wei Mengwei Chen Xi Guo Shuai Tang Yihui Yuan Ning Wang 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(26):2208002
Uranium extraction from natural seawater is one of the most promising routes to address the shortage of uranium resources. By combination of ligand complexation and photocatalytic reduction, porous framework-based photocatalysts have been widely applied to uranium enrichment. However, their practical applicability is limited by poor photocatalytic activity and low adsorption capacity. Herein, atomically dispersed Cu implanted UiO-66-NH2 (Cu SA@UiO-66-NH2) photocatalysts are prepared via ligand-assistant iced photocatalytic reduction route. N—Cu–N moiety acts as an effective electron acceptor to potentially facilitate charge transfer kinetics. By contrast, there exist Cu sub-nanometer clusters by the typical liquid phase photoreduction, resulting in a relatively low photocatalytic activity. Cu SA@UiO-66-NH2 adsorbents exhibit superior antibacterial ability and improved photoreduction conversion of the adsorbed U(VI) to insoluble U(IV), leading to a high uranium sorption capacity of 9.16 mg-U/g-Ads from natural seawater. This study provides new insight for enhancing uranium uptake by designing SA-mediated MOF photocatalysts. 相似文献
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在恒定直流下,采用高纯石墨棒为原料,混合无机酸溶液为电解液,采用一步电化学剥离法制备石墨烯(G),所制备的G可稳定分散在N,N-二甲基甲酰胺(DMF)溶液中。以钛酸丁脂和G为前驱物,采用溶胶-凝胶法在N2氛围和高温加热下制备出G/nano TiO2复合光催化材料;利用XRD、FTIR、紫外-可见分光光度计(UV-Vis)、XPS、SEM和TEM等技术对G和G/nano TiO2复合材料进行了结构性能及微观形态表征。以3,5-二硝基水杨酸(DNS)为探针物,研究了在缺氧的水体中G/nano TiO2不同投加量的光催化效率与DNS降解机制。结果表明:采用恒压一步电化学剥离法所制备的G层与层之间剥离程度良好,片层通透性较高,六碳环上生成的含氧活性基团较少,G共轭π键结构保持良好;所制备的G/nano TiO2复合材料中TiO2结晶良好,颗粒紧密结合,且被固定在有褶皱的G上;降解实验发现,G/nano TiO2复合材料具有降解DNS良好性能,且投加量对其光催化活性有直接的影响;在缺氧状态下,DNS主要发生光催化还原反应,使苯环上的硝基还原成氨基,生成5-氨基水杨酸和苯三酚等中间产物,部分发生光催化氧化反应,生成CO2和H2O。 相似文献
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Wenda Hu Yuting Zhang Xin Zhang Lvzhuo Dong Sisi Wang 《Journal of Experimental Nanoscience》2016,11(6):433-444
This paper presents a novel visible-light photocatalyst, graphene-modified Ag2S (GR/Ag2S), prepared by a facile and effective hydrothermal method with AgNO3, thioacetamide and graphene oxide (GO) as the precursor. The catalytic activities of the GR/Ag2S hybrids with different GR content (2%, 4%, 6%) were evaluated by photocatalytic decolourisation of rhodamine B (RhB) solution under visible-light irradiation. The improved photocatalytic activity of GR/Ag2S composites compared with pure Ag2S is observed and attributed to the enhanced absorption of organic dyes and increased separation efficiency of photogenerated electron?hole pairs. The 4% GR/Ag2S sample exhibits the best photocatalytic activity than the others. 相似文献
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为探索用于染料废水处理的新型矿物材料光催化染料复合剂的合成和效果,采用硅藻土表面包覆TiO2,制备TiO2-硅藻土纳米复合光催化剂,研究不同TiO2包覆量、煅烧温度、干燥温度、催化剂用量因素对复合光催化剂降解次甲基蓝效果的影响。结果表明:复合光催化剂的最佳合成条件为:煅烧温度500℃,干燥温度70℃,TiO2包覆量为25%,复合光催化剂处理次甲基蓝用量1g/L。所制备纳米级TiO2-硅藻土纳米复合光催化剂对次甲基蓝的脱色率可达90%。 相似文献