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三维有序多孔g-c_(3)n_(4)-cu_(2)O-TiO_(2)异质结的光催化性能

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Science china Materials 2022年第1期65卷 139-146页

作者：陈犇余婧汪锐张祥功贺贝贝金俊王欢文公衍生 Faculty of Materials Science and chemistry China University of GeosciencesWuhan 430074China Wuhan Institute of Marine Electric Propulsion China Shipbuilding Industry CorporationWuhan 430064China

本文通过模板法与光沉积法成功制备了具有三维有序多孔结构的g-c_(3)n_(4)-cu_(2)O-TiO_(2)光催化剂,并详细研究了特殊多孔结构对原制备样品光催化性能的影响.与原有的光催化剂相比,多孔结构的g-c_(3)n_(4)-cu_(2)O-TiO_(2)具有更高的... 详细信息

本文通过模板法与光沉积法成功制备了具有三维有序多孔结构的g-c_(3)n_(4)-cu_(2)O-TiO_(2)光催化剂,并详细研究了特殊多孔结构对原制备样品光催化性能的影响.与原有的光催化剂相比,多孔结构的g-c_(3)n_(4)-cu_(2)O-TiO_(2)具有更高的比表面积和更多的活性位点,从而加速了光生电子-空穴的分离效率.因而,该光催化剂表现出良好的光催化性能,最大产氢率可达12,108μmol g^(-1) h^(-1),是原始对比样品产氢率的5倍左右.g-c_(3)n_(4)-cu_(2)O-TiO_(2)对于光催化性能的增强可归因于其双p-n异质结和稳健的多孔结构.光沉积cu_(2)O在光催化过程中起协同催化作用,外层包覆的g-c3n4层保护cu_(2)O以防止催化剂氧化.此外,本文探究了该催化剂的光催化机理.本工作为开发具有高效光催化活性的低成本异质结光催化剂开辟了新途径.

关键词：光沉积光催化剂多孔结构光催化机理异质结 c3n4 产氢率分离效率

Enhancing both selectivity and coking-resistance of a single-atom Pd1/c3n4 catalyst for acetylene hydrogenation

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nano Research 2017年第4期10卷 1302-1312页

作者： Xiaohui Huang Yujia Xia Yuanjie cao Xusheng Zheng Haibin Pan Junfa Zhu chao Ma Hengwei Wang Junjie Li Rui You Shiqiang Wei Weixin Huang Junling Lu Department of chemical Physics iChEM CAS Key Laboratory of Materials for Energy Conversion University of Science and Technology of China Hefei 230026 China national Synchrotron Radiation Laboratory University of Science and Technology of China Hefei 230029 China Hefei national Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Hefei 230026 China

Selective hydrogenation is an important industrial catalytic process in chemical upgrading, where Pd-based catalysts are widely used because of their high hydrogenation activities. However, poor selectivity and short catalyst lifetime because of heavy coke formation have been major concerns. In this work, atomically dispersed Pd atoms were successfully synthesized on graphitic carbon nitride （g-c3n4） using atomic layer deposition. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy （HAADF-STEM） confirmed the dominant presence of isolated Pd atoms without Pd nanoparticle （nP） formation. During selective hydrogenation of acetylene in excess ethylene, the g-c3n4-supported Pd nP catalysts had strikingly higher ethylene selectivities than the conventional Pd/Al2O3 and Pd/SiO2 catalysts. In-situ X-ray photoemission spectroscopy revealed that the considerable charge transfer from the Pd nPs to g-c3n4 likely plays an important role in the catalytic performance enhancement. More impressively, the single-atom Pd1/c3n4 catalyst exhibited both higher ethylene selectivity and higher coking resistance. Our work demonstrates that the single-atom Pd catalyst is a promising candidate for improving both selectivity and coking-resistance in hydrogenation reactions.

关键词： single-atom catalyst Pd catalyst atomic layer deposition acetylene hydrogenation c3n4 selectivity coke formation support effect

Phase Transition of Graphitic-c3n4 under High Pressure by In Situ Resistance Measurement in a Diamond Anvil cell

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chinese Physics Letters 2005年第6期22卷 1347-1349页

作者：韩永昊骆继锋高春晓马红安郝爱民李延春李晓东刘景李明刘洪武邹广田 StateKeyLaboratoryforSuperhardMaterials InstituteofAtomicandMolecularPhysicsJilinUniversityChangchun130012 BeijingSynchrotronRadiationLaboratory InstituteofHighEnergyPhysicsChineseAcademyofSciencesBeijing100039

In situ resistance measurement of Graphitic-c3n4 has been performed under high pressure in a diamond anvil cell. The result reveals that there are changes of electron transport behaviour. As the pressure increases from ambient to 30GPa, three abnormal resistance changes can be found at room temperature and two are found at 77K. The abnormal resistance dropped at 5GPa is close to the phase transition pressure from the Pm2 structure to the p structure predicted by Lowther et al. [Phys. Rev. B 59 (1999) 11683] Another abnormal change of resistance at 12GPa is related to the phase transition from g-c3n4 to cubic-c3n4 [Teter and Hemley, Science 271 (1996) 53].

关键词： DAc c3n4

Structure and electronic structure of S-doped graphitic c_3n_4 investigated by density functional theory

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chinese Physics B 2012年第10期21卷 380-386页

作者：陈刚高尚鹏 Department of Materials Science Fudan University School of Physical Science and Technology Yunnan University

The structures of the heptazine-based graphitic c3n4 and the S-doped graphitic c3n4 are investigated by using the density functional theory with a semi-empirical dispersion correction for the weak long-range interaction between layers.The corrugated structure is found to be energetically favorable for both the pure and the S-doped graphitic c3n4.The S doptant is prone to substitute the n atom bonded with only two nearest c atoms.The band structure calculation reveals that this kind of S doping causes a favorable red shift of the light absorption threshold and can improve the electroconductibility and the photocatalytic activity of the graphitic c3n4.

关键词： photocatalyst c3n4 density functional theory dopant

n和F共掺杂c_(3)n_(4)的制备及其可见光催化性能

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无机化学学报 2022年第10期38卷 2047-2055页

作者：薛彪傅炀杰谭盟张超李宁毅杨凌轩郑淑贞王齐浙江工商大学环境科学与工程学院杭州310018

针对氮化碳(c_(3)n_(4))光生电荷易复合、光催化性能有限的不足,我们制备n和F共掺杂c_(3)n_(4)(nF⁃c_(3)n_(4)),以提升其光催化性能。利用nH_(4)F在高温下原位分解产生的HF和nH_(3),对c_(3)n_(4)刻蚀的同时实现n和F双元素共掺杂。以氯化... 详细信息

针对氮化碳(c_(3)n_(4))光生电荷易复合、光催化性能有限的不足,我们制备n和F共掺杂c_(3)n_(4)(nF⁃c_(3)n_(4)),以提升其光催化性能。利用nH_(4)F在高温下原位分解产生的HF和nH_(3),对c_(3)n_(4)刻蚀的同时实现n和F双元素共掺杂。以氯化铵(nH_(4)cl)为对照,制备n掺杂c_(3)n_(4)(n⁃c_(3)n_(4))。利用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线光电子能谱(XPS)、X射线衍射(XRD)、比表面积测试和电化学表征手段研究n、F共掺杂对c_(3)n_(4)形貌、成分、结构和物化性质等的影响规律。相比于c_(3)n_(4)和n⁃c_(3)n_(4),nF⁃c_(3)n_(4)呈多孔状,比表面积增大,光生电荷的生成、分离和转移均被促进,nF⁃c_(3)n_(4)光催化还原cr(Ⅵ)的速率是c_(3)n_(4)的2.6倍、n⁃c_(3)n_(4)的1.7倍。进一步考察了不同前驱体(尿素、双氰胺和三聚氰胺)对制备c_(3)n_(4)的影响,发现以尿素为前驱体的c_(3)n_(4)与nH_(4)F的质量比为3∶2时,nF⁃c_(3)n_(4)呈现最佳的光催化性能。催化剂用量、光照强度、空穴捕获剂浓度的增加和pH的降低均能提高cr(Ⅵ)还原速率。在nF⁃c_(3)n_(4)浓度为0.1 g·L^(-1)、pH=3、c_(EDTA⁃2na)=2 mmol·L^(-1)、40 min可见光照射后,cr(Ⅵ)去除率达到90%。5次循环实验表明,优化制备的nF⁃c_(3)n_(4)光催化还原cr(Ⅵ)的性能保持良好,具有较高的稳定性。

关键词：光催化 c3n4 cr(Ⅵ)还原 n、F共掺杂

c3n4对水中重金属离子的吸附去除及其活化PMS作用

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C3N4对水中重金属离子的吸附去除及其活化PMS作用

作者：郭荣南昌航空大学

学位级别：硕士

人类长期高强度的生产活动干扰了各种元素的生物地球化学循环,造成了水体有机污染、重金属污染、化肥和农药污染等,严重危害水环境安全和人体健康。工业废水中重金属的吸附去除和有机污染物减排是解决上述问题最有效的策略,也是保障重... 详细信息

人类长期高强度的生产活动干扰了各种元素的生物地球化学循环,造成了水体有机污染、重金属污染、化肥和农药污染等,严重危害水环境安全和人体健康。工业废水中重金属的吸附去除和有机污染物减排是解决上述问题最有效的策略,也是保障重金属资源可持续利用的国家重大需求。然而,工业废水中重金属离子种类及含量各异,吸附材料对不同离子的吸附容量差异较大,重金属回收后利用方式单一,使重金属吸附减排技术推广困难。因此,综合考虑吸附材料的制备及其吸附容量形成的关键因素,本文以成本低廉的无机非金属材料g-cn为研究对象,开展其对重金属吸附去除的提效及耦合高级氧化技术去除废水中有机污染物的研究,以期为进一步削减废水中的重金属和有机污染物存量,开拓重金属吸附材料的新用途提供理论依据和技术支撑。(1)本文首先以单氰胺、双氰胺、三聚氰胺、硫脲、尿素等五种富氮化合物为前驱体,通过热处理制备cn材料,研究其对水中Mn,Pb和cu的吸附性能,开展g-cn吸附去除水中重金属离子的成本效益核算。结果表明,以三聚氰胺和尿素为前驱体制备的M-cn和U-cn材料具有优良的重金属离子吸附效果和较低的制备成本,其对重金属离子的吸附过程与普通g-cn材料相同,符合拟一级动力学模型,以物理吸附为主。(2)为了进一步提升g-cn对重金属离子的吸附性能,继续选择以三聚氰胺为前驱体,以na cl为硬模板制备多孔g-cn,探讨盐模板法对g-cn的改性作用及其影响因素。结果表明,盐模板合成法制备的g-cn(S-cn)对Pb的吸附能力大幅提升,吸附过程与Langmuir等温吸附模型相符,为单层吸附,理论最大吸附容量为362.62 mg/g,与实验结果基本一致。继续对吸附动力学数据进行模型拟合,发现S-cn对Pb的吸附更符合准二级动力学模型,属于化学吸附。通过g-cn和S-cn吸附Pb前后的SEM和TEM分析,可以看出S-cn和Pb-cn比g-cn拥有更丰富的微孔,且在吸附过程中存在质子交换现象。因此,盐模板法制备的S-cn可改变g-cn固有的平面周期性及其结构,使cn暴露出更多的基团,有利于吸附作用。(3)基于“以废治废”的理念,在成功制备具有高效吸附重金属离子能力的S-cn基础上,研究S-cn对高价值金属钴离子的吸附及其回收利用于活化过硫酸钾(PMS)降解酚类污染物的能力。通过控制吸附过程中cn对co的吸附量,对比研究不同co负载量S-cn(co-cn)活化过硫酸钾降解对氯苯酚(4-cP)的效果。结果表明,S-cn吸附的co越多,活化PMS的能力越强,对4-cP的降解效果越好。水中共存物质对降解效果有不同的影响,其中腐殖酸(HA)和cl明显抑制4-cP的降解,cO和nO也有轻微的抑制作用,这主要是由于阴离子和有机质与4-cP之间共同竞争氧化活性物种所致。然而,HPO却能在一定程度上促进降解作用,可能是因为磷酸盐和钴之间形成六种特异性配位结构,从而促进了co/co还原过程中的电子转移。微酸和中性条件更有利于反应进行,在p H=5和7时,4-cP仅在1 min内便被完全去除,说明co-cn活化PMS的p H适用范围具有很强的实际应用潜力。此外,该p H条件可避免co泄漏。催化氧化机理研究表明,硫酸根自由基和单线态氧在降解中起重要作用。综上所述,本文基于绿色制造理念,选择低成本高效益的富氮前驱体合成g-cn并对其进行盐模板改性,充分提升其重金属离子吸附性能;在g-cn吸附具有催化效应的高价值金属后,将其用于激活过硫酸盐产生硫酸根自由基降解难处理有机污染物,为吸附剂与吸附质的资源化回收利用提供一种新的思路。

关键词： c3n4 重金属离子交换过硫酸盐活化酚类污染物

2020 Roadmap on two-dimensional nanomaterials for environmental catalysis

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chinese chemical Letters 2019年第12期30卷 2065-2088页

作者： Yulu Yang Mingguang Wu Xingwang Zhu Hui Xu Si Ma Yongfeng Zhi Hong Xia Xiaoming Liu Jun Pan Jie-Yinn Tang Siang-Piao chai Leonardo Palmisano Francesco Parrino Junli Liu Jianzhong Ma Ze-Lin Wang Ling Tan Yu-Fei Zhao Yu-Fei Song Pardeep Singh Pankaj Raizada Deli Jiang Di Li R.A.Geioushy Jizhen Ma Jintao Zhang Song Hu Rongjuan Feng Gang Liu Minghua Liu Zhenhua Li Mingfei Shao neng Li Jiahe Peng Wee-Jun Ong nikolay Kornienko Zhenyu Xing Xiujun Fan Jianmin Ma School of Physics and Electronics Hunan UniversityChangsha 410082China School of the Environment and Safety Engineering Institute for Energy ResearchJiangsu UniversityZhenjiang 212013China college of chemistry Jilin UniversityChangchun 130012China State Key Laboratory on Integrated Optoelectronics College of Electronic Science and TechnologyJilin UniversityChangchun 130012China Key Laboratory for Powder Metallurgy Central South UniversityChangsha 410083China Multidisciplinary Platform of Advanced Engineering Chemical Engineering DisciplineSchool of EngineeringMonash UniversityJalan Lagoon SelatanBandar SunwaySelangor 47500Malaysia University of Palermo Department of EngineeringPalermo 90128Italy University of Trento Department of Industrial EngineeringTrento 38123Italy School of Materials Science and Engineering Shaanxi University of Science&TechnologyXi'an 710021China college of Bioresources chemistry and Materials Engineering Shaanxi University of Science&TechnologyXi'an 710021China State Key Laboratory of chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China School of chemistry Faculty of Basic SciencesShoolini UniversitySolanHP 173229India Himalayan centre for Excellence in nanotechnology Shoolini UniversitySolanmHP 173229India School of chemistry and chemical Engineering Jiangsu UniversityZhenjiang 212013China Institute for Energy Research Jiangsu UniversityZhenjiang 212013China nanomaterials and nanotechnology Department Advanced Materials DivisionCentral Metallurgical R&D Institute(CMRDI)Cairo 11421Egypt Key Laboratory for colloid and Interface chemistry Ministry of EducationSchool of Chemistry and Chemical Engineering Shandong UniversityJi'nan 250100China national Laboratory for Molecular Science(BnLMS) CAS Laboratory of ColloidInterface and Chemical ThermodynamicsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China cAS Key Laboratory of nanosystem and Hierarchical Fabrication CAS Center for Excellence i

Environmental catalysis has drawn a great deal ofattention due to its clean ways to produce useful chemicals or carry out some chemical processes.Photocatalysis and electrocatalysis play important roles in these fields.They can decompose and remove organic pollutants from the aqueous environment,and prepare some fine chemicals.Moreover,they also can carry out some important reactions,such as 02 reduction reaction(ORR),O2 evolution reaction(OER),H2 evolution reaction(HER),cO2 reduction reaction(c02 RR),and n2 fixation(nRR).For catalytic reactions,it is the key to develop high-performance catalysts to meet the demand fortargeted reactions.In recentyears,two-dimensional(2 D) materials have attracted great interest in environmental catalysis due to their unique layered structures,which offer us to make use of their electronic and structural characteristics.Great progress has been made so far,including graphene,black phosphorus,oxides,layered double hydroxides(LDHs),chalcogenides,bismuth-based layered compounds,MXenes,metal organic frameworks(MOFs),covalent organic frameworks(cOFs),and others.This content drives us to invite many famous groups in these fields to write the roadmap on two-dimensional nanomaterials for environmental catalysis.We hope that this roadmap can give the useful guidance to researchers in future researches,and provide the research directions.

关键词： Two-dimensional materials Graphene Black phosphorus c3n4 Metal organic frameworks MXenes

novel BiVO4@c3n4@GO composites with Higher Photocatalytic Performance

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china Petroleum Processing & Petrochemical Technology 2019年第2期21卷 50-57页

作者： Liu Yanxiu Guo Zhi Wang Lijuan Lyu Wenxue Song Hua Wang Xueqin Provincial Key Laboratory of Oil & Gas chemical Technology College of Chemistry & Chemical Engineering Northeast Petroleum University Daqing 163318 Shuntian chemical Group Linyi 2076001 Postdoctoral center of northeast Petroleum Univerxity Daqing 163318 Daqing chemical Research center of Petrochemical Research Institute Daqing 163714 Daqing Petroleum chemical Engineering company Daqing 163714

BiVO4, BiVO4@c3n4 and BiVO4@c3n4@GO composite photo-catalysts were synthesized, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), Fourier transform infrared spectroscopy (FT-IR), and Brunauer-Emmett-Teller (BET) surface area techniques. The photocatalytic activity was evaluated on the degradation of methylene blue (MB) under visible light irradiation, which denoted that the BiVO4@c3n4@GO ternary composite outperformed the binary composite BiVO4@c3n4 and BiVO4. Then the effects of catalyst dosage, initial pH value, and initial methylene blue concentration on the degradation process were investigated systematically. The improvement of visible-light photocatalytic degradation performance was attributed to the enhanced visible light absorption, larger surface area, higher adsorption ability, and prolonged lifetime of photo-generated electron-hole pairs. The recycle experiments results showed that the BiVO4@c3n4@GO composite had excellent photo-stability for MB photocatalytic degradation.

关键词： BiVO4 c3n4 graphene oxide visible light photocatalyst

Synthesis of mesoporous polymeric carbon nitride exhibiting enhanced and durable visible light photocatalytic performance

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chinese Science Bulletin 2014年第7期59卷 688-698页

作者： Fan Dong Yuhan Li Wingkei Ho Haidong Zhang Min Fu Zhongbiao Wu chongqing Key Laboratory of catalysis and Functional Organic Molecules College of Environmental and Biological Engineering Chongqing Technology and Business University Department of Science and Environmental Studies The Hong Kong Institute of Education Department of Environmental Engineering Zhejiang University

A thiourea precursor was employed to synthesize mesoporous carbon nitride(c3 n4) by a thermal polycondensation process with high surface area SiO2 and nanosphere SiO2 as two types of hard templates. The resultant mesoporous c3 n4 samples have high surface areas(105–112 m2/g) and mesopores with narrow sizes distribution(9.3 nm). Photocatalytic performance was evaluated by removal of nO in air under visible light irradiation. The results showed that mesoporous c3 n4 samples exhibited significantly improved photocatalytic activity in comparison with bulk c3 n4, which also exceeded that of n-doped TiO2 and c-doped TiO2. The activity enhancement can be ascribed to the synergistic effects of large surface area and pore volume, enhanced light-harvesting ability, increased redox potential, and reduced recombination of charge carriers. In addition to the high activity, the mesoporous c3 n4 samples also showed high photochemical stability. The mesoporous c3 n4 photocatalysts with enhanced and durable activity could provide a new efficient material for environmental pollution control.

关键词：光催化性能氮化碳介孔高分子高比表面积光催化活性 c3n4 耐用