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Recent advances in quantum dot catalysts for hydrogen evolution:Synthesis,characterization,and photocatalytic application 被引量:2
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作者 Haiwei Su Weikang Wang +5 位作者 Run Shi Hua Tang Lijuan Sun Lele Wang qinqin liu Tierui Zhang 《Carbon Energy》 SCIE EI CAS CSCD 2023年第9期1-37,共37页
Photocatalytic water splitting is beneficial for the effective mitigation of global energy and environmental crises.Owing to multi-exciton generation,impressive light harvesting,and excellent photochemical properties,... Photocatalytic water splitting is beneficial for the effective mitigation of global energy and environmental crises.Owing to multi-exciton generation,impressive light harvesting,and excellent photochemical properties,the quantum dot(QD)-based catalysts reveal a considerable potential in photocatalytic hydrogen(H_(2))production compared with bulk competitors.In this review,we summarize the recent advances in QDs for photocatalytic H_(2) production by enumerating different synthetic and characterization strategies for QDs.Various QDs-based photocatalysts are introduced and summarized in categories,and the role of different QDs in varied systems,as well as the mechanism and key factors that enhance the photocatalytic H_(2) generation performance,is discussed.Finally,conclusions and future perspectives in the exploration of highly efficient QDs-based photocatalysts for innovative applications are highlighted. 展开更多
关键词 CHARACTERIZATION functions of QDs hydrogen evolution reaction quantum dots SYNTHESIS
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纳米高熵合金实现光催化剂肖特基势垒的调控用于光催化制氢与苯甲醇氧化耦合反应
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作者 孙利娟 王伟康 +3 位作者 路平 刘芹芹 王乐乐 唐华 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第8期90-100,共11页
半导体表面修饰助催化剂可以降低界面反应势垒,提高界面反应速率.近期,含有至少五种主要元素且原子浓度为5%至35%的单相固溶体新型高熵合金(HEA)备受关注.与双金属或三金属纳米颗粒相比,HEA具有活性位点多、物理化学性质独特和热力学相... 半导体表面修饰助催化剂可以降低界面反应势垒,提高界面反应速率.近期,含有至少五种主要元素且原子浓度为5%至35%的单相固溶体新型高熵合金(HEA)备受关注.与双金属或三金属纳米颗粒相比,HEA具有活性位点多、物理化学性质独特和热力学相对稳定等优势.理论研究表明,HEA的多种金属元素能够各自发挥作用,并在协同效应下展现出较好的催化性能.此外,HEA可以缩短活性位点之间的距离,增加吸附能,优化产物结构.尽管HEA应用前景广阔,但以其作为助催化剂同时进行氢气生产和增值精细化学合成的双功能光催化剂鲜有报道.本文采用传统尿素热聚合法制备了g-C_(3)N_(4)纳米片,将其处理得到质子化的g-C_(3)N_(4)(HCN),同时采用低温油相合成法制备了直径为2 nm的Pt_(18)Ni_(26)Fe_(15)Co_(14)Cu_(27)(HEA)纳米颗粒,并通过静电自组装方法,构筑了2D/0D HCN/HEA复合光催化剂.采用透射电子显微镜与原子力显微镜等方法对催化剂结构进行表征,结果表明,HEA纳米颗粒与质子化的g-C_(3)N_(4)纳米片紧密结合.紫外可见漫反射光谱、紫外光电子能谱以及电化学表征结果表明,HEA与HCN之间形成肖特基结,有效地加速电荷迁移并减少载流子的复合.原位表面光电压成像结果表明,光生电子从HCN纳米片通过肖特基结转移到HEA助催化剂.电化学线性扫描伏安法与阻抗测试表明,HEA极大地降低了HCN的产氢过电势,有效地促进了界面产氢速率,同时HEA的引入提高了HCN催化剂的电子传导速率.通过调控HEA与HCN的负载比例,复合光催化剂实现了高效的光催化产氢与苯甲醇选择性氧化为苯甲醛的耦合反应.其中,最佳样品光催化产氢速率达到2.4 mmol g^(-1)h^(-1),苯甲醛产率达到5.44 mmol g^(-1)h^(-1),分别是纯HCN的958倍和6.6倍.综上,本文为合理设计高性能光催化剂实现高效氧化还原偶联反应提供参考. 展开更多
关键词 高熵合金 肖特基结 光催化析氢 苯甲醇氧化 异质结
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利用有机助剂提高TiO_2光催化产氢和降解性能(英文) 被引量:6
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作者 沈珺 王瑞 +3 位作者 刘芹芹 杨小飞 唐华 杨进 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第3期380-389,共10页
采用助催化剂加速光催化材料中空穴-电子对的分离提高光催化效率的有效方法.本文以有机分子草酰胺(OA)作为新型助催化剂来促进TiO2光催化材料的光生载流子分离,从而增强其光催化H2释放和染料降解性能.最佳TiO2-OA复合光催化剂上H2的析... 采用助催化剂加速光催化材料中空穴-电子对的分离提高光催化效率的有效方法.本文以有机分子草酰胺(OA)作为新型助催化剂来促进TiO2光催化材料的光生载流子分离,从而增强其光催化H2释放和染料降解性能.最佳TiO2-OA复合光催化剂上H2的析出和罗丹明B的光催化效率分别达到2371μmol g–1 h–1和1.43×10–2 min–1,分别是TiO2的2.4和3.8倍.系统研究了光催化增强的可能机理,并提出OA凭借其π-共轭结构作为助催化剂,不仅增强了TiO2的光吸收,而且促进了空穴转移,因而达到了加速电荷分离的效果.利用湿化学法合成了TiO2-OA光催化材料,并采用X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、红外光谱(FT-IR)以及紫外-可见漫反射光谱(UV-vis)等表征方法对该催化剂的结构特征、微观形貌和光学性能进行分析,并研究了TiO2-OA复合材料的光催化性能. SEM和TEM结果表明, TiO2-OA呈方形,尺寸约为30nm.OA含量为30wt%的TiO2-OA样品在用于制氢的光催化水分解反应中表现最佳.同时研究了TiO2-OA光催化剂的光催化机理,用对苯醌、乙二胺四乙酸二钠和正丁醇进行了自由基捕捉剂实验.结果表明,羟基自由基在降解有机染料过程中起主要作用.通过光电流测试、材料价带导带位置计算以及·O2和·OH定量实验并结合文献分析认为,掺入具有独特π-共轭结构的OA可以提供空穴转移位点,从而极大地促进TiO2和OA之间光生电子-空穴的分离和转移.本工作可能为构建具有新型有机助催化剂的高效光催化体系开辟了一条新途径. 展开更多
关键词 二氧化钛 草酰胺 助催化剂 光催化 制氢 染料降解
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热电子驱动氧化钨/石墨化氮化碳S-型异质结实现宽光谱光催化产氢活性 被引量:3
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作者 刘芹芹 何旭东 +3 位作者 彭进军 于晓慧 唐华 张军 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第9期1478-1487,共10页
近年来,等离子体材料因具有独特的局域表面等离子体共振(LSPR)效应,可实现可见光到近红外范围内光利用,因此引起人们的广泛关注.利用等离子体材料(贵金属或重掺杂半导体材料)合理构建异质结构,可以同时拓宽光催化剂的光谱响应范围,抑制... 近年来,等离子体材料因具有独特的局域表面等离子体共振(LSPR)效应,可实现可见光到近红外范围内光利用,因此引起人们的广泛关注.利用等离子体材料(贵金属或重掺杂半导体材料)合理构建异质结构,可以同时拓宽光催化剂的光谱响应范围,抑制载流子的复合,从而提高光催化活性.在已报道的等离子体半导体中,WO_(3‒x)具有无毒、价廉以及光谱响应宽等优异特性.本文通过将一维等离子体W_(18)O_(49)纳米线负载到2D g-C_(3)N_(4)纳米片上,构建了WO_(3‒x)/HCN S型异质结光催化剂.在可见光下光催化产氢活性测试中,纯相质子化氮化碳(HCN)的产氢活性相对较低,为259μmol·g^(−1)·h^(−1),而W_(18)O_(49)/HCN复合材料的产氢活性显著高于HCN,其中性能最优的W_(18)O_(49)/HCN复合材料产氢速率为892μmol·g^(−1)·h^(−1),约为HCN的3.4倍.在550 nm单色光照射下,W_(18)O_(49)/HCN复合材料的产氢速率仍有41.5μmol·g^(−1)·h^(−1),纯相HCN和W_(18)O_(49)均未有H2生成.在420,450,520 nm处测得的W_(18)O_(49)/HCN复合材料的表观量子效率分别为6.21%,1.28%和0.14%.W_(18)O_(49)纳米线起着扩展光吸附和热电子供体的双重作用,使WO_(3‒x)/g-C_(3)N_(4)具有宽光谱响应的光催化分解水活性.等离子体W_(18)O_(49)纳米线可以产生热电子,热电子转移到HCN的导带(CB),参与水还原反应,实现宽光谱的光催化产氢活性.利用固体紫外测试确定了W_(18)O_(49)/HCN复合材料能带结构,与传统的WO_(3)催化剂相比,W_(18)O_(49)在500‒1200 nm处表现出明显的尾部吸收,这是由于W_(18)O_(49)大量的氧空位引起的LSPR效应.而W_(18)O_(49)/HCN异质结具有比HCN更长的吸收边.通过第一原理密度泛函理论模拟计算了W_(18)O_(49)和HCN的功函数,分别为5.73和3.95 eV.因此,当HCN与W_(18)O_(49)结合形成紧密的界面时,电子会从做功函数小的HCN向做功函数大的W_(18)O_(49)移动,直至达到费米能级平衡,形成内建电场.此外,由于电子数量的减少,HCN的能带边缘向上弯曲,而由于电子的捕获,W_(18)O_(49)能带边缘向下弯曲,这种向上与向下的能带弯曲是S型结构的典型特征之一,这也与XPS测试结果相吻合.W_(18)O_(49)/HCN异质结内建电场驱动WO_(3–x)中导带(CB)的电子向g-C_(3)N_(4)的价带(VB)移动.在该设计中,效率低的电子和空穴被重新组合并排出,而具有高氧化还原能力的功能电子和空穴则被保留下来.不仅如此,S-scheme有望同时引导光生电子和热电子运动,从而避免逆电荷传递,有利于热电子的有效利用.W_(18)O_(49)和g-C_(3)N_(4)匹配的带隙所产生的S-scheme可以导致较强的氧化还原能力和较高的光诱导电荷迁移速率.对HCN与W_(18)O_(49)/HCN光电性能的测试结果表明,1D/2D W_(18)O_(49)/HCN异质结的构建可以充分改善光生电子-空穴对的分离和迁移,进而表现出更好的光催化活性.电子自旋共振结果也证实了W_(18)O_(49)/HCN中S型电荷转移机制. 展开更多
关键词 石墨化氮化碳 W18O49 S型异质结 光催化产氢 宽光谱
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可持续释放银离子和活性氧的ZnO/Ag/rGO三元新型光催化抗菌剂(英文) 被引量:10
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作者 吴赟炎 张莉莉 +4 位作者 周亚洲 李毅 刘芹芹 胡娟 杨娟 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第5期691-702,共12页
由于具有独特的物理与化学性质,银纳米粒子被广泛应用于传感器、电化学、光催化等多个领域.在生物领域,银纳米粒子可以通过释放银离子有效地解决细菌感染问题,但是其本身的毒性不可忽略.为了减小银纳米粒子的潜在毒性,迫切需要寻找一种... 由于具有独特的物理与化学性质,银纳米粒子被广泛应用于传感器、电化学、光催化等多个领域.在生物领域,银纳米粒子可以通过释放银离子有效地解决细菌感染问题,但是其本身的毒性不可忽略.为了减小银纳米粒子的潜在毒性,迫切需要寻找一种可持续释放银离子(Ag^+)的新型复合光催化抗菌剂.已有研究报道可将银纳米粒子负载在氧化铝、凝胶和二氧化硅上形成银基抗菌材料,但是大多数材料中银纳米颗粒尺寸较大,分布不均匀,且仅靠快速释放的银离子进行抗菌.本文通过一步溶剂热法制备了ZnO/Ag/rGO三元光催化抗菌剂,其中分别由银纳米粒子和氧化锌(ZnO)形成的银离子和活性氧(ROS)可对大肠杆菌和金黄色葡萄球菌产生协同抗菌作用.负载在还原氧化石墨烯(rGO)上的银纳米粒子持续释放出微量的银离子,后者通过库仑引力牢固地吸附在带负电荷的细菌细胞膜上,从而干扰细菌DNA合成,进而使细菌丧失分裂繁殖能力;与还原氧化石墨烯和银纳米粒子复合的氧化锌可以产生更多的O_2^(·–)和·OH等自由基,具有氧化能力的自由基可分解细菌细胞膜使细菌破裂死亡.银纳米粒子的表面等离子体共振效应不仅可以拓宽氧化锌半导体材料的光吸收范围,而且可以作为电子捕获阱捕获电子,加速光生电子与空穴的分离,有效抑制光生载流子的复合.与其他银基抗菌材料相比,该材料可以实现了30天低浓度银离子持续释放,并利用产生的活性氧和银离子稳定高效地进行抗菌.采用XRD,XPS,SEM,TEM,HRTEM,PL和ESR等表征方法分析了材料的结构、形貌、化学组成、元素价态及光学性质,并通过抑菌圈、最低抑菌浓度(MIC)和最低杀菌浓度(MBC)等性能测试比较了材料的抗菌性能.XRD和XPS结果证明银和氧化锌纳米粒子成功地负载在还原氧化石墨烯上.SEM,TEM和HRTEM分析发现还原氧化石墨烯上的银和氧化锌纳米粒子分布均匀,尺寸较小(5–10 nm).PL和ESR表征表明ZnO/Ag/rGO相比于ZnO/rGO和Ag/rGO有更好的载流子分离和自由基产生能力.因此,ZnO/Ag/rGO材料对大肠杆菌和金黄色葡萄球菌具有更低的最低抑菌浓度(MIC_(E.coli)=100×10^(-6)μg/mL,MIC_(S.aureus)=80×10^(-6)μg/mL)和最低杀菌浓度,该材料在抗菌领域具有潜在的应用前景. 展开更多
关键词 氧化锌 银纳米粒子 还原氧化石墨烯 银离子持续释放 协同抗菌机制 活性氧
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Co(Ⅱ)-空穴和Pt-电子助催化剂协同作用增强P掺杂g-C3N4光催化产氢性能(英文) 被引量:3
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作者 孙扣华 沈珺 +4 位作者 刘芹芹 唐华 张明义 Syed Zulfiqar 雷春生 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第1期72-81,共10页
石墨相氮化碳(g-C3N4)是一种新型的有机半导体材料,具有独特的层状结构、合适的能带位置、简单的制备方法以及出色的稳定性等特点,因而被广泛应用于光催化产氢领域.但是,较高的光生载流子的复合率和受限的迁移率大大地限制了g-C3N4的光... 石墨相氮化碳(g-C3N4)是一种新型的有机半导体材料,具有独特的层状结构、合适的能带位置、简单的制备方法以及出色的稳定性等特点,因而被广泛应用于光催化产氢领域.但是,较高的光生载流子的复合率和受限的迁移率大大地限制了g-C3N4的光催化产氢性能.目前,大量的研究证实块状g-C3N4的液相剥离、表面改性、元素掺杂、与其他半导体复合构筑异质结以及负载助催化剂等方法可以在一定程度上提高g-C3N4的光催化产氢性能.但是单一的g-C3N4改性方法往往并不能获得最理想的光催化产氢性能,因此,本文采用低温磷化法制备了二价钴(Co(II))修饰的磷(P)掺杂的g-C3N4纳米片(Co(II)/PCN),同时实现了掺杂P原子和负载空穴助催化剂Co(II),该催化剂表现出出色的光催化产氢性能.在光催化制氢过程中,铂(Pt)纳米颗粒作为电子助催化剂成功的负载在Co(II)/PCN上.光催化实验结果表明,最佳的Pt/Co(II)/PCN复合材料光催化产氢速率达到774μmol·g^?1·h^?1,比纯相的g-C3N4纳米片(89.2μmol·g^?1·h^?1)提升8.6倍.同时优化的光催化剂具有良好的光催化稳定性,并在402 nm处具有2.76%的量子产率.XRD,TEM,STEM-EDX和AFM结果证明,成功制备了纳米片状形貌的g-C3N4及其复合材料,催化剂中均匀的分布着Co和P元素.通过XPS证明了P-N的存在以及Co(II)的存在,并且Co(II)是以一种无定型的CoOOH的形式吸附在g-C3N4表面.光照后的TEM证明Pt颗粒成功的负载在Co(II)/PCN表面.UV-vis DRS表明,由于P的掺杂以及Co(II)的修饰,Co(II)/PCN相比于g-C3N4纳米片在可见光区域光吸收有了明显的增强.通过稳态和瞬态光致发光光谱分析,同时结合电化学分析表征(i-t、EIS)以及电子顺磁共振技术分析,证实了Co(II)/PCN高效光催化性能的原因可能是由于更高效的光生载流子分离效率.本文对Pt/Co(II)/PCN可能的光催化增强机理提出了设想.P的掺杂可以优化g-C3N4的电子结构,提高其光生载流子分离效率.而以Pt作为电子助催化剂,可以有效地捕获P掺杂的g-C3N4导带中的光生电子,进而发生水还原产氢反应;以Co(II)作为空穴助催化剂,可以捕获价带中的光生空穴,进而发生三乙醇胺氧化反应.通过采用不同功能的助催化剂,实现P掺杂g-C3N4光生电子空穴的定向分流,促进了P掺杂g-C3N4的光生载流子的分离,从而提高催化剂的光催化产氢性能.本文可以为设计具有空穴-电子双助催化剂的光催化产氢系统提供一个新的思路. 展开更多
关键词 光催化产氢 空穴助催化剂 电子助催化剂 磷掺杂氮化碳
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2D/0D氮化碳与MoS_2量子点直接Z型光催化剂的构筑及光催化性能(英文) 被引量:7
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作者 付彦惠 李治均 +2 位作者 刘芹芹 杨小飞 唐华 《Chinese Journal of Catalysis》 CSCD 北大核心 2017年第12期2160-2170,共11页
近年来,光催化技术作为一种"绿色"技术,在解决环境问题和能源危机等方面有着广泛的应用.新型可见光响应的半导体光催化材料g-C_3N_4具有二维(2D)纳米片结构,合适的禁带宽度(Eg=2.7 eV),优异的化学稳定性和低廉成本得到广泛的... 近年来,光催化技术作为一种"绿色"技术,在解决环境问题和能源危机等方面有着广泛的应用.新型可见光响应的半导体光催化材料g-C_3N_4具有二维(2D)纳米片结构,合适的禁带宽度(Eg=2.7 eV),优异的化学稳定性和低廉成本得到广泛的研究.但是,g-C_3N_4光催化剂本身的光生电子-空穴对复合几率高以及可见光响应范围窄等缺点,使其在光催化领域应用中具有一定的局限性.因此,提高g-C_3N_4半导体材料的光催化活性成为近年的研究热点.众所周知,Z型光催化体系的构筑不仅使材料具有较强的氧化还原能力而且有利于其光生电子-空穴的有效分离.但传统Z型光催化体系由于贵金属的引入、复杂的反应体系限制了其在实际领域中的应用.因此,构筑无电子介体的直接Z型光催化体系成为光催化领域的研究热点之一.与块状材料相比,零维(0D)量子点材料具有带隙可调性,可见光和近红外区域的强光收集能力等性能,在光催化领域具有广阔的应用前景.MoS_2量子点具有优异的光学和电子性能,因此,在催化、荧光检测、生物成像领域有重要的应用价值.我们结合水热和微乳溶液法合成了直接Z型g-C_3N_4/MoS_2 QDs(2D/0D)复合光催化材料,并采用X射线衍射(XRD)、X射线光电子能谱(XPS)、原子力显微镜(AFM),透射电子显微镜(TEM)以及紫外可见漫反射光谱(UV-vis)等表征方法对该催化剂的结构特征、微观形貌和光学性能进行分析.并研究了g-C_3N_4/MoS_2 QDs复合材料在可见光下的光催化性能.XRD,XPS结果表明,复合材料由g-C_3N_4,MoS_2组成.TEM和高斯分布结果表明,MoS_2 QDs具有良好的分散性,其尺寸小于5 nm,g-C_3N_4纳米片由具有皱纹和不规则折叠结构的薄层组成,在g-C_3N_4/MoS_2 QDs复合材料中可以看到少量的MoS_2量子点沉积在片状g-C_3N_4的表面上.光催化性能测试结果进一步表明,7%MoS_2 QDs/g-C_3N_4在可见光下具有优异的光催化性能:可见光照射12 min内,RhB的降解效率可达100%,降解速率常数是纯g-C_3N_4的8.8倍.为了进一步研究g-C_3N_4/MoS_2异质结光催化剂的光催化机理,用对苯醌、乙二胺四乙酸二钠和丁醇进行了自由基捕捉剂实验.结果表明,超氧自由基在降解有机染料过程中起主要作用,羟基自由基和空穴在增强的光催化性能中发挥相对较小的作用.通过光电流测试、材料价带导带位置计算以及·O_2^-和·OH定量实验结果并结合文献分析认为,MoS_2量子点和g-C_3N_4之间优良的界面接触以及由直接Z型结构产生的光生电荷载体的有效分离使其光催化性能得到显著提升. 展开更多
关键词 光催化 直接Z构型 二维 零维 g-C3N4 MoS2量子点
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二维/一维BiOBr_(0.5)Cl_(0.5)/WO_(3)S型异质结助力光催化CO_(2)还原 被引量:6
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作者 朱弼辰 洪小洋 +2 位作者 唐丽永 刘芹芹 唐华 《物理化学学报》 SCIE CAS CSCD 北大核心 2022年第7期45-55,共11页
S型异质结不但可以提高载流子的分离效率,还可以维持较强的氧化还原能力。因此,构建S型异质是提高光催化二氧化碳还原反应的有效途径。本研究通过静电自组装法构建了具有近红外光响应(>780 nm)的二维BiOBr_(0.5)Cl(0.5)纳米片和一维W... S型异质结不但可以提高载流子的分离效率,还可以维持较强的氧化还原能力。因此,构建S型异质是提高光催化二氧化碳还原反应的有效途径。本研究通过静电自组装法构建了具有近红外光响应(>780 nm)的二维BiOBr_(0.5)Cl(0.5)纳米片和一维WO_(3)纳米棒S型异质结光催化剂,并用于高效还原二氧化碳。能带位置和界面电子相互作用的综合分析表明:在光催化二氧化碳还原反应过程中,BiOBr_(0.5)Cl(0.5)/WO_(3)遵循S型电子转移路径;不仅提高了载流子的高效分离,还维持了两相(BiOBr_(0.5)Cl(0.5)和WO_(3))较高的氧化还原能力。此外,二维纳米片/一维纳米棒的结构使得半导体之间具备良好的界面接触,有利于载流子的分离,且暴露更多的活性位点,最终提高催化效率。结果显示,BiOBr_(0.5)Cl(0.5)/WO_(3)异质结催化剂表现出较高的CO_(2)还原能力和CO选择性,CO的产率高达16.68μmol∙g^(−1)∙h^(−1),分别是BiOBr_(0.5)Cl(0.5)的1.7倍和WO_(3)的9.8倍。本工作为构建S型二维/一维异质结光催化剂高效还原二氧化碳提供了新的思路。 展开更多
关键词 二维/一维异质结构 BiOBr_(0.5)Cl(0.5)纳米片 WO3纳米棒 二氧化碳还原 S型异质结
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利用掺杂诱导的金属-N活性位点和带隙调控提升石墨相氮化碳的光催化产氢性能 被引量:2
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作者 于晓慧 苏海伟 +3 位作者 邹建平 刘芹芹 王乐乐 唐华 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第2期421-432,共12页
由于石墨相氮化碳(g-C_(3)N_(4))的独特结构和性质,特别是其具有合适的能带结构位置及可调控的晶体结构,被广泛应用于光催化产氢反应中.然而,纯相氮化碳具有较快的光生电荷复合速率,这使其光催化产氢活性较低.目前,利用非金属或过渡金... 由于石墨相氮化碳(g-C_(3)N_(4))的独特结构和性质,特别是其具有合适的能带结构位置及可调控的晶体结构,被广泛应用于光催化产氢反应中.然而,纯相氮化碳具有较快的光生电荷复合速率,这使其光催化产氢活性较低.目前,利用非金属或过渡金属原子掺杂可有效提升电荷分离速度,从而提高光催化产氢活性.相比于非金属掺杂,g-C_(3)N_(4)的三嗪环中的吡啶氮可提供丰富的孤电子对,可将过渡金属离子留在框架结构中以形成金属-N键,在催化反应中充当活性位点.本文采用简单的热聚合方法将过渡金属原子(M=Fe,Co和Ni)掺杂在g-C_(3)N_(4)中,从而实现了g-C_(3)N_(4)的原子级结构的调控.结合X射线衍射仪技术、傅里叶变换红外吸收光谱仪、X射线光电子能谱分析、扫描电子显微镜和透射电子显微镜分析,结果表明,金属原子被成功引入g-C_(3)N_(4)中,且不破坏其原有结构,掺杂后的g-C_(3)N_(4)仍呈现片状形貌.结合XPS和DFT计算结果发现,掺杂的过渡金属原子会进入三嗪环中与周围N配位形成金属-N键;活性H原子会优先吸附于金属-N键上来参与水分解反应,证实了金属-N键为光催化产氢反应中的活性位点,并且过渡金属原子的掺杂有利于光催化反应进行.g-C_(3)N_(4)中的过渡金属原子掺杂导致活性H原子吸附能降低,使得光催化产氢反应更容易进行.此外,对光电流、阻抗、瞬态荧光光谱、固体紫外可见光谱和电子顺磁共振等测试结果表明,光生电子可沿着金属-N键迁移,从而加速了光生载流子的分离;过渡金属原子掺杂可减小g-C_(3)N_(4)的带隙并提升导带位置,从而促进了对光的吸收,提高还原能力.与纯相的g-C_(3)N_(4)相比,掺杂过渡金属原子的g-C_(3)N_(4)表现出更高的光催化产氢活性,其中,Co掺杂的样品呈现出最高的产氢活性.综上,本文研究结果表明过渡金属原子的掺杂可增强g-C_(3)N_(4)的光催化产氢性能,从而有助于开发出高效的光催化剂. 展开更多
关键词 石墨相氮化碳 光催化产氢 金属-N活性位点 过渡金属掺杂 带隙调控
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Band Engineering and Morphology Control of Oxygen‑Incorporated Graphitic Carbon Nitride Porous Nanosheets for Highly Efficient Photocatalytic Hydrogen Evolution 被引量:3
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作者 Yunyan Wu Pan Xiong +7 位作者 Jianchun Wu Zengliang Huang Jingwen Sun qinqin liu Xiaonong Cheng Juan Yang Junwu Zhu Yazhou Zhou 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第3期95-106,共12页
Graphitic carbon nitride(g-C3N4)-based photocatalysts have shown great potential in the splitting of water.However,the intrinsic drawbacks of g-C3N4,such as low surface area,poor diffusion,and charge separation effici... Graphitic carbon nitride(g-C3N4)-based photocatalysts have shown great potential in the splitting of water.However,the intrinsic drawbacks of g-C3N4,such as low surface area,poor diffusion,and charge separation efficiency,remain as the bottleneck to achieve highly efficient hydrogen evolution.Here,a hollow oxygen-incorporated g-C3N4 nanosheet(OCN)with an improved surface area of 148.5 m2 g^−1 is fabricated by the multiple thermal treatments under the N2/O2 atmosphere,wherein the C–O bonds are formed through two ways of physical adsorption and doping.The physical characterization and theoretical calculation indicate that the O-adsorption can promote the generation of defects,leading to the formation of hollow morphology,while the O-doping results in reduced band gap of g-C3N4.The optimized OCN shows an excellent photocatalytic hydrogen evolution activity of 3519.6μmol g^−1 h^−1 for~20 h,which is over four times higher than that of g-C3N4(850.1μmol g^−1 h^−1)and outperforms most of the reported g-C3N4 catalysts. 展开更多
关键词 Graphitic carbon nitride nanosheet Hollow morphology Oxygen incorporating Multiple thermal treatment Photocatalytic hydrogen evolution
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Unveiling the role of metallic CoP@Ni_(2)P sea-urchin-like nanojunction as a photothermal cocatalyst for enhancing the H_(2) generation and benzaldehyde formation over CdZnS nanoparticles
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作者 Fenghua Wang Jinhe Li +4 位作者 Xiaohui Yu Hua Tang Jing Xu Lijuan Sun qinqin liu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第15期49-60,共12页
Aiming to develop a photocatalyst that can simultaneously produce valuable chemicals and clean H_(2) fuel for promoting the utilization efficiency of solar energy,herein,a sea-urchin-like CoP@Ni_(2)P binary nanojuncti... Aiming to develop a photocatalyst that can simultaneously produce valuable chemicals and clean H_(2) fuel for promoting the utilization efficiency of solar energy,herein,a sea-urchin-like CoP@Ni_(2)P binary nanojunction was employed as an efficient photothermal cocatalyst to couple with zero-dimensional CdZnS(CZS)solid solution for achieving superior coordinative redox reaction.The CoP@Ni_(2)P/CZS hybrid displayed a high solar-driven H_(2) generation rate of 40.92 mmol g^(–1) h^(–1) coupling with a benzaldehyde formation rate of 20.33 mmol g^(–1) h^(–1),which was 16.4 and 8.0 times higher than that of bare CZS.Furthermore,the CoP@Ni_(2)P/CZS hybrid also achieved a high photothermal H_(2) production under a broad light range from 420 to 720 nm,and the H_(2) production reached 44.48μmol g^(–1) h^(–1) under the 720 nm light illumination.The enhanced catalytic performance can be ascribed to that the CoP@Ni_(2)P nanojunction with photothermal effect can speed up the separation and transport of carriers,offer more catalytic active sites,and induce an increase in temperature to optimize reaction kinetics.This study may open a facile route to design novel binary metal phosphides with dual functions in photocatalysis for the full exploitation of solar energy. 展开更多
关键词 H2 production Selective oxidation PHOTOTHERMAL CoP@Ni_(2)P cocatalyst CdZnS solid solution
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A retrospective study of patients complaining of nontraumatic acute abdominal pain,admitted in the emergency department of an urban hospital in China
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作者 Guanguan Luo qinqin liu +1 位作者 Zhongxiang Zhang Xiaoqing Jin 《Emergency and Critical Care Medicine》 2023年第4期149-155,共7页
Background:Nontraumatic acute abdominal pain(AAP)accounts for a large proportion of emergency department(ED)admissions.This study aimed to explore the underlying correlations among basic information,imaging examinatio... Background:Nontraumatic acute abdominal pain(AAP)accounts for a large proportion of emergency department(ED)admissions.This study aimed to explore the underlying correlations among basic information,imaging examinations,and diagnoses.Methods:A total of 7453 patients complaining of AAP,admitted to the ED of Zhongnan Hospital of Wuhan University,were enrolled in this retrospective study from January 1 to December 30,2019.We collected the following information from the patients:sex,age,date of visit,pain location,nature of pain,level of severity,imaging(computed tomography,x-ray,and ultrasound),diagnosis,and outcomes(re-lease from the hospital,transfer to another hospital,transfer to another department,observation room,hospitalization,or death).Results:According to this study,AAP was more common in female than male.A total of 82.11%patients of AAP were in level 3 of se-verity,while 0.19%patients were in level 1.A total of 77.20%of the patients had undergone imaging.Swelling pain and colic are the 2 most common types of AAP.Nonspecific abdominal pain(NSAP)is the most common diagnosis.In the diagnosis of NSAP and gastroenteritis,female patients were more prevalent than male patients,but for renal colic,male patients were 3 times as many as female patients.Non-specific abdominal pain,biliary colic,and cholecystitis are the 3 leading causes in patients 65 years or older.Nonspecific abdominal pain,renal colic,and gastroenteritis are the 3 leading causes of AAP in patients younger than 65 years.Conclusion:With the help of imaging,clinicians can specify a diagnosis and perform corresponding treatment in most cases.However,making a precise diagnosis of AAP within a short period is still challenging.Further research should be conducted to seek safer and more effective techniques to streamline clinicians’work. 展开更多
关键词 Abdominal pain DIAGNOSIS Emergency department EPIDEMIOLOGY GASTROENTEROLOGY
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Supramolecular precursor strategy for the synthesis of holey graphitic carbon nitride nanotubes with enhanced photocatalytic hydrogen evolution performance 被引量:15
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作者 Xiaoshuai Wang Chao Zhou +5 位作者 Run Shi qinqin liu Geoffrey I. N. Waterhouse Lizhu Wu Chen-Ho Tung Tierui Zhang 《Nano Research》 SCIE EI CAS CSCD 2019年第9期2385-2389,共5页
A simple one-step thermal polymerization method was developed for synthesis of holey graphitic carbon nitride nanotubes,involving direci eating of mixtures of melamine and urea or melamine and cyanuric acid in specifi... A simple one-step thermal polymerization method was developed for synthesis of holey graphitic carbon nitride nanotubes,involving direci eating of mixtures of melamine and urea or melamine and cyanuric acid in specific mass ratios.Supramolecular structures formed betweer the precursor molecules guided nanotube formation.The porous and nanotubular structure of the nanotubes facilitated efficient charge carrier nigration and separation,thereby enhancing photocatalytic Hz production in 20 vol.%lactic acid under visible light irradiation.Nanotubes synthesized using melamine and urea in a 1:10 mass ratio(denoted herein as CN-MU nanotubes)exhibited a photocatalytic hydroger production rate of 1,073.6μmol·h^-1·^-g with Pt as the cocatalyst,a rate of 4.7 and 3.1 times higher than traditional Pt/g-CN4 photocatalysts prepared from graphitic carbon nitride(g-CN4)obtained by direct thermal polymerization of melamine or urea,respectively.On the basis of their outstanding performance for photocatalytic H2 production,it is envisaged that the holey g-C3N4 nanotubes will find widespread uptake in other areas,including photocatalytic CO2 reduction,dye-sensitized solar cells and photoelectrochemical sensors. 展开更多
关键词 graphitic CARBON NITRIDE holey NANO TUBES PHOTOCATALYSIS VISIBLE-LIGHT response hydroge n evolution
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Removal of trimethoprim and sulfamethoxazole in artificial composite soil treatment systems and diversity of microbial communities 被引量:2
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作者 qinqin liu Miao Li +7 位作者 Rui liu Quan Zhang Di Wu Danni Zhu Xuhui Shen Chuanping Feng Fawang Zhang Xiang liu 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2019年第2期147-156,共10页
Four artificial composite soil treatment systems(ACSTs)fed with reclaimed water containing trimethoprim(TMP)and sulfamethoxazole(SMX)were constructed to investigate SMX and TMP biodegradation efficiency,ammonia and ni... Four artificial composite soil treatment systems(ACSTs)fed with reclaimed water containing trimethoprim(TMP)and sulfamethoxazole(SMX)were constructed to investigate SMX and TMP biodegradation efficiency,ammonia and nitrite removal conditions and the microbial community within ACST layers.Results showed SMX and TMP removal rates could reach 80% and 95%,respectively,and removal rates of ammonia and nitrite could reach 80% and 90%,respectively,in ACSTs.The MiSeq sequencing results showed that microbial community structures of the ACSTs were similar.The dominant microbial community in the adsorption and biodegradation layers of the ACSTs contained Proteobacteria,Chloroflexi,Acidobacteria,Firmicutes,Actinobacteria and Nitrospirae.Firmicutes and Proteobacteria were considerably dominant in the ACST biodegradation layers.The entire experimental results indicated that Nitrosomonadaceae_uncultured,Nitrospira and Bacillus were associated with nitrification processes,while Bacillus and Lactococcus were associated with SMX and TMP removal processes.The findings suggest that ACSTs are appropriate for engineering applications. 展开更多
关键词 TRIMETHOPRIM SULFAMETHOXAZOLE Reclaimed water BIODEGRADATION AEROBIC NITRIFICATION Microbial community
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Efficient photocatalytic hydrogen evolution coupled with benzaldehyde production over 0D Cd_(0.5)Zn_(0.5)S/2D Ti_(3)C2 Schottky heterojunction 被引量:2
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作者 Junnan TAO Mingyuan WANG +5 位作者 Guiwu liu qinqin liu Lei LU Neng WAN Hua TANG Guanjun QIAO 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2022年第7期1117-1130,共14页
Converting water into hydrogen fuel and oxidizing benzyl alcohol to benzaldehyde simultaneously under visible light illumination is of great significance,but the fast recombination of photogenerated carriers in photoc... Converting water into hydrogen fuel and oxidizing benzyl alcohol to benzaldehyde simultaneously under visible light illumination is of great significance,but the fast recombination of photogenerated carriers in photocatalysts seriously decreases the conversion efficiency.Herein,a novel dual-functional 0D Cd_(0.5)Zn_(0.5)S/2D Ti_(3)C2 hybrid was fabricated by a solvothermally in-situ generated assembling method.The Cd_(0.5)Zn_(0.5)S nano-spheres with a fluffy surface completely and uniformly covered the ultrathin Ti_(3)C2 nanosheets,leading to the increased Schottky barrier(SB)sites due to a large contact area,which could accelerate the electron–hole separation and improve the light utilization.The optimized Cd_(0.5)Zn_(0.5)S/Ti_(3)C2 hybrid simultaneously presents a hydrogen evolution rate of 5.3 mmol/(g·h)and a benzaldehyde production rate of 29.3 mmol/(g·h),which are~3.2 and 2 times higher than those of pristine Cd_(0.5)Zn_(0.5)S,respectively.Both the multiple experimental measurements and the density functional theory(DFT)calculations further demonstrate the tight connection between Cd_(0.5)Zn_(0.5)S and Ti_(3)C2,formation of Schottky junction,and efficient photogenerated electron–hole separation.This paper suggests a dual-functional composite catalyst for photocatalytic hydrogen evolution and benzaldehyde production,and provides a new strategy for preventing the photogenerated electrons and holes from recombining by constructing a 0D/2D heterojunction with increased SB sites. 展开更多
关键词 Cd_(0.5)Zn_(0.5)S Ti_(3)C2 photocatalysis hydrogen BENZALDEHYDE Schottky heterojunction
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Construction 0D TiO_(2) nanoparticles/2D CoP nanosheets heterojunctions for enhanced photocatalytic H_(2) evolution activity 被引量:2
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作者 qinqin liu Jinxin Huang +2 位作者 Hua Tang Xiaohui Yu Jun Shen 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2020年第21期196-205,共10页
It is still of gigantic challenging to design and to optimize photocatalytic systems with cost-efficiency for photocatalytic hydrogen evolution from water splitting.Herein,noble-metal-free 2D CoP nanosheets were prepa... It is still of gigantic challenging to design and to optimize photocatalytic systems with cost-efficiency for photocatalytic hydrogen evolution from water splitting.Herein,noble-metal-free 2D CoP nanosheets were prepared by a phosphorization method using Co(OH)2 nanosheets as precursors,and then employed as photocatalytic cocatalyst and template to make 0D Ti O2 nanoparticles in-situ grow on the surface for construction of 0D/2D TiO_(2)/CoP hybrid by a simple hydrothermal method.The TiO2/CoP hybrid with the optimal ratio of CoP cocatalyst(1 wt.%)manifested significantly improved photocatalytic H_(2) evolution rate of 0.604 mmol g^(-1) h^(-1),which is tenfold in comparison to pure TiO2(0.06 mmol g^(-1) h^(-1).The mechanism of performance enhancement was fully investigated and supposed that 2D CoP nanosheets cocatalyst can enhance the photo-absorption and provide more active sites for water reduction reaction;furthermore,2D CoP nanosheets with smaller work function and high conductivity would form an Ohmicjunction with TiO_(2) nanoparticles,which can significantly accelerate the separation of photo-generated charge carriers and improve the exploitation of the photoexcited electrons in water redox reaction.This work is anticipated to impel more perspicacity into synthesizing innovative photocatalytic systems with 2D transition metal phosphides cocatalysts for attaining high photocatalytic H_(2) evolving pursuit. 展开更多
关键词 Photocatalytic H_(2)evolution CoP nanosheets TiO_(2) 0D/2D heterojunction
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Simultaneous Photocatalytic Oxygen Production and Hexavalent Chromium Reduction in Ag_(3)PO_(4)/C_(3)N_(4)S-scheme Heterojunction 被引量:1
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作者 Tao Yang Pengke Deng +3 位作者 Lele Wang Jie Hu qinqin liu Hua Tang 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2022年第6期23-30,共8页
The low separation/migration efficiency is a major obstacle that limits the practical application of semiconductor-photocatalysts. Constructing S-scheme heterojunction is an ideal strategy for providing high photocata... The low separation/migration efficiency is a major obstacle that limits the practical application of semiconductor-photocatalysts. Constructing S-scheme heterojunction is an ideal strategy for providing high photocatalytic activity via accelerating charge separation. Herein, an AgPO/CNcomposite was synthesized by coupling AgPOparticle with CNhollow spheres in-situ via a precipitation method. The S-scheme hete-rojunction between AgPOand CNcould accelerate the charge separation and retain high photoredox ability, which synchronously realized high photocatalytic oxygen production and hexavalent chromium reduction. The optimized Ag3PO4/CNcomposite shows a high oxygen production rate up to 803.31 μmol·g·hand a high conversion(87.9%) of Cr(Ⅵ) to Cr(Ⅲ). In addition, CNhollow spheres affords higher reaction efficiency than that of CNtube, CNbulk and CNsheet, which indicates that the hollow sphere structure can provide more active sites and adsorption sites in the photocatalytic process. This work offers an effective way in developing a dual-function S-scheme heterojunction for clean energy production and environmental protection. 展开更多
关键词 S-scheme charge transfer route Ag_(3)PO_(4)/C_(3)N_(4) Cr(Ⅵ)reduction O_(2)production photocatalysis
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The removal of trimethoprim and sulfamethoxazole by a high infiltration rate artificial composite soil treatment system 被引量:3
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作者 qinqin liu Miao Li +3 位作者 Fawang Zhang Hechun Yu Quan Zhang Xiang liu 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2017年第2期133-142,共10页
Sulfamethoxzole (SMX) and trimethoprim (TMP), two combined-using sulfonamide antibiotics, have gained increasing attention in the surface water, groundwater and the drinking water because of the ecological risk. T... Sulfamethoxzole (SMX) and trimethoprim (TMP), two combined-using sulfonamide antibiotics, have gained increasing attention in the surface water, groundwater and the drinking water because of the ecological risk. The removal of TMP and SMX by artificial composite soil treatment system (ACST) with different infiltration rates was systematically investigated using K+, Na+, Ca2+, Mg2+ hydrogeochemical indexes. Batch experiments showed that the sorption onto the low-cost and commercially available clay ceramsites was effective for the removal of SMX and TMP from water. The column with more silty clay at high infiltration rate (1.394 m·d^-1) had removal rates of 80% to 90% for TMP and 60% to 70% for SMX. High SMX and TMP removal rates had a higher effluent concentration of K+, Ca2+ and Mg2+ and had a lower effluent Na+ concentration. Removal was strongly related to sorption. The results showed that the removal of SMX and TMP was related to hydrogeochemical processes. In this study, ACST is determined to be applicable to the drinking water plants. 展开更多
关键词 TnmethoprimSulfamethoxazoleArtificial composite soil treatmentHydrogeochemical processesIon exchange
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Removal of sulfamethoxazole and trimethoprim from reclaimed water and the biodegradation mechanism 被引量:2
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作者 qinqin liu Miao Li +7 位作者 Xiang liu Quan Zhang Rui liu Zhenglu Wang Xueting Shi Jin Quan Xuhui Shen Fawang Zhang 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2018年第6期61-68,共8页
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Interlinking climate change with waterenergy-food nexus and related ecosystem processes in California case studies
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作者 qinqin liu 《Ecological Processes》 SCIE EI 2016年第1期166-179,共14页
Global climate change creates critical challenges with increasing temperature,reducing snowpack,and changing precipitation for water,energy,and food,as well as ecosystem processes at regional scales.Ecosystem services... Global climate change creates critical challenges with increasing temperature,reducing snowpack,and changing precipitation for water,energy,and food,as well as ecosystem processes at regional scales.Ecosystem services provide life support,goods,and natural resources from water,energy,and food,as well as the environments.There are knowledge gaps from the lack of conceptual framework and practices to interlink major climate change drivers of water resources with water-energy-food nexus and related ecosystem processes.This paper provided an overview of research background,developed a conceptual framework to bridge these knowledge gaps,summarized California case studies for practices in cross sector ecosystem services,and identified future research needs.In this conceptual framework,climate change drivers of changing temperature,snowpack,and precipitation are interlinked with life cycles in water,energy,food,and related key elements in ecosystem processes.Case studies in California indicated climate change affected variation in increasing temperature and changing hydrology at the regional scales.A large variation in average energy intensity values was also estimated from ground water and federal,state,and local water supplies both within each hydrological region and among the ten hydrological regions in California.The increased regional temperature,changes in snowpack and precipitation,and increased water stresses from drought can reduce ecosystem services and affect the water and energy nexus and agricultural food production,as well as fish and wildlife habitats in the Sacramento-San Joaquin Delta(Delta)and Central Valley watersheds.Regional decisions and practices in integrated management of water,energy,food,and related ecosystem processes are essential to adapt and mitigate global climate change impacts at the regional scales.Science and policy support for interdisciplinary research are critical to develop the database and tools for comprehensive analysis to fill knowledge gaps and address ecosystem service complexity,the related natural resource investment,and integrated planning needs. 展开更多
关键词 Ecosystem services ECOSYSTEM Climate change Water Energy Food and environments Agricultural practices Ecosystem processes Sustainable natural resource Integrated resource management California Interdisciplinary research
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