共查询到20条相似文献,搜索用时 11 毫秒
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Tongtong Liu Wenbin Gao Qiqi Wang Dr. Meiling Dou Dr. Zhengping Zhang Prof. Feng Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(46):20603-20607
High-performance electrocatalysts for the hydrogen evolution reaction (HER) have an important role to play in the development of renewable energy. Platinum remains the most efficient known HER electrocatalyst. Therefore, it is necessary to find ways to maximize Pt utilization in actual practical applications. Herein we demonstrate a facile strategy for synthesizing RuCeOx-supported, selectively loaded, atomic Pt (0.49 wt. %) (denoted Pt/RuCeOx-PA) by photoactivation at ambient temperature and pressure. Through the photoelectron transfer at the Mott-Schottky heterojunction in RuCeOx, Pt atoms became embedded into the RuO2 lattice. The resulting selectively loaded Pt-O-Ru moieties in Pt/RuCeOx-PA give a stronger hydrogen spillover effect than Pt complexes randomly loaded by either chemical activation or thermal activation. As a result, Pt/RuCeOx-PA shows superior HER performance to the materials prepared by random loading and is even better than a commercial Pt/C catalyst with much higher Pt loading (20 wt. %) at high current densities (from 50–600 mA cm−2). 相似文献
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Photocatalytic hydrogen production using stable metal-organic frameworks (MOFs), especially the titanium-based MOFs (Ti-MOFs) as photocatalysts is one of the most promising solutions to solve the energy crisis. However, due to the high reactivity and harsh synthetic conditions, only a limited number of Ti-MOFs have been reported so far. Herein, we synthesized a new amino-functionalized Ti-MOFs, named NH2-ZSTU-2 (ZSTU stands for Zhejiang Sci-Tech University), for photocatalytic hydrogen production under visible light irradiation. The NH2-ZSTU-2 was synthesized by a facile solvothermal method, composed of 2,4,6-tri(4-carboxyphenylphenyl)-aniline (NH2-BTB) triangular linker and infinite Ti-oxo chains. The structure and photoelectrochemical properties of NH2-ZSTU-2 were fully studied by powder X-ray diffraction, scanning electron microscope, nitro sorption isotherms, solid-state diffuse reflectance absorption spectra, and Mott–Schottky measurements, etc., which conclude that NH2-ZSTU-2 was favorable for photocatalytic hydrogen production. Benefitting from those structural features, NH2-ZSTU-2 showed steady hydrogen production rate under visible light irradiation with average photocatalytic H2 yields of 431.45 μmol·g−1·h−1 with triethanolamine and Pt as sacrificial agent and cocatalyst, respectively, which is almost 2.5 times higher than that of its counterpart ZSTU-2. The stability and proposed photocatalysis mechanism were also discussed. This work paves the way to design Ti-MOFs for photocatalysis. 相似文献
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《中国化学》2018,36(1):31-36
Using CuSO4 as the copper source, nanostructured copper with four different morphologies was obtained by electrodeposition method on FTO substrates. The as‐synthesized Cu/FTO samples were characterized by X‐ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), Raman, X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDS), and transmission electron microscopy (TEM). The effects of electrodeposition potential and electrodeposition time on the Cu/FTO samples and the photocatalytic performance were investigated systematically. The results showed that the Cu/FTO samples were well‐crystallized and the morphologies could be changed from nanoslices to nanodendrites structure with the negative shift of the depositing potential. The electrodeposition potential and time have a significant effect on the amount of H2 evolution. The obtained Cu nanospheres which were prepared at the potential of −0.65 V for 600 s showed the best photocatalytic behavior. The mechanisms for the photocatalytic activities were also discussed. 相似文献
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Dr. Anindya Roy Dr. Michael D. Vaughn Dr. John Tomlin Garrett J. Booher Dr. Gerdenis Kodis Chad R. Simmons Prof. James P. Allen Prof. Giovanna Ghirlanda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(28):6240-6246
Hybrid protein–organometallic catalysts are being explored for selective catalysis of a number of reactions, because they utilize the complementary strengths of proteins and of organometallic complex. Herein, we present an artificial hydrogenase, StrepH2, built by incorporating a biotinylated [Fe–Fe] hydrogenase organometallic mimic within streptavidin. This strategy takes advantage of the remarkable strength and specificity of biotin-streptavidin recognition, which drives quantitative incorporation of the biotinylated diironhexacarbonyl center into streptavidin, as confirmed by UV/Vis spectroscopy and X-ray crystallography. FTIR spectra of StrepH2 show characteristic peaks at shift values indicative of interactions between the catalyst and the protein scaffold. StrepH2 catalyzes proton reduction to hydrogen in aqueous media during photo- and electrocatalysis. Under photocatalytic conditions, the protein-embedded catalyst shows enhanced efficiency and prolonged activity compared to the isolated catalyst. Transient absorption spectroscopy data suggest a mechanism for the observed increase in activity underpinned by an observed longer lifetime for the catalytic species FeIFe0 when incorporated within streptavidin compared to the biotinylated catalyst in solution. 相似文献
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Shufang Ji Prof. Yang Qu Dr. Tao Wang Yuanjun Chen Prof. Guofeng Wang Xue Li Dr. Juncai Dong QiuYu Chen Wanying Zhang Zedong Zhang Shiyou Liang Prof. Rong Yu Dr. Yu Wang Prof. Dingsheng Wang Prof. Yadong Li 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(26):10738-10744
The solar-driven photocatalytic reduction of CO2 (CO2RR) into chemical fuels is a promising route to enrich energy supplies and mitigate CO2 emissions. However, low catalytic efficiency and poor selectivity, especially in a pure-water system, hinder the development of photocatalytic CO2RR owing to the lack of effective catalysts. Herein, we report a novel atom-confinement and coordination (ACC) strategy to achieve the synthesis of rare-earth single erbium (Er) atoms supported on carbon nitride nanotubes (Er1/CN-NT) with a tunable dispersion density of single atoms. Er1/CN-NT is a highly efficient and robust photocatalyst that exhibits outstanding CO2RR performance in a pure-water system. Experimental results and density functional theory calculations reveal the crucial role of single Er atoms in promoting photocatalytic CO2RR. 相似文献
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Bioinspired Hierarchical Nanotubular Titania Immobilized with Platinum Nanoparticles for Photocatalytic Hydrogen Production 下载免费PDF全文
Dr. Xiaoyan Liu Jiao Li Dr. Yiming Zhang Prof. Jianguo Huang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(20):7345-7349
A bioinspired nanocomposite composed of platinum nanoparticles and nanotubular titania was fabricated in which the titania matter was templated by natural cellulose substance. The composite possesses three‐ dimensional hierarchical structures, and ultrafine metallic platinum particles with sizes of ca. 2 nm were immobilized uniformly on the surfaces of the titania nanotubes. Such a nanocomposite with 1.06 wt % of platinum content shows the optimal photocatalytic hydrogen production activity from water splitting of 16.44 mmol h?1 g?1, and excessive loading of platinum results in poorer photocatalytic performance. The structural integrity of the nanocomposite upon cyclic water‐splitting processes results in its sufficient photocatalytic stability. 相似文献
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Shufang Ji Yang Qu Tao Wang Yuanjun Chen Guofeng Wang Xue Li Juncai Dong QiuYu Chen Wanying Zhang Zedong Zhang Shiyou Liang Rong Yu Yu Wang Dingsheng Wang Yadong Li 《Angewandte Chemie (International ed. in English)》2020,59(26):10651-10657
The solar‐driven photocatalytic reduction of CO2 (CO2RR) into chemical fuels is a promising route to enrich energy supplies and mitigate CO2 emissions. However, low catalytic efficiency and poor selectivity, especially in a pure‐water system, hinder the development of photocatalytic CO2RR owing to the lack of effective catalysts. Herein, we report a novel atom‐confinement and coordination (ACC) strategy to achieve the synthesis of rare‐earth single erbium (Er) atoms supported on carbon nitride nanotubes (Er1/CN‐NT) with a tunable dispersion density of single atoms. Er1/CN‐NT is a highly efficient and robust photocatalyst that exhibits outstanding CO2RR performance in a pure‐water system. Experimental results and density functional theory calculations reveal the crucial role of single Er atoms in promoting photocatalytic CO2RR. 相似文献
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石墨相氮化碳(g-C3N4)是一类非金属聚合物半导体材料, 具有良好的可见光响应、 优异的化学稳定性和可调节的能带结构, 在光催化分解水制氢、 空气净化、 环境修复等领域有着广阔的应用前景. 目前, g-C3N4光催化分解水的研究主要聚焦析氢半反应, 而牺牲试剂的氧化反应以及光生空穴则未被加以利用. 光催化苯甲醇氧化反应具有较高的选择性, 在光催化制氢的同时还能够获得苯甲醛. 我们结合最新国内外研究成果, 系统地综述了g-C3N4在光催化苯甲醇氧化耦合制氢方面的应用, 从分子改性、 显微结构及缺陷调控、 非金属元素掺杂、 金属负载和复合材料设计等5个方面介绍了g-C3N4光催化苯甲醇氧化提升性能的研究策略. 重点总结了g-C3N4的结构和光生载流子分离效率对催化性能的影响, 并对g-C3N4光催化苯甲醛氧化耦合制氢的后续发展进行了展望. 相似文献
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硫化氢(H2S)作为一种剧毒、恶臭的强腐蚀性气体,广泛来源于人类活动和自然界,对动植物生存和环境都具有较大的危害。光催化分解H2S制氢是一种理想的H2S处理技术,可以同时实现H2S的转移和清洁能源氢气的产生。近年来,金属硫化物由于其优异的可见光响应、恰当的能带结构和对H2S有高的稳定性,因此被广泛地应用于光催化分解H2S制氢。本文对近年来国内外金属硫化物驱动H2S资源化利用制氢领域取得的重要进展进行了概述和总结,探讨了不同反应媒介下光催化分解H2S制氢机制;特别关注了一些为实现高效稳定光催化H2S资源化利用制氢的优异调控策略;最后,对H2S资源化利用的挑战和前景进行了展望。 相似文献
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通过光还原沉积法, 利用氧空位诱导作用, 在Ni掺杂的缺陷态TiO2纳米管阵列(TNT-Ni)上得到金属 Pd含量不同的Pd-TNT-Ni催化剂. 采用场发射扫描电子显微镜(SEM)、 X射线光电子能谱(XPS)、 紫外-可见 漫反射(UV-Vis DRS)、 表面光电压(SPV)、 光致发光光谱(PL)和电化学测试等表征手段, 探究了Pd与Ni掺杂的缺陷态TiO2纳米管阵列之间的强相互作用对其光吸收特性和载流子分离及传输效率的影响, 阐明了强相互 作用对材料光催化活性的调控机理, 提出了Pd增强Pd-TNT-Ni光催化性能的作用机理. 结果表明, 通过光还 原法制备的Pd纳米颗粒尺寸为10~20 nm的Pd120-TNT-Ni样品的光响应值为4.22 mA/cm2, 是未负载Pd样品光 响应值(1.14 mA/cm2)的3.7倍, 其具有最佳的平均产氢速率(5.16 mmol·g?1·h?1), 是TNT样品平均产氢速率 (0.45 mmol·g?1·h?1)的12倍, 表明Pd与缺陷态TiO2纳米管阵列之间的强相互作用驱动了载流子的分离及传输, 且Pd作为电子捕获势阱及反应活性位点, 显著提高了材料的光催化性能. 相似文献
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Dr. Lan Hui Prof. Yurui Xue Huidi Yu Chao Zhang Prof. Bolong Huang Prof. Yuliang Li 《Chemphyschem》2020,21(19):2145-2149
Graphdiyne, as a magical support, can anchor zero valence metal atoms, providing us with an opportunity to develop emerging catalysts with the maximized active sites and selectivity. Herein we report high-performance atom catalysts (ACs), Cu0/GDY, by anchoring Cu atoms on graphdiyne (GDY) for hydrogen evolution reaction (HER). The activity and selectivity of this catalyst are obviously superior to that of commercial 20 wt.% Pt/C, and the turnover frequency of 30.52 s−1 is 18 times larger than 20 wt.% Pt/C. Density functional theory (DFT) calculations demonstrate that the strong p-d coupling induced charge compensation leads to the zero valence state of the atomic-scaled transition metal catalyst. Our results show the strong advantages of graphdiyne-anchored metal atom catalysts in the field of electrochemical catalysis and opens up a new direction in the field of electrocatalysis. 相似文献
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Boosting Photocatalytic Hydrogen Production of a Metal–Organic Framework Decorated with Platinum Nanoparticles: The Platinum Location Matters 下载免费PDF全文
Juan‐Ding Xiao Qichao Shang Prof. Dr. Yujie Xiong Prof. Dr. Qun Zhang Prof. Dr. Yi Luo Prof. Dr. Shu‐Hong Yu Prof. Dr. Hai‐Long Jiang 《Angewandte Chemie (International ed. in English)》2016,55(32):9389-9393
Improving the efficiency of electron–hole separation and charge‐carrier utilization plays a central role in photocatalysis. Herein, Pt nanoparticles of ca. 3 nm are incorporated inside or supported on a representative metal–organic framework (MOF), UiO‐66‐NH2, denoted as Pt@UiO‐66‐NH2 and Pt/UiO‐66‐NH2, respectively, for photocatalytic hydrogen production via water splitting. Compared with the pristine MOF, both Pt‐decorated MOF nanocomposites exhibit significantly improved yet distinctly different hydrogen‐production activities, highlighting that the photocatalytic efficiency strongly correlates with the Pt location relative to the MOF. The Pt@UiO‐66‐NH2 greatly shortens the electron‐transport distance, which favors the electron–hole separation and thereby yields much higher efficiency than Pt/UiO‐66‐NH2. The involved mechanism has been further unveiled by means of ultrafast transient absorption and photoluminescence spectroscopy. 相似文献
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Palladium versus Platinum: The Metal in the Catalytic Center of a Molecular Photocatalyst Determines the Mechanism of the Hydrogen Production with Visible Light 下载免费PDF全文
Michael G. Pfeffer Dr. Bernhard Schäfer Dr. Grigory Smolentsev Dr. Jens Uhlig Dr. Elena Nazarenko Dr. Julien Guthmuller Dr. Christian Kuhnt Dr. Maria Wächtler Prof. Dr. Benjamin Dietzek Prof. Dr. Villy Sundström Prof. Dr. Sven Rau 《Angewandte Chemie (International ed. in English)》2015,54(17):5044-5048
To develop highly efficient molecular photocatalysts for visible light‐driven hydrogen production, a thorough understanding of the photophysical and chemical processes in the photocatalyst is of vital importance. In this context, in situ X‐ray absorption spectroscopic (XAS) investigations show that the nature of the catalytically active metal center in a (N^N)MCl2 (M=Pd or Pt) coordination sphere has a significant impact on the mechanism of the hydrogen formation. Pd as the catalytic center showed a substantially altered chemical environment and a formation of metal colloids during catalysis, whereas no changes of the coordination sphere were observed for Pt as catalytic center. The high stability of the Pt center was confirmed by chloride addition and mercury poisoning experiments. Thus, for Pt a fundamentally different catalytic mechanism without the involvement of colloids is confirmed. 相似文献
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Yu Tao Jianping Guan Jian Zhang Shouyao Hu Runze Ma Huanran Zheng Jiaxin Gong Zechao Zhuang Shoujie Liu Honghui Ou Dingsheng Wang Yu Xiong 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(21):e202400625
Single-metal atomic sites and vacancies can accelerate the transfer of photogenerated electrons and enhance photocatalytic performance in photocatalysis. In this study, a series of nickel hydroxide nanoboards (Ni(OH)x NBs) with different loadings of single-atomic Ru sites (w-SA-Ru/Ni(OH)x) were synthesized via a photoreduction strategy. In such catalysts, single-atomic Ru sites are anchored to the vacancies surrounding the pits. Notably, the SA-Ru/Ni(OH)x with 0.60 wt % Ru loading (0.60-SA-Ru/Ni(OH)x) exhibits the highest catalytic performance (27.6 mmol g−1 h−1) during the photocatalytic reduction of CO2 (CO2RR). Either superfluous (0.64 wt %, 18.9 mmol g−1 h−1; 3.35 wt %, 9.4 mmol−1 h−1) or scarce (0.06 wt %, 15.8 mmol g−1 h−1; 0.29 wt %, 21.95 mmol g−1 h−1; 0.58 wt %, 23.4 mmol g−1 h−1) of Ru sites have negative effect on its catalytic properties. Density functional theory (DFT) calculations combined with experimental results revealed that CO2 can be adsorbed in the pits; single-atomic Ru sites can help with the conversion of as-adsorbed CO2 and lower the energy of *COOH formation accelerating the reaction; the excessive single-atomic Ru sites occupy vacancies that retard the completion of CO2RR. 相似文献
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对硫化镉反蛋白石结构光子晶体薄膜进行了可控合成,用巯基乙酸修饰的纳米晶和P(St-MMA-SPMAP)高分子小球共组装,成功地构筑了反蛋白石结构并用于可见光光解水产氢。结果表明,在可见光(λ≥420 nm)照射下,Cd S-310反蛋白石结构薄膜的光解水产氢性能比硫化镉纳米颗粒提高了一倍。这主要是因为等级孔结构反蛋白石光子晶体特性对催化剂的光催化性能的提升:首先,反蛋白石的周期性结构增加了光子在材料中的传播,提高了催化剂对太阳光的利用率;同时,大孔孔壁是由纳米颗粒堆积而成的,在反应中提供了更多的反应活性位点;此外,孔结构有利于物质的传输和分子的吸附。 相似文献
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Frontispiece: Palladium versus Platinum: The Metal in the Catalytic Center of a Molecular Photocatalyst Determines the Mechanism of the Hydrogen Production with Visible Light 下载免费PDF全文
Michael G. Pfeffer Dr. Bernhard Schäfer Dr. Grigory Smolentsev Dr. Jens Uhlig Dr. Elena Nazarenko Dr. Julien Guthmuller Dr. Christian Kuhnt Dr. Maria Wächtler Prof. Dr. Benjamin Dietzek Prof. Dr. Villy Sundström Prof. Dr. Sven Rau 《Angewandte Chemie (International ed. in English)》2015,54(17)
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采用高温熔盐法制备了Bi9P2O18Cl单晶。单晶X射线衍射分析表明Bi9P2O18Cl从室温到低温发生晶体到晶体的相变。室温下,该化合物(α相)属于单斜空间群P21/m(11),单胞参数:a=1.149 10(7) nm,b=0.540 64(4) nm,c=1.463 69(9) nm,β=93.741(6)°,V=0.907 38(10) nm3;而在100 K下,该化合物(β相)属于单斜空间群P21/n(14),单胞参数:a=1.790 56(4) nm,b=0.538 870(10) nm,c=1.915 57(4) nm,β=103.693(2)°,V=1.795 76(6) nm3。另外,采用高温固相反应法,合成了高纯的Bi9P2O18Cl粉末样品,该样品展示了较好的光催化产氢性能,产氢量可达33.69μmol·g-1·h-1。 相似文献