One-pot fabrication of a double Z-scheme CeCO<sub>3</sub>OH/g-C<sub>3</sub>N<sub>4</sub>/CeO<sub>2</sub> photocatalyst for nitrogen fixation under solar irradiation
作者:Xiangwen Feng、Huan Chen、Fang Jiang、Xin Wang
DOI:10.1039/c9cy00281b
日期:——
2Ce-CN) was synthesized by a facile in situ self-sacrificing hydrothermal method, using CeCl3 and graphitic carbon nitride (g-C3N4) as precursors. 2Ce-CN exhibited an enhanced nitrogen photofixation activity of approximately 1.16 mM g−1 h−1 without adding any sacrificial agent, which was four times higher than that of pristine g-C3N4. The nitrogen photofixation performance was attributed to a combination
甲CECO 3 OH / GC 3 Ñ 4 /的CeO 2的三元催化剂(以下简称为2CE-CN)通过一个浅显的合成原位自我牺牲水热法,使用加入CeCl 3和石墨氮化碳(GC 3 Ñ 4)作为前体。2Ce-CN在不添加任何牺牲剂的情况下显示出约1.16 mM g -1 h -1的增强的氮光固定活性,是原始gC 3 N 4的四倍。。氮的光固定性能归因于以下原因的组合。首先,氮在Ce 3+位点的化学吸附激活了N N键。其次,光生以CeO的导带(CB)的电子2转移到价带(VB)GC的3 Ñ 4,而在GC的CB电子3 Ñ 4转移到CECO的VB 3 OH,结果紧密接触化学结合的界面 该电子转移显示为双重Z方案机制。载流子复合率降低,在CeCO 3的CB中留下更多的电子OH将吸附的氮还原为氨。第三,CeO 2中Ce 4+和Ce 3+之间的化合价变化进一步促进了氮氢化反应。这种简单的自我牺牲方法为设计具有出色光催化活性的功能性gC
MnO<sub>x</sub>–CeO<sub>2</sub>@TiO<sub>2</sub> core–shell composites for low temperature SCR of NO<sub>x</sub>
Surface Science 2017, 416, 183–190). The incipient wetness impregnation method prepared samples also show better catalytic performance for CO oxidation than the samples prepared via deposition-precipitation method. Characterization results reveal that the small sizes as well as the oxidation states of the gold nanoparticles contribute to the higher activity than the deposition-precipitation samples. For
CeO 2的氧空位,高的储氧能力以及Ce 3+和Ce 4+之间的易交谈性使其在催化方面表现出出色的性能。氧化态。本文采用水热法制备了不同形貌的氧化铈纳米材料。发现通过初始湿润浸渍法制备的二氧化铈上的金颗粒比通过沉积-沉淀法制备的二氧化铈上的金颗粒更小且更均匀(Applied Surface Science 2017,416,183–190)。初湿含浸法制备的样品也比通过沉积-沉淀法制备的样品表现出更好的CO氧化催化性能。表征结果表明,金纳米颗粒的小尺寸以及其氧化态比沉积沉淀样品具有更高的活性。对于初湿浸渍样品,0.5%Au / CeO 2NT在70°C时可以达到100%CO转化,这表明活性和稳定性比0.5%Au / CeO 2棒和0.5%Au / CeO 2 NC更好。XPS结果表明,这是因为0.5%Au / CeO 2 NT的Ce 3+ / Ce 4+和Auδ + / Au 0高于0.5%Au
Porous CeO2 nanorod-catalyzed synthesis of poly-substituted imino-pyrrolidine-thiones
Porous CeO2 nanorod has been used as efficient and recyclable heterogeneous catalyst for the synthesis of highly functionalized imino-pyrrolidine-thiones via the reaction of aromatic aldehyde (especially one bearing an electron-donating group), malononitrile, isocyanide and unactivated weakly acidic heterocyclic thiophenol. The high catalytic efficiency of porous CeO2 nanorod in this reaction was discussed
Preparation of nanostructured CeCO3OH particles from aqueous solutions and gels containing biological polymers and their thermal conversion to CeO2
作者:Hiroaki Uchiyama、Reiko Sakaue、Hiromitsu Kozuka
DOI:10.1039/c3ra43580f
日期:——
Nanostructured CeCO3OH particles were prepared from aqueous solutions and gels containing CeCl3 and biological polymers (gelatin and agar) by the addition of (NH4)2CO3 solutions. The morphologies of the CeCO3OH products depended on the kind and concentration of the biological polymers. Sheaf- and cocoon-like CeCO3OH particles of ca. 2 μm in size consisting of fine particles of ca.10 nm in diameter were obtained from the precursor solutions containing gelatin. On the other hand, CeCO3OH precipitates with inhomogeneous size and shape were obtained from the precursor solutions and gels containing agar. Such morphological variation of CeCO3OH particles was thought to be due to the suppression of nucleation and growth of CeCO3OH crystals by the biological polymers. The CeCO3OH particles thus obtained were converted to CeO2 particles by the heat treatment at 600 °C, and the morphology as well as nanostructure remained during the heat treatment.