Small
·
2023
·
IF 13.3
Kai Zhang,Cuiping Xu,Xingjian Zhang,Zhiyi Huang,Qixiang Pian,Kunhong Che,Xiaokun Cui,Yueru Hu,Yimin Xuan
The chemical inertness of CO 2 molecules makes their adsorption and activation on a catalyst surface one of the key challenges in recycling CO 2 into chemical fuels. However, the traditional template synthesis and chemical modification strategies used to tackle this problem face severe structural collapse and modifier deactivation issues during the often-needed post-processing procedure. Herein, a CO 2 self-selective hydrothermal growth strategy is proposed for the synthesis of CeO 2 octahedral nanocrystals that participate in strong physicochemical interactions with CO 2 molecules. The intense affinity for CO 2 molecules persists during successive high-temperature treatments required for Ni deposition. This demonstrates the excellent structural heredity of the CO 2 self-selective CeO 2 nanocrystals, which leads to an outstanding photothermal CH 4 productivity exceeding 9 mmol h -1 m cat -2 and an impressive selectivity of >99%. The excellent performance is correlated with the abundant oxygen vacancies and hydroxyl species on the CeO 2 surface, which create many frustrated Lewis-pair active sites, and the strong interaction between Ni and CeO 2 that promotes the dissociation of H 2 molecules and the spillover of H atoms, thereby greatly benefitting the photothermal CO 2 methanation reaction. This self-selective hydrothermal growth strategy represents a new pathway for the development of effective catalysts for targeted chemical reactions.
研究领域:
材料科学
·
催化化学
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2017
·Vol. 83
·期 2
·308-314
·
IF 1.575
Wang Li,Li Yanhong,Shi Min,Ma Wenle,Cui Hongtao
Abstract In this work, nanosphere-like and nanowire shaped CeO 2 nanocrystals were prepared at room temperature utilizing the epoxide precipitation reaction in aqueous and ethanolic solutions. It was found that the shape of CeO 2 nanocrystals depends on the reaction kinetics of epoxide in solution. The isotropic growth of nanocrystals in aqueous solution resulted in the formation of CeO 2 nanocrystals with sphere-like shape, while the anisotropic growth of nanocrystals in ethanolic solution led to the nanowire shape of CeO 2 nanocrystals. The anisotropic growth of nanocrystals was attributed to the high surface energy of their {110} facet induced from the active reaction of epoxide in ethanolic solution. The reaction kinetics of epoxide affected not only the size and crystallinity of CeO 2 nanocrystals, but also their shape. As a result, the produced CeO 2 nanocrystals had different electrochemical performance. As an electrode material for application in supercapacitor, the nanosphere-like CeO 2 nanocrystals presented better electrochemical performance and longer cycle life than the packed CeO 2 nanowires. Graphical Abstract Nanosphere-like and nanowire shaped CeO2 nanocrystals were prepared utilizing the epoxide precipitation reaction in aqueous and ethanolic solutions. It was found that the shape of CeO2 nanocrystals depends on the reaction kinetics of epoxide in solution. The isotropic growth of nanocrystals in aqueous solution produced CeO2 nanocrystals with sphere-like shape, while the anisotropic growth of nanocrystals in ethanolic solution produced nanowire shaped CeO 2 . As an electrode material for application in supercapacitor, the nanosphere-like CeO 2 nanocrystals presented better electrochemical performance and longer cycle life than the packed CeO 2 nanowires.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2022
·Vol. 24
·期 18
·3369-3379
·
IF 3.756
Yang Xu,Xiaodong Hao,Xishuo Zhang,Tong Wang,Zhuangzhuang Hu,Yujiao Chen,Xinyi Feng,Wen Liu,Fangyuan Hao,Xingang Kong,Chaozheng He,Shufang Ma,Bingshe Xu
Oxygen vacancy (VO) engineering has proved to be an effective approach for improving the hydrogen evolution reaction (HER) performance of low-cost metal oxide electrocatalysts. Cerium dioxide (CeO2), an abundant rare-earth metal oxide, is famous for its easy formation of VO and high oxygen mobility, which is believed to be conducive to its application in electrocatalytic HER. Herein, this study reports a facile modification strategy using rGO as a conductive support for CeO2 nanocrystals and introducing the transition metal Ni as the active dopant, resulting in the construction of the Ni–rGO/CeO2 electrocatalyst. It is found that rGO decoration prevents the aggregation of CeO2 NCs and increases the VO concentration in the CeO2 nanocrystals as well, while the introduced Ni leads to further formation of VO and serves as the active site for the HER reaction. Thus, the Ni–rGO/CeO2 electrocatalyst shows relatively low overpotential, a low Tafel slope, and great stability for HER, which is attributed to the synergistic effect of rGO decoration and Ni doping. This kind of facile strategy is promising for the design of noble-metal-free and low-cost electrocatalysts by the functional modification of CeO2-based nanocatalysts.
研究领域:
材料科学
·
电催化
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Xiaodong Hao,Tingting Wei,Qiheng Ma,Yuhao Zhou,Yang Yang,Yunxiang Jing,Xinyi Feng,Xishuo Zhang,Jin Zhang,Deqiang Yin,Zhen-Hong He,Shufang Ma,Bingshe Xu
The advancement of cost-effective and highly efficient electrocatalysts for hydrogen evolution is pivotal in fostering the progress of clean energy technologies. In this study, we present a reforming approach aimed at facile fabrication of the Cr-CeO2/rGO electrocatalyst. This involves incorporating a limited quantity of reduced graphene oxide (rGO) to serve as a conductive scaffold for CeO2 nanocrystals (NCs) while also introducing Cr, a transition metal, as an active dopant. It is found that the introduction of Cr and rGO induces charge transfer, leading to enhanced electrical conductivity and the creation of additional active sites on the nanocomposite surface. The synergy between rGO and CeO2, along with Cr doping in CeO2, significantly improves HER performance. The representative sample of the Cr(5%)-CeO2/rGO catalyst demonstrates a low overpotential of 83 mV at a current density of 10 mA cm–2, a low Tafel slope of 81 mV dec–1, and excellent stability under alkaline conditions. Significantly, this value of overpotential is reduced by 81 and 127 mV compared to those of the CeO2/rGO nanocomposites and the pristine CeO2 NCs. Theoretical density functional theory calculations additionally validate the phenomenon of charge transfer and improved HER properties, with Cr-CeO2 displaying a favorable Gibbs free energy (ΔGH*) for H* adsorption. This study offers novel insights into the design of precious metal electrocatalysts featuring functional interfaces and a wealth of active sites, holding great promise for industrial applications in clean energy conversion and storage.
研究领域:
材料科学
·
能源技术
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2020
·
IF 2.029
Jian Pan,Junchao Qian,Zhengying Wu,Chengbao Liu,Yiyang Liu,Yucheng Qian
The increasing demand for power storage device with high energy density forces the scientists to design new materials as electrodes. In this work, hollyhock stalks were converted into porous carbon host for growth of MnO and CeO 2 nanocrystals hydrothermally. The obtained biocarbon with macro-meso-micro porous structure provides excellent electron transport properties, while the nano-size MnO-CeO2 (<10 nm) on it grants high capacitance. Due to the unique nanostructure of carbon skeleton and ultra-large surface areas (514.4 m 2 g −1 ), the MnO-CeO 2 nanocrystals/porous carbon displays excellent electrochemical capacitance performance (162 F·g −1 at 0.5 A·g −1 ) and cycle stability. The specific capacity remains 99.3% efficiency after 1000 cycles at 500 mA·g −1 .
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
·
2015
·Vol. 32
·期 6
·652-660
·
IF 3.081
Zhi-Gang Wang,Wen-Zhi Bi,Shu-Cui Ma,Nan Lv,Ji-Lin Zhang,De-Hui Sun,Jia-Zuan Ni
CeO 2 nanocrystals (CN) with different morphologies (i.e., cube, octahedron, and rod) are prepared and the facet-dependent effect of these CeO 2 nanocrystals on the adsorption and dephosphorylation of phosphorylated molecules is investigated for the first time using the model p-nitrophenyl disodium orthophorphate (p-NPP). Due to their different surface atomic configurations, the {111} and {110} facets have much higher adsorption capacity and kinetic catalytic activities than {100} facets. All the CeO 2 nanocrystals can intensely promote the dephosphorylation reaction owing to the strong interaction between Ce cations and phosphoryl oxygens resulting in the cleavage of phosphoester bonds. As was expected, the above facet-dependent effect can be verified by the practical application results of the CeO 2 nanocrystals on the capture and dephosphorylation of phosphopeptides. Thus, surface engineering could be a useful and feasible strategy for not only fundamentally understanding the interaction between crystal facets and molecules but also effectively developing high-performance functional materials.
研究领域:
材料科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）