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Jeong ES, Hwang IH, Han SW. Dispersion and stability mechanism of Pt nanoparticles on transition-metal oxides. Sci Rep 2022; 12:13652. [PMID: 35953693 PMCID: PMC9372059 DOI: 10.1038/s41598-022-17638-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 07/28/2022] [Indexed: 11/09/2022] Open
Abstract
The heterogeneous catalysts of Pt/transition-metal oxides are typically synthesized through calcination at 500 °C, and Pt nanoparticles are uniformly and highly dispersed when hydrogen peroxide (H2O2) is applied before calcination. The influence of H2O2 on the dispersion and the stability of Pt nanoparticles on titania-incorporated fumed silica (Pt/Ti-FS) supports was examined using X-ray absorption fine structure (XAFS) measurements at the Pt L3 and Ti K edges as well as density functional theory (DFT) calculations. The local structural and chemical properties around Pt and Ti atoms of Pt/Ti-FS with and without H2O2 treatment were monitored using in-situ XAFS during heating from room temperature to 500 °C. XAFS revealed that the Pt nanoparticles of H2O2-Pt/Ti-FS are highly stable and that the Ti atoms of H2O2-Pt/Ti-FS support form into a distorted-anatase TiO2. DFT calculations showed that Pt atoms bond more stably to oxidized-TiO2 surfaces than they do to bare- and reduced-TiO2 surfaces. XAFS measurements and DFT calculations clarified that the presence of extra oxygen atoms due to the H2O2 treatment plays a critical role in the strong bonding of Pt atoms to TiO2 surfaces.
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Affiliation(s)
- Eun-Suk Jeong
- Department of Physics Education and Institute of Fusion Science, Jeonbuk National University, Jeonju, 54896, Korea
| | - In-Hui Hwang
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Sang-Wook Han
- Department of Physics Education and Institute of Fusion Science, Jeonbuk National University, Jeonju, 54896, Korea.
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Mao Z, Chen J, Wang Y, Xia J, Zhang Y, Zhang W, Zhu H, Hu X, Chen H. Copper metal organic framework as natural oxidase mimic for effective killing of Gram-negative and Gram-positive bacteria. NANOSCALE 2022; 14:9474-9484. [PMID: 35748350 DOI: 10.1039/d2nr01673g] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Nanozymes have been widely studied as substitutes for natural enzymes. However, the delicacy of their structures and their unclear catalytic sites make it difficult to maintain their structural robustness and catalytic durability. By mimicking active catalytic sites of natural enzymes and combining them with distinct channels of metal organic frameworks (MOFs), an active copper mimetic oxidase enzyme (Cu-MOF) was designed and synthesized with good structure and clear catalytic sites for improvement in catalytic activity. The Cu-MOFs showed excellent oxidase-like activity with a low Km of 1.09 mM and exogenous ROS generation capacity. The Cu-MOFs exhibited antibacterial efficacy at a low concentration of 12.5 μg mL-1 by an oxidative stress response. These Cu-MOFs with their simple design and effective oxidase mimicking show attractive application prospects in the field of antibacterial and enzyme catalysis.
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Affiliation(s)
- Zhihui Mao
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
- School of Life Sciences, Shanghai University, Shanghai, 200444, China.
| | - Jie Chen
- School of Life Sciences, Shanghai University, Shanghai, 200444, China.
- School of Medicine, Shanghai University, Shanghai, 200444, China
| | - Yindian Wang
- School of Life Sciences, Shanghai University, Shanghai, 200444, China.
| | - Junjie Xia
- School of Life Sciences, Shanghai University, Shanghai, 200444, China.
| | - Yajing Zhang
- School of Qianweichang, Shanghai University, Shanghai, 200444, China
| | - Weiwen Zhang
- School of Qianweichang, Shanghai University, Shanghai, 200444, China
| | - Han Zhu
- School of Life Sciences, Shanghai University, Shanghai, 200444, China.
| | - Xiaojun Hu
- School of Life Sciences, Shanghai University, Shanghai, 200444, China.
| | - Hongxia Chen
- School of Life Sciences, Shanghai University, Shanghai, 200444, China.
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Bacirhonde PM, Dzade NY, Chalony C, Park J, Jeong ES, Afranie EO, Lee S, Kim CS, Kim DH, Park CH. Reduction of Transition-Metal Columbite-Tantalite as a Highly Efficient Electrocatalyst for Water Splitting. ACS APPLIED MATERIALS & INTERFACES 2022; 14:15090-15102. [PMID: 35324159 DOI: 10.1021/acsami.1c21742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We successfully report a liquid-liquid chemical reduction and hydrothermal synthesis of a highly stable columbite-tantalite electrocatalyst with remarkable hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance in acidic media. The reduced Fe0.79Mn0.21Nb0.16Ta0.84O6 (CTr) electrocatalyst shows a low overpotential of 84.23 mV at 10 mA cm-2 and 103.7 achieved at 20 mA cm-2 current density in situ for the HER and OER, respectively. The electrocatalyst also exhibited low Tafel slopes of 104.97 mV/dec for the HER and 57.67 mV/dec for the OER, verifying their rapid catalytic kinetics. The electrolyzer maintained a cell voltage of 1.5 V and potential-time stability close to that of Pt/C and RuO2. Complementary first-principles density functional theory calculations identify the Mn sites as most active sites on the Fe0.75Mn0.25Ta1.875Nb0.125O6 (100) surface, predicting a moderate Gibbs free energy of hydrogen adsorption (ΔGH* ≈ 0.08 eV) and a low overpotential of η = 0.47 V. The |ΔGMnH*| = 0.08 eV on the Fe0.75Mn0.25Ta1.875Nb0.125O6 (100) surface is similar to that of the well-known and highly efficient Pt catalyst (|ΔGPtH*| ≈ 0.09 eV).
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Affiliation(s)
- Patrick M Bacirhonde
- Department of Bionanosystem Engineering, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
- Department of Bionanotechnology and Bioconvergence Engineering, Graduate School, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
- Department of Geology and Mining Exploration, University of Goma, 204 Goma, Democratic Republic of Congo
| | - Nelson Y Dzade
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, Wales CF10 3AT, U.K
- Department of Energy and Mineral Engineering, Pennsylvania State University, University Park, State College, Pennsylvania 16802, United States
| | - Carmen Chalony
- Department of Bionanosystem Engineering, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
- Department of Bionanotechnology and Bioconvergence Engineering, Graduate School, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
| | - Jeesoo Park
- Department of Bionanosystem Engineering, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
- Department of Bionanotechnology and Bioconvergence Engineering, Graduate School, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
| | - Eun-Suk Jeong
- Division of Science Education and Institute of Fusion Science, Jeonbuk National University, Jeonju, Jeonbuk 54896 Republic of Korea
| | - Emmanuel O Afranie
- Department of Materials Science and Engineering, Chungnam National University, 99 Daehang-no, Yuseong-gu, Daejeon 305-764, Republic of Korea
| | - Sunny Lee
- Department of Bionanosystem Engineering, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
- Department of Bionanotechnology and Bioconvergence Engineering, Graduate School, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
| | - Cheol Sang Kim
- Department of Bionanotechnology and Bioconvergence Engineering, Graduate School, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
- Division of Mechanical Design Engineering, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
| | - Do-Hwan Kim
- Division of Science Education and Institute of Fusion Science, Jeonbuk National University, Jeonju, Jeonbuk 54896 Republic of Korea
- Department of Energy Storage/Conversion Engineering of Graduate School, Jeonbuk National University, Jeonju, Jeollabuk-do 54896, Republic of Korea
| | - Chan Hee Park
- Department of Bionanotechnology and Bioconvergence Engineering, Graduate School, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
- Division of Mechanical Design Engineering, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
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