Nanocomposite of polyaniline and a layered niobate acid host: Synthesis, electrochemical studies, and photocatalytic properties

2013 ◽  
Vol 34 (6) ◽  
pp. 834-841 ◽  
Author(s):  
Huajun Zhu ◽  
Xiao Yao ◽  
Sudong Hua
Keyword(s):  
Photocatalytic Properties ◽  
Electrochemical Studies ◽  
Layered Niobate ◽  
Host Synthesis

Tuning the pore structures and photocatalytic properties of a 2D covalent organic framework with multi-branched photoactive moieties

Nanoscale ◽  
2020 ◽  
Vol 12 (30) ◽  
pp. 16136-16142
Author(s):  
Xuan Wang ◽  
Ming-Jie Dong ◽  
Chuan-De Wu
Keyword(s):  
Photocatalytic Properties ◽  
Effective Strategy ◽  
Covalent Organic Framework ◽  
Highly Efficient ◽  
Pore Structures ◽  
Local Connection ◽  
Organic Framework

An effective strategy to incorporate accessible metalloporphyrin photoactive sites into 2D COFs by establishing a 3D local connection for highly efficient photocatalysis was developed.

A Pyridinic Fe-N4 Macrocycle Effectively Models the Active Sites in Fe/N-Doped Carbon Electrocatalysts

2020 ◽  
Author(s):  
Travis Marshall-Roth ◽  
Nicole J. Libretto ◽  
Alexandra T. Wrobel ◽  
Kevin Anderton ◽  
Nathan D. Ricke ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Active Sites ◽  
Catalytic Properties ◽  
Reduction Reaction ◽  
Iron Phthalocyanine ◽  
Electrochemical Studies ◽  
Onset Potential ◽  
Nitrogen Doped Carbon ◽  
Iron Active Sites

Iron- and nitrogen-doped carbon (Fe-N-C) materials are leading candidates to replace platinum in fuel cells, but their active site structures are poorly understood. A leading postulate is that iron active sites in this class of materials exist in an Fe-N<sub>4</sub> pyridinic ligation environment. Yet, molecular Fe-based catalysts for the oxygen reduction reaction (ORR) generally feature pyrrolic coordination and pyridinic Fe-N<sub>4</sub> catalysts are, to the best of our knowledge, non-existent. We report the synthesis and characterization of a molecular pyridinic hexaazacyclophane macrocycle, (phen<sub>2</sub>N<sub>2</sub>)Fe, and compare its spectroscopic, electrochemical, and catalytic properties for oxygen reduction to a prototypical Fe-N-C material, as well as iron phthalocyanine, (Pc)Fe, and iron octaethylporphyrin, (OEP)Fe, prototypical pyrrolic iron macrocycles. N 1s XPS signatures for coordinated N atoms in (phen<sub>2</sub>N<sub>2</sub>)Fe are positively shifted relative to (Pc)Fe and (OEP)Fe, and overlay with those of Fe-N-C. Likewise, spectroscopic XAS signatures of (phen<sub>2</sub>N<sub>2</sub>)Fe are distinct from those of both (Pc)Fe and (OEP)Fe, and are remarkably similar to those of Fe-N-C with compressed Fe–N bond lengths of 1.97 Å in (phen<sub>2</sub>N<sub>2</sub>)Fe that are close to the average 1.94 Å length in Fe-N-C. Electrochemical studies establish that both (Pc)Fe and (phen<sub>2</sub>N<sub>2</sub>)Fe have relatively high Fe(III/II) potentials at ~0.6 V, ~300 mV positive of (OEP)Fe. The ORR onset potential is found to directly correlate with the Fe(III/II) potential leading to a ~300 mV positive shift in the onset of ORR for (Pc)Fe and (phen<sub>2</sub>N<sub>2</sub>)Fe relative to (OEP)Fe. Consequently, the ORR onset for (phen<sub>2</sub>N<sub>2</sub>)Fe and (Pc)Fe is within 150 mV of Fe-N-C. Unlike (OEP)Fe and (Pc)Fe, (phen<sub>2</sub>N<sub>2</sub>)Fe displays excellent selectivity for 4-electron ORR with <4% maximum H<sub>2</sub>O<sub>2</sub> production, comparable to Fe-N-C materials. The aggregate spectroscopic and electrochemical data establish (phen<sub>2</sub>N<sub>2</sub>)Fe as a pyridinic iron macrocycle that effectively models Fe-N-C active sites, thereby providing a rich molecular platform for understanding this important class of catalytic materials.<p><b></b></p>

New Insights into the Nature of the Band Gap of CuGeO3 Nanoparticles: Synthesis, Electronic Structure, and Optical and Photocatalytic Properties

2019 ◽  
Author(s):  
Victor Y. Suzuki ◽  
Luís Henrique Cardozo Amorin ◽  
Natália H. de Paula ◽  
Anderson R. Albuquerque ◽  
Julio Ricardo Sambrano ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Material Design ◽  
Photocatalytic Properties ◽  
Critical Parameters ◽  
Synthetic Approach ◽  
Microwave Assisted ◽  
Theoretical Approaches ◽  
Nanoparticles Synthesis ◽  
First Time

<p>We report, for the first time, new insights into the nature of the band gap of <a>CuGeO<sub>3</sub> </a>(CGO) nanocrystals synthesized from a microwave-assisted hydrothermal method in the presence of citrate. To the best of our knowledge, this synthetic approach has the shortest reaction time and it works at the lowest temperatures reported in the literature for the preparation of these materials. The influence of the surfactant on the structural, electronic, optical, and photocatalytic properties of CGO nanocrystals is discussed by a combination of experimental and theoretical approaches, and that results elucidates the nature of the band gap of synthetized CGO nanocrystals. We believe that this particular strategy is one of the most critical parameters for the development of innovative applications and that result could shed some light on the emerging material design with entirely new properties.</p> <p><b> </b></p>

Hydrothermal Synthesis and Photocatalytic Properties of Cu-doped BiVO4 Microsheets

2013 ◽  
Vol 28 (3) ◽  
pp. 287-294 ◽  
Author(s):  
Guo-Cong LIU ◽  
Zhen JING ◽  
Xi-Bing ZHANG ◽  
Xian-Feng LI ◽  
Hong LIU
Keyword(s):  
Hydrothermal Synthesis ◽  
Photocatalytic Properties

Preparation of Pt-loaded TiO2 Nanotubes/Nanocrystals Composite Photocatalysts and Their Photocatalytic Properties

2011 ◽  
Vol 26 (7) ◽  
pp. 747-752 ◽  
Author(s):  
Wei-Wei YU ◽  
Qing-Hong ZHANG ◽  
Guo-Ying SHI ◽  
Yao-Gang LI ◽  
Hong-Zhi WANG
Keyword(s):  
Photocatalytic Properties ◽  
Composite Photocatalysts
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