Barium Doped ZnO Nano-Particles: Preparation and Evaluation of their Catalytic Activity

2014 ◽  
Vol 10 (2) ◽  
pp. 312-317 ◽  
Author(s):  
Ali Reza Rajabi ◽  
Saeid Jabbarzare ◽  
Mohammad Reza Mohammad Shafiee ◽  
Majid Ghashang
2008 ◽  
Vol 139 ◽  
pp. 41-46 ◽  
Author(s):  
K. Okazaki-Maeda ◽  
Y. Morikawa ◽  
Shingo Tanaka ◽  
Masanori Kohyama

Pt nano-particles are supported on carbon materials at the electrode catalysts of protonexchange menbrane fuel cells. Pt nano-particles are desirable to be strongly adsorbed on carbon materials for high dispersion, although strong Pt-C interactions may affect the catalytic activity of small clusters. Thus we have examined H-atom absorption on Pt clusters supported or unsupported on graphene sheets, using first-principles calculations. For Pt-atom/graphene systems, a H atom is more weakly adsorbed than for a free Pt atom, and the H-Pt interaction becomes weaker if the interaction between a Pt atom and graphene becomes stronger. For the Ptn-cluster/graphene systems (n=2-4), the H-Pt interactions are also substantially changed from those for free Pt clusters. In the Pt clusters on graphene, the Pt-Pt distances are substantially changed associated with the electronicstructure changes by the Pt-C interactions. These structural and electronic changes in the Pt clusters as well as the presence of graphene itself seem to cause the changes in the absorption energies and preferential sites of H-atom absorption.


2009 ◽  
Vol 2 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Fatemeh F. Bamoharram ◽  
Majid M. Heravi ◽  
Mina Roushani ◽  
Maryam R. Toosi ◽  
Ladan Jodeyre

2018 ◽  
Vol 4 (4) ◽  
pp. 135-141 ◽  
Author(s):  
V. Porkalai ◽  
B. Sathya ◽  
D. Benny Anburaj ◽  
G Nedunchezhian ◽  
S. Joshua Gnanamuthu ◽  
...  

Recently, transition metal (TM) and rare earth ion doped II–VI semiconductor nanoparticles have received much attention because such doping can modify and improve optical properties of II–VI semiconductor nanoparticles by large amount. In this study, undoped, La doped and La+Ag co-doped ZnO nano particles have been successfully synthesized by sol-gel method using the mixture of Zinc acetate dihydrate and ethanol solution. The powders were calcinated at 600 °C for 2 h. The effect of lanthanum and lanthanum-silver incorporation on the structure, morphology, optical and electrical conductivity were examined by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Absorption (EDAX), Fourier transform infrared spectroscopy (FTIR), UV and Photo Luminescence (PL) Characterization. The average particle size of the synthesized ZnO nanoparticles is calculated using the Scherrer formula and is found to be of less than 20 nm. Luminescences properties were found to be enhanced for the La and La+Ag co-doped ZnO nanoparticles.


Author(s):  
Vinay Kumar ◽  
Rupinder Singh ◽  
Inderpreet Singh Ahuja

Construction is the part of human activity which is directly linked to urbanization for moving ahead on the path of growth and prosperity. Construction activities in past centuries are now part of our precious heritage. The repair and maintenance of heritage structures are of great importance for present-day researchers. One of the most common damage these century-long constructions faces are in form of surface cracks. In the present study, investigations were performed for a 3D printing-based customized solution for crack repair and maintenance of heritage structures. In this study, polyvinylidene fluoride (PVDF) polymer was reinforced with graphene (Gr) and Mn-doped ZnO nano-particles to prepare a smart composite material for crack repair and restoration. The composite was successfully 3D printed on fused deposition modeling (FDM) based 3D printer after investigating its rheological, thermal, and mechanical properties. The in-house developed composite was tested for smart characteristics to use as a programmable solution for filling cracks. The piezoelectric property and dielectric constant of 3D printed disk-shaped composite (PVDF-Gr-Mn-ZnO) were obtained after DC poling (to be used as stimulus) of the functional prototype. The results of the study suggest that the electro-active nature, volumetric change, and charge storing capacity of the additively manufactured composite may be used practically to acquire the shape of cavity/crack present in the constructed wall and repair the damages that occurred in a heritage site. The photoluminescence (PLS) and atomic force microscopy (AFM) analysis was used to ascertain the properties of the prepared composite. Also, the results obtained from the morphological analysis are reported to support the outcomes of the research.


2019 ◽  
Vol 469 ◽  
pp. 118-130 ◽  
Author(s):  
Tareque Odoom-Wubah ◽  
Qun Li ◽  
Qiang Wang ◽  
Most Zubaida Rukhsana Usha ◽  
Jiale Huang ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document