Hierarchically Self-assembled Super Structural TiO2 Microspheres: Enhanced Excitonic Efficiency as Photocatalyst and Photoanode Material

MRS Advances ◽  
2015 ◽  
Vol 1 (59) ◽  
pp. 3877-3882
Author(s):  
Arunkumar Shanmugasundaram ◽  
Pratyay Basak ◽  
Sunkara V. Manorama

ABSTRACTComplex three-dimensional (3-D) super structural TiO2 architectures with controlled shape and size were synthesized by a facile hydrothermal synthesis route by using titanium tetrachloride (TiCl4) as the metal precursor and hydrochloric acid (HCl)/ammonium chloride (NH4Cl) as the mineralizer/structure directing agent. Several interesting hierarchical architectures like: (i) nanoparticles assembled spheres (NPAS), (ii) nanowires assembled spheres (NWAS), (iii) nanorods assembled spheres (NRAS), and (iv) nanosheets assembled spheres (NSAS) were achieved by the controlled variation of crystal structure modifier. The synthesized materials were characterised in detail by different analytical techniques and the findings are consistent. To demonstrate the superior performances of the as prepared materials the photocatalytic and photo-voltaic performances were investigated. The results demonstrate that these synthesized materials exhibits enhanced photocatalytic activity (efficiency is ∼ 91%) towards the degradation of RhB and as a photoanode in DSSCs the maximum energy conversion efficiency is ∼5%, attributed primarily to the unique hierarchical mesoporous structure of the TiO2 architectures.

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Buzuayehu Abebe ◽  
H. C. Ananda Murthy ◽  
Enyew Amare Zereffa

AbstractZinc oxide (ZnO) is a fascinating semiconductor material with many applications such as adsorption, photocatalysis, sensor, and antibacterial activities. By using a poly (vinyl alcohol) (PVA) polymer as a capping agent and metal oxides (iron and manganese) as a couple, the porous PVA-aided Zn/Fe/Mn ternary oxide nanocomposite material (PTMO-NCM) was synthesized. The thermal, optical, crystallinity, chemical bonding, porosity, morphological, charge transfer properties of the synthesized materials were confirmed by DTG/DSC, UV–Vis-DRS, XRD, FT-IR, BET, SEM-EDAX/TEM-HRTEM-SAED, and CV/EIS/amperometric analytical techniques, respectively. The PTMO-NCM showed an enhanced surface area and charge transfer capability, compared to ZnO. Using the XRD pattern and TEM image analysis, the crystalline size of the materials was confirmed to be in the nanometer range. The porosity and superior charge transfer capabilities of the PTMO-NCM were confirmed from the BET, HRTEM (IFFT)/SAED, and CV/EIS analysis. The adsorption kinetics (adsorption reaction/adsorption diffusion) and adsorption isotherm test confirmed the presence of a chemisorption type of adsorbate/methylene blue dye-adsorbent/PTMO-NCM interaction. The photocatalytic performance was tested on the Congo red and Acid Orange-8 dyes. The superior ascorbic acid sensing capability of the material was understood from CV and amperometric analysis. The noble antibacterial activities of the material were also confirmed on both gram-negative and gram-positive bacteria.


2020 ◽  
Vol 49 (8) ◽  
pp. 2381-2396 ◽  
Author(s):  
Philipp Gotico ◽  
Zakaria Halime ◽  
Ally Aukauloo

The progress in CO2 reduction catalyst design was examined starting from simple metalloporphyrin structures and progressing to three-dimensional active architectures.


Author(s):  
Guro Sørli ◽  
Muhammad Mohsin Azim ◽  
Magnus Ronning ◽  
Karina Mathisen

The first successful synthesis of hierarchical CuSAPO-34 (3.9 wt.% Cu) is reported using the polymer Pluronic F127 as mesoporous structure directing agent (SDA). X-ray absorption spectroscopy (XAS) proved single site...


2006 ◽  
Vol 951 ◽  
Author(s):  
Sorapong Pavasupree ◽  
Supachai Ngamsinlapasathian ◽  
Yoshikazu Suzuki ◽  
Susumu Yoshikawa

ABSTRACTNanorods/nanoparticles TiO2 with mesoporous structure were synthesized by hydrothermal method at 150 °C for 20 h. The samples characterized by XRD, SEM, TEM, SAED, HRTEM, and BET surface area. The nanorods had diameter about 10-20 nm and the lengths of 100-200 nm, the nanoparticles had diameter about 5-10 nm. The prepared material had average pore diameter about 7-12 nm. The BET surface area and pore volume of the sample are about 203 m2/g and 0.655 cm3/g, respectively. The nanorods/nanoparticles TiO2 with mesoporous structure showed higher photocatalytic activity (I3− concentration) than the nanorods TiO2, nanofibers TiO2, mesoporous TiO2, and commercial TiO2 (ST-01, P-25, JRC-01, and JRC-03). The solar energy conversion efficiency (η) of the cell using nanorods/nanoparticles TiO2 with mesoporous structure was about 7.12 % with Jsc of 13.97 mA/cm2, Voc of 0.73 V and ff of 0.70; while η of the cell using P-25 reached 5.82 % with Jsc of 12.74 mA/cm2, Voc of 0.704 V and ff of 0.649.


2017 ◽  
Vol 129 (44) ◽  
pp. 13969-13973 ◽  
Author(s):  
Gan Jia ◽  
Wen Zhang ◽  
Guozheng Fan ◽  
Zhaosheng Li ◽  
Degang Fu ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Maryam Haghighi ◽  
Karamatollah Rezaei

Pectin-based gelled systems have gained increasing attention for the design of newly developed food products. For this reason, the characterization of such formulas is a necessity in order to present scientific data and to introduce an appropriate finished product to the industry. Various analytical techniques are available for the evaluation of the systems formulated on the basis of pectin and the designed gel. In this paper, general analytical approaches for the characterization of pectin-based gelled systems were categorized into several subsections including physicochemical analysis, visual observation, textural/rheological measurement, microstructural image characterization, and psychorheological evaluation. Three-dimensional trials to assess correlations among microstructure, texture, and taste were also discussed. Practical examples of advanced objective techniques including experimental setups for small and large deformation rheological measurements and microstructural image analysis were presented in more details.


2018 ◽  
Vol 192 ◽  
pp. 01032
Author(s):  
Zhen-Qiang Song ◽  
Sriyuttakrai Sathin ◽  
Wei Li ◽  
Kazuhiro Ohyama ◽  
ShiJie Zhu

The dielectric elastomer generator (VHB 4905, 3M) with diaphragm configuration was investigated with the constant-voltage harvesting scheme in order to investigate its energy harvesting ability. The maximum energy density and energy conversion efficiency is measured to be 65 J/kg and 5.7%, respectively. The relatively low efficiency indicates that higher energy conversion efficiency is impeded by the viscosity of the acrylic elastomer, suggesting that higher conversion efficiency with new low-viscosity elastomer should be available.


2021 ◽  
Author(s):  
Gabriela de los Angeles Gonzalez de Lucio ◽  
Claudia Finger ◽  
Erik Saenger

<p>The Ruhr district meets the necessary elements to carry out geothermal projects due to its geothermal potential and demand, as it is a densely populated industrial area. Currently, there are projects for direct use, whereas projects for electricity generation are planned. The latter, due to greater depths, reservoir enhancement techniques are required in some cases. This may increase the associated seismic risk which should be elaborated in detail.</p><p>With available data, a three-dimensional geological and structural model was created. The shallower parts have been widely studied and documented by mining activity in the Ruhr region during the last century.  Below a depth of 1 km, data are scarce, and uncertainties increase. The full elastic wavefield emitted by a realistic seismic source has been simulated using a finite differences scheme and the derived geological model. The elastic properties were estimated with well data. The source has common characteristics of real seismic events in the area.</p><p>The wave propagation simulations let us analyze the seismic response with different sources and velocities models. Three cases are considered, two seismic events with distinct depths based on real events. The third case is based on the proposed location of a deep geothermal project.</p><p>Especially for the case with the deeper source, the areas with relatively high amplitudes of displacement correlated with structural features of the model. Applying the imaging condition of maximum energy density allows us to define zones with a potentially increased seismic risk that should be monitored more closely.</p>


2021 ◽  
pp. 1-23
Author(s):  
Dandan Pang ◽  
Aibing Zhang ◽  
Zhenfei Wen ◽  
Baolin Wang ◽  
Ji Wang

Abstract Thermoelectric power generators (TEGs) have been attracted increasing attention recently due to their capability of converting waste heat into useful electric energy without hazardous emissions. This paper develops a theoretical model to analyze the thermoelectric performance of TEGs with cylindrical legs. The influence of heat convection loss between lateral surfaces of thermoelectric legs and ambient environment on the energy conversion efficiency is investigated. For the idealized model, closed-form solutions of optimal electric current, maximum power output and maximum energy conversion efficiency are obtained, a new dimensionless impact factor H is introduced to capture the heat convection effect. The impact factor H depends on the ratio of heat conductivity to heat convection coefficient and geometry size of thermoelectric legs, as well as the temperature ratio of heat sink to hot source. The performance can be evaluated by the figure of merit, impact factor H and temperature gradient across the hot source and heat sink for a well-designed TEG with cylindrical legs. For the case of considering contact resistance, it is found that there exists an optimal leg's height for maximum energy conversion efficiency due to the heat convection on lateral surfaces of thermoelectric leg. The proposed theoretical model in this paper will be very helpful in the designing of actual TEG devices.


2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Irish Lorraine B. PABUAYON ◽  
Yazhou SUN ◽  
Wenxuan GUO ◽  
Glen L. RITCHIE

Abstract Recent technological advances in cotton (Gossypium hirsutum L.) phenotyping have offered tools to improve the efficiency of data collection and analysis. High-throughput phenotyping (HTP) is a non-destructive and rapid approach of monitoring and measuring multiple phenotypic traits related to the growth, yield, and adaptation to biotic or abiotic stress. Researchers have conducted extensive experiments on HTP and developed techniques including spectral, fluorescence, thermal, and three-dimensional imaging to measure the morphological, physiological, and pathological resistance traits of cotton. In addition, ground-based and aerial-based platforms were also developed to aid in the implementation of these HTP systems. This review paper highlights the techniques and recent developments for HTP in cotton, reviews the potential applications according to morphological and physiological traits of cotton, and compares the advantages and limitations of these HTP systems when used in cotton cropping systems. Overall, the use of HTP has generated many opportunities to accurately and efficiently measure and analyze diverse traits of cotton. However, because of its relative novelty, HTP has some limitations that constrains the ability to take full advantage of what it can offer. These challenges need to be addressed to increase the accuracy and utility of HTP, which can be done by integrating analytical techniques for big data and continuous advances in imaging.


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