Microfluidic Photocatalytic Water-Splitting Reactors

2012 ◽  
Author(s):  
Syed Saad Ahsan ◽  
David Erickson
Keyword(s):  
Water Splitting ◽  
Sol Gel ◽  
Reaction Rates ◽  
Transfer Efficiency ◽  
Kinetic Properties ◽  
Wet Impregnation ◽  
Co Catalyst ◽  
Photocatalytic Water Splitting ◽  
Photocatalytic Reactions ◽  
Kinetics Of

In this work, we present a novel microfluidic photocatalytic water-splitting reactor. Optofluidics offers advantages over conventional reactors in terms of improved photon transfer efficiency and mass transfer efficiency and are therefore the ideal platform for photocatalytic reactions. Our device is a planar optofluidic device which we used to study the kinetics of Platinum-Impregnated Titanium Oxide as the oxygen and hydrogen producing photocatalyst redox mediated by Iodide/Iodate species. We deposit our catalysts via a sol-gel method while the platinum co-catalyst is added by wet impregnation via reduction in Sodium Borohydride. The reactions are performed under a 100W Hg lamp and reaction rates are inferred by measuring the depletion of the two Iodine species via UV-vis absorption spectrophotometry. Our results indicate that reaction rates and efficiencies can be enhanced by using an optofluidic platform as opposed to the conventional slurry reactor used in previous experiments for this class of reaction. We believe that the micro-optofluidic platform of our device offers the benefit of measuring the kinetic properties of these class of reactions quickly and cheaply for the goals of further optimization.

Mo-doped BiVO4 thin films – high photoelectrochemical water splitting performance achieved by a tailored structure and morphology

2017 ◽  
Vol 1 (8) ◽  
pp. 1830-1846 ◽  
Author(s):  
Martin Rohloff ◽  
Björn Anke ◽  
Siyuan Zhang ◽  
Ulrich Gernert ◽  
Christina Scheu ◽  
...  
Keyword(s):  
Thin Films ◽  
Water Splitting ◽  
Sol Gel ◽  
Surface Recombination ◽  
Photoelectrochemical Water Splitting ◽  
Transfer Efficiency ◽  
Hole Transfer ◽  
Structure And Morphology ◽  
Sol Gel Synthesis ◽  
Reduced Surface

Facile sol–gel synthesis of Mo:BiVO4 thin films with optimized morphology results in reduced surface recombination and enhanced hole transfer efficiency.

Assembly of thiacalix[4]arene-supported high-nuclearity Cd24 cluster with enhanced photocatalytic activity

Nanoscale ◽  
2018 ◽  
Vol 10 (30) ◽  
pp. 14448-14454 ◽  
Author(s):  
Cheng Shi ◽  
Min Zhang ◽  
Xinxin Hang ◽  
Yanfeng Bi ◽  
Liangliang Huang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Water Splitting ◽  
Co Catalyst ◽  
Photocatalytic Water Splitting

A high-nuclearity Cd24 cluster built from Cd4-thiacalix[4]arene SBUs and in situ generated peroxyphosphate PO53− exhibited significant photocatalytic water splitting activity in absence of a co-catalyst.

scholarly journals Mechanism for spontaneous oxygen and hydrogen evolution reactions on CoO nanoparticles

2019 ◽  
Vol 7 (12) ◽  
pp. 6708-6719 ◽  
Author(s):  
Kyoung-Won Park ◽  
Alexie M. Kolpak
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
High Efficiency ◽  
Applied Bias ◽  
Co Catalyst ◽  
Photocatalytic Water Splitting ◽  
Overall Water Splitting ◽  
Nanoparticle Suspensions ◽  
Hydrogen Evolution Reactions ◽  
Coo Nanoparticles

Overall photocatalytic water splitting with a high efficiency has recently been observed for CoO nanoparticle suspensions in the absence of an applied bias or co-catalyst. This study clarifies the mechanism of spontaneous overall water splitting with the prominent efficiency observed on the CoO nanoparticle.

scholarly journals Current Issues in Sol-Gel Reaction Kinetics

1990 ◽  
Vol 180 ◽  
Author(s):  
Roger A. Assink ◽  
Bruce D. Kay
Keyword(s):  
Reaction Kinetics ◽  
Sol Gel ◽  
Early Time ◽  
Acid Catalyst ◽  
Reaction Rates ◽  
Reaction Conditions ◽  
Reaction Rate Constants ◽  
Condensation Reactions ◽  
Experimental Findings ◽  
Kinetics Of

ABSTRACTThis paper surveys a few of the current issues in sol-gel reaction kinetics. Many times seemingly modest changes in reactants or reaction conditions can lead to substantial differences in the overall reaction rates and pathways. For example, qualitative features of the reaction kinetics can depend on catalyst concentration. At very high acid-catalyst concentrations, reverse reactions are significant for TMOS solgels, while for moderate acid-catalyst concentrations, reverse reactions are substantially reduced. The reaction kinetics of two similar tetraalkoxysilanes: tetramethoxysilane (TMOS) and tetraethoxysilane (TEOS), can be markedly different under identical reaction conditions. Under acid-catalyzed reaction conditions, a TMOS sol-gel undergoes both water- and alcoholproducing condensation reactions while a TEOS sol-gel undergoes only water-producing condensation. The early time hydrolysis and condensation reactions of a TMOS sol-gel are statistical in nature and can be quantitatively described by a few simple reaction rate constants while the reaction behavior of a TEOS sol-gel is markedly nonstatistical. A comprehensive theory of sol-gel kinetics must address these diverse experimental findings.

A Rapid Solar Reduction Method to TiO2/MoO2/Graphene Nanocomposites for Photocatalytic Water Splitting

2015 ◽  
Vol 1738 ◽  
Author(s):  
Jyothirmayee Aravind.S.S ◽  
Kandalam Ramanujachary ◽  
Timothy D. Vaden ◽  
Amos Mugweru
Keyword(s):  
Water Splitting ◽  
Reduction Method ◽  
High Current Density ◽  
Phase Identification ◽  
Co Catalyst ◽  
Graphene Nanocomposites ◽  
Photocatalytic Water Splitting ◽  
Earth Abundant ◽  
Co Reduction ◽  
Interesting Area

ABSTRACTSemiconductor photocatalysis has emerged as an interesting area of research since the discovery of Honda-Fujishima effect. In this study, TiO2/MoO2/graphene composites have been prepared by a solar radiation-assisted co-reduction method, wherein ammonium tetrathiomolybdate salt and graphite oxide are reduced to MoO2 and graphene respectively along with TiO2. The method involved the utilization of focused pulses of natural sunlight using a simple convex lens, thereby eliminating the need for harmful reducing agents. The compound was characterized by XRD and SEM for phase identification and morphology. The TiO2/MoO2/graphene composite exhibits superior photocatalytic water splitting activity without using a co-catalyst. In addition, we demonstrate the electrocatalytic hydrogen production using this earth abundant catalyst, which shows high current density (60 mA/cm2) and low Tafel slope (47 mV/dec). The hydrogen evolved during photocatalysis was detected by gas chromatography.

Facile synthesis of porous hybrid materials based on Calix-3 dye and TiO2 for high photocatalytic water splitting performance with excellent stability

2019 ◽  
Vol 7 (7) ◽  
pp. 2993-2999 ◽  
Author(s):  
Jian-Feng Huang ◽  
Jun-Min Liu ◽  
Li-Min Xiao ◽  
Yu-Hui Zhong ◽  
Liang Liu ◽  
...  
Keyword(s):  
Water Splitting ◽  
Hybrid Materials ◽  
Hybrid Material ◽  
Sol Gel ◽  
Pt Nanoparticles ◽  
Facile Synthesis ◽  
Gel Method ◽  
Photocatalytic Water Splitting ◽  
First Time ◽  
Excellent Stability

A highly robust hybrid material Calix-3-TiO2 based on calixarene dye and TiO2 is prepared by a facile sol–gel method for the first time. When Pt nanoparticles are introduced onto the hybrid, the catalysts display efficient and persistent photocatalytic water splitting activities.

scholarly journals Unraveling the synergy between metal–organic frameworks and co-catalysts in photocatalytic water splitting

2020 ◽  
Vol 8 (39) ◽  
pp. 20493-20502
Author(s):  
Stefano Falletta ◽  
Patrick Gono ◽  
Zhendong Guo ◽  
Stavroula Kampouri ◽  
Kyriakos C. Stylianou ◽  
...  
Keyword(s):  
Water Splitting ◽  
Photocatalytic Performance ◽  
Metal Organic Frameworks ◽  
Water Systems ◽  
Band Alignment ◽  
Co Catalyst ◽  
Photocatalytic Water Splitting ◽  
Co Catalysts ◽  
Metal Organic

Theoretical methodologies for the band alignment at MOF/co-catalyst/water systems revealing the electronic and atomistic mechanisms underlying their photocatalytic performance.

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