Surface Basicity of Metal@TiO2 to Enhance Photocatalytic Efficiency for CO2 Reduction

2021 ◽  
Author(s):  
Lei Jin ◽  
Ehab Shaaban ◽  
Scott Bamonte ◽  
Daniel Cintron ◽  
Seth Shuster ◽  
...  
Keyword(s):  
Co2 Reduction ◽  
Photocatalytic Efficiency ◽  
Surface Basicity

scholarly journals Valence Regulation of Ultrathin Cerium Vanadate Nanosheets for Enhanced Photocatalytic CO2 Reduction to CO

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1115
Author(s):  
Lujia Ding ◽  
Qiutong Han ◽  
Hong Lu ◽  
Yong Yang ◽  
Gang Lu ◽  
...  
Keyword(s):  
Co2 Reduction ◽  
Catalytic Efficiency ◽  
State Regulation ◽  
Photocatalytic Reaction ◽  
Photocatalytic Efficiency ◽  
Structure Directing Agent ◽  
Valence States ◽  
Cerium Vanadate ◽  
One Step ◽  
The Relationship

Atomic valence state regulation is an advantageous approach for improving photocatalytic efficiency and product selectivity. However, it is difficult to precisely control the ratio of the different valence states on the surface and the relationship between the surface valence change and catalytic efficiency in the photocatalytic reaction process is unclear. Herein, CeVO4 ultrathin nanosheets were fabricated by one-step solvothermal method with ethanolamine (MEA) as the structure-directing agent. The ratio of the concentrations of intrinsic Ce4+ and Ce3+ ions is precisely modulated from 19.82:100 to 13.33:100 changed by the volume of MEA added without morphology modification. The photocatalytic efficiency increases as the concentrations of intrinsic Ce4+ and Ce3+ ions decrease and CV3 (prepared with 3 mL of MEA) shows the highest CO generation rate approximately 6 and 14 times larger than CV (prepared without MEA) and CV1 (prepared with 1 mL of MEA), respectively, in the photocatalytic CO2 reduction. Interestingly, about 6.8% photo-induced Ce4+ ions were generated on the surface of the catalysts during the photocatalytic CO2 reduction without any phase and morphology changes for CV3. The photocatalytic reaction mechanism is proposed considering the intrinsic and photo-induced Ce4+ ions to obtain efficient photocatalysts.

TiO2 nanosheet-anchoring Au nanoplates: high-energy facet and wide spectra surface plasmon-promoting photocatalytic efficiency and selectivity for CO2 reduction

RSC Advances ◽  
2016 ◽  
Vol 6 (85) ◽  
pp. 81510-81516 ◽  
Author(s):  
Meng Wang ◽  
Qiutong Han ◽  
Yong Zhou ◽  
Ping Li ◽  
Wenguang Tu ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
Co2 Reduction ◽  
High Energy ◽  
Hydrocarbon Fuels ◽  
Photocatalytic Reduction ◽  
Photocatalytic Efficiency

An Au–TiO2 nanocomposite consisting of (001) exposed TiO2 nanosheet-anchored Au nanoplates was successfully fabricated and applied for the photocatalytic reduction of CO2 into hydrocarbon fuels.

scholarly journals Aligning Oxygen Vacancies Oriently: Electric-Field Inducing Conductive Channels in TiO2 Film to boost Photocatalytic Conversion of CO2 into CO

2020 ◽  
Author(s):  
Junming Li ◽  
Wenxia Su ◽  
Jun Li ◽  
Lu Wang ◽  
Jun Ren ◽  
...  
Keyword(s):  
Electric Field ◽  
Tio2 Film ◽  
Oxygen Vacancies ◽  
Co2 Reduction ◽  
Reduction Reaction ◽  
Photocatalytic Efficiency ◽  
Electron Hole ◽  
Oxide Semiconductors ◽  
Recombination Centers ◽  
Co2 Reduction Reaction

Abstract Oxide semiconductors are widely used in the photocatalytic fields and introducing oxygen vacancies is an effective strategy to reduce the band gap, and consequently, improve their photocatalytic efficiency. However, oxygen vacancies in bulk often act as the recombination centers of electron-hole pairs, which would accelerate the recombination of electron-hole pairs and reduce carrier migration rate. Therefore, for achieving excellent photocatalytic performance in oxide photocatalysts, taking good advantage of oxide vacancies is very crucial. In this paper, we propose a strategy of electric field treatment and apply it in the TiO2 film with oxygen vacancies to promote the photocatalytic efficiency. After treated by an electric field, conductive channels consisting of oxygen vacancies are formed in TiO2 film, which makes the resistance greatly decreased by almost 6×103 times. In the photocatalytic CO2 reduction reaction, the yield of CO in the electric-field-treated TiO2 film can reach up to 1.729 mmol·gcat-1·h-1, which is one of the best performance among the reported TiO2-based catalysts. This work provides an effective and feasible way for enhancing photocatalytic activity through electric field and this method is promising to be widely used in the field of catalysis.

Selectively triggering photoelectrons for CO2-to-CH4 reduction over {110} SrTiO3 with dual-metal sites

2021 ◽  
Author(s):  
Lei Lu ◽  
Xiaopeng Zhu ◽  
Shaomang Wang ◽  
Taozhu Li ◽  
Shicheng Yan ◽  
...  
Keyword(s):  
Active Sites ◽  
Co2 Reduction ◽  
Reduction Reaction ◽  
Photocatalytic Efficiency ◽  
The Poor ◽  
Strong Adsorption ◽  
Weak Adsorption ◽  
Adsorption Of Co ◽  
Surface Active ◽  
Dual Metal

Abstract In this article, the roles of surface-active sites in dominating photoelectron selectivity for CO2 reduction products are well demonstrated over photocatalyst models of {100} SrTiO3 and {110} SrTiO3. On the easily exposed {100} facets terminated with Sr-O atoms, photoelectrons are of 8 mol % for CH4 and 92 mol % for CO generation. The Sr-O-Ti configuration in the {110} facets could enrich the surface charge density due to the lower interface resistance for higher photocatalytic efficiency (1.6-fold). The dual sites of Ti and adjacent Sr atoms are active for strong adsorption and activation of the generated CO* species from primary CO2 reduction on the surface, thus kinetically favoring the activity of photoelectrons (73 mol %) in hydrogenation for CH2* species and hence CH4 product. Inversely, the poor CH4 selectivity is due to difficulty in subsequent photoelectron reduction reaction by the weak adsorption of CO* at the single-Sr site on the {100} facets, independent of the electron and proton concentration. Our results may offer some illuminating insights into the design of a highly efficient photocatalyst for selective CO2 reduction.

The Plains CO2 Reduction (PCOR) Partnership: CO2 Sequestration Demonstration Projects Adding Value to the Oil and Gas Industry

2013 ◽  
Author(s):  
Charles D. Gorecki ◽  
Edward N. Steadman ◽  
John A. Harju ◽  
James A. Sorensen ◽  
John A. Hamling ◽  
...  
Keyword(s):  
Co2 Sequestration ◽  
Oil And Gas ◽  
Co2 Reduction ◽  
Oil And Gas Industry ◽  
Gas Industry

An NADH-Inspired Redox Mediator Strategy to Promote Second-Sphere Electron and Proton Transfer for Cooperative Electrochemical CO2 Reduction Catalyzed by Iron Porphyrin

2020 ◽  
Author(s):  
Peter T. Smith ◽  
Sophia Weng ◽  
Christopher Chang
Keyword(s):  
Proton Transfer ◽  
Co2 Reduction ◽  
Iron Porphyrin ◽  
Redox Mediators ◽  
Reservoir Properties ◽  
Proton Reduction ◽  
Electrochemical Co2 Reduction ◽  
Starting Point ◽  
Rate Improvement ◽  
Molecular Catalysts

We present a bioinspired strategy for enhancing electrochemical carbon dioxide reduction catalysis by cooperative use of base-metal molecular catalysts with intermolecular second-sphere redox mediators that facilitate both electron and proton transfer. Functional synthetic mimics of the biological redox cofactor NADH, which are electrochemically stable and are capable of mediating both electron and proton transfer, can enhance the activity of an iron porphyrin catalyst for electrochemical reduction of CO<sub>2</sub> to CO, achieving a 13-fold rate improvement without altering the intrinsic high selectivity of this catalyst platform for CO<sub>2</sub> versus proton reduction. Evaluation of a systematic series of NADH analogs and redox-inactive control additives with varying proton and electron reservoir properties reveals that both electron and proton transfer contribute to the observed catalytic enhancements. This work establishes that second-sphere dual control of electron and proton inventories is a viable design strategy for developing more effective electrocatalysts for CO<sub>2</sub> reduction, providing a starting point for broader applications of this approach to other multi-electron, multi-proton transformations.

CO2 Reduction to Propanol by Copper Foams: A Pre- and Post-Catalysis Study

2020 ◽  
Author(s):  
Jennifer A. Rudd ◽  
Ewa Kazimierska ◽  
Louise B. Hamdy ◽  
Odin Bain ◽  
Sunyhik Ahn ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Photoelectron Spectroscopy ◽  
Carbon Capture ◽  
Surface Composition ◽  
Co2 Reduction ◽  
Structural Rearrangement ◽  
Copper Electrode ◽  
Ex Situ ◽  
X Ray ◽  
Copper Electrodes

The utilization of carbon dioxide is a major incentive for the growing field of carbon capture. Carbon dioxide could be an abundant building block to generate higher value products. Herein, we describe the use of porous copper electrodes to catalyze the reduction of carbon dioxide into higher value products such as ethylene, ethanol and, notably, propanol. For <i>n</i>-propanol production, faradaic efficiencies reach 4.93% at -0.83 V <i>vs</i> RHE, with a geometric partial current density of -1.85 mA/cm<sup>2</sup>. We have documented the performance of the catalyst in both pristine and urea-modified foams pre- and post-electrolysis. Before electrolysis, the copper electrode consisted of a mixture of cuboctahedra and dendrites. After 35-minute electrolysis, the cuboctahedra and dendrites have undergone structural rearrangement. Changes in the interaction of urea with the catalyst surface have also been observed. These transformations were characterized <i>ex-situ</i> using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. We found that alterations in the morphology, crystallinity, and surface composition of the catalyst led to the deactivation of the copper foams.

Graphene Supported Tungsten Carbide as Catalyst for Electrochemical Reduction of CO2

2019 ◽  
Author(s):  
Sahithi Ananthaneni ◽  
Rees Rankin
Keyword(s):  
Tungsten Carbide ◽  
Electrochemical Reduction ◽  
Low Cost ◽  
Co2 Reduction ◽  
Platinum Group Metal ◽  
Reduction Reaction ◽  
Metal Carbides ◽  
Depth Study ◽  
Reduction Of Co2 ◽  
Co2 Reduction Reaction

<div>Electrochemical reduction of CO2 to useful chemical and fuels in an energy efficient way is currently an expensive and inefficient process. Recently, low-cost transition metal-carbides (TMCs) are proven to exhibit similar electronic structure similarities to Platinum-Group-Metal (PGM) catalysts and hence can be good substitutes for some important reduction reactions. In this work, we test graphenesupported WC (Tungsten Carbide) nanocluster as an electrocatalyst for the CO2 reduction reaction. Specifically, we perform DFT studies to understand various possible reaction mechanisms and determine the lowest thermodynamic energy landscape of CO2 reduction to various products such as CO, HCOOH, CH3OH, and CH4. This in-depth study of reaction energetics could lead to improvements and develop more efficient electrocatalysts for CO2 reduction.<br></div>

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