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

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.

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DFT Study on Regulating the Electronic Structure and CO2 Reduction Reaction in BiOBr/Sulphur-Doped G-C3N4 S-Scheme Heterojunctions

Frontiers in Nanotechnology ◽

10.3389/fnano.2021.698351 ◽

2021 ◽

Vol 3 ◽

Author(s):

Xingang Fei ◽

Liuyang Zhang ◽

Jiaguo Yu ◽

Bicheng Zhu

Keyword(s):

Photocatalytic Activity ◽

Electric Field ◽

Density Functional ◽

Co2 Reduction ◽

Photogenerated Electron ◽

Reduction Reaction ◽

High Photocatalytic Activity ◽

Reduction Activity ◽

Element Doping ◽

Co2 Reduction Reaction

Photocatalytic CO2 reduction is a promising method to mitigate the greenhouse effect and energy shortage problem. Development of effective photocatalysts is vital in achieving high photocatalytic activity. Herein, the S-scheme heterojunctions composed by BiOBr and g-C3N4 with or without S doping are thoroughly investigated for CO2 reduction by density functional theory (DFT) calculation. Work function and charge density difference demonstrate the existence of a built-in electric field in the system, which contributes to the separation of photogenerated electron-hole pairs. Enhanced strength of a built-in electric field is revealed by analysis of Bader charge and electric field intensity. The results indicate that S doping can tailor the electronic structures and thus improve the photocatalytic activity. According to the change in absorption coefficient, system doping can also endow the heterojunction with increased visible light absorption. The in-depth investigation indicates that the superior CO2 reduction activity is ascribed to low rate-determining energy. And both of the heterojunctions are inclined to generate CH3OH rather than CH4. Furthermore, S doping can further reduce the energy from 1.23 to 0.44 eV, indicating S doping is predicted to be an efficient photocatalyst for reducing CO2 into CH3OH. Therefore, this paper provides a theoretical basis for designing appropriate catalysts through element doping and heterojunction construction.

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Graphene Supported Tungsten Carbide as Catalyst for Electrochemical Reduction of CO2

10.26434/chemrxiv.8280986 ◽

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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Optimizing Reaction Conditions and Gas Diffusion Electrodes Applied in the CO2 Reduction Reaction to Formate to Reach Current Densities up to 1.8 A cm–2

ACS Sustainable Chemistry & Engineering ◽

10.1021/acssuschemeng.1c00199 ◽

2021 ◽

Author(s):

Armin Löwe ◽

Maximilian Schmidt ◽

Fabian Bienen ◽

Dennis Kopljar ◽

Norbert Wagner ◽

...

Keyword(s):

Co2 Reduction ◽

Gas Diffusion ◽

Reduction Reaction ◽

Gas Diffusion Electrodes ◽

Reaction Conditions ◽

Current Densities ◽

Co2 Reduction Reaction

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Theoretical Insight on Highly Efficient Electrocatalytic CO2 Reduction Reaction of Monoatom Dispersion Catalyst (Metal-Nitrogen-Carbon)

Electrocatalysis ◽

10.1007/s12678-021-00662-x ◽

2021 ◽

Author(s):

Zhijia Zhang ◽

Ling Guo ◽

Yu Han ◽

Lingxiao Jiao

Keyword(s):

Co2 Reduction ◽

Reduction Reaction ◽

Highly Efficient ◽

Catalyst Metal ◽

Co2 Reduction Reaction ◽

Theoretical Insight

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An Insight into Anchoring of Cobalt Phthalocyanines onto Carbon: Efficiency of the CO2 Reduction Reaction

ACS Applied Energy Materials ◽

10.1021/acsaem.0c02645 ◽

2021 ◽

Vol 4 (2) ◽

pp. 1442-1448

Author(s):

Jing-Jing Ma ◽

Hong-Lin Zhu ◽

Yue-Qing Zheng ◽

Miao Shui

Keyword(s):

Co2 Reduction ◽

Reduction Reaction ◽

Carbon Efficiency ◽

Cobalt Phthalocyanines ◽

Co2 Reduction Reaction ◽

Insight Into

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Three-dimensional porous copper-decorated bismuth-based nanofoam for boosting electrochemical reduction of CO2 to formate

Inorganic Chemistry Frontiers ◽

10.1039/d1qi00065a ◽

2021 ◽

Author(s):

Yingchun Zhang ◽

Changsheng Cao ◽

Xintao Wu ◽

Qi-Long Zhu

Keyword(s):

Current Density ◽

High Current Density ◽

Three Dimensional ◽

Co2 Reduction ◽

Reduction Reaction ◽

High Current ◽

Porous Copper ◽

Reduction Of Co2 ◽

Co2 Reduction Reaction ◽

Wide Potential

Bismuth (Bi)-based nanomaterials are considered as the promising electrocatalysts for electrocatalytic CO2 reduction reaction (CO2RR), but it is challenging to achieve high current density and selectivity in a wide potential...

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