Atomically-thin Bi2MoO6 nanosheets with vacancy pairs for improved photocatalytic CO2 reduction

Abstract Exploring efficient strategies to increase CO2 photoreduction performance is a key challenge in the energy conversion field. Herein, a cooperative role involving an ultrathin 2D structure and surface defects is employed to design defective Bi2MoO6 ultrathin nanosheets, to boost the CO2 photoreduction activity under water with no sacrificial agent, co-catalyst or extra photosensitizer. Bi2MoO6 ultrathin nanosheets with surface “Bi O″ vacancy pairs are grown via a template-directed strategy, as proved by STEM-ADF and positron annihilation spectroscopy. The engineered “Bi O″ vacancy pairs tune the local atomic structure, electronic structure of Bi2MoO6 and serve as charge separation centers to boost the electron-hole separation. Meanwhile, the defective ultrathin structure favors the CO2 adsorption, activation and CO desorption processes. With the merits of atomically-thin configuration and surface defects, the defective Bi2MoO6 ultrathin nanosheets display 2.55 times improved CO formation rate than their bulk counterpart under light irradiation.

[1]  Jinhua Ye,et al.  Synthesis of bismuth molybdate photocatalysts for CO2 photo-reduction , 2019, Journal of CO2 Utilization.

[2]  Cheng Yan,et al.  Defect-Rich Bi12 O17 Cl2 Nanotubes Self-Accelerating Charge Separation for Boosting Photocatalytic CO2 Reduction. , 2018, Angewandte Chemie.

[3]  Landong Li,et al.  Sub-10 nm rutile titanium dioxide nanoparticles for efficient visible-light-driven photocatalytic hydrogen production , 2015, Nature Communications.

[4]  Yi Luo,et al.  Atomic-Layer-Confined Doping for Atomic-Level Insights into Visible-Light Water Splitting. , 2015, Angewandte Chemie.

[5]  W. Xu,et al.  Enhanced performance of photoelectrochemical water oxidation using a three-dimensional interconnected nanostructural photoanode via simultaneously harnessing charge transfer and coating with an oxygen evolution catalyst , 2016 .

[6]  Yangen Zhou,et al.  Monolayered Bi2WO6 nanosheets mimicking heterojunction interface with open surfaces for photocatalysis , 2015, Nature Communications.

[7]  Xubiao Luo,et al.  Synthesis of hierarchical flower-like Bi2MoO6 microspheres as efficient photocatalyst for photoreduction of CO2 into solar fuels under visible light , 2016 .

[8]  Hua-ming Li,et al.  Ultrathin 2D Photocatalysts: Electronic‐Structure Tailoring, Hybridization, and Applications , 2018, Advanced materials.

[9]  Huijuan Liu,et al.  Formation of Bi2WO6 Bipyramids with Vacancy Pairs for Enhanced Solar‐Driven Photoactivity , 2015 .

[10]  S. Zhai,et al.  Hydrogenated Bismuth Molybdate Nanoframe for Efficient Sunlight-Driven Nitrogen Fixation from Air. , 2016, Chemistry.

[11]  L. Dai,et al.  Defect Chemistry of Nonprecious‐Metal Electrocatalysts for Oxygen Reactions , 2017, Advanced materials.

[12]  J. Shang,et al.  Efficient Visible Light Nitrogen Fixation with BiOBr Nanosheets of Oxygen Vacancies on the Exposed {001} Facets. , 2015, Journal of the American Chemical Society.

[13]  Yi Luo,et al.  Defect-Mediated Electron-Hole Separation in One-Unit-Cell ZnIn2S4 Layers for Boosted Solar-Driven CO2 Reduction. , 2017, Journal of the American Chemical Society.

[14]  Chong Xiao,et al.  Vacancy Engineering for Tuning Electron and Phonon Structures of Two‐Dimensional Materials , 2016 .

[15]  Yang Zheng,et al.  Atomic Interface Engineering and Electric‐Field Effect in Ultrathin Bi2MoO6 Nanosheets for Superior Lithium Ion Storage , 2017, Advanced materials.

[16]  K. Domen,et al.  Recent advances in semiconductors for photocatalytic and photoelectrochemical water splitting. , 2014, Chemical Society reviews.

[17]  Li Wang,et al.  Titanium-defected undoped anatase TiO2 with p-type conductivity, room-temperature ferromagnetism, and remarkable photocatalytic performance. , 2015, Journal of the American Chemical Society.

[18]  Yi Xie,et al.  Highly Efficient and Exceptionally Durable CO2 Photoreduction to Methanol over Freestanding Defective Single-Unit-Cell Bismuth Vanadate Layers. , 2017, Journal of the American Chemical Society.

[19]  Xubiao Luo,et al.  Hierarchical CeO 2 /Bi 2 MoO 6 heterostructured nanocomposites for photoreduction of CO 2 into hydrocarbons under visible light irradiation , 2018 .

[20]  R. German,et al.  The gravitational effects on low solid-volume fraction liquid-phase sintering , 1995, Journal of Materials Science.

[21]  Tierui Zhang,et al.  Defect‐Rich Ultrathin ZnAl‐Layered Double Hydroxide Nanosheets for Efficient Photoreduction of CO2 to CO with Water , 2015, Advanced materials.

[22]  Y. Zhang,et al.  Bi2 MoO6 Nanostrip Networks for Enhanced Visible-Light Photocatalytic Reduction of CO2 to CH4. , 2017, Chemphyschem : a European journal of chemical physics and physical chemistry.

[23]  S. Yin,et al.  The first synthesis of Bi self-doped Bi2MoO6-Bi2Mo3O12 composites and their excellent photocatalytic performance for selective oxidation of aromatic alkanes under visible light irradiation. , 2017, Chemical communications.

[24]  Yi Xie,et al.  Efficient Visible-Light-Driven CO2 Reduction Mediated by Defect-Engineered BiOBr Atomic Layers. , 2018, Angewandte Chemie.

[25]  Wu Lei,et al.  Controllable synthesis of flower-root shaped Bi2O3/Bi2MoO6 heterostructures as an efficient photocatalyst under visible light irradiation , 2019, Journal of Photochemistry and Photobiology A: Chemistry.

[26]  S. Pennycook,et al.  Atom-by-atom structural and chemical analysis by annular dark-field electron microscopy , 2010, Nature.

[27]  Hua-ming Li,et al.  The synergistic role of carbon quantum dots for the improved photocatalytic performance of Bi2MoO6. , 2015, Nanoscale.

[28]  Yunlin Liu,et al.  Crystal Defect Engineering of Aurivillius Bi2MoO6 by Ce Doping for Increased Reactive Species Production in Photocatalysis , 2016 .

[29]  Yi Xie,et al.  Single Unit Cell Bismuth Tungstate Layers Realizing Robust Solar CO2 Reduction to Methanol. , 2015, Angewandte Chemie.