Graphene-wrapped Pt/TiO2 photocatalysts with enhanced photogenerated charges separation and reactant adsorption for high selective photoreduction of CO2 to CH4

Abstract Artificial photosynthesis efficiency for selective CO2 conversion to CH4 as chemical energy-rich molecule is dependent on the photogenerated charges separation and reactant adsorption property of photocatalyst. Here we report a novel fabrication of core-shell-structured photocatalysts of Pt/TiO2-nanocrystals wrapped by reduced graphene oxide (rGO) sheets ((Pt/TiO2)@rGO). The ultrafine anatase TiO2 nanocrystals with coexposed {001} and {101} facets acted as the fountain of the photogenerated charges primitively. Pt nanoparticles (NPs) deposited on the TiO2 nanocrystals can gather and transfer the stimulated electrons originated from anatase TiO2 nanocrystals. The all-solid-state electron multiple transmission (EMT) system with TiO2-nanocrystal(core)-Pt(mediator)-rGO(shell) nanojunction is not only favorable to the vectorial electron transfer of TiO2 → Pt → rGO and enhance the separation efficiency of photogenerated electrons and holes, but also the surface residual hydroxyl and extended π bond of wrapping rGO sheets can improve the adsorption and activation capabilities for CO2 reactant. (Pt/TiO2)@rGO ternary photocatalysts exhibit excellent performance for the multi-electron process of selective photocatalytic CO2 conversion to CH4. Among the prepared catalysts, (Pt/TiO2)@rGO-2 catalyst shows the highest photocatalytic activity and selectivity for CO2 conversion, i.e., the formation rate of CH4 is 41.3 μmol g−1 h−1 and the selectivity of CO2 conversion to CH4 product is 99.1%, and its apparent quantum efficiency for CH4 product is 1.93%. As a heuristic the fabrication of core-shell structured (Pt/TiO2)@rGO photocatalysts will stimulate more novel ideas for application to light-chemical energy conversion.

[1]  Pingquan Wang,et al.  Synthesis of hierarchical bismuth-rich Bi4O5BrxI2-x solid solutions for enhanced photocatalytic activities of CO2 conversion and Cr(VI) reduction under visible light , 2017 .

[2]  Xuezhong Gong,et al.  Modulating charge transport in semiconductor photocatalysts by spatial deposition of reduced graphene oxide and platinum , 2015 .

[3]  Jacek K. Stolarczyk,et al.  Photocatalytic reduction of CO2 on TiO2 and other semiconductors. , 2013, Angewandte Chemie.

[4]  H. Fu,et al.  Exceptional Photocatalytic Activity of 001-Facet-Exposed TiO2 Mainly Depending on Enhanced Adsorbed Oxygen by Residual Hydrogen Fluoride , 2013 .

[5]  Meiqing Shen,et al.  Single-crystal-like titania mesocages. , 2011, Angewandte Chemie.

[6]  Jae-Young Choi,et al.  Efficient Reduction of Graphite Oxide by Sodium Borohydride and Its Effect on Electrical Conductance , 2009 .

[7]  Ying-hua Liang,et al.  Removal of Cr(VI) by 3D TiO2-graphene hydrogel via adsorption enriched with photocatalytic reduction , 2016 .

[8]  Yili Zhang,et al.  Facile Approach for the Syntheses of Ultrafine TiO2 Nanocrystallites with Defects and C Heterojunction for Photocatalytic Water Splitting , 2016 .

[9]  Huijun Zhao,et al.  Optimization synthesis of carbon nanotubes-anatase TiO2 composite photocatalyst by response surface methodology for photocatalytic degradation of gaseous styrene , 2012 .

[10]  Xiaobo Chen,et al.  Titanium dioxide-based nanomaterials for photocatalytic fuel generations. , 2014, Chemical reviews.

[11]  Yuehe Lin,et al.  Graphene/TiO2 nanocomposites: synthesis, characterization and application in hydrogen evolution from water photocatalytic splitting , 2010 .

[12]  Chen Li,et al.  Surface heterojunction between (001) and (101) facets of ultrafine anatase TiO2 nanocrystals for highly efficient photoreduction CO2 to CH4 , 2016 .

[13]  A. Fujishima,et al.  Photoelectrocatalytic reduction of carbon dioxide in aqueous suspensions of semiconductor powders , 1979, Nature.

[14]  H. Yang,et al.  Solvothermally controllable synthesis of anatase TiO2 nanocrystals with dominant {001} facets and enhanced photocatalytic activity , 2010 .

[15]  Yajun Wang,et al.  AuPd/3DOM-TiO2 catalysts for photocatalytic reduction of CO2: High efficient separation of photogenerated charge carriers , 2017 .

[16]  M. Jaroniec,et al.  Hydrogen Production by Photocatalytic Water Splitting over Pt/TiO2 Nanosheets with Exposed (001) Facets , 2010 .

[17]  Wenjun Jiang,et al.  Separation-free TiO 2 -graphene hydrogel with 3D network structure for efficient photoelectrocatalytic mineralization , 2017 .

[18]  Y. Xiong,et al.  Facet‐Engineered Surface and Interface Design of Photocatalytic Materials , 2016, Advanced science.

[19]  A. Mohamed,et al.  Highly reactive {001} facets of TiO2-based composites: synthesis, formation mechanism and characterization. , 2014, Nanoscale.

[20]  T. Tachikawa,et al.  Evidence for crystal-face-dependent TiO2 photocatalysis from single-molecule imaging and kinetic analysis. , 2011, Journal of the American Chemical Society.

[21]  Sanjaya D. Perera,et al.  Hydrothermal synthesis of graphene-TiO 2 nanotube composites with enhanced photocatalytic activity , 2012 .

[22]  T. Peng,et al.  Graphitic carbon nitride (g-C3N4)-Pt-TiO2 nanocomposite as an efficient photocatalyst for hydrogen production under visible light irradiation. , 2012, Physical chemistry chemical physics : PCCP.

[23]  A. Mohamed,et al.  Noble metal modified reduced graphene oxide/TiO2 ternary nanostructures for efficient visible-light-driven photoreduction of carbon dioxide into methane , 2015 .

[24]  Photocatalytic CO2 reduction by TiO2 and related titanium containing solids , 2012 .

[25]  Darren Delai Sun,et al.  Self‐Assembling TiO2 Nanorods on Large Graphene Oxide Sheets at a Two‐Phase Interface and Their Anti‐Recombination in Photocatalytic Applications , 2010 .

[26]  T. Kajino,et al.  A highly efficient mononuclear iridium complex photocatalyst for CO2 reduction under visible light. , 2013, Angewandte Chemie.

[27]  Huijun Zhao,et al.  Synthesis of carbon nanotube-anatase TiO₂ sub-micrometer-sized sphere composite photocatalyst for synergistic degradation of gaseous styrene. , 2012, ACS applied materials & interfaces.

[28]  N. Zhang,et al.  Visible-Light-Driven Oxidation of Primary C–H Bonds over CdS with Dual Co-catalysts Graphene and TiO2 , 2013, Scientific Reports.

[29]  Hongtao Yu,et al.  “Mulberry-like” CdSe Nanoclusters Anchored on TiO2 Nanotube Arrays: A Novel Architecture with Remarkable Photoelectrochemical Performance , 2009 .

[30]  Jian Liu,et al.  Photocatalysts of 3D Ordered Macroporous TiO2-Supported CeO2 Nanolayers: Design, Preparation, and Their Catalytic Performances for the Reduction of CO2 with H2O under Simulated Solar Irradiation , 2014 .

[31]  G. Watson,et al.  A Density Functional Theory + U Study of Oxygen Vacancy Formation at the (110), (100), (101), and (001) Surfaces of Rutile TiO2 , 2009 .

[32]  M. Xing,et al.  Developing stretchable and graphene-oxide-based hydrogel for the removal of organic pollutants and metal ions , 2018 .

[33]  H. Arandiyan,et al.  3DOM BiVO4 supported silver bromide and noble metals: High-performance photocatalysts for the visible-light-driven degradation of 4-chlorophenol , 2015 .

[34]  Z. Zou,et al.  Effective separation and transfer of carriers into the redox sites on Ta3N5/Bi photocatalyst for promoting conversion of CO2 into CH4 , 2018 .

[35]  Maor F. Baruch,et al.  Light-Driven Heterogeneous Reduction of Carbon Dioxide: Photocatalysts and Photoelectrodes. , 2015, Chemical reviews.

[36]  Tomoki Akita,et al.  All-solid-state Z-scheme in CdS–Au–TiO2 three-component nanojunction system , 2006, Nature materials.

[37]  T. Tatsumi,et al.  Photocatalytic reduction of CO2 with H2O on Ti-MCM-41 and Ti-MCM-48 mesoporous zeolite catalysts , 1998 .

[38]  Xue-Zhong Sun,et al.  Photo-reduction of CO2 Using a Rhenium Complex Covalently Supported on a Graphene/TiO2 Composite. , 2016, ChemSusChem.

[39]  B. Cao,et al.  Hollow spherical RuO2@TiO2@Pt bifunctional photocatalyst for coupled H2 production and pollutant degradation , 2016 .

[40]  G. Lu,et al.  Enhanced Photoactivity of Oxygen-Deficient Anatase TiO2 Sheets with Dominant {001} Facets , 2009 .

[41]  Wei Xiao,et al.  Enhanced photocatalytic CO₂-reduction activity of anatase TiO₂ by coexposed {001} and {101} facets. , 2014, Journal of the American Chemical Society.

[42]  T. Nagao,et al.  Light assisted CO2 reduction with methane over group VIII metals: Universality of metal localized surface plasmon resonance in reactant activation , 2017 .

[43]  Yongfa Zhu,et al.  Visible Photocatalytic Activity Enhancement of ZnWO4 by Graphene Hybridization , 2012 .

[44]  Sibo Wang,et al.  Imidazolium Ionic Liquids, Imidazolylidene Heterocyclic Carbenes, and Zeolitic Imidazolate Frameworks for CO2 Capture and Photochemical Reduction. , 2016, Angewandte Chemie.

[45]  H. Fu,et al.  Efficient TiO2 Photocatalysts from Surface Hybridization of TiO2 Particles with Graphite‐like Carbon , 2008 .

[46]  Qinghong Zhang,et al.  Photocatalytic conversion of carbon dioxide with water into methane: platinum and copper(I) oxide co-catalysts with a core-shell structure. , 2013, Angewandte Chemie.

[47]  Yajun Wang,et al.  Fabrication of inverse opal TiO2-supported Au@CdS core–shell nanoparticles for efficient photocatalytic CO2 conversion , 2015 .

[48]  Nan Zhang,et al.  Improving the photocatalytic performance of graphene-TiO2 nanocomposites via a combined strategy of decreasing defects of graphene and increasing interfacial contact. , 2012, Physical chemistry chemical physics : PCCP.

[49]  Jie Han,et al.  Nanostructured hybrid shells of r-GO/AuNP/m-TiO₂ as highly active photocatalysts. , 2015, ACS applied materials & interfaces.

[50]  Ying Li,et al.  Copper and iodine co-modified TiO2 nanoparticles for improved activity of CO2 photoreduction with water vapor , 2012 .

[51]  H. Yamashita,et al.  Design of macroporous TiO2 thin film photocatalysts with enhanced photofunctional properties , 2011 .

[52]  Zhenyi Zhang,et al.  Selective photocatalytic decomposition of formic acid over AuPd nanoparticle-decorated TiO2 nanofibers toward high-yield hydrogen production , 2015 .

[53]  Jonas Baltrusaitis,et al.  Status and perspectives of CO2 conversion into fuels and chemicals by catalytic, photocatalytic and electrocatalytic processes , 2013 .

[54]  M. Bonn,et al.  Probing the charge separation process on In2S3/Pt-TiO2 nanocomposites for boosted visible-light photocatalytic hydrogen production , 2016, 1608.02804.

[55]  Yan Zhao,et al.  Graphene quantum dots modified mesoporous graphite carbon nitride with significant enhancement of photocatalytic activity , 2017 .

[56]  D. Zhao,et al.  Ordered mesoporous black TiO(2) as highly efficient hydrogen evolution photocatalyst. , 2014, Journal of the American Chemical Society.

[57]  Jin Zou,et al.  Anatase TiO2 single crystals with a large percentage of reactive facets , 2008, Nature.

[58]  Mark C Hersam,et al.  Minimizing graphene defects enhances titania nanocomposite-based photocatalytic reduction of CO2 for improved solar fuel production. , 2011, Nano letters.

[59]  Tao Wu,et al.  Self-doped Ti3+ enhanced photocatalyst for hydrogen production under visible light. , 2010, Journal of the American Chemical Society.

[60]  N. English,et al.  Photo-induced charge separation across the graphene-TiO2 interface is faster than energy losses: a time-domain ab initio analysis. , 2012, Journal of the American Chemical Society.

[61]  D. Du,et al.  Enhancing charge density and steering charge unidirectional flow in 2D non-metallic semiconductor-CNTs-metal coupled photocatalyst for solar energy conversion , 2017 .

[62]  Z. Zou,et al.  Low temperature preparation and visible light photocatalytic activity of mesoporous carbon-doped crystalline TiO2 , 2007 .

[63]  Wei Zhang,et al.  Bi metal sphere/graphene oxide nanohybrids with enhanced direct plasmonic photocatalysis , 2017 .