In Situ Synthesis of Mesoporous TiO2 Nanofibers Surface-Decorated with AuAg Alloy Nanoparticles Anchored by Heterojunction Exhibiting Enhanced Solar Active Photocatalysis.

We designed an electrospinning synthesis protocol to obtain in situ, the mesoporous TiO2 nanofibers, which are surface-decorated with plasmonic AuAg nanoparticles (AuAg-mTNF-H). Such alloy nanoparticles are found to be partially exposed on the surface of the nanofibers. Characterization by HRTEM and EDS confirmed the formation of 1:1 AuAg alloy nanoparticles on the surface of TiO2 nanofibers with heterojunction at the interfaces. On the basis of electron microscopic characterization, we proposed that during the formation of the nanofibers, the incorporated metal ions with surface capping of negative charges migrated towards the outer surface of the nascent fibers under the influence of high positive voltage required for electrospinning. As a result, after the subsequent thermal treatment, the crystallization of TiO2 nanofibers and the formation of alloy nanoparticles took place, leading to the formation of a deep heterojunction through partial embedment of the nanoparticles. The formation of AuAg alloy also restricted the oxidation of Ag, thus making the nanoparticles highly stable in ambient condition. Accordingly, such unique AuAg-mTNF-H photocatalyst shows strong light absorption property covering the entire range of visible wavelengths with stability. The solar light harvesting property of AuAg-mTNF-H was verified by monitoring solar light induced H2 evolution via water splitting and photodecomposition of MB. In both the cases AuAg-mTNF-H showed excellent H2 evolution and photodecomposition of dye.

[1]  R. Snyders,et al.  N-Doped TiO2 Photocatalyst Coatings Synthesized by a Cold Atmospheric Plasma. , 2019, Langmuir : the ACS journal of surfaces and colloids.

[2]  Yin‐Hsuan Chang,et al.  Core–Shell Heterostructures of Rutile and Anatase TiO2 Nanofibers for Photocatalytic Solar Energy Conversion , 2019, ACS Applied Nano Materials.

[3]  M. Maillard,et al.  Photoelectrochemical Behavior of Silver Nanoparticles inside Mesoporous Titania: Plasmon-Induced Charge Separation Effect. , 2019, Langmuir : the ACS journal of surfaces and colloids.

[4]  Li-ping Zhu,et al.  Hollowsphere Nanoheterojunction of g-C3N4@TiO2 with High Visible Light Photocatalytic Property. , 2019, Langmuir : the ACS journal of surfaces and colloids.

[5]  O. Ersen,et al.  Mapping the Photocatalytic Activity and Ecotoxicology of Au, Pt/TiO2 Composite Photocatalysts , 2018, ACS Sustainable Chemistry & Engineering.

[6]  E. Diemuodeke,et al.  Energy, exergy, environmental and economic analysis of an agricultural waste-to-energy integrated multigeneration thermal power plant , 2018, Energy Conversion and Management.

[7]  F. Dong,et al.  Photocatalytic Oxidative Dehydrogenation of Ethane Using CO2 as a Soft Oxidant over Pd/TiO2 Catalysts to C2H4 and Syngas , 2018, ACS Catalysis.

[8]  N. Sandhyarani,et al.  Enhanced Solar Hydrogen Evolution over In Situ Gold–Platinum Bimetallic Nanoparticle-Loaded Ti3+ Self-Doped Titania Photocatalysts , 2018 .

[9]  Liang Wu,et al.  Cocatalyzing Pt/PtO Phase-Junction Nanodots on Hierarchically Porous TiO2 for Highly Enhanced Photocatalytic Hydrogen Production. , 2017, ACS applied materials & interfaces.

[10]  Adam D. Dunkelberger,et al.  Plasmonic Aerogels as a Three-Dimensional Nanoscale Platform for Solar Fuel Photocatalysis. , 2017, Langmuir : the ACS journal of surfaces and colloids.

[11]  Maneesh Kumar Singh,et al.  Purely Visible-Light-Induced Photochromism in Ag-TiO2 Nanoheterostructures. , 2017, Langmuir : the ACS journal of surfaces and colloids.

[12]  N. S. Amin,et al.  Synergistic effect in plasmonic Au/Ag alloy NPs co-coated TiO2 NWs toward visible-light enhanced CO2 photoreduction to fuels , 2017 .

[13]  Wilson A. Smith,et al.  Hot Carrier Generation and Extraction of Plasmonic Alloy Nanoparticles , 2017, ACS photonics.

[14]  Junhe Yang,et al.  Effects of sacrificial reagents on photocatalytic hydrogen evolution over different photocatalysts , 2017, Journal of Materials Science.

[15]  Su‐Un Lee,et al.  Metal-Semiconductor Heteronanocrystals with Desired Configurations for Plasmonic Photocatalysis. , 2016, Journal of the American Chemical Society.

[16]  C. Gopinath,et al.  Bimetallic and Plasmonic Ag–Au on TiO2 for Solar Water Splitting: An Active Nanocomposite for Entire Visible‐Light‐Region Absorption , 2016 .

[17]  Hong Chen,et al.  Fabrication of TiO2/C3N4 heterostructure for enhanced photocatalytic Z-scheme overall water splitting , 2016 .

[18]  Chengming Wang,et al.  Enhanced full-spectrum water splitting by confining plasmonic Au nanoparticles in N-doped TiO2 bowl nanoarrays , 2016 .

[19]  Ying Dai,et al.  Energy transfer in plasmonic photocatalytic composites , 2016, Light: Science & Applications.

[20]  Lei Wang,et al.  Electrospun TiO2 Nanofibers Surface-Loaded with Ag Nanoparticles as a Sensitizer and Their Enhanced Effect in Photocatalytic Applications , 2015 .

[21]  J. Jang,et al.  Fabrication of Au@Ag core/shell nanoparticles decorated TiO2 hollow structure for efficient light-harvesting in dye-sensitized solar cells. , 2015, ACS applied materials & interfaces.

[22]  S. Lenaerts,et al.  Plasmonic gold–silver alloy on TiO2 photocatalysts with tunable visible light activity , 2014 .

[23]  H. Ishii,et al.  Dispersed-nanoparticle loading synthesis for monodisperse Au-titania composite particles and their crystallization for highly active UV and visible photocatalysts. , 2014, Langmuir : the ACS journal of surfaces and colloids.

[24]  E. Mazur,et al.  An Analytic Model for the Dielectric Function of Au, Ag, and their Alloys , 2014 .

[25]  Z. Yaakob,et al.  Au/TiO2 Reusable Photocatalysts for Dye Degradation , 2013 .

[26]  K. Klabunde,et al.  Photocatalytic water splitting on Au/TiO2 nanocomposites synthesized through various routes: Enhancement in photocatalytic activity due to SPR effect , 2013 .

[27]  Nicole K. Scharko,et al.  Photooxidation of ammonia on TiO2 as a source of NO and NO2 under atmospheric conditions. , 2013, Journal of the American Chemical Society.

[28]  Say Chye Joachim Loo,et al.  Mesoporous plasmonic Au-TiO2 nanocomposites for efficient visible-light-driven photocatalytic water reduction , 2012 .

[29]  Zhi Wei Seh,et al.  Janus Au‐TiO2 Photocatalysts with Strong Localization of Plasmonic Near‐Fields for Efficient Visible‐Light Hydrogen Generation , 2012, Advanced materials.

[30]  Shunsuke Tanaka,et al.  Photocatalytic H2O2 Production from Ethanol/O2 System Using TiO2 Loaded with Au–Ag Bimetallic Alloy Nanoparticles , 2012 .

[31]  S. Linic,et al.  Water splitting on composite plasmonic-metal/semiconductor photoelectrodes: evidence for selective plasmon-induced formation of charge carriers near the semiconductor surface. , 2011, Journal of the American Chemical Society.

[32]  Kang Wang,et al.  Surface plasmon enhanced photoconductance and single electron effects in mesoporous titania nanofibers loaded with gold nanoparticles , 2010 .

[33]  Bingqing Wei,et al.  Photocatalytic hydrogen generation using a nanocomposite of multi-walled carbon nanotubes and TiO2 nanoparticles under visible light irradiation , 2009, Nanotechnology.

[34]  Yunfeng Lu,et al.  Mesoporous Au/TiO2 nanocomposites with enhanced photocatalytic activity. , 2007, Journal of the American Chemical Society.

[35]  G. De,et al.  A New Approach for the Synthesis of Au−Ag Alloy Nanoparticle Incorporated SiO2 Films , 2005 .

[36]  G. De,et al.  Synthesis of Au nanoparticle doped SiO2–TiO2 films: tuning of Au surface plasmon band position through controlling the refractive index , 2005 .

[37]  E. Fanizza,et al.  Role of Metal Nanoparticles in TiO2/Ag Nanocomposite-Based Microheterogeneous Photocatalysis , 2004 .

[38]  Michael Grätzel,et al.  Conversion of sunlight to electric power by nanocrystalline dye-sensitized solar cells , 2004 .

[39]  L. Miao,et al.  Fabrication, characterization and Raman study of anatase-TiO2 nanorods by a heating-sol–gel template process , 2004 .

[40]  A. Licciulli,et al.  Copper-ruby monoliths by the sol-gel process , 1996 .

[41]  Paul Mulvaney,et al.  Influence of the Medium Refractive Index on the Optical Properties of Single Gold Triangular Prisms on a Substrate , 2008 .

[42]  Allen J. Bard,et al.  Artificial Photosynthesis: Solar Splitting of Water to Hydrogen and Oxygen , 1995 .