Surface-Modified Titanium Dioxide Nanofibers with Gold Nanoparticles for Enhanced Photoelectrochemical Water Splitting

Abstract

High-stability, high-efficiency, and low-cost solar photoelectrochemical (PEC) water splitting has great potential for hydrogen-energy applications. Here, we report on gold/titanium dioxide (Au/TiO2) nanofiber structures grown directly on a conductive indium tin oxide substrate, and used as photoelectrodes in PEC cells for hydrogen generation. The titanium dioxide nanofibers (TiO2 NFs) are synthesized using electrospinning, and are surface-modified by the deposition of gold nanoparticles (Au NPs) using a simple photoreduction method. The structure and morphology of the materials were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The surface plasmon resonance (SPR) of the Au NPs was investigated by ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy. The PEC properties of the as-prepared photoelectrodes were measured. The obtained photoconversion efficiency of 0.52% under simulated-sunlight illumination by a 150 W xenon lamp of the Au/TiO2 NFs structure with 15 min UV irradiation for Au NP deposition was the highest value from comparable structures. Working photoelectrode stability was tested, and the mechanism of the enhanced PEC performance is discussed.

Au nanoparticle-decorated TiO2 hollow fibers with enhanced visible-light photocatalytic activity toward dye degradation

“…4d shows that the XPS Au 4f had doublet peaks at 87.8 and 84.5 eV corresponding to the zero-valence state (Au 0 ) of Au 4f 7/2 (87.8 eV) and Au 4f 5/2 (84.1 eV), which are consistent with the values reported in literature. 36,44,50 This result again confirmed the presence of AuNPs on the THF in accordance with the discussion above.…”

“… 44–48 For Au/THF, the Ti 2p doublet peaks gradually shifted about 0.2 eV to a higher binding energy, thus indicating the electron transfer between AuNPs and THF supports. 36,44,45,49 A slight shift in binding energy was also observed for the XPS O 1s spectrum of Au/THF ( Fig. 4c ).…”

Dry Hydrogen Production in a Tandem Critical Raw Material-Free Water Photoelectrolysis Cell Using a Hydrophobic Gas-Diffusion Backing Layer

“…The existence of several concerns related to the increasing energy demand and the related environmental crisis [1][2][3][4][5][6] indicates the need to identify innovative, effective and low cost solutions. Photoelectrochemical water splitting (PWS) [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] is recognised as a promising strategy and it attracts particular interest for storing solar energy into the chemical bonds of hydrogen as fuel [26][27][28], which can be further utilised in fuel cells [29][30][31][32][33][34], internal combustion engines and to progressively decarbonize industrial processes [35][36][37][38][39].…”

Ag-decorated TiO2 Nanofibers for Surface-enhanced Raman Scattering

“…The TiO2 nanofibers (TiO2 NFs) were synthesized employing electro-spinning method similar to the previous report [16]. Briefly, 0.4 grams of poly(vinylpyrrolidone) was dissolved in 8 mL of ethanol and stirred for 2 h. Next, 6 mL of titanium tetraisopropoxide and 4 mL of acetic acid were added to the as-prepared solution and stirred for 60 min at room temperature to obtain a sufficiently viscous solution for electro-spinning.…”