Synergetic effect of Ni and Au nanoparticles synthesized on titania particles for efficient photocatalytic hydrogen production

Abstract

Au and/or Ni nanoparticles were synthesized by radiolysis on TiO 2 (commercial P25) at various composition (metal content). The modified photocatalysts were characterized by High Resolution Transmission Microscopy (HRTEM), Energy-Dispersive X-ray Spectroscopy (EDS), UV-Vis Diffuse Reflectance Spectroscopy (DRS) and X-Ray Photoelectron Spectroscopy (XPS). The charge-carrier mobility was studied by Time Resolved Microwave Conductivity (TRMC). The photocatalytic activities were tested under UV-visible irradiation using polychromatic and monochromatic light (action spectrum analysis of apparent quantum efficiency). Surface modified TiO 2 with Au and Ni nanoparticles showed high photocatalytic activity for hydrogen evolution from aqueous methanol solution. The enhanced hydrogen evolution rate was obtained for TiO 2 co-modified with Au and Ni, where synergetic effect of the two metals was revealed. A very small amount of gold associated to nickel (atomic ratio Ni:Au 5:1 with a total optimized metal loading of 0.5at%) can induce a significant increase in H 2 formation.

Influence of an Electronic Structure of N-TiO2 on Its Photocatalytic Activity towards Decomposition of Acetaldehyde under UV and Fluorescent Lamps Irradiation

“…The fast decay in this short range is caused mostly by an electron-hole recombination and scavenging of electrons, which can also occur. Similar analyses of TRMC signals were performed and published elsewhere [17,18]. It can be observed, that under laser excitation at λ = 360 nm, N-TiO2 prepared at 500 °C showed the highest TRMC signal and at the same time the lowest one under excitation at λ = 460 nm.…”

Enhanced photocatalytic, electrochemical and photoelectrochemical properties of TiO2 nanotubes arrays modified with Cu, AgCu and Bi nanoparticles obtained via radiolytic reduction

“…It was often observed, that bimetallic nanoparticles exhibit synergistic properties compared to their monometallic counterparts [34]. Titania modified with bimetallic nanoparticles such as PdPt [35], AgPt, AuAg [36], AuCu [29], [36], AuPd [32], AgCu [30] NiAu [37] displayed higher catalytic and photocatalytic activity in the comparison with the samples decorated with only one metal.…”

Exceptional Catalytic Activities and Sensing Performance of Palladium Decorated Anisotropic Gold Nanoparticles

“…Formation of relatively larger sized Au particles indicates that the nucleation was sporadic followed by slow growth. This is expected as the metal ions are confined within the oil phase whereas the reduction would be initiated at the oil‐water interface because radiolytic reduction takes place due to solvated electrons in water ,. Twinning of some of the particles was also observed indicating the effect of confinement and binding by CTAB.…”