Exploring the mechanisms of metal co-catalysts in photocatalytic reduction reactions: Is Ag a good candidate?

DOI: 10.1016/j.apcata.2015.10.023

Authors: Qian Yang (Aarhus University) , Wilm Jones (Cardiff University) , Peter P. Wells (Rutherford Appleton Laboratory) , David Morgan (Cardiff University) , Lichun Dong (Chongqing University) , Baoshan Hu (Chongqing University) , Nikolaos Dimitratos (Rutherford Appleton Laboratory) , Mingdong Dong (Aarhus University) , Mike Bowker (Rutherford Appleton Laboratory) , Flemming Besenbacher (Aarhus University) , Ren Su (Aarhus University) , Graham Hutchings (Rutherford Appleton Laboratory)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Applied Catalysis A: General , VOL 518 , PAGES 213-220

State: Published (Approved)
Published: October 2015
Diamond Proposal Number(s): 8071

Abstract: Metal co-catalysts are essential for enhancing photocatalytic performance, especially in reduction reactions using semiconductor photocatalyst materials as a consequence of the reduced recombination kinetics of charge carriers by spatial charge separation. Generally Au, Pd, Pt, and their alloys are more promising candidates than Ag for photocatalytic H2 evolution experiments, although Ag can trap more electrons having more negative reduction potential than that of Au, Pd, and Pt. Here we have synthesized and examined well-defined Au, Ag, and core-shell structured Au–Ag nanoparticles as co-catalysts for TiO2 in photocatalytic H2 evolution. By varying the dissolved oxygen in the reaction suspension, we found that selective photocatalytic reduction can be achieved by fine tuning the co-catalyst materials. Whilst Au NPs are superior for proton reduction, Ag NPs exhibits excellent performance for oxygen reduction. All core-shell structured Au–Ag NPs show non-selectivity in photocatalytic reduction of proton and oxygen

Journal Keywords: Photocatalysis; Co-Catalyst; Core–Shell Structure; Hydrogen Evolution; Au; Ag; Reaction Mechanisms

Diamond Keywords: Photocatalysis

Subject Areas: Chemistry, Materials


Instruments: B18-Core EXAFS

Added On: 26/11/2015 11:02

Discipline Tags:

Physical Chemistry Catalysis Energy Materials Chemistry Materials Science

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) Extended X-ray Absorption Fine Structure (EXAFS)