Cu2O photocatalyst : Activity enhancement driven by concave surface

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

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Author(s)

  • Xinxin Lu
  • Judy N. Hart
  • Yin Yao
  • Cui Ying Toe
  • Jason Scott

Related Research Unit(s)

Detail(s)

Original languageEnglish
Article number100422
Number of pages8
Journal / PublicationMaterials Today Energy
Volume16
Online published21 May 2020
Publication statusPublished - Jun 2020

Abstract

The study of the Cu2O concave surfaces has attracted significant attention, in which most work to date has focused primarily on investigating the formation mechanism and catalytic performance. However, the photoinduced charge behavior of concave surfaces and the origins of improved photocatalytic performance, that are important for understanding photogenerated charge separation and migration, have not been thoroughly explored. Here, we demonstrate that the presence of concave surfaces on the Cu2O {100} facet facilitates the capture of photogenerated electrons. Density functional theory (DFT) calculations of the surface energies and charge distribution revealed that the concave surfaces are catalytically active due to the presence of under-coordinated copper atoms with increased charge relative to copper atoms on flat surfaces. This was further supported by comparing the surface potentials of the concave and flat regions on the Cu2O {100} surface, which were measured by Kelvin probe force microscopy (KPFM). The obtained surface potentials confirmed that the {100} concave surfaces have a gradient decrease of surface work function, inducing an efficient built-in electric field. This was visually demonstrated by the selective photodeposition of Pt particles on the concavities of the {100} surfaces. The charge distribution effect was observed and verified by both the theoretical and experimental means, whereby Cu2O particles with the {100} concave surfaces exhibited better performance in both photoelectrochemical (PEC) measurement and photocatalytic H2 evolution.

Research Area(s)

  • Cu2O concave surface, Photoelectrochemistry, Photocatalytic activity, DFT calculations, KPFM measurement

Citation Format(s)

Cu2O photocatalyst : Activity enhancement driven by concave surface. / Lu, Xinxin; Hart, Judy N.; Yao, Yin; Toe, Cui Ying; Scott, Jason; Ng, Yun Hau.

In: Materials Today Energy, Vol. 16, 100422, 06.2020.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal