Visible-light-responsive photocatalysts toward water oxidation based on NiTi-layered double hydroxide/reduced graphene oxide composite materials

ACS Appl Mater Interfaces. 2013 Oct 23;5(20):10233-9. doi: 10.1021/am402995d. Epub 2013 Oct 9.

Abstract

A visible-light responsive photocatalyst was fabricated by anchoring NiTi-layered double hydroxide (NiTi-LDH) nanosheets to the surface of reduced graphene oxide sheets (RGO) via an in situ growth method; the resulting NiTi-LDH/RGO composite displays excellent photocatalytic activity toward water splitting into oxygen with a rate of 1.968 mmol g(-1) h(-1) and a quantum efficiency as high as 61.2% at 500 nm, which is among the most effective visible-light photocatalysts. XRD patterns and SEM images indicate that the NiTi-LDH nanosheets (diameter: 100-200 nm) are highly dispersed on the surface of RGO. UV-vis absorption spectroscopy exhibits that the introduction of RGO enhances the visible-light absorption range of photocatalysts, which is further verified by the largely decreased band gap (∼1.78 eV) studied by cyclic voltammetry measurements. Moreover, photoluminescence (PL) measurements indicate a more efficient separation of electron-hole pairs; electron spin resonance (ESR) and Raman scattering spectroscopy confirm the electrons transfer from NiTi-LDH nanosheets to RGO, accounting for the largely enhanced carrier mobility and the resulting photocatalytic activity in comparison with pristine NiTi-LDH material. Therefore, this work demonstrates a facile approach for the fabrication of visible-light responsive NiTi-LDH/RGO composite photocatalysts, which can be used as a promising candidate in solar energy conversion and environmental science.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Graphite / chemistry*
  • Hydroxides / chemistry*
  • Light
  • Nanostructures / chemistry
  • Nickel / chemistry*
  • Oxidation-Reduction
  • Oxides / chemistry
  • Titanium / chemistry*
  • Water / chemistry*

Substances

  • Hydroxides
  • Oxides
  • Water
  • Graphite
  • Nickel
  • hydroxide ion
  • Titanium