Visible-light-responsive photocatalysts toward water oxidation based on NiTi-layered double hydroxide/reduced graphene oxide composite materials.
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.
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology , Beijing 100029, P. R. China.
Bei
B
Li
Yufei
Y
Zhao
Shitong
S
Zhang
Wa
W
Gao
Min
M
Wei
D002384:Catalysis; D006108:Graphite / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry*; D008027:Light; D049329:Nanostructures / Q000737:chemistry; D009532:Nickel / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D006878:Hydroxides; D010087:Oxides; D014867:Water; D006108:Graphite; D009532:Nickel; C031356:hydroxide ion; D014025:Titanium