Photocatalytic water splitting on Au/HTiNbO5 nanosheets

Abstract

The layered potassium titanium niobate, KTiNbO5, is known as a photocatalyst for hydrogen production from water splitting under UV light. Here we show that titanium niobate nanosheets with a slit like framework can be obtained by exfoliation of KTiNbO5 followed by proton exchange. Gold nanoparticles were deposited on the titanium niobate nanosheets using deposition-precipitation (DP), photo-deposition (PD) and impregnation (IMP) method in order to improve photocatalytic hydrogen production from water splitting.These catalysts were characterized by powder X-ray diffraction patterns (XRD), inductively coupled plasma mass spectrometry (ICP-MS), UV–visible spectroscopy (UV–vis), and Transmission Electron Microscopy (TEM). The gold loaded titanium niobate nanosheets prepared by the DP method consisted of a good metal-semiconductor interface which allowed for a much higher efficient electron–hole separation.In this paper, we developed a facile method of preparing titanium niobate nanosheets containing gold nanoparticles. The titanium niobate nanosheets with Au cocatalyst prepared by the DP method showed a uniform dispersion of gold nanoparticles with an average gold particle size of 3 nm and exhibited an ultra-high photocatalytic water splitting activity, which was 56 times higher than that exhibited by the origin KTiNbO5 photocatalyst.