Enhanced H₂ production activity under solar irradiation over N-doped TiO₂ prepared using pyridine as a precursor: a typical sample of N-doped TiO₂ series

Abstract

A series of N-doped TiO₂ photocatalysts were synthesized by simple hydrolysis method using titanium isopropoxide and pyridine precusors. XRD studies of all the catalysts showed a single anatase phase and TEM results confirmed that the particles obtained by this procedure are of nano size and in the range of 3–5 nm. UV–vis DRS of N-doped TiO₂ catalysts clearly show an enhanced absorption in the visible light region, and the band gaps are seen decreasing as the content of doped nitrogen increases. The formation of oxynitride linkages is evidenced by the FTIR results. Further the XPS analysis confirms the presence of Ti-O-N linkage, and the binding energy values indicate that the doped nitrogen is either interstitial or chemisorbed. The photocatalytic activity of N-doped TiO₂ catalysts is evaluated for hydrogen production in methanol: water mixture under solar light irradiation and 0.5 wt% N-doped TiO₂ has shown a stable and high activity, 3500 μ mol/h/g.cat. The enhanced hydrogen production activity of N-doped TiO₂ catalysts is attributed to the high surface area of the catalysts containing doped nitrogen mostly at the interstitial positions and enhanced visible light absorption.

Keywords:

• N-doped TiO₂
• Methanol
• Water mixtures
• Hydrogen production
• Solar light

Acknowledgement

We authors thanks our colleague K.Q. Wang for his help sample testing and L.L. Xiao for assistance with the language.