Titanium–indium oxy(nitride) with and without RuO2 loading as photocatalysts for hydrogen production under visible light from water

Titanium–indium (oxy)nitride composite materials with and without RuO2 loadings were produced by treating TiO2–In2O3 mixed powders with ammonia at high temperature (700–850 °C) (Elemental analysis indicated an empirical formula of TiIn0.029O0.63N1.4).We have found that ammonolysis of TiO2 to form Ti (oxy)nitride or In2O3 to form In (oxy)nitride do not give composites active toward methanol–water under visible light, but TiO2 and In2O3 mixed together do give composites active toward methanol–water under visible light. Ti–In (oxy)nitride powders modified by surface loading with RuO2 nanoparticles at 3 wt% achieves the highest H2 evolution activity under visible light irradiation. The composite material did not react in the dark, but upon irradiation with visible light, the hydrogen production rate under illumination goes way up to 30 μmol h−1 and the turnover number shows that this is a photocatalytic reaction.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (146 K)Download as PowerPoint slideHighlights► Titanium–indium (oxy)nitrides as active water splitting catalysts. ► Ruthenium Oxide enhanced hydrogen generation. ► The XPS data shows Ti4+ could be reduced to 3+ and 2+ upon ammonia treatment with In2O3 presence. ► Long-lived catalyst in water/methanol.