Utilizing intrinsic defective TiO₂ for visible light driven H₂ production is a hot international research topic. Until now, most of the related researches focus on blue TiO₂ (Ti³⁺ defected TiO₂). However, co-catalysts (e.g. Pt, NiO_x) are required during the catalytic process. The approach is economically unattractive and environmentally contaminative.

With the support of national natural science foundation of China and the Fujian Provincial Orienting Sci & Tech Project, the ultra-small (~3 nm) yellow defective TiO₂ nanoparticles have been firstly synthesized without introducing any external dopants by the research team led by Prof. WAMG Yuansheng at the Key Laboratory of Design and Assembly of Functional Nanostructures, Chinese Academy of Sciences.

The titanium vacancies (acceptor) and titanium interstitials (donor) that incorporated in the yellow TiO₂ are evidenced by various characterization techniques, and their formation mechanism is proposed. The acceptor-donor defects in the yellow TiO₂ can not only initiate but also promote the visible light driven H₂ production.

This is evidenced by co-catalyst free photocatalytic performance (~1.3 μmol/g/h), and the activity is greatly promoted when elongating the UV light pretreatment time. In addition, the yellow TiO₂ shows excellent chemical stability during the catalytic process, which indicates great potential application in energy and environmental area.

The related work has been published in Nano Energy, 2016, 24, 63-71. Please see http://www.sciencedirect.com/science/article/pii/S2211285516300519.

Scheme1. Intrinsic defects in yellow TiO₂ and its visible light activity for H₂ production.(Image by Prof. WANG's group)