Photocatalytic water splitting is a sustainable energy technique that harnesses sunlight to break down water into oxygen and hydrogen, thereby generating green hydrogen—an eco-friendly fuel—without depending on fossil fuels. This method relies on a substance known as a photocatalyst to drive the reaction forward.
While titanium dioxide (TiO 2 ) has long been studied as a promising semiconductor for photocatalytic water splitting, its efficiency has been hindered by rapid charge recombination and insufficient charge separation.
Now, however, a research team led by Prof. Liu Gang from the Institute of Metal Research (IMR) of the Chinese Academy of Sciences (CAS) has achieved a breakthrough in photocatalytic water splitting by developing a scandium (Sc)-doped titanium dioxide (TiO 2 ) semiconductor in the rutile crystal phase. The study is published in the American Chemical Society Journal .
The newly developed material exhibited an apparent quantum yield (AQY) of 30.3%. This metric reflects the proportion of photons contributing to effective water splitting. Additionally, it showed a solar-to-hydrogen (STH) efficiency of 0.34%, representing the fraction of captured solar energy transformed into hydrogen energy. These figures establish fresh standards for TiO₂-based materials. 2 -performed photocatalytic complete water splitting under normal (unpressurized, unheated) conditions.
To surmount the difficulties related to TiO2 2 , the research team utilized a two-pronged strategy. Initially, they focused on Scصند 3+ Doping successfully removed harmful Tiankanite. 3+ Defects, notorious for capturing charges and leading to energy dissipation, were addressed next. The researchers designed an interface at the intersection of the (101) and (110) crystal planes, producing a natural electric field. This field prompts electrons and holes to move toward different facets, thereby enhancing water reduction and oxidation processes.
Prof. Liu stated, "This two-pronged strategy not only reduces charge recombination caused by defects but also emulates the effective charge separation seen in p-n junctions within solar cells."
The results highlight the considerable business opportunities presented by titanium dioxide doped with scandium. 2 , particularly given China's abundant titanium and scandium resources. With an established industrial supply chain for titanium dioxide and advanced rare earth processing capabilities, this innovation could pave the way for scalable and cost-effective hydrogen production.
"Our design strategy—suppressing defects and leveraging crystal anisotropy—aligns perfectly with China's resource strengths and industrial infrastructure," said Prof. Liu. The team now aims to enhance light absorption and integrate the material into scalable solar-driven systems.
More information: Fei Qin et al, Spontaneous Exciton Dissociation in Sc-Doped Rutile TiO 2 For Photocatalytic Total Water Splitting With an Apparent Quantum Efficiency of 30%, American Chemical Society Journal (2025). DOI: 10.1021/jacs.5c01936
Provided by the Chinese Academy of Sciences
This tale was initially released on Massima . Subscribe to our newsletter For the most recent updates on science and technology news.