Photocatalytic water splitting has attracted significant interest as a cost-effective means to convert sustainable solar energy into valuable chemicals. Its efficiency is sensitive to reaction conditions and experimental setup. 

Due to the lack of testing standards, it is difficult to compare the results obtained by different research groups or provide a reliable guide for large-scale implementation.

Recently, an international research team initiated the establishment of international efficiency accreditation and testing protocols for particulate photocatalysts toward solar fuel production.

Their perspective, published in Joule, was expected to serve as a useful guide for developing a well-recognized testing standard and for further promoting research advances in the field of photocatalytic solar energy conversion.

A research group led by Prof. LI Can and Prof. LI Rengui from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), Prof. Kazunari Domen from The University of Tokyo, Prof. Lianzhou Wang from The University of Queensland, Prof. Kazuhiro Sayama from the National Institution of Advanced Industrial Science and Technology, and Prof. Gang Liu from the Institute of Metal Research, CAS, are involved in the study.

Efficiency accreditation and testing protocols for particulate photocatalysts toward solar fuel roduction (Image by LI Rengui) 

The researchers discussed the protocols for reliable determination of the efficiency of the overall photocatalytic water splitting reaction based on particulate photocatalysts.

They also proposed to establish accreditation research laboratories for efficiency certification toward the launch of a figure of merit - a "best research photocatalyst efficiencies" chart.

This initiative would provide an important platform for establishing standard testing protocols for photocatalytic water splitting and for improving the solar-to-hydrogen conversion efficiency in practical applications.

This work was supported by the National Natural Science Foundation of China.