Efficiency Accreditation and Testing Protocols for Particulate Photocatalysts toward Solar Fuel Production

Photocatalytic water splitting has attracted great interest as a means of cost-effective conversion of sustainable solar energy to valuable chemicals. However, the absence of authorized efficiency measurement methods results in the accumulation of unverifiable and often misleading data, wasting the investment and resources of the research community and impeding the progress in the research field. Herein, testing protocols for reliable efficiency reporting of photocatalytic overall water splitting are discussed based on particulate photocatalysts. The sources of error and standard reporting protocols for hydrogen evolution rate, light source calibration, and solar-to-hydrogen (STH) efficiency have been revisited and recommended. The establishment of accreditation research laboratories is proposed for efficiency certification toward the launch of the figure of merit, a “best research photocatalyst efficiencies” chart. This initiative will provide an important platform for establishing standard testing protocols in photocatalytic water splitting and accelerating the STH conversion efficiency improvement toward practical application.