Toward Standardized and Comparable Reporting for Sacrificial Photocatalytic Hydrogen Evolution

Journal article, 2026

Sacrificial photocatalytic hydrogen evolution has advanced rapidly, yet meaningful benchmarking remains hindered by inconsistent metrics and the incomplete reporting of key experimental parameters. In this Perspective, we outline a minimal "reporting set"-intended to be practical for authors, reviewers, and editors-that improves transparency and enables cross-study comparison. We further show that the widely used mass-normalized hydrogen evolution rate (HER) can be strongly affected by the experimental conditions. As a simple step toward improved comparability, we advocate incorporating the irradiation surface area into rate reporting and introduce an area-mass normalized metric (HERA,M), which markedly improves cross-study consistency. In addition, we explored solar-to-chemical conversion SCC(H2) as a complementary metric tailored for sacrificial hydrogen evolution and a diagnostic tool "HER x SCC" to identify trade-offs associated with photocatalyst concentrations. Finally, we propose a two-axis benchmarking concept (HERA,M and SCC(H2)) to visualize performance and report quality simultaneously.