Determine the relative contributions and dynamics of photothermal and nonthermal photocatalysis

Determine the extent, timescale, and efficacy of photothermal and nonthermal mechanisms in plasmonic photocatalysis.

Background

The paper addresses the longstanding difficulty of distinguishing photothermal heating from nonthermal processes, including hot-carrier-mediated mechanisms, in plasmonic photocatalysis. These mechanisms can interact synergistically, while conventional measurements generally do not resolve their distinct temporal behavior.

The authors introduce pump-pump photocatalysis as an operando excitation-correlation technique intended to distinguish time-sensitive nonthermal responses from comparatively slower photothermal effects. The stated unresolved problem concerns the broader quantitative characterization of these mechanisms: how strongly each contributes, on what timescales they operate, and how effectively they enhance chemical reactivity under different conditions.