Carrier-Dynamics-Regulated BiOI/Au/TiO2 Z-Scheme Photoanode for Selective Glycerol Photoelectrooxidation and Mass-Transfer-Enhanced Continuous-Flow Operation.

Selective conversion of biomass-derived glycerol into high-value chemicals is challenged by poor selectivity and mass-transfer limitations. Here, a BiOI/Au/TiO2 photoanode is developed, where plasmonic Au mediators facilitate a transition from Type-II to Z-scheme charge transfer. This heterojunction preserves strongly oxidative holes on the TiO2 surface, as confirmed by femtosecond transient absorption spectroscopy and spatially resolved MnOx photodeposition. In situ characterizations and density functional theory (DFT) reveal that this hole-rich interface strengthens specific primary hydroxyl (pri-OH) adsorption, lowering the rate-determining dehydrogenation barrier to ∼0.6 eV. It also promotes rapid glyceraldehyde (GLAD) desorption, suppressing over-oxidation. In a static H-cell, the photoanode achieves 87% GLAD selectivity with a glycerol conversion rate of 341.25 mmol·m-2·h-1. To overcome diffusion limitations, computational fluid dynamics (CFD) simulations were employed to design a continuous-flow reactor for the 100 cm2 large-area photoanode. The flow system prevents product accumulation, boosting GLAD selectivity from 48% (H-cell) to 77% for the large-area electrode, with enhanced glycerol conversion (60.34%) and stable 120 h operation. This work provides a laboratory scale-up by integrating nanoscale reprogramming with macroscale reactor engineering.