Carrier‐Dynamics‐Regulated BiOI/Au/TiO ₂ Z‐Scheme Photoanode for Selective Glycerol Photoelectrooxidation and Mass‐Transfer‐Enhanced Continuous‐Flow Operation

Abstract

ABSTRACT Selective conversion of biomass‐derived glycerol into high‐value chemicals is challenged by poor selectivity and mass‐transfer limitations. Here, a BiOI/Au/TiO 2 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 TiO 2 surface, as confirmed by femtosecond transient absorption spectroscopy and spatially resolved MnO x 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 cm 2 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.