Unique Tio2@Cu Phthalocyanine Core-Shell Photoanodes Via Molecular Interface Engineering for Effective Solar-Driven Upgrading of Glycerol

Abstract

Solar-driven photoelectrochemical (PEC) oxidation of glycerol to high-value glyceraldehyde (GLD) and 1,3-dihydroxyacetone (DHA) offers a sustainable route for biomass valorization. Herein, a novel core-shell structured TiO2@CuPc(C) photoanode was fabricated via molecular interface engineering using 3,4-dihydroxybenzonitrile (DHBN) as a coordination agent. The optimized heterojunction significantly enhances interfacial charge transfer, suppresses carrier recombination, and improves photogenerated hole utilization. Under 1.0 V vs. RHE and AM 1.5 G illumination, the TiO2@CuPc(C) achieves remarkable yields of 107.4 mmol m-2 h-1 for GLD and 50.1 mmol m-2 h-1 for DHA, representing 2.9- and 3.2-fold enhancements over pristine TiO2, respectively. In-situ spectroscopic studies and radical trapping experiments confirm the pivotal roles of photogenerated holes and hydroxyl radicals in driving selective oxidation. This work underscores the significance of coordination-induced interfacial engineering in designing robust photoanodes for sustainable biomass valorization.

Keywords: TiO2 photoanodes, Core-shell structure, Cu phthalocyanine, PEC oxidation, glycerol upgrading to glyceraldehyde