Glycerol Valorization and Electricity Co-generation over a Cu-WO₃ Photoanode in a Photocatalytic Fuel Cell

Regarded as a promising next-generation energy conversion system, photocatalytic fuel cells (PFCs) can efficiently utilize solar energy for fuel conversion with simultaneous electricity generation. However, prevailing PFC designs predominantly prioritize complete fuel mineralization, overlooking the selective valorization into value-added chemicals. Herein, we reported a rationally designed PFC system based on a Cu-doped WO₃ photoanode for concurrent glycerol upgrading and power generation. The optimized photoanode achieved a glycerol conversion of 5.48 mmol L^-1 h^-1 while delivering an open-circuit voltage of 0.50 V and a short-circuit current density of 5.5 mA cm^-2. Mechanistic studies and density functional theory calculations revealed that Cu was doped into the WO₃ lattice in a substitutional form, which modulated the electronic structure and selectivity to value-added products. Designed PFC achieved a maximum power output of 0.8 mW cm^-2 while maintaining a selectivity of over 75% toward valuable C3 and C2 products.