Coupling the photo-oxidation of biomass derived substrates with water splitting in a photoelectrochemical (PEC) cell is a broadly discussed approach intended to enhance efficiency of hydrogen generation at the cathode. Here, we report a PEC device employing a nanostructured semitransparent WO₃ photoanode that, irradiated with simulated solar light achieves large photocurrents of 6.5 mA cm⁻² through oxidation of glucose, a common carbohydrate available in nature that can be obtained by processing waste biomass. The attained photocurrents are in a large part due to the occurrence of the photocurrent doubling, where oxidation of glucose by the photogenerated positive hole is followed by injection by the formed intermediate of an electron into the conduction band of WO_3. Selection of an appropriate supporting electrolyte enabled effective reforming of glucose into valuable products: gluconic and glucaric acids, erythrose and arabinose with up to 64% total Faradaic yield attained at ca 15% glucose conversion.

N-type semiconducting WO₃ is widely investigated as a photoanode operating in water and seawater splitting devices. Because of the propensity of WO₃ to favor photo-oxidation of acidic electrolyte anions and, in parallel, the formation on the electrode surface of the peroxo species, the choice of the appropriate electrolyte to allow stable operation of the photoanode is of critical importance. Our results from structural and photoelectrochemical tests performed using mesoporous WO₃ photoanodes exposed to 80 h long photoelectrolysis in a 1 M aq. methanesulfonic acid supporting electrolyte demonstrate the photostability of both the WO₃ photomaterial and the CH₃SO₃H electrolyte. The reasons for the stability of aqueous solutions of CH₃SO₃H are discussed on the basis of earlier literature reports.

A novel hybrid system based on NAD-dependent glucose dehydrogenase immobilized on gold nanoparticles (AuNPs) covered with C₇₀fullerene has been developed for effective biosensing and quantitative detection of glucose.