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In this work, a photocatalytic fuel cell (PFC) with membrane electrode assembly (MEA) structure was designed for simultaneous organic compounds degradation and electricity generation. For the photoanode, the TiO 2 with the quantum-dot sensitization by CdS-ZnS was used to broaden the absorption spectrum to visible light. For the cathode, an air-breathing mode was utilized to enhance the oxygen transport. The performance of the developed PFC was evaluated under different operation conditions, including the light intensity, liquid flow rate, concentrations of electrolyte and organics. Results indicated that the designed PFC could yield good performance. The increase of the light intensity and electrolyte concentration could improve the PFC performance. It is also found that when the flow rate was increased, the PFC performance dropped down in the testing range. Too high organics concentration led to the decrease of the PFC performance. [ABSTRACT FROM AUTHOR]

In this study, a novel ternary hybrid CdS/SiO 2 /TiO 2 film was proposed as the phonoanode for the photocatalytic fuel cell. The samples were characterized by X-ray diffraction, scanning electron microscopy and UV–vis absorption. The photoelectrochemical activity of the ternary hybrid electrode was characterized by the photocurrent-time transient response, linear sweep voltammetry and electrochemical impedance spectroscopy. It was shown that CdS/SiO 2 /TiO 2 yielded much higher photoelectrochemical activity than CdS/TiO 2 and bare TiO 2 did. The photoanode with CdS/SiO 2 /TiO 2 showed the highest photocurrent density of 4.6 mA cm −2 , exhibiting a 40% improvement over the conventional CdS/TiO 2 photoanode. The roles of SiO 2 and CdS in such a ternary configuration were elaborated. It was demonstrated that CdS could act as an excellent visible light captaturer to generate photo-induced charge carriers, and SiO 2 as a passivation layer to suppress the interfacial recombination of electrons and holes. Moreover, SiO 2 could allow for more CdS to be deposited at the photoanode owing to its high adsorption capacity. In addition, the effects of the SiO 2 content and the SILAR cycle time on the performance of the CdS/SiO 2 /TiO 2 photoanode were investigated. An optimal SiO 2 content of 10% could yield the best performance. Increasing the SILAR cycle time could improve the photoelectrochemical activity. [ABSTRACT FROM AUTHOR]

In this work, a membraneless photocatalytic fuel cell (PFC) with a solar responsive photoanode and an air-breathing cathode was developed to simultaneously degrade the wastewater and generate electricity. The performance characteristics of the developed PFC was examined for the real application purpose. Particular attention was paid to investigate the effect of the fuel and electrolyte types on the cell performance. Experimental results showed that the alkaline electrolyte yielded the maximum power density of 4.1 mW cm −2 , which was much better than the neutral electrolyte with the maximum power density of 0.5 mW cm −2 . Long-term performance measurements also showed that the cell performance was rather stable under the alkaline electrolyte but dramatically reduced under the neutral electrolyte in the 3-hour constant current density operation. Regarding the fuel types, the PFC exhibited appreciable performance for both alcohols and saccharides. Methanol and glycerol produced the maximum power densities of 4.08 and 2.58 mW cm −2 , while D-glucose and D-xylose generated the maximum power densities of 3.92 and 3.67 mW cm −2 , respectively. The difference in the cell performance can be attributed to the difference in the molecular structure, i.e., the fuel with a simpler molecular structure and a shorter carbon chain could yield better performance. Besides, the PFCs also showed favorable performances in some complex wastes, such as artificial sewage, Coca Cola and urine. For the air-breathing cathode design, the oxygen concentration effect on the PFC performance was also studied. It was found that increasing the oxygen concentration from 5% to pure oxygen led to the improvement of the maximum power density from 3.5 to 5.2 mW cm −2 . [ABSTRACT FROM AUTHOR]